nasa flight experiments x-24creport moc a3265 20 january 1975 nasa flight experiments x-24c final...
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~ PEN00260 J REPORT MDCA3265
NASA FLIGHT EXPERIMENTS
X-24C
FINAL BRIEFING
-}-.--_______________ -----l
... 1
N1CDONNELL AIRCRAFT COIWPANY .. /
MCDONNELL DOUG~ CORPORII&TION
J
REPORT MOC A3265 20 JANUARY 1975
NASA FLIGHT EXPERIMENTS X-24C
FINAL IBRIEFING
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b), 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
COPY NO. ----!/-'.Z'-_
/MCDONNELL AIRCRAFT CO/MPANY
Box 516, Saint Louis, Missouri 63166 - Tel_ (314)232-0232
/
_CDONNELL DOUG~ CORPORATION
------~-
REPORT Moe A3265 20 JANUARY 1975
FOREWORD
This report summarizes the results of an investigation performed
at McDonnell Aircraft Company (MCAIR), a division of McDonnell Douglas
Corporation, P.O. Box 516, St. Louis, Missouri, 63166, to define and
cost an actively cooled fail safe structural system flight experiment
and an integral liquid hydrogen fuel tank structural system flight
experiment for the X-24C research aircraft program. The study was
conducted under NASA Contract NASl-13631 with a period of performance
from 8 November 1974 to 20 January 1975.
The principal investigators were Mr. A. H. Baker on the hydro
gen tank experiment and Mr. R. L. Herring on the active cooling ex
periment. This activity was conducted within the MCAIR Hypersonic
Aircraft Systems group managed by Mr. C. J. Pirrello. The Hypersonic
Aircraft Systems group is part of the HCAIR Advanced Aircraft Engi
neering Division directed by Hr. H. D. A1tis. Cost estimates were
conducted within the Contracts Division under the direction of
Hr. D. T. Mueller.
LIST OF PAGES
Title Page 1 through 175
MCDONNELL AIRCRAFT COMPANY
:1>ZZ oi UlO Co $:c $:(") :l>j :co -<Z
REPORT Moe A3265 20JANUARY 1975
SCOPE
Each experiment was investigated separately. For each, a
conceptual design of the airframe structure was developed along
with a conceptual design of the associated functional subsystem
elements. The design, development and testing required to assure
the flightworthiness of each experiment was determined, with the
ground rule that the experiment be capable of field installation
at the test site in the basic X-24C research aircraft. The manu
facturing plan was based on an experimental shop approach. Flight
test requirements were defined and a flight test plan developed.
Where appropriate critical technologies and long lead development
on procurement items were identified. Finally, the overall pro
gram schedule was developed and rough order of magnitude costs
were determined in constant 1974 dollars.
IKCDONNELL AIRCRAFT COIKPANY
2
REPORT MDe A3265 20 JANUARY 1975
SCOPE
• DEVELOP A CONCEPTUAL DESIGN
• DETERMINE DESIGN, DEVEL REQUI REMENTS
.• DEFINE MANUFA
~.IlP?\L TECHNOLOGIES AND LONG
• PROVIDE R.O.M. COSTS AND SCHEDULE GP74-1039-24
MCDONNELL AIRCRAFT COMPANV
3
REPORT MDe A3265 20 JANUARY 1975
STUDY APPROACH AND ASSUMPTIONS
Due to the short study period involved, the conceptual design
was developed with a minimum of analytical effort. Good engineer
ing judgement was used based on the results of related studies
currently in progress at MCAIR. It was assumed that all the detail
design and performance information on the basic X-24C airplane
would be readily available.
Structural and functional interfaces were assumed to be estab
lished at go-ahead and coordinated by the X-24C vehicle contractor.
All provisions for the experiments were assumed to be previously
incorporated in the basic X-24C, thus no costs were included to
cover modifications to the basic vehicle to accommodate the exper
iment.
MCDONNE ...... AIRCRAFT COMPANY
4
REPORT Moe A3265 20 JANUARY 1975
STUDY APPROACH AND ASSUMPTIONS
• CONCEPTUAL DESIGN
• NO STRESS OR WEIGHTS ANALYSIS
• MINIMAL THERMAL AND SYSTEM ANALYSIS
• NO TRADE STUDIES - USE JUDGMENT
• BASIC X-24C DETAIL AIRFRAME AND SUBSYSTEM DESIGN AND PERFORMANCE REQUIREMENTS ARE AVAILABLE
• INTERFACES ESTABLISHED AT ATP
• STRUCTURAL PROVISIONS FOR EXPERIMENTS INCORPORATED IN
BASIC X-24C
• SYSTEM CONTRACTOR COORDINATES INTERFACES GP74-1039-12
MCDONNELL AIRCRAFT COMPANV
5
REPORT Moe A3265 20JANUARY 1975
EXPERIMENTS GENERAL ARRANGEMENT
The integral liquid hydrogen tank is an all-welded design of 2219 aluminum. The
shell of the multi-bubble design is integrally stiffened in an "isogrid" pattern. The
intersecting cones forming the bubbles provide straight-line load carrying elements
and have planar webs at each intersection to carry shear and react internal pressure
loadings. Elliptically domed tank ends, one of which includes an access door, are in
cluded to increase volumetric efficiency at minimum weight. Thermally induced changes
in tank size with respect to basic aircraft structure are accommodated by motion of the
monoball-ended support l~nks. Load carrying continuity is not affected by this motion.
Operational elements of the liquid hydrogen system such as the supply port, vent
and dump lines are identified here. Provisions for these lines must be made in the
basic x-24c aircraft. The helium bottle located aft of the tank is the source of pres
surant and purge gas necessary to function of the system.
The actively cooled fin structure is designed to operate at an average surface
temperature of 250°F, representative of actively cooled, hypersonic cruise aircraft
concepts. The fin leading edge selected is a low drag cooled concept. The active
cooling system is configured with an efficient coolant utilizing hydrogen as the heat
sink. The integrated system includes a failure detection system, which will provide
pilot warning"of malfunction. Provisions must be made for routing of coolant lines
between the fin and payload bay, the failure detection system (FDS) control unit, en
vironmental control of the control unit, wiring between the fin and payload bay and
between the payload bay and cockpit. Aircraft power must be supplied to the FDS and
the cooling system.
6
REPORT Moe A3265 20JANUARY 1975
EXPERIMENTS GENERAL "ARRANGEMENT
ACTIVELY COOLED FIN
INTEGRAL LH2 TANK"
~-
GP74-1039-106
MCDONNELL AIRCRAFT COMPANY
7
REPORT Moe A3265 20 JANUARY 1975
THE VALUE OF FLIGHT TESTING
The ques tion has often been asked, "Why mus t we flight test, \vhy can't we learn all
\ve need to know from ground testing?" Decision makers would like a simple straightforward
answer to a very involved question. In our view, the three Cs, Commitment, Confirmation
and Confidence, are answers to the question. In the scientific technological community,
knowledge is only fact after many observations and experimental verifications have been
achieved. Knowledge is not accepted on the basis of faith. It has been said that "one
test is worth a thousand expert opinions."
It is evident that the value of a flight test program is derived not only from the
laboratory development and testing which precedes the flight tests. However, the flight
test program demands a level of commitment which will yield flightworthy hardware. not
just a lab specimen, and focuses a necessary level of physical and financial resources to
the program.
Neither ground test nor analyses can predict the response of an aircraft in flight.
Thus, a value of flight test is Confirmation. The response of the aircraft will be to
the real environment, facts not judgement will be available. If there are any major de
sign flaws they will be uncovered and solved in a cost effective manner.
Scaling effects and correlation of predictions to actuals will contribute in a great
measure to the most precious commodity of confidence. Decision makers require reasonable
assurance of success and budgetary responsibility before committing to a major program.
Certainly a level of confidence is available from a strictly theoretical analysis of a
particular functional system. However, Confidence is increased when experimental labora
tory knowledge is added to the data base. But only through the repeated successful demon
stration of the functional performance of the system will the unknown then become the
design practice of production systems.
MCDONNELL AIRCRAFT COMPANY
8
REPORT Moe A3265 20 JANUARY 1975
THE VALUE OF FLIGHT TESTING
• COMMITMENT • HARDWARE - NOT PAPER OR LAB EXPERIMENTS
• FOCUS RESOURCES
• CONFIRMATION • RESPONSE OF AIRCRAFT IN REAL ENVIRONMENT
• UNCOVER AND SOLVE A MAJOR DESIGN FLAW
• FACTSNOTJUDGMENT
• CONFIDENCE • FROM UNKNOWN TO DESIGN PRACTICE GP74-1039-10
• NO SURPRISES MCDONNELL AIRCRAFT cOItifPANY
9
REPORT MDe A3265 20 JANUARY 1975
STRUCTURAL FLIGHT EXPERIMENTS
Accepting the need for flight testing of advanced structural tech
nologies we are faced with an equally perplexing question, "Hhat should
be the nature of a structural experiment?"
Certainly no one will argue with the premise that it should be flight
weight not boiler plate structure. In our view there is a direct corre
lation between size of the structural specimen and the confidence gained
in the technology being demonstrated--small gains with small structural
panels and large gains with large structural assemblies. A major
structural assembly will simulate all its intended design functions.
It can house the required furnishings and functional systems, provide a
suitable aerodynamic surface, sustain loads, heating, vibration and
acoustics and provide the required stiffness. A major structural assembly
will be exposed to many of the handling and maintenance operations asso
ciated with operational systems, whereas small panels are usually treated
with kid gloves. Thus, in our view, small panels are suitable to perform
exploratory research. Major assemblies are necessary to substantially
advance the state-of-the-art.
MCDONNELL AIRCRAFT COMPANY
10
REPORT MDe A3265 20 JANUARY 1975
STRUCTURAL FLIGHT EXPERIMENTS
• MUST BE FLIGHT WEIGHT STRUCTURE
• MUST BE MAJOR STRUCTURAL ASSEMBLY NOT
SMALL PANELS
• MUST SIMULATE SIGNIFICANT DESIGN AND FUNCTIONAL ASPECTS OF OPERATIONAL AIRCRAFT
GP74-1039-11
MCDONNE ...... AIRCRAFT COMPANY
11
REPORT Moe A3265 20JANUARY 1975
ACTIVELY COOLED PANEL INSTALLED ON ASSET
To support our conviction that small panels are only adequate
to conduct exploratory research, let us review the ASSET program.
An insulated actively cooled panel was flown on ASSET (ASV-3) in
July of 1964. !1aximum speed and altitude were 18,000 ft/sec and
212,000 ft, respectively. The test panel covered an area of 24
inches by 12 inches, was furnished by the Bell Aerosystems Company
and installed at the back under surface of the vehicle as shown
for the flight demonstration by MCAIR.
MCDONNELL AIRCRAFT COMPANY
12
REPORT Moe A3265 20 JANUARY 1975
ACTIVELY COOLED PANEL INSTALLED ON ASSET
15000 F
13
BELL ACTIVELY . COOLED PANEL
GP74-1039-91
MCDONNELL AIRCRAFT CONIPANY
REPORT MDe A3265 20 JANUARY 1975
BELL ACTIVELY COOLED PANEL EXPERIMENT
The chart shows some of the details of the ASSET actively cooled panel flight
experiment. A l2-inch by 24-inch aluminum panel containing integrally tubed coolant
passages was installed at the aft end of the vehicle as part of the bottom surface
structure replacing the titanium structural floor. A propylene glycol/water mixture
was pumped through the panel during the flight to cool the panel to acceptable
levels. The panels were further protected by an external thermal protection system
as shown. This thermal protection system consisted of two columbium heat shield
panels and a radiation barrier insulation system. The heat shield panels were fab
ricated from a slat array of D-14 columbium alloy members and cross-channels attached
with D-14 rivets and protected with an LB-2 slurry coating.
We suggest that while this experiment essentially demonstrated some basic prin
ciples of an actively cooled structure, it did not convince the critical structural
design engineer of the readiness of active cooling for system application. Perhaps
this is because of: (1) The small scale of the test panel, 2 ft 2 ; (2) the low level
heating experienced by the cooled panel due to the heat shielding; (3) the non
critically of the cooled panel. The vehicle could have survived without the cooling
system functioning; (4) the simplicity of the system compared to an operational
aircraft system; or (5) only one flight and, thus, incomplete investigation of the
total operational environment.
Whatever the reason or combination of reasons it is clear that confidence to
proceed forward with structural technology has historically been gained in a system
atic series of steps with ultimate commitment preceded by a significant structural
demonstration.
MCDONNELL AIRCRAFT COMPANY
14
REPORT Moe A3265 20 JANUARY 1975
BELL ACTIVELY COOLED
PANEL EXPERIMENT
RELIEF VALVE
DOUBLE WALL TUBE SHEET - BONDED AND
RIVETED TO STRUCTURAL FLOOR (ALLOW TEMP. 160°F)
RESERVOIR
GEAR PUMP
BYPASS ~ ..
VALVE
a....--------------1 INSULATION PACKAGE .I!;~~~~~~~~~~~0.75
0.003 INCONEL FOI L ,t ';:;= : T COVERING SUBMICRON j "'-0.25 REFRASIL
POWDER (ADL-17) AND FIBERFRAX OUTER WALL INSULATION
SURFACE PANEL (ONE OF TWO SECTIONS SHOWN)
COMPONENT AND COOLING SYSTEM SCHEMA TIC
GP74-103989
MCDONNELL AIRCRAFT COItIIPANY
15
REPORT Moe A3265 20 JANUARY 1975
GENERAL COSTING GROUND RULES
The cost analysis was based on the ground rules indicated on
the chart. A minimum management and development experimental shop
philosophy was used to minimize costs. Details of this approach
will be discussed later. It was assumed that the experiments for
the X-24C would be developed such that provisions for the experi
ment could be incorporated in the basic aircraft at initial fabri
cation and thus avoid the costly modification approach.
MCDONNELL AIRCRAFT COMPANY
16
REPORT Moe A3265 20 JANUARY 1975
GENERAL COSTING GROUND RULES
• ONE FLIGHT ARTICLE
• LOW COST PROGRAM MANAGEMENT APPROACH
• PROVISIONS IN BASIC AIRCRAFT TO ACCOMMODATE
EXPERIMENT, CHARGED TO EXPERIMENT
• BUDGETARY 1974 DOLLARS GP74-1039-13
MCDONNELL AIRCRAFT COItIIPANY
17
REPORT Moe A3265 20JANUARY 1975
COST AND SCHEDULE SUMMARY
(Integral Fuel Tank)
Our study indicates that the integral fuel tank experiment
will require 17.5 months from go-ahead to delivery. We have
allowed an additional 7.5 months for installation and checkout
of the experiment at the test site, conducting the flight
test program and evaluating the flight test data. Thus. the
total program span is 25 months. The costs and span time for
each program phase is given in the chart. More detailed descrip
tion of the work elements and costs will be presented later. The
total program budgeting cost is just under $4.9 million given
constant in 1974 dollars. You will note that the management costs,
which represent approximately 5% of the total costs, are listed
as a separate item since they apply to all phases of the program.
MCDONNELL AIRCRAFT COMPANY
18
REPORT MDe A3265 20 JANUARY 1975
COST AND SCHEDULE
SUMMARY
YEARS FROM GO-AHEAD ACTIVITY
1 2 3
PROGRAM MANAGEMENT, INTERFACE COORDINATION I AND CONTROL, DOCUMENTATION
DESIGN, DEVELOPMENT AND TEST I
(PHASE I)
TOOLING, FABRICATION AND I
ASSEMBL Y (PHASE IT)
FLIGHT TESTING (PHASE ill) I I
TOTAL COST*
*Constant 1974 Dollars
COST*
274,000
2,055,000
2,318,000
205,000
4,852,000 G P 74-1 039-99
MCDONNELL AIRCRAFT COMPANY
19
REPORT Moe A3265 20 JANUARY 1975
COST AND SCHEDULE SUHMARY
(Active Cooling System)
Twenty-four months are required from go-ahead to
delivery of the active cooling system experiment. The
design and development of the heat exchanger is a sig
nificant time pacing item. We have allowed 7 months for
the test phase which 'results in a total program span of
31 months. The total,program budgeting cost is approxi
mately $5.8 million given in constant 1974 dollars.
MCDONNEL.L. AIRCRAFT COMPANY
20
REPORT MDe A3265 20 JANUARY 1975
COST AND SCHEDULE
SUMMARY
ACTIVITY YEARS FROM GO-AHEAD
COST* 1
PROGRAM MANAGEMENT, INTERFACE COORDINATION AND CONTROL, DOCUMENTATION
DESIGN, DEVELOPMENT AND TEST (PHASE I)
TOOLING, FABRICATION AND ASSEMBL Y (PHASE II)
FL I G HT TESTI NG (PHASE :m)
*Constant 1974 Dollars
21
2 3
I 326,000
1 3,397,000
1 1,856,000
1 198,000
TOTAL COST* 5,777,000
GP74-1039-9
_CDONNELL AIRCRAFT CO_PANY
"tJ :D o Cl :Dr }>o $:~ mC"l rO mC/l $:-1 m Z -I C/l
REPORT Moe A3265 20 JANUARY 1975
LOW COST PROGRAM ELEMENTS
Achieving the best product at the lowest cost is a utopia seldom achieved.
Minimizing costs generally results in either reducing the specified capability
required of the product or accepting the risk that the product will not perform as
desired. If this were not axiomatic then the new low cost approach would be the
new norm from which one would again want to reduce cost. Thus the low cost program
elements we have listed in the charts must be considered relative elements, i.e.,
an approach which will provide risks acceptable for an experimental research program
but not acceptable for a high production program. Specifics of each item will be
discussed in the following charts.
ItIICDONNE ...... AIRCRAFT COItIIP'ANY
22
REPORT Moe A3265 20 JANUARY 1975
LOW COST PROGRAM ELEMENTS
• RESPONSIBLE MANAGEMENT
• NO EXTRANEOUS CONTROLS
• DEFINITIVE DRAWING SYSTEM
• AUSTERE GROUND TESTING
• EXPERIMENTAL SHOP
• MINIMAL CONTRACTOR FLIGHT TEST SUPPORT GP74-1039-77
MCDONNEL.L. AIRCRAFT C~PAN'"
23
REPORT MDe A3265 20 JANUARY 1975
PROGRAM MANAGEMENT
More reliance must be placed on the ability of a singular individual to make
the right decisions ~vithout the benefit of input from his peers. The program manager
must have the full corporate authority to make decisions on the spot which affect all
elements of the program, technical problems, schedule and cost. The personnel assigned
to such a program should be the more experienced people who work at a higher rate of
pay than the average individual but require little supervision thus increasing the
overall cost productivity.
Adhering to a crisp schedule is a must--time is money.
A centralized project location wherein the engineering procurement and manufacturing
team are located in close proximity cuts down the lines of communication and increases
direct communication to resolve problems in an expeditious manner.
MCDONNELL AIRCRAFT COMPANY
24
REPORT Moe A3265 20 JANUARY 1975
PROGRAM MANAGEMENT
• CORPORATE AUTHORITY FOR DECISIONS
• CRISP PROGRAM SCHEDULE
• CENTRALIZED PROJECT LOCATION
GP74-1039-78
MCDONNELL AIRCRAFT COMPANY
25
---- ------
REPORT Moe A3265 20 JANUARY 1975
PROGRAM CONTROL
Each of the controls that are negated on the chart are part of the normal
systematic means of assuring a quality end product. The larger more complex the
product, the more important such controls are. How then do we propose to assure
reasonable quality and dependability if all controls are removed.
The answer is to place a great burden on the integrity and expected performance
of the contractor. Each individual, be he engineer or assembly man, must accept the
responsibility of doing his job right the first time. Close coordination with all
vendors is essential. The customer/contractor coordination must take on a routine
rather than periodic nature to assure current visibility to progress and problems
and rapid decision making.
MCDONNEL.L. AIRCRAFT COMPANY
26
REPORT MDe A3265 20 JANUARY 1975
PROGRAM CONTROLS
• NO MANAGEMENT INFO SYSTEM
• NO PIECE PARTS CONTROL
• NO ZERO DEFECTS PROGRAM
• NO MAINTAINABILITY/RELIABILITY PROGRAM
• NO QUALITY ASSURANCE CAD'S
• NO MIL SPECS - DRAWINGS SHOW REQUIREMENTS
• CLOSE CUSTOMER/CONTRACTOR COORDINATION GP74-1039-79
MCDONNEl.l. AIRCRAFT COMPANY
27
REPORT Moe A3265 20 JANUARY 1975
DRAWINGS
The experiment program would be a one of a kind endeavor, with close teaming of
all the functional groups permitting a greatly simplified drawing system. Detail parts
and subassemblies could all be made from a common drawing rather than requiring a number
of drawings. The skill of the manufacturing people could be used in making the best
installation and in making things fit. Thus the engineer would not have to work out
all the details on the drawing, but would only indicate general requirements and
arrangements on the drawing. Developments of such things as line routing would be made
on the actual hard,..rare from similar minimum development information drawings.
Where needed engineering would provide sketches to clarify details. Minimum
information would be put on the drawing, for example, a field callout could be des
criptive enough to negate the need for a bill of material. Fewer drawings would result.
Checking would be done by the designer not another individual charged with
checking. The burden is greater on the designer to assure that it is done right, the
first time.
The question of using the Cathode Ray Tube in the design/manufacturing process is
rather uncertain. Our experience at MCAIR indicates that even for a one of a kind item
the CRT is a fantastic tool which will reduce costs. Since it would probably require
much data to convince people of this we have chosen to cost on the basis of not using
the CRT. However we believe it is an attractive option.
MCDONNELL AIRCRAFT COMPANY
28
REPORT MDC A3265 20 JANUARY 1975
DRAWINGS
• MANUFACTURING DEVELOPMENT DRAWINGS
• SOME SKETCH TYPE
• MINIMUM INFORMATION - FEWER DRAWINGS
• NO CHECKING
• CRT DESIGN TOOL AVAILABLE
GP74-1039-80
MCDONNELL AIRCRAFT COMPANY
29
REPORT MDe A3265 20 JANUARY 1975
DEVELOPMENT AND FLIGHTWORTIIINESS APPROACH
For costing purposes we assumed that all the wind tunnel tests will have been
completed on the basic X-24C program and that no new tests would be required.
The structural verification program would consist of conducting failure tests on
the most critical components. The flight article would then be used (rather than a
separate assembly) and tested to 115% of the design limit load (not the normal ultimate
of 150%) to provide confidence in the load paths and interactions. This combined
approach entails greater risk but should be satisfactory for an experimental aircraft.
Fatigue tests of course are a luxury for this type program. We have assumed that no
mockups, spatial, engineering or functional, would be developed. This approach, at
least on paper, will save money. The functional operation of all subsystem components
integrated in the vehicle will be verified through bench tests as well as in the
assembled sys tem.
MCDONNELL AIRCRAFT COMPANV
30
-I
REPORT Moe A3265 20 JANUARY 1975
DEVELOPMENT AND
FLIGHTWORTHINESS APPROACH
• NO WIND TUNNEL TESTS
• CRITICAL COMPONENT STRUCTURAL FAILURE TESTS
• STRUCTURAL PROOF (115%) FLIGHTWORTHINESS TESTS
• NO FATIGUE TESTS
• NO MOCKUPS
• SUBSYSTEM FUNCTIONAL AND OPERATIONAL VERIFICATION
GP74-1039-81
MCDONNELL AIRCRAFT COItIfPANV
31
REPORT Moe A3265 20 JANUARY 1975
EXPERIHENTAL SHOP
The experiment will be assembled in an experimental shop with limited access. This shop will be equipped with the tooling required to assemble the airframe, test equipment for checkout of installed systems and proof loading, work benches, storage area, inspection supplies, and basic simple machinery to make simple parts. Sheet metal and machined detail parts will be made in shops within walking distance of the experimental shop. Additionally, we will house the project service personnel there, such as engineers, tool designers, production planners, industrial engineers, production control and direct line management personnel. All assembly functions will be performed by highly skilled experimental mechanics.
All shop orders and instructions will be originated by production planning. Normal channels of paperwork will be cut to basics only, with orders and written instructions hand carried directly to those performing the actual operations.
Assembly tooling will consist of the fewest possible tools containing only those features required to control contours and physical interfaces, maintain critical dimensions and locations of structural components to the accuracy specified in the design of the aircraft. The durability will be sufficient to properly build one aircraft.
Machined details will be made on standard machines as far as economically practicable. In all cases, special holding and positioning fixtures will be avoided and depend on setups and simple clamping devices augmented with tracer guided cutting for the machined parts.
Tool design will use sketch type drawings containing only essential information backed up with a liaison function.
All shop orders will be printed on a distinctive color paper to act as an easily recognized flag. This flag will signify a priority for all operations and handling.
MCDONNELL AIRCRAFT COMPANY
32
REPORT MDC A3265 20 JANUARY 1975
EXPERIMENTAL SHOP
Q WOOD, FIBERBOARD TOOLING WITH "C" CLAMPS AND TEMPORARY
HOLDING DEVICES
CI 20 TO 25% SUBASSEMBLY TOOLS
• SHOP LAYOUTS IN LIEU OF TEMPLATES
• SHOP ORDERS FOR TOOLS, DETAIL PARTS AND ASSEMBLIES
• SIMPLIFIED PARTS ROUTING
• NO SPECIAL CONVENIENCE TOOLS - TRIM AND HAND CUT
tI ENGINEERING/MANUFACTURING/INSPECTION TEAMING
GP74-' 039-82
MCDONNELL AIRCRAFT COMPANY
33
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST SUPPORT
It was assumed that the major burden for the flight test program would be borne
by the customer.
The experiment contractor would provide technical support for the installation and
checkout of the experiment in the X-24C aircraft and supply knowledgable personnel for
assistance and consultation during the flight operations.
The customer would be responsible for all the test planning, conducting the
tests, analyzing data, evaluating results and preparing whatever reports deemed
necessary.
MCDONNELL AIRCRAFT COMPANY
34
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST SUPPORT
• EXPERIMENT CONTRACTOR PROVIDES TECHNICAL SUPPORT FOR INSTALLATION AND CHECKOUT
• GOVERNMENT CONDUCTS TESTS, REDUCES AND ANALYZES DATA, WRITES FINAL REPORT
• CONTRACTOR AVAILABLE FOR CONSULTATION
GP74-1039-83
MCDONNELL AIRCRAFT COMPANY
35
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m!: XP "C m:00 ~I m-< ZO -t:O o
Cl m z
REPORT Moe A3265 20 JANUARY 1975
INTEGRAL LIQUID HYDROGEN TANK EXPERIMENT
A number of studies have been conducted to evaluate liquid hydrogen tank structural
arrangement for hypersonic cruise aircraft. Fuselage/tank structural arrangements that
have been proposed for these vehicles consist of either integral or non-integral tanks
with circular or intersecting-circle type (multi-bubble) cross sections. Circular cross
section cylindrical tanks, both integral and non-integral, appear to offer reasonable
vehicle performance and are nearly state-of-the-art designs. The analytical studies
indicate, however, that structural weight and volume utilization advantages may be
attained using the relatively undeveloped integral multi-bubble concept for vehicles
with non-circular fuselage cross sections.
The objective of this experimental program would be to design and develop such a
tank and flight test it aboard a generic version of the X-24C aircraft. The fuselage/
tank structural system would be installed, with the required functional LH2 system
components, by interchanging it with the basic aircraft payload bay. The basis for this
conceptual design study is the -12F version of the X-24C, geometric and flight
characteristics of which were provided by NASA.
MCDONNELL AIRCRAFT COMPANY
36
/
/
REPORT MDe A3265 20 JANUARY 1975
HyDRO ........
\ \
\ \
\ \ \ "', \ )
I I
( TANK
'~\ ------------ )---------- GP74-1039-26
MCDONNE ......
37
A'RCRAFTC OIIIfPANY
REPORT MDe A3265 20 JANUARY 1975
EXPERIMENT PROGRAM OBJECTIVES
The specific objectives of this program are to develop a flight weight, flight
worthy, thermostructural system and associated subsystems and then to demonstrate
the integrated system within the total flight environment. This demonstration is
significant since it is nearly impossible to simulate all aspects of such an environ
ment simultaneously on the ground.
The thermostructural system will consist of an integral, multi-bubble, liquid
hydrogen fuel tank, its transition and support structure, and the thermal protection
system. The thermal protection system would not be developed as a part of this .
program, since it is intended to use the identical heat shield system as used on the
basic X-24C and reuse as much as possible of the existing heat shields for the tank
experiment.
The liquid hydrogen functional subsystem will provide the capability to vent,
pressurize, and purge the fuel tank, and to dump fuel.
Demonstration of the integrated system will be conducted throughout the full
flight envelope of the X-24C test aircraft, both for normal and simulated emergency
conditions. Ground operations will familiarize crews with all phases of handling
the system including inspection, maintenance, and cryogenic fuel handling.
MCDONNELL A'RCRAIFT COIMPANY
38
REPORT MDe A3265 20 JANUARY 1975
EXPERIMENT PROGRAM OBJECTIVES
• DEVELOP A FLIGHTWORTHY THERMO-STRUCTURAL SYSTEM
• STRUCTURAL TANK FOR LH2 CONTAINMENT
• TRANSITION AND SUPPORT STRUCTURE
• DEVELOP FLIGHTWORTHY SUBSYSTEMS
• VENT
• PRESSURIZATION
• DUMP
• PURGE
• DEMONSTRATE THE INTEGRATED SYSTEM WITHIN THE TOTAL ENVIRONMENT
• FLIGHT OPERATION
e GROUND OPERATIONS (INSPECTION AND MAINTENANCE) GP74-1039-20 MCDONNELL AIRCRAFT COMPANY
39
REPORT Moe A3265 20 JANUARY 1975
DESIGN CONCEPT
The design concept defined for this experiment encompasses the operational aspects of the same systems which would be used in future hypersonic cruise vehicles. Illustrated here is the assembled experiment package as it would appear in the payload bay of the X-24C aircraft.
It is from the tank portion of the thermo-structural system that this experiment derives its name. The tank itself is of a substantial size, being approximately eight feet long. Its multi-bubble design features integrally-machined stiffeners and straightline load carrying elements which are the same type design details currently being proposed for future hypersonic cruise vehicles. Domed tank ends are included for increased volumetric efficiency at minimum weight. Thermally induced changes in tank dimensions relative to the remainder of the aircraft structure are accommodated by motion of the support structure connecting them. Detail fabrication and assembly procedures are similar to those that would be used for the tanks of larger vehicles.
The thermal protection system utilizes the basic X-24C aircraft system. It has been assumed that a major portion of the payload hay heat shields will be reused for the experiment. New shields would he fahricated only for those areas in which access or thermal motion accommodations differ from the basic aircraft.
Access to the tank interior is gained by removing two heat shields, unbolting two of the tank support links, and removing the manhole cover in the aft dome of the center tank bubble. These provisions allow maintenance and inspection of the tank, even with the experiment package installed aboard the X-24C aircraft. Structural integrity of the package will not be impaired by removal of the links with the flight test aircraft static on the ground.
Operational elements of the liquid hydrogen system such as the supply port, vent and dump lines are identified here. Provisions for these lines must be made in the basic X-24C aircraft. The helium bottle located aft of the tank is the source of pressurant and purge gas necessary to function of the system.
NrCDONNELL AIRCRAFT CONrPANY
40
STA 206
--
REPORT MDe A3265 20 JANUARY 1975
DESIGN CONCEPT
--- --
INTEGRAL LH2
TANK
TANK ACCESS
LH2 DUMP LINE
41
STA 326
LH2 VENT LINE
GP74-1039-64
MCDONNELL AIRCRAFT COMPANY
REPORT MOC A3265 20 JANUARY 1975
OVERALL DESIGN CONSIDERATIONS
As a basis for developing a conceptual design for this experiment certain ground
rules ,.,ere established and assumptions made. A basic ground rule ~.,as that all load
redistribution between the basic aircraft and the integral tank be accomplished within
the experiment. The effect of this ground rule was to eliminate any weight or design
penalties to the basic X-24C aircraft resulting from accommodation of this experiment.
It was assumed that the all welded tank construction would use 2219 aluminum alloy since
extensive materials property data is available. Thus the possible expense of material
characterization testing could be eliminated. The tank was designed to have planar webs
at the bubble intersections and straight line elements to provide a practical fabrication
approach and to minimize structural discontinuities. Access to the tank interior while
the experiment is on board the X-24C aircraft is provided for inspection and maintenance
during the program.
The tank external insulation is purged with dry nitrogen gas to prevent cryopumping.
A major cost saving assumption was that the basic aircraft heat shields would be reused
wherever possible on the experiment installation.
Design of the liquid hydrogen system utilized a gaseous helium pressurant to main
tain a tank pressure of 20 psig, dump the hydrogen in a maximum time of thirty seconds,
and purge the empty tank four times for safety. An important design goal was to maximize
the amount of liquid hydrogen carried in the experiment, within the design constraints
dis cussed above and within the limited design flexibility afforded by the X-24C payload
compartment geometry.
MCDONNELL AIRCRAFT COMPANY
42
REPORT MDe A3265 20 JANUARY 1975
OVERALL DESIGN CONSIDERATIONS
• STRUCTURAL DESIGN • LOAD REDISTRIBUTION COMPLETE WITHIN PAYLOAD BAY
• TANK CONSTRUCTED FROM WELDED 2219 ALUMINUM ALLOY
• TANK 8 FT LONG, WITH PLANAR WEBS AND STRAIGHT LINE ELEMENTS
• ACCESS FOR INSPECTION AND MAINTENANCE
• THERMAL DESIGN • N2 PURGED EXTERNAL TANK INSULATION
• MAXIMUM REUSE OF BASIC X-24C HEAT SHIELDS
• LH2 SYSTEM DESIGN • GASEOUS He PRESSURIZATION TO 20 PSIG
• 30 SEC MAXIMUM DUMP TIME
• PURGE EMPTY TANK 4 TIMES
o MAXIMUM LH2 CONTAINMENT
43
GP74-1039-19
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
STRUCTURAL CONCEPT
Illustrated here is the structural concept of the experiment package. The tran
sition structure will mate with interchangeable splice patterns at the forward and aft
ends of the X-24C payload bay. This structure redistributes the basic aircraft
internal loads into discrete loads at the ends of the support links. Those loads are
then transflitted to the structural (integral) tank through the links. Monoball rod
ends allml1 the links to follow thermally induced relative motion between the tank and
the basic aircraft structure thereby minimizing thermal stresses while maintaining
basic load carrying capability. Dimensional changes in the tank resulting from
chilling it with liquid hydrogen amount to nearly six tenths of a percent.
The tank structure is an all welded construction of 2219 aluminum alloy. The
body of the tank consists of three intersecting cones the shells of which are stiffened
by machined flanges in an "Isogrid" pattern. This concept was developed by the
Douglas Aircraft Company in conjunction with the National Aeronautics and Space
Administration. A web is placed at each bubble intersection to carry shear and to
allow internal pressure loads to be self-reacting at minimum weight. The domed tank
ends are also of machined "Isogrid" construction.
/MCDONNELL AIRCRAFT CO/MPANY
44
REPORT MDe A3265 20 JANUARY 1975
STRUCTURAL CONCEPT
/
TRANSITION STRUCTURE
• SPLICES • REDISTRIBUTES LOADS
'- SUPPORT STRUCTURE • TRANSMITS AI RCRAFT LOADS
• ACCOMMODATES THERMAL MOTION (DIMENSIONALLY 0.6%)
TANK STRUCTURE • CARRIES AIRCRAFT LOAD
• CONTAINS LH2 • ISOGRID CONSTRUCTION
GP74-1039-70
• WELDED 2219 ALUMINUM ALLOY MCDONNE ...... AIRCRAFT COMPANY
45
REPORT Moe A3265 20 JANUARY 1975
THERMAL PROTECTION SYSTEM
The thermal protection system for the experiment serves the two-fold purpose of
protecting the basic structure (the tank) from aerodynamic heating and minimizing
boiloff of the liquid hydrogen fuel being carried. The heat shields will be basically
those used on the X-24C aircraft. It has been assumed as an economy measure that
seventy-five percent of the payload bay panels can be reused on the experiment with
new shields being introduced where access or thermal deflection criteria differ from
the basic aircraft. These nonstructural panels have a pattern of slotted attachment
holes so that no thermal stresses are induced in them. Air loads on the panels are
transmitted directly to the tank by the titanium support structure.
Tank insulation is laminated from two different types of insulation. The inner
layer, bonded to the tank outer surface, is closed cell, freon blown, polyurethane
foam. This insulation provides a good thermal barrier at minimum weight but would
deteriorate if exposed directly to radiation temperatures from the heat shields.
Therefore a fibrous insulation of the microquartz type, which can withstand these
temperatures, is bonded to the outside of the polyurethane foam. It is, in turn,
covered with a foil thickness layer of perforated aluminum. The fibrous insulation
layer is then purged to 0.5 psi with dry gaseous nitrogen which prevents crvopumping
at minimized insulation thickness.
MCDONNELL AIRCRAFT COMPANY
46
REPORT Moe A3265 20 JANUARY 1975
THERMAL
PROTECTION SYSTEM
TANK INSULATION
• MINIMIZES LH2 BOILOFF • PREVENTS CRYOPUMPING • N2 PURGED (0.5 PSIG) • WITHSTANDS HIGH AND LOW
EXPOSURE TEMPERATURE
INSULATION FIBROUS
POLYURETHANE FOAM
47
. .yo] l" J= 5=J ~\- -14 ~ T .75 IN. IN. 1 IN.
HEAT SHIELDS
• SUPPORTED FROM TANK • REUSES 75% OF X-24 SHIELDS • ACCOMMODATES THERMAL
DEFLECTIONS
GP74-1039-63
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
LIQUID HYDROGEN SYSTEM
The operational functions of this system have been mentioned previously.
They are the same as those that would be incorporated in a larger hypersonic
cruise aircraft with only fuel pumps missing. The X-24c research aircraft
will spend extended time aboard a carrier aircraft so it is necessary that
pylon connections and carrier aircraft provisions provide safe venting and
dumping of the hydrogen under these conditions. It is also desirable that
provisions be available for "topping-off" the hydrogen tank just prior to
launch.
The helium pressurization system was sized to provide the capability
to maintain a constant tank pressure of 20 psig and then to dump the full
hydrogen load in a maximum of thirty seconds and also purge the empty tank
four times.
Fuel outlets located at the lowest point in each bubble of the tank,
gather the fuel at a central point for delivery to the dump lines and masts.
A valved alternate outlet line is also provided so that liquid hydrogen can
be supplied to alternate experiment combinations if desired.
/MCDONNELL AIRCRAFT CO/MPANY
48
He PRESSURIZATION '20 PSIG
30 SEC DUMP 4 PURGE CYCLES
FUEL OUTLETS TO: X-24 DUMP MAST
CARRIER AIC DUMP MAST ALT EXPERIMENT
REPORT MDe A3265 20 JANUARY 1975
LIQUID HYDROGEN SYSTEM
VENT AND SERVICING OPERATE EXTERNALLY
OR TO CARRIER AIC
STA 206 ------·l ----.
.. ----.-_------: I ALT. EXPERIMENT LINE
STA 326
DUMP LINE
[/f l} ~--~~r\: \: __ ,.L __ :.:=--_ .. -=-, no
/I"-"~: 'e.
.- : (~ ( I . , : : \ I' ~--- , -.~:
.___ 1
----- : -------.J
49
OPERATIONAL SYSTEM ELEMENTS
NO SPECIAL SUPPORT EQUIPMENT
GP74·1039·61
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
EXPERIMENT INSTALLATION
By nature of its design this experiment offers simple installa
tion into the x-24c aircraft. After disassembly of the FS 206 splice
the forward fuselage section is hoisted away from the aircraft. The
payload bay is then removed and disassembled and the experiment pack
age is installed by attaching it to the FS 326 interchangeable splice.
The forward fuselage is reinstalled by connecting it at FS 206 and
the aircraft is again a complete structural entity. All systems
leading to or passing through the payload bay must be connected. In
stallation of the heat shields then completes the assembly.
MCDONNEL.L. AIRCRAFT COMPANY
50
STA 206
\
REPORT MDe A3265 20 JANUARY 1975
EXPERIMENT INSTALLATION
- --
STD AI RLOG DOLLY
STA 326 I
1. REMOVE FORWARD FUSELAGE 2. DISASSEMBLE PAYLOAD BAY 3. INSTALL TANK EXPERIMENT 4. REINSTALL FORWARD FUSELAGE 5. CONNECT SYSTEMS, VENT AND DUMP LINES 6. INSTALL HEAT SHIELDS
HOISTING BRIDLE
X-24C PAYLOAD
BAY
51
JACK STAND
GP74103965
MCDONNELL AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
COST AND SCHEDULE SUMMARY
This chart presents a summary of the integral liquid hydrogen tank experiment
program cost and schedule. A schedule and the accompanying cost is provided for
each of the four major program segments: (1) Program Management, Interface Coordi
nation and Control, and Documentation; (2) Phase I - Design, Development and Test;
(3) Phase II - Tooling, Fabrication and Assembly; and (4) Phase III - Flight Test.
Each of these program segments will be discussed in more detail in later charts.
Total cost of the program is estimated to be approximately 4.9 million 1974 dollars
and it is anticipated that the program would be completed in 25 months.
It is interesting to note that Phase I and II costs are nearly equal and that
together they form more than 90% of the total program costs. Flight test costs,
however, represent only slightly more than 4% of the total with the program manage
ment function comprising the remainder.
NlCDONNELL AIRCRAFT CONIPANY
52
REPORT MDe A3265 20 JANUARY 1975
COST AND SCHEDULE
SUMMARY
ACTIVITY YEARS FROM GO-AHEAD
1 2 3
PROGRAM MANAGEMENT, INTERFACE COORDINATION I AND CONTROL, DOCUMENTATION
DESIGN, DEVELOPMENT AND TEST I
(PHASE I)
TOOLING, FABRICATION AND I
ASSEMBL Y (PHASE IT)
FLIGHT TESTING (PHASE ill) I
TOTAL COST*
*Constant 1974 Dollars
53
COST*
274,000
2,055,000
2,318,000
205,000
4,852,000 GP74-1039-99
REPORT MDe A3265 20 JANUARY 1975
PHASE I - DESIGN, DEVELOPMENT AND TESTING
In the following charts we will review in more
detail the significant elements of Phase I, which
affect the design, development and test costs.
54
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
PHASE I
DESIGN, DEVELOPMENT AND TESTING
GP74-1039-23
MCDONNELL AIRCRAFT C~PANV
55
REPORT MDe A3265 20 JANUARY 1975
NO COST DESIGN INFORMATION/ITEMS
An important part of the cost basis for this experi
ment is the assumption that certain design information/
items are available to the experiment contractor at "No
Cost". The representative list of items presented here
would be expected to be available in final form at the
time of authorization to proceed.
MCDONNELL AIRCRAFT COMPANY
56
REPORT Moe A3265 20JANUARY 1975
NO COST DESIGN
INFORMATION/ITEMS
• STRUCTURAL DESIGN CRITERIA/DESIGN LOADS/ STIFFNESS REQUIREMENTS
• AIRCRAFT TRAJECTORY/AERODYNAMIC CHARACTERISTICS
• DRAWING /TOOLING ADEQUATE TO DESIGN AND CONSTRUCT THE STRUCTURAL SPLICES AT FS 206, 326
• AERODYNAMIC HEATING CHARACTERISTICS FOR HEAT SHIELD DESIGN
• THERMAL DESIGN OF HEAT SHIELDS
• INTERFACE CONTROL DOCUMENTATION
GP74-1039-74
MCDONNEL.L. A'RCRAFT COItIIPANY
57
REPORT MDe A3265 20 JANUARY 1975
INTERFACE CONTROL DOCUMENTATION
Interface control documentation in the form of drawings, specifica
tions and reports, containing information adequate to define any special
design requirements, is a vital program element. Generation and utili
zation of this data ensures that both the aircraft and experiment
contractors incorporate proper provisions for the experiment in the
aircraft. The type of information assumed to be available is listed
on this chart.
MCDONNELL AIRCRAFT COMPANY
58
\
REPORT MDC A3265 20 JANUARY 1975
INTERFACE CONTROL DOCUMENTATION
INFORMATION ADEQUATE TO DEFINE DETAILS OF:
o TOTAL ENVIRONMENTS - TEMPERATURE, PRESSURE, HUMIDITY, ACCELERATION, VIBRATION, DEFLECTIONS, ACOUSTICAL LOADS
o EXPERIMENTS PAYLOAD BAY - ROUTING/MOUNTING
• COCKPIT DESIGN/CONSOLES - EXPERIMENT CONTROLS INTERFACE
• AIRCRAFT POWER SYSTEMS
• HYDROGEN VENT/DUMP PROVISIONS
o CARRIER AIRCRAFT INTERFACE WITH X-24C
o ON BOARD INSTRUMENTATION SYSTEMS AND PROVISIONS FOR ADDED INSTRUMENTATION
CD FLIGHT TEST FACILITY INSTRUMENTATION SYSTEM GP74-1039-73
MCDONNELL AIRCRAFT COMPANY
59
REPORT MDe A3265 20 JANUARY 1975
DESIGN, DEVELOPMENT AND TESTING TASKS
Six major program tasks are identified here for the design, development and testing phase of the integral liquid hydrogen tank experiment. A brief description of each task was written in order to provide a proper basis for cost estimation.
Task 1 - Program Management, Interface Coordination and Control, and Program Document~tion - extends throughout the program. Personnel assigned to this task would be the prime contact to provide NASA with visibility to the program. In addition to technical management and control of budgets and schedules, their responsibilities would include coordination and control, both internal and external, of interface requirements and program documentation.
Task 2 - Preliminary Design - starts with the "no-cost" information provided at authorization to proceed and culminates, three months later, in the design freeze of a final design concept for the experiment. This concept would be arrived at by means of a series of layout drawings and trade studies, backed by technical analysis, aimed at optimization of the experiment to meet program objectives.
Task 3 - Procurement Specifications - would be written and released for those elements of the experiment which were determined, at the time of design freeze, to be more economically bought than made in-house. Technical requirements for flightworthiness qualification of these elements would be included in the procurement specifications.
Task 4 - Shop Drawings - would be created using as a basis the final layout drawings from the preliminary design task. Full release of these drawings would occur twelve months after authorization to proceed. The low cost approach to this design function previously discussed would be followed.
Task 5 - Technical Design Analysis - would be made of the thermo-structural functional systems to analytically verify the design adequacy of the experiment. major efforts would involve strength and thermodynamic analyses.
and The
Task 6 - Development Testing and Planning - would be conducted throughout the predelivery phases of this program. This task involves developing and coordinating the test plans, conducting the tests and evaluating the results.
MCDONNELL AIRCRAFT COMPANY
60
REPORT MDe A3265 20 JANUARY 1975
DESIGN, DEVELOPMENT AND TEST TASKS
1. PROGRAM MANAGEMENT, INTERFACE COORDINATION AND CONTROL, PROGRAM DOCUMENTATION
2 PRELIMINARY DESIGN • STRUCTURAL LAYOUTS
• EQUIPMENT AND SYSTEM LAYOUTS
• TRADE STUDIES
• ANALYSIS
3. PROCUREMENT SPECIFICATIONS
4. SHOP DRAWINGS
5. TECHNICAL DESIGN ANALYSIS • THERMODYNAMICS
• WEIGHTS
• STRENGTH • SYSTEM DESIGN
6. DEVELOPMENT TESTING AND PLANNING • DEFINE, SCHEDULE AND COORDINATE ALL TEST PLANS
• COORDINATE, TEST AND EVALUATE - ELEMENT TESTS - SUBCOMPONENT TESTS - PURCHASE PART TESTS
GP74-1039-29
- FLIGHT WORTHINESS TESTS MCDONNELL AIRCRAFT COIt/IPANV
61
REPORT Moe A3265 20JANUARY 1975
TYPICAL ELEMENT TESTING
Element testing is an extremely important portion
of this program phase. It can be used either as part
of development of a design concept or as pre-fabrication
verification of design details. Typical of the element
testing envisioned for this program is the three concept
comparative test of isogrid stiffener splices shown here.
The results of such tests would be used as part of the
basis for selection of the type of splice to be used. For
costing purposes it was assumed that three element tests
of this nature would be required.
MCDONNELL AIRCRAFT COMPANY
62
REPORT Moe A3265 20JANUARY 1975
TYPICAL ELEMENT TESTING
SPECIMENS TESTED TO FAILURE
ISOGRID STIFFENER SPLICE DEVELOPMENT
TAPERED JOINT
I
MECHANICAL ATTACHMENT
63
~ I
1+ + + + J
I WELDED JOINT
I
I •
\ ]1 l I [ { GP74-1 039-1 03
MCDONNELL AIRCRAFT COMPANY
REPORT MOC A3265 20 JANUARY 1975
SUBCOMPONENT FAILURE TESTING
The sub-tasks of structural analysis and element testing are only two of the
essential steps envisioned in the approach to demonstration of structural flight
worthiness. Once critical elements have been analytically identified and their
structural capability verified by element test the process will be repeated for sub
components of the experiment structure. Analysis would be used to identify the most
critical of the subcomponents and they will be tested to failure. The purpose of the
tests would be to verify the capability of the subcomponents to sustain ultimate loading.
For purposes of cost estimation three subcomponents were identified, they are a link
with its end fittings, a link-to-transition structure attach fitting, and a tank wall
segment machined to have the final isogrid design.
It is intended that the combination of analysis and failure testing so far
identified be followed by structural proof testing, for both symmetrical and
unsymmetrical conditions, to 115% of design limit load. This proof testing would be
conducted using the completely assembled experiment package and would complete demon
stration of its structural integrity.
MCDONNELL AIRCRAFT COMPANY
64
REPORT Moe A3265 20 JANUARY 1975
SUBCOMPONENT FAILURE TESTING
LINK AND FITTINGS
o 4 FT
V
A TTACH FITTINGS
65
ISOGRID
GP74-1039-104
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
FLIGHTWORTHINESS TESTING
Final flightworthiness testing of the completed experiment would be conducted
in two segments, in plant test and tests conducted at Edwards Air Force Base.
Testing prior to delivery would combine structural proof tests with prelim
inary operational checks of the liquid hydrogen system. There would be two struc
tural tests loading the structure to 115% of design limit load, for the maximum
symmetrical and unsymmetrical conditions. The pressurized liquid hydrogen system
would be exercised simultaneously with the structural test using liquid nitrogen
to simulate the cryogenic fuel. In this manner the systems operational aspects
under deflected geometry may be verified.
After delivery the liquid hydrogen system would again be tested without the
superposition of structural loading but using liquid hydrogen. A final check
for leakage and operation of the hydrogen system would be conducted after in
stallation of the experiment package in the flight test aircraft.
If it is determined by NASA that a ground vibration test of the experiment
is required it would be 'conducted on board the X-24C aircraft at Edwards Air
Force Base. This test, however, is not included in either the schedule times or
cost of this program.
MCDONNELL AIRCRAFT COMPANY
66
REPORT MDe A3265 20 JANUARY 1975
. - ~-.-.. - - -_ ... - - ----_ .. _. -_ .. '
FLIGHT WORTHINESS TESTING
PRIOR TO DELIVERY:
• EXPERIMENT TESTED AS A UNIT
• LN2 IN TANK • 2 LOADING CONDITIONS - SYMMETRIC AND UNSYMMETRIC
• 115% DESIGN LIMIT LOADS
• PRESSURE
• CRYOGENIC TEMPERATURES
• LH2 SYSTEM OPERATION
• DEFLECTED GEOMETRY
AFTER DELIVERY:
• LH2 SYSTEM FINAL CHECK
o GROUND VIBRATION TEST
GP74-1039-69
MCDONNELL AIRCRAFT COMPANY
67
REPORT MDe A3265 20 JANUARY 1975
STRUCTURAL FLIGHTWORTHINESS VERIFIED
The steps leading to verification of structural flightworthiness
of the experiment package have now all been identified. Careful
analysis would be generated to cover each structural element, both to
verify its adequacy and to identify its relative criticality. Element
testing would then be used to validate the analysis and develop ele
mental design concepts. Failure testing of the three most critical
subcomponents would add confidence that all of the subassembly details
are adequate to carry their calculated ultimate loads. Proof tests of
the assembled package then verify both the capability to carry 115% of
design limit load and internal load distributions. The combined analyt
ical and testing programs would then generate confidence that the X-24C,
with the tank experiment installed, could fly safely to the full extent
of its design envelope.
NlCDONNEI..I.. AIRCRAFT CONIPANY
68
REPORT MDe A3265 20 JANUARY 1975
STRUCTURAL
FLIGHTWORTHINESS
VERIFIED
• ANALYSIS
• ELEMENT TESTS TO FAILURE
• SUBCOMPONENT TESTS TO FAI LURE
• PROOF TESTS TO 115% LIMIT LOAD
{). AIRCRAFT CLEARED TO FULL FLIGHT ENVELOPE
GP74-1039-71
MCDONNELL AIRCRAFT COMPANY
69
REPORT MDe A3265 20 JANUARY 1975
LH2 SYSTEM COMPONENT QUALIFICATION
It is anticipated that most of the components of
the liquid hydrogen system would be procured items. As
such they would be qualification tested as individual
components by the subcontracting vendor. That qualifi
cation testing, which includes function under predicted
service conditions and component ultimate strength,
would qualify the components for assembly into the ex
periment package system without further testing by the
experiment contractor.
MCDONNELL AIRCRAFT COMPANY
70
REPORT Moe A3265 20 JANUARY 1975
~'\ (~?-j
LH2 SYSTEM COMPONENT
QUALIFICATION
• PROCURED ITEMS: BOTTLES, VALVES, SEALS & LINES
• TESTED BY VENDOR FOR: • FUNCTION UNDER PREDICTED ENVIRONMENT • STRENGTH
• COMPONENTS QUALIFIED ON RECEIPT
GP74-1039-30
IMCDONNELL AIRCRAFT COIMPANY
71
REPORT MDe A3265 20 JANUARY 1975
PHASE I - DESIGN, DEVELOPMENT AND TEST COST .;ND SCHEDULE SUMMARY
In this chart the Phase I total cost of nearly 2.2 million dollars
is broken down into individual costs for eacll of the tasks previously
identified. Costs are given both in manhours and dollars. The schedule
indicates the seventeen month time span for this phase and critical
milestones such as design freeze and 100% release of the shop drawings,
which are respectively at three and twelve months after authorization
to proceed.
Comparison of costs shown here shows total engineering costs to be
only slightly greater than the cost of testing with the combination
comprising the bulk of the cost.
MCDONNELL AIRCRAFT COMPANY
72
--~~~----------------------------~~~--~--- ------
REPORT MDe A3265 20 JANUARY 1975
PHASE I DESIGN, DEVELOPMENT AND TEST COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 1234 5 6 7 8 910111213141516171819202122232425~2728293031 MANHOURS
ATP .()
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, PROG RAM DOCUM ENTATION ------ -- --h=:::~=:::~=:::~=:::~=:::~;::j
TASK 2 - PRELIMINARY DESIGN ______ -,. DESIGN FREEZE ________________________ j __ j}
TASK 3 - PROCUREMENT SPECS _______ ---- --1>' 90%
TASK 4 - SHOP DRAWINGS ______________ _ ____ ~ (')....LL..,().100%
TASK 5 - TECH_DESIGN ANALYSIS ______ t~~:::::::*=*~~~~ TASK 6 - DEVELOPMENT TESTING AND PLANNING _________________________________ ~~=*~**=*~~£;>)o
TEST PLANS ------------------------------+--- -'m>' ELEMENT & SUBCOMP_ TESTS_______ _ __ _ __ h:~~O)o
PURCHASE PARTS TESTS ___________ __ _ ____ ____ )
FLiGHTWORTHINESS TESTS __________ J_ J ________________ ~::::n
*Constant 1974 Dollars PHASE I TOTALS
4,930
8,200
900
20,840
11,240
32,250
78,360
COST*
136,000
229,000
25,000
581,000
313,000
907,000
(6,000) CFE
2,191,000 GP7410J99a
I nformation contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
MCDONNELL AIRCRAFT COMPANY
73
REPORT Moe A3265 20 JANUARY 1975
PHASE II - TOOLING, FABRICATION ANT' ASSEl-ffiLY
The low cost ground rules and assumptions used to estimate costs for Phase II
have been discussed previously. It should be emphasized, hmvever, that close
coordination and cooperation between management, manufacturing, quality control and
engineering are absolutely essential during this phase in order that a high quality,
low cost product result. In the following charts we will review in more detail the
significant elements of Phase II which effect the tooling, fabrication and assembly
costs.
MCDONNELL AIRCRAFT COMPANY
74
REPORT MDe A3265 20 JANUARY 1975
PHASE n
TOOLING, fABRICATION AND ASSEMBLY
GP74-1039-31
MCDONNELL AIRCRAFT COMPANY
75
REPORT MDe A3265 20JANUARY 1975
TOOLING, FABRICATION AND ASSEMBLY TASKS
The end product of the program is a complete assembl~T of the experiI'lent package
with all subsystems operative and completely checked out. As previously explained,
the liquid hydrogen system will have been filled, pressurized and drained in-plant using
liquid nitrogen as a safety measure. The system will also have been pressurized with
gaseous helium so that "sniffer" leak checks could be made.
This phase of the experiment includes tool design and fabrication, manufacture
of detail parts, assembly into subcomponents and finally into the finished experiment
structural assembly. Installation of the required instrumentation and systems then
completes the experiment package. Manufacturing supervision will be charged with main
taining quality while producing this assembly at minimum cost.
MCDONNELL AIRCRAFT COIMPANY
76
REPORT MDe A3265 20 JANUARY 1975
T(Q)OlLING, FABRICATION AND ASSEMBLY TASKS
• TOOL DESIGN
• TOOL FABRICATION
• PARTS FABRICATION
• SUBASSEMBLY
• STRUCTURAL ASSEMBLY
• INSTRUMENTATION INSTALLATION
• SYSTEMS INSTALLATION
• PREPARATION AND DELIVERY
(TASK 7)
77
GP74-1039-28
MCDONNELL AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
PHASE II - TOOLING, FABRICATION AND ASSEMBLY COST AND SCHEDULE SUMMARY
Phase II involves a 13-1/2 month effort at a cost of $2.4 million. Included
in this total is that portion of the Program Management cost, attributable to the
Phase II effort. These costs, which are attributed primarily to manufacturing
tasks, have been further subdivided (consistent with the tasks shown in the
previous chart) in order to provide more insight to the cost elements. Material
costs and the procured hardware (CFE) costs are also presented.
An important cost element in this phase is the engineering support of the
manufacturing operation which involves some 21,000 manhours and nearly $600,000.
Close coordination between the manufacturing and engineering functions will be
essential to achievement of the low cost program goals previously discussed. This
will involve clarification of drawings and sketches as problems arise and documen
tation of necessary modifications. Engineering personnel will also be responsible
for the liaison function, that is resolution of inspection "squawks" and timely
recommendations for and approval of repairs.
I nformation contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b), 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
78
IWCDONNELL AIRCRAFT COIWPANY
REPORT MDe A3265 ':10 JANUARY 1975
PHASE n TOOLING, FABRICATION AND
ASSEMBLY COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 123456789101112131415161718192021222324252627281293031 MANHOURS COST*
ATP.(~
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, PROGRAM DOCUMENTATION ________________ ~::;::;::;::;::;::;*;::;*~
TASK 7 - TOOLING, FABRICATION IA
AND ASSEMBL Y--------------------------- - -- - -~=:=~~::::::=~*~=PI
MATERIALS ORDERED
TOOL DESIGN & FABRICATION ___________ t=;*~~ADI
FABRICATION & SUBASSEMBLY --- ---- - --h=~=:=;~~*l
ALL CFE RECEIVED ___________________ - -- _______ J- _ J- -.(~ FINAL ASSEMBLY, SYSTEMS AND INSTRUMENTATION INSTALLATION ________________________ __ _ ____ _ __ _ ____ _ ____ ->\,.
PREPARATION AND SHII~____________ _1. _ __ _ __ Jo
*Constant 1974 Dollars
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
PHASE II TOTALS
79
2,460 69,000
79,890 2,318,000
- (198,000)
(44,700) (1,160,000)
(8,418) (197,000)
- (11,000)
(5,612) , (131,000)
- (30,000)
82,350 2,387,000
GP74-1039102
MCDONNEL.L. AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
PHASE III - FLIGHT TEST
The third, and final, phase of the integral liquid hydrogen tank program ~l7ould
be flight test of the installed experiment package. After the package is delivered
to Edwards Air Force Base it would be installed in place of the payload bay of the
X-24C flight test aircraft and final checkouts made. Flight testing on a "ride-along"
basis could then commence. Significant cost elements of this phase are reviewed
in the following charts.
MCDONNELL AIRCRAFT COMPANY
80
REPORT MDe A3265 20 JANUARY 1975
PHASE m FLIGHT TEST
81
GP74-1039-27
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST OBJECTIVES
The primary objective of the Phase III flight test program is to demonstrate
the integrated experiment within a total hypersonic flight environment. By doing
so with this representative system, confidence would be gained that similar systems
for larger hypersonic cruise aircraft are practical.
This program would demonstrate that integral liquid hydrogen tanks are practi
cal for cryogenic fuel containment in aircraft and that load redistribution systems
that accommodate thermal motions are a state-of-the-art reality.
By means of appropriate measurements taken during the flight tests, it would
be demonstrated that the thermal protection system chosen for this experiment
functions according to prediction.
Flight testing would also serve to demonstrate all the operational aspects of
a functional liquid hydrogen fuel and pressurization system.
In summary, all of these demonstrations would significantly contribute to the
technology data base and design confidence for this type of structural system.
NlCDONNELL AIRCRAFT CONIPANY
82
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST OBJECTIVES
DEMONSTRATE THE INTEGRATED EXPERIMENT
WITHIN A TOTAL HYPERSONIC FLIGHT ENVIRONMENT
C) DEMONSTRATE A FLIGHT WORTHY INTEGRAL LH2 TANK o FUEL CONTAINMENT
• LOAD DISTRIBUTIONS
e DEMONSTRATE A FUNCTIONING THERMAL PROTECTION SYSTEM • TEMPERATURE DISTRIBUTION AND HISTORY
• NO CRYOPUMPING • MINIMIZED FUEL BOILOFF
• DEMONSTRATE AN OPERATIONAL LH2 SYSTEM
• FILL • VENT • DUMP • INSPECT ~ MAINTAIN
NORMAL FLIGHT OPERA TION
EMERGENCY FLIGHT CONDITIONS GP74-1039-67
GROUND OPERA TIONS MCDONNELL AIRCRAFT COMPANY
83
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST PLAN
The proposed flight test plan would utilize varying parameters such as Mach
number, dynamic pressure, load factor, and hydrogen dump rates to assess the
performance of each of the systems. The thermo-structural system would be sub
jected to the full range of aircraft load factors with fuel quantities varying
from empty to full. The thermal protection system would be subjected to a
gradual buildup of aerodynamic heating rates and the liquid hydrogen system
would have demonstrated its capability to deliver fuel at rates varying from
slow to emergency dump.
The program starts with three familiarization flights to accommodate the
pilot to varying rates of fuel usage. Following flights utilize gradual buildups
in flight parameters and simulated fuel usage rates to accomplish the flight test
objectives. Emergency flight conditions necessitating fuel dump are simulated in
two of the flights.
ItIICDONNELL AIRCRAFT COItllPANY
84
TEST CONDITIONS
FLT DYN LOAD MACH
PRESS. FACTOR
1 4 LOW LOW
2 4 LOW LOW
3 4 LOW LOW
4 5 LOW LOW
5 5 MED 0 6 5 HIGH 0 7 6 LOW 0 8 6 ® 0 9 6 ® G) 10 6 ® 0 11 6 HIGH MAX
12 6 HIGH MAX
REPORT MDC A3265 20 JANUARY 1975
FLIGHT TEST PLAN
OBJECTIVES
FAMILIARIZATION, LH2 STAYS ON BOARD
FAMILIARIZATION, SLOW LH2 DUMP, SIMULATE USAGE
FAMILIARIZATION, FAST LH2 DUMP, SIMULATE EMERGENCY
START BUILDUP OF M, G, q, VARY LH2 DUMP RATE
BUILDUP OF G, q, VARY LH2 DUMP RATE
BUILDUP OF G, q, VARY LH2 DUMP RATE
BUILDUP OF M, G, VARY LH2 DUMP RATE
BUILDUP OF G, q, VARY LH2 DUMP RATE
BUILDUP OF G, q, VARY LH2 DUMP RATE
BUILDUP OF G, q, VARY LH2 DUMP RATE
MAX FLIGHT CONDITION - SLOW DUMP RATE
MAX FLIGHT CONDITION - SIMULATE EMERGENCY DUMP
o Gradual Load Factor Buildup ® Gradual Dynamic Pressure Buildup Scheduled Maintenance/Ground Operation Provides Servicing/Maintainability Data
GP74-1039-84
MCDONNEL.L. AIRCRAFT COItIIPANY
85
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST INSTRUMENTATION
Twenty measurands have been identified as the minimum required to monitor
demonstration of the experiment package performance during flight test. Strain
gages, an accelerometer, thermocouples and pressure transducers would be installed
during final assembly of the experiment. This instrumentation would be used to
monitor the same quantities during ground testing and during flight test. The
instrumentation would be designed to be compatible with the airborne instrumen
tation recorder and telemetry system in the X-24C.
IMCDONNEI..I.. AIRCRAFT COIMPANY
86
REPORT Moe A3265 20 JANUARY 1975
Fl~GHT TEST
INSTRUMENTATION
CD STRAIN GAGES -10 - VERIFY OVERALL AIRCRAFT LOADS AND INTERNAL DISTRIBUTION
• ACCELEROMETER - 1 (TRI-AX) VERIFY LOAD FACTORS AND VIBRATION ENVIRONMENT
• THERMOCOUPLES - 6 - VERIFY TEMPERATURES, DISTRIBUTIONS AND HISTORIES
o PRESSURE TRANSDUCERS - 3 - VERIFY TANK AND LINE PRESSURES, MONITOR HYDROGEN FLOW RATES
GP74-1039-76 MCDONNEL.L. AIRCRAFT COMPANV
87
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST TASKS
Flight test tasks would be performed in conjunction with NASA personnel with
the experiment contractor providing support and analysis only on an "as required"
basis.
Final checkout of the liquid hydrogen system would include fill, pressurization,
leak and dump tests of the system using liquid hydrogen and facilities available at
the flight test site. The experiment would then be installed aboard the X-24C
aircraft and a final leak check would be conducted.
If necessitated by NASA requirements, the flight test aircraft would then be
placed on jacks and a ground vibration test to verify satisfaction of stiffness
requirements would be conducted.
The aircraft would then be ready for further ground crew familiarization and
flight test.
/MCDONNELL AIRCRAFT CO/MPANY
88
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST TASKS
• LH2 SYSTEM FINAL CHECKOUT
• INSTALL EXPERIMENT IN X-24C
• PERFORM GVT IF REQUIRED
• EXPERIMENT CHECKOUT
• PROVIDE SUPPORT AND ANALYSIS AS REQUI RED
GP74-1039-44
MCDONNELL AIRCRAFT COMPANY
89
REPORT MDe A3265 20 JANUARY 1975
BASIS FOR FLIGHT TEST COST
The ground rules and assumptions used for estimating flight test
costs are presented here. They emphasize the minimal role of the
experiment contractor in this phase of the program. NASA would use
personnel and facilities already dedicated to the basic X-24C flight
test program to reduce their cost associated with this experiment.
MCDONNELL AIRCRAFT COIHPANY
90
REPORT MDe A3265 20 JANUARY 1975
BASIS FOR FLIGHT TEST COSTS
., FLIGHT TESTS AT EDWARDS AFB
CD X-24C AIRCRAFT FLOWN AND MAINTAINED BY NASA
e TEST FACILITIES PROVIDED BY NASA
o DATA REDUCTION BY NASA
o MINIMUM CONTRACTOR SUPPORT
6) 12 FLIGHTS AT RATE OF 3 PER MONTH
(J DATA COLLECTION BY ON BOARD X-24C SYSTEMS
o LH2 AND ASSOCIATED EQUIPMENT AVAILABLE AT EAFB
o FINAL LH2 SYSTEM CHECK CONDUCTED AT EAFB
o GVT CONDUCTED ON BOARD X-24C IF REQUIRED GP74-1039-32
MCDONNELL AIRCRAFT COIKPANY
91
REPORT Moe A3265 20 JANUARY 1975
PHASE III - FLIGHT TEST COST AND SCHEDULE SUMMARY
Minimized contractor participation in this program phase is reflected by its
low cost. A six week installation and checkout period is followed by flight test.
It is anticipated that flight testing could be conducted on a "ride-along" basis
at the rate of three flights per month. The remaining two month period would be
utilized in analysis and evaluation of flight testing results. Phase III would
be completed in 7-1/2 months.
The chart indicates a subdivision of cost for the various activities in
Phase III with an allocation of approximately 700 manhours per month for contractor
support during the last six months of the program.
IHCDONNELL AIRCRAFT COIHPANY
92
REPORT MDe A3265 20 JANUARY 1975
I~"\ PHASE ill (~~2j
FLIGHT TEST COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 123456789101112131415161718192021222324252627281293031 MANHOURS COST*
ATP .oC~
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, PROGRAM DOCUMENTAT�ON _________ - -T ---- ---- ----- --- ----- ----TASK 8 - FLIGHT TESL _________________ -1---- _L ----- --- -- ----- ----- ,
DELIVERY OF EXPERIMENT. _______ ---- ---- - --r- ---- - ---- -11--)- J-kl LH2 SYSTEM FINAL CHECKOUT
AND INSTALLATION IN X-24C _____ ---- - -r ---T -TT -r --r -_cO
:~~;~:~::~~~:::~::~~:~T:::: 1 T: ]TPlP-l---I--r~ >
:::~;:~ ;~:P:~~~~~~I~~::::: 1 : I Il: :rl-_ -_--_-__ -_--_- _-__ -_-.I_-J1_-__ -_ -_~:
*Constant 1974 Dollars Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b), 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
FLIGHT TEST TOTALS
93
2,460 69,000
7,630 205,000
(91,400)
}
700M/H } PER MO. (113,600) AVERAGE
10,090 274,000
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
PROGRAM COST AND SCHEDULE SUMMARY
In summary, demonstration of the integrated tank experiment within
the full flight envelope of the X-24C would be completed in 25 months at
a cost of 4.85 million dollars. The cost of each program phase, with its
associated manhour expenditure, is indicated here.
IfIICDONNELL AIRCRAFT COIfIIPANY
94
REPORT Moe A3265 20JANUARY 1975
I~'\ ("-~~ [)~
PROGRAM COST AND SCHEDULE SUMMARY (~--ACTIVITY MONTHS FROM GO-AHEAD MAN HOURS COST*
1 2 3 4 5 6 7 8 9 10 1112 13 14 15 16 17 18 1920 21 22 23 24 25 26 2/28 29 30 31
ATP.( ).
TASK 1 - PROGRAM MANAGEM~NT, INTERFACE COORD AND CONTROL, PROGRAM DOCUMENTATION _________ ,. 9,850 274,000
PHASE I - DESIGN, DEVELOPMENT AND TEST __________________________________ ). 73,430 2,055,000
PHASE II - TOOLING FABRICATION AND ASSEMBLY __________________________ lI\ 79,890 2,318,000
__ 1. .1 _ _ J_ PHASE III - FLIGHT TEST .---------- _____ ,. 7,630 205,000 - -- - -- - - -- - - -
*Constant 1974 Dollars PROGRAM TOTALS 170,800 4,852,000
A DEMONSTRATED LH2 SYSTEM/TANK INTEGRATION WITHIN ITS TOTAL Information contained h.erein is privileged HYPERSONIC ENVIRONMENT or conf,dent,al InformatIon of McDonnell Douglas Corporation and exempt from pub· lic disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government. 95
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
CRITICAL TECHNOLOGIES AND LONG LEAD ITEMS
Assessment of the conceptual design and test program indicates that
no technology areas or long lead time procurement problems exist which
would indicate potential program delays. The assumed availability of
2219 aluminum plate for construction of the tank, however, could be
critical to both cost and schedule since current availability is quite
limited.
MCDONNELL AIRCRAFT COMPANY
96
REPORT MDe A3265 20 JANUARY 1975
CRiTICAL TECHNOLOGIES
AND lONG lEAD ITEMS
TECHNOLOGI ES - NONE
LONG LEAD ITEMS - NONE
MATERIALS: 2219 ALUMINUM ASSUMED AVAILABLE FOR TANK
GP74-1030-41
MCDONNEL.L. AIRCRAFT COMPANY
97
REPORT Moe A3265 20 JANUARY 1975
X-24c PROGRAM IMPACT OF EXPERIMENT ACCOMMODATION
Several areas of the basic X-24C aircraft program deserve special consideration in that
early attention to these details would minimize the impact of accommodation of the integral
liquid hydrogen tank experiment.
Careful attention must be paid, for instance, to design of the FS 206 and 326 struc
tural splices so that they are readily made interchangeable with simple tooling. In areas
outside the payload bay space, routing and mounting provisions must be made for vent and
dump line routing and the dump control itself. Design of the aircraft controls routing
through the bay must consider eventual installation of the tank experiment. If the tank
is to be used as a liquid hydrogen source for alternate or combined experiments, plumbing
of the hydrogen from the tank to the point of use must be considered. In addition, cost
savings could be incurred by considering access requirements to the tank experiment in
design of the basic X-24c thermal protection system heat shields. Requirements for data
collection during the tank experiment flight tests should also be considered in design of
the basic X-24C instrumentation system.
Special tools will be required for installation of the experiment. They will include
tooling, supplied by the aircraft contractor, for the FS 206 and 326 interchangeable
splices, vent and dump masts, and supports for such items as controls, electrical wiring,
and plumbing. The cost of such tooling has not been included in the experiment program
estimates. These requirements should be considered early in the X-24C program.
Perhaps the most important single requirement resulting from accommodation of the
tank experiment is the necessity for the X-24c-12F weight and C.G. envelope used for
design to include the effects of this experiment. Failure to do so could require con
siderable ballast during the flight test program in order to result in a controllable
aircraft.
IMCDONNELL AIRCRAFT COIMPANY
98
REPORT MDe A3265 20 JANUARY 1975
X-24C PROGRAM IMPACT OF
EXPERIMENT ACCOMMODATION
• INTERFACES AND STRUCTURAL PROVISIONS • FS 206, 326 SPLICES
• VENT AND DUMP LINE ROUTING
• DUMP CONTROL ROUTING AND COCKPIT INSTALLATION
• CONTROLS ROUTING IN PAYLOAD BAY
• LH2 ROUTING FOR ALTERNATE EXPERIMENTS
• PAYLOAD BAY SHINGLES (COMMONALITY)
• INSTRUMENTATION
• SPECIAL TOOLS • FS 206, 326 SPLICES
• VENT AND DUMP MASTS
• CONTROLS, ELECTRICAL AND PLUMBING SUPPORTS
• BASIC AIRCRAFT DESIGN • WEIGHT AND C.G. ENVELOPE
99
--- --- -----
GP74-1039-43
REPORT MDe A3265 20 JANUARY 1975
VERSATILE TEST BED
The integral liquid hydrogen tank experiment has great potential aboard the
X-24C as a test bed for alternate and combined flight experiments. It could
readily be used as a source of cryogenic hy~ogen to be used as fuel for an
experimental scramjet engine or as a heat sink for an active cooling system.
The support structure for the X-24C heat shield is adaptable to a number of
alternate thermal protection systems and the liquid hydrogen tank could be the
basis for testing a variety of external insulative concepts as well as internal
vapor barriers. This adaptability should make possible the "ride-along" flight
test program which has been proposed and reduce overall X-24C flight test program
costs by providing a ready, on-board, source of liquid hydrogen.
MCDONNEL.L. AIRCRAFT COMPANY
100
-,
REPORT MDe A3265 20 JANUARY 1975
• LH2 FUELED SCRAMJET
• ACTIVE COOLING SYSTEMS
• ALTERNATE THERMAL PROTECTION SYSTEMS
• LH2 FUEL TANK • EXTERNAL INSULATION
• INTERNAL VAPOR BARRIER
GP74-1039-42
MCDONNELL AIRCRAFT COMPANV
- 101
» -no r:! -< elm IO -io rno Xr -c -rnz :DC) ~CIl rn-< ZCll -i~
:5:
REPORT Moe A3265 20 JANUARY 1975
ACTIVE COOLING SYSTEM FLIGHT EXPERIMENT
A number of investigations have identified active cooling of the airframe structure
as a promising thermo-structural design concept for hydrogen fueled high speed aircraft.
Cooled structure which allows the use of conventional aluminum material offers poten
tial advantages in terms of weight, cost, fabricability, and service life. In systems
of this type, coolant is pumped to the cooled aircraft surfaces, to absorb the aero
dynamic heat, and then is returned to a coolant-to-hydrogen heat exchanger. Heat is
rejected to the hydrogen fuel and the coolant recirculated to the surface panels.
Active cooling systems, involving a complete flow distribution system with the
required mechanical components and electronic controls, are susceptible to failures.
System failure could result in a catastrophic structural failure due to exceeding the
temperature capability of the material. Thus, a method or approach to providing "fail
safe" operation is required.
The usual approach to fail-safe operation of cooling systems is through redundancy.
However, full redundancy in a cooling system of the type under consideration is not
necessarily fail-safe and certainly not lightweight. An alternate approach to pro
viding fail-safe operation is to provide means to detect a failure and abort the flight
to achieve safe flight conditions. This is the approach considered in the design of
the active cooling system flight experiment.
NlCDONNELL AIRCRAFT CONIPANY
102
REPORT MDe A3265 20 JANUARY 1975
ACTIVE COOLING SYSTEM
FLIGHT EXPERIMENT
103
GP74-1039-3
MCDONNELL AIRCRAFT COMPANY
-~-- --
REPORT Moe A3265 20 JANUARY 1975
EXPERIMENT PROGRAM OBJECTIVES
Actively cooled structure for hydrogen fueled high speed aircraft shows poten
tial for significant reductions in weight-size-cost of the aircraft. However, the
systems raise concern over risk of cooling system failure, and with it loss of
structural and aircraft integrity. Thus, our experimental objectives are: develop
a flightworthy fail-safe thermo-structural system; develop flightworthy functional
subsystems; and demonstrate the integrated system within the total environment.
The first of these objectives can be met by development of actively cooled
aluminum structure with the inherent capability to survive a cooling system failure.
The second objective can be met by development of an active (convective) cooling
system with circulating coolant and hydrogen as a heat sink. and by development of
a failure detection system to provide the pilot an indication to take corrective action
in case of cooling system failure. The third objective can be met with a flight
test program allowing investigation of normal flight operation, abort flight
conditions, and ground operations.
MCDONNEL.L. AIRCRAFT COMPANY
104
REPORT Moe A3265 20 JANUARY 1975
EXPERIMENT PROGRAM OBJECTIVES
DEVELOP A FLIGHTWORTHY FAIL-SAFE THERMO-STRUCTURAL SYSTEM
• ACTIVELY COOLED ALUMINUM STRUCTURE
DEVELOP FLIGHTWORTHY FUNCTIONAL SUBSYSTEMS
• ACTIVE COOLING SYSTEM WITH HYDROGEN HEAT SINK
• FAILURE DETECTION SYSTEM WITH PILOT INDICATION TO TAKE CORRECTIVE
ACTION
DEMONSTRATE THE INTEGRATED SYSTEM WITHIN THE TOTAL ENVIRONMENT
• NORMAL FLIGHT OPERATION
• ABORT FLIGHT CONDITIONS - "FAIL-SAFE"
o GROUND OPERATIONS - SYSTEM CHECK- OUT AND MAINTAINABILITY
GP74-1039-4
MCDONNEL.L. AIRCRAFT COMPANY
105
REPORT Moe A3265 20 JANUARY 1975
LOCATION OPTIONS FOR COOLED STRUCTURE TEST
Five locations on the X-24C research aircraft were considered as viable
candidate locations for the fail safe actively cooled structure experiment.
Considerations were: (1) the test location must provide a significant surface
area; (2) the test location must provide reasonable simulation of the typical
range of heating rates experienced by Mach 6 aircraft concepts, (3) the exper
iment must integrate with the basic aircraft with a minimum cost impact; and
(4) the location should not interfere with the integration of other potential
experiments. On the basis of these factors, the centerline vertical stabilizer
was selected as the best overall location for the test of actively cooled structure.
ItIICDONNEI...I... AIRCRAFT COItllPANY
106
REPORT Moe A3265 20 JANUARY 1975
LOCATION OPTIONS FOR COOLED
STRUCTURE TEST
• NOSEWHEEL WELL DOORS
• PAYLOAD BAY LOWER SURFACE
• WING STRUCTURE
• OUTBOARD VERTICALS
• CENTERLINE VERTICAL STABILIZER
SELECTED ~ GP74-1039-90
MCDONNEL.L. AIRCRAFT COMPANY
107
REPORT Moe A3265 20 JANUARY 1975
OVERALL DESIGN CONSIDERATIONS
The centerline vertical stabilizer offers a significant structural compo
nent for demonstration of actively cooled structure. The experiment structural
system is designed to be interchangeable with the basic "hot" stabilizer and
also to adapt and utilize the basic X-24c speed brake. In this way costs will be
minimized. The actively cooled structure is designed to operate at an average
surface temperature of 250oF, representative of actively cooled, hypersonic cruise
aircraft concepts. The fin leading edge selected is a low drag cooled concept.
The active cooling system is configured with an efficient coolant utilizing
hydrogen as the heat sink. The integrated system includes a failure detection
system, which will provide pilot warning of malfunction. The structure must be
capable of surviving a tr~nsient heat pulse during abort, without requiring
refurbishment.
IWCDONNEL.L. AIRCRAFT COIWPANY
108
STRUCTURAL DESIGN
REPORT MDe A3265 20 JANUARY 1975
OVERALL DESIGN CONSIDERATIONS
e INTERCHANGEABLE ACTIVELY COOLED FIN
e ACCOMMODATES BASIC AIRCRAFT SPEED BRAKE
THERMAL DESIGN
o ACTIVELY COOLED STRUCTURE AT AVERAGE SURFACE TEMPERATURE OF 250°F
o SHARP ACTIVELY COOLED LEADING EDGE APPLICABLE TO HYPERSONIC CRUISE
AIRCRAFT
• ACTIVE COOLING SYSTEM WITH AQUEOUS METHANOL COOLANT AND HYDROGEN
HEAT SINK
Q FAILURE DETECTION SYSTEM TO PROVIDE WARNING OF FAILURE/MALFUNCTION
TO PILOT
o STRUCTURE CAPABLE OF SURVIVING ABORT HEATING GP74-1039-5
MCDONNELL AIRCRAFT COMPANY
109
REPORT Moe A3265 20 JANUARY 1975
DESIGN FEATURES OF CONCEPT
This chart illustrates some of the design features of the integrated active
cooling concept. The interchangeable actively cooled fin structure must interface ~vith
the basic fin mounting structure and the basic speed brake.
Provisions must be included in the basic design of the aircraft for the required
subsystem interfacing. This will require space for routing of coolant lines between
the fin and payload bay, space for the failure detection system (FDS) control unit,
environmental control of the control unit, space for wiring between the fin and payload
bay and between the payload bay and cockpit. Aircraft power must be supplied to the
FDS and the cooling system. The illustrated equipment and fin installation provides
insight as to the aircraft areas affected by accomodation of the actively cooled struc
ture experiment. Interface coordination and control will be an important facet of the
experiment programs.
NfCDONNELL AIRCRAFT CONfPANY
110
REPORT Moe A3265 20 JANUARY 1975
DESIGN FEATURES OF CONCEPT
., MOUNTING AND ROUTING PROVISIONS INCORPORATED IN BASIC AIRCRAFT
• ACTIVE COOLING SYSTEM - SELF CONTAINED UNIT IN PAYLOAD BAY
ACTIVELY COOLED
ACTIVE COOLING SYSTEM
WIRING TO COCKPIT
STRUCTURE l __ --, FAILURE DETECTION /1
SYSTEM CONTROL UNIT .,,-- ~l
.... ! .--_. ~--<-\-- -- \ ;;;§§F-§~?~~~':{-: /\(\ '. r--~------ --.-~~\
:::: \. (' _ /'" i . \ ---- ( y'" --' \
./? .~ ~. " .~-------~:l-'-- ... -~~"' 1 ./ _/ /'" , ••• _--;.. .J'
.r"\ - /"'''' 'v·-· - .. ,--- \ ,-_------"" ... ------- ~/ ~ _/"'''' i\ _.-~~:-""-"'-"'-"'--;-- i_fJ' ~".".--- ' _____ -_-- _=-:-:".=-.d--<.-~~--------------:-:~~' ?~~;::;:::;.;.-;;.--
c..-----.... I ... ..., __ ( __ J ______ ---------------------------------------- -------------------------------------- ----------.. ----------------------------- ( . .' .... H Y DR 0 G E N
PAYLOAD BAY COOLANT VENT/DUMP
COOLANT RETURN SUPPLY LINE LINE
GP74-1039-6
MCDONNEL.L. AIRCRAFT COItIfPANY
111
REPORT Moe A3265 20 JANUARY 1975
FIN GENERAL ARRANGEMENT
The general arrangement of the actively cooled centerline vertical stabilizer is
illustrated. As shown, the fin is basically a wedge slab design \"ith a low drag swept
leading edge. The leading edge diameter is 3/8 inch and the sweep angle 50 degrees.
The wedge total angle is 10 degrees. The fin is configured to utilize the hot speed
brake, the speed brake actuator, and hinge-line seals of the basic aircraft vertical
stabilizer design. The fin is designed to attach to the aircraft fuselage structure by
9 lug type attach points and will be interchangeable with the basic fin design.
MCDONNELL AIRCRAFT CONfPANY
112
REPORT MDe A3265 20 JANUARY 1975
FIN GENERAL ARRANGEMENT
3/8 IN. DIA (COOLED) LEADI NG EDGE
6.17 FT
2.61 FT
~
100
WEDGE ANGLE
113
BASIC SPEED BRAKE
BASIC ACTUATOR AND HINGE LINE SEALS
INTERFACE WITH BASIC AIRFRAME
GP741039·7
MCDONNELL AIRCRAFT COIMPANY
REPORT MDe A3265 20 JANUARY 1975
FIN STRUCTURAL DESIGN CONCEPT
This chart illustrates some of the details of the actively cooled fin structure.
Master tooled, lug type, attach points, as shown, are a representative means of
achieving an interchangeable interface with the basic airframe structure. A root
closure torque box is provided for redistribution of lug loads.
The fin structure consists of aluminum honeycomb sandwich panels, mechanically
attached to aluminum spars and ribs. The panels are fabricated from an alundnum
outer skin, a non-perforated aluminum honeycomb core and an aluminum inner skin. The
coolant tubes and manifolds are brazed to the outer skin. The outer skin/tube
assembly, the honeycomb core, and the inner skin are bonded together with FM 400
adhesive. The coolant manifolds are designed to serve as edge closures for the honey
comb sandwich. The tubes and manifolds can be assembled and completely bench checked
prior to complete panel assembly.
A high degree of damage tolerance is achieved. The non-perforated honeycomb
core will contain the coolant, providing tubing fail-safe capability. The panel can
sustain significant local overheating. The tube-to-skin bonds act as inhibitors to
crack growth.
MCDONNELL AIRCRAFT COMPANY
114
REPORT Moe A3265 20 JANUARY 1975
FIN STRUCTURAL DESIGN CONCEPT
LOCKALLOY
SPARS AND RIBS
FWD MANIFOLD (ALUMINUM) ALUMINUM SKIN
COOLANT TUBE (ALUMINUM)
-$-
~FC2SFFF£+3-------+ I FUSELAGE
(TYP) 9 PLACES
115
GP74-103917 MCDONNE ...... AIRCRAFT COMPANY
REPORT MOC A3265 20 JANUARY 1975
FIN THERMAL DESIGN CONCEPT
A typical coolant distribution is shown. Aqueous methanol, se
lected as the coolant, enters a supply manifold at the bottom of the
fin. Alternate tubes carry the coolant to either a manifold at 2/3
span or to the tip manifold. The coolant is then directed to the
leading edge manifold and then returned to the active cooling system
where heat is rejected to hydrogen heat sink via a coolant-to-hydrogen
heat exchanger. The cooled skin panels are of aluminum skin-honeycomb
core with "Dee" shaped coolant tubes. The leading edge is cooled by
the flow of coolant through the integrated leading edge coolant return
manifold. In case of cooling system failure, the outer surface skin
must have sufficient mass to absorb the abort heating. Thus, the skin
thickness is a function of abort heat load.
MCDONNELL AIRCRAFT COMPANY
116
REPORT MDe A3265 20 JANUARY 1975
FIN THERMAL DESIGN CONCEPT
COOLANT RETURN
COOLANTTUBE~ MANI:OLDS
--F~L2~-=""~Ll 1'1'1 {fyi\ A-A --..- fisJ llc~ll LLI
LOCKALLOY FWD MANIFOLD LEADING EDGE
DISTRIBUTION MANIFOLD
~ COOLANt
SUPPLY
BASIC SPEED BRAKE
DISTRIBUTION MANIFOLD
THICKENED ALUMINUM SKIN
TYPICAL COOLANT TUBES
GP741039-B
B-B COOLANT RETURN -
MCDONNELL AIRCRAFT COMPANY
117
REPORT Moe A3265 20 JANUARY 1975
SUBSTANTIAL AREAS OPERATE AT HEATING RATES ABOVE 5
This chart illustrates the heating rate distribution for I
a typical hypersonic transport at Mach 6 at an altitude of I
105,000 ft. A substantial portion of the actively cooled
surface will experience cruise condition heating rates greater 2
than 5 BTU/FT sec. This indicates that the activel~ cooled
structure associated with an active cooling flight experiment
should be capable of operation within a heating rate environ
ment resulting in rates between 5 to 10 BTU/FT2
sec.
IKCDONNELL AIRCRAFT COIKPANV
118
REPORT Moe A3265 20 JANUARY 1975
SUBSTANTIAL AREAS OPERATE ~~\ AT HEATING RATES ABOVE 5 ~
TYPICAL M = 6 CRUISE HST (ACTIVELY COOLED)
UPPER SURFACE
1.5
l
1 t 5
LOWER SURFACE q (BTU/FT2 SEC)
GP74-1039-16
MCDONNELL AIRCRAFT COMPANY
119
REPORT Moe A3265 20 JANUARY 1975
NORMAL OPERATING HEATING RATES
This chart illustrates typical heating rate histories
for the cooled centerline.vertical stabilizer. Cruise time
at r1ach 6 is assumed to be 60 seconds and descent from cruise
is assumed to be at maximum aircraft lift-to-drag ratio.
This type of flight profile was selected to insure a cooling
system design of adequate cooling capacity. Increasing angle
of attack above the 5°_6° angle at (L/n) max would tend to
decrease the fin average heating rate and decreasing cruise
time at maximum Mach number would tend to reduce the total
flight heat load and, thus, the total amount of heat sink
required. A number of options are available, as indicated
above, in terms of angle of attack and cruise time. As shown
on the chart, heating rates at the selected cruise condition
vary from values a little above 10 BTU/ft2
sec down to values
below 7 BTU/ft2 sec. This would give simulation of the higher
heating rate areas on a Mach 6 cruise aircraft. Additional
options are available and are discussed in the following
chart.
MCDONNEL.L. AIRCRAFT COMPANY
120
q - HEATING
RATE
REPORT Moe A3265 20 JANUARY 1975
NORMAL OPERATING HEATING RATES
DESCENT AT LID = 2.5
10 j-CRUISE AT M = 6, ALTITUDE = 89,000 FT
8~------~~~~-+~------~------~------~
6r------+Hr------~~~~~-T-------~------~
BTU/FT2 SEC 4 r------H-I---t-------+--~~~-----~-----~
2r---~~~-------+--------~~~~~----~
o--~----~------~------~--------~----~~ o 100 200 300 400 500 TIME - SEC GP74-1039-85
MCDDNNE ........ AIRCRAFT COMPANY
121
REPORT Moe A3265 20 JANUARY 1975
EXPERIHENT SHfULATES HAXIHUM OPERATIONAL HEATING RATES
The heating rate distribution exhibited is typical for the centerline
vertical stabilizer at Mach 6 and an altitude of 89,000 ft. Dynamic pres
sure at this condition is 1000 PSF. Aircraft angle of attack is 5 degrees.
As shown, the heating rates (turbulent flow) vary from 12 BTU/ft2
sec near
the leading edge to about 7 BTU/ft2
sec on the aft lower portion of the
fin. Operation at a dynamic pressure of 500 PSF at lIach 6 (105,000 ft
altitude) would reduce these heating rate values to approximately 50 per
cent of the illustrated values. This will give the capability to investi
gate the range of heating rates from abort 3 BTU/ft2
sec up to the 12
BTU/ft2 sec. Thus, this range of heating rates includes the heating rates
experienced over a major portion of the surface of a Mach 6 aircraft and
experimental simulation would be good within this altitude range. The
actively cooled fin is designed for the heating rates associated with
operation at a dynamic pressure of 1000 PSF.
MCDONNELL AIRCRAFT COMPANY
122
REPORT MDe A3265 20 JANUARY 1975
EXPERIMENT SIMULATES MAXIMUM OPERATIONAL
HEATING RATES
M = 6 CRUISE AT 89,000 FT ALTITUDE TWALL = 250°F .
q LEADING.EDGE = 89.3 BTU/FT2SEC (DIA = 3/8 IN.)
CONSTANTq (BTU/FT2 SEC)
HOT SPEED BRAKE
GP74-1039-15
MCDONNELL AIRCRAFT COIfIfPANY
123 \
REPORT MDe A3265 20 JANUARY 1975
FLIGHT ABORT CONSIDERATIONS
In order to provide a "fail-safe" capability to the actively
cooled structure a number of factors must be considered in the system
design and operational utilization. A failure detection system,
capable of providing fast response detection of a system failure or
malfunction, must be provided. The feasibility of utilizing an abort
trajectory to reduce descent heating and total descent heat load,
must be verified. An adequate structural capability must be provided
to survive the heating loads during abort with the associated cooling
system failure effects considered in determining the strength capa
bility required of the fin. All these factors were considered in
the conceptual design of this experiment.
MCDONNELL AIRCRAFT COMPANY
124
REPORT Moe A3265 20 JANUARY 1975
FLIGHT ABORT CONSIDERATIONS
• FAST RESPONSE FAILURE/MALFUNCTION DETECTION
• ABORT TRAJECTORY TO REDUCE HEAT LOAD
• ADEQUATE HEAT ABSORPTION CAPABILITY TO HANDLE
ABORT HEATING
FAIL-SAFE CAPABILITY GP74-1039-14
MCDONNELL AIRCRAFT' COMPANY
125
._----------
REPORT MOC A3265 20 JANUARY 1975
ABORT TRAJECTORY REDUCES DESCENT HEATING
Maneuvering the aircraft during an abort can result
in significant reductions in the abort heat load. This
is illustrated by the comparison of the high lift-to-drag
ratio (2.5) descent, the low LID (0.58) descent at low
angle of attack with speed brakes deployed, and the mini
mum heating descent. The minimum heating descent utilizes
a constant 2.5g pitch up which transitions to a 90° bank
angle - 30 angle of attack condition. For this trajectory,
the descent heat load for a typical location on the center
line vertical fin is only about 11 percent of the high
LID descent heat load. Thus it appears entirely feasible
to significantly reduce total heat input loads by such
traj ectories.
MCDONNEL.L. AIRCRAFT COMPANY
126
REPORT MDe A3265 20 JANUARY 1975
ABORT TRAJECTORY REDUCES DESCENT HEATING
q - HEATING RATE
BTU/FT2 SEC
10------~----~----~----------~----~ START ABO~T~TW = 250°F MACH 6 CRUISE
A AL T = 89,000 FT X = 3 FT 8~----~~~4-----~-----+----~----~
~HIGH LID DESCENT /' Q = 951 BTU/FT2
LOW LID DESCENT Q = 219 BTU/FT2
MINIMUM HEATING DESCENT
O~L---~--~~~~~~~~~~~----~
o 100 200
127
300 TIME - SEC
400 500 600 GP74-1039-86
"'CD~NE&'&' AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
SPEED AND DESCENT TRAJECTORY DETERMINE SKIN THICKNESS
The capability of a bare unprotected aluminum skin to survive the
heating during the abort descent depends upon the flight speed at abort
initiation and the type of trajectory utilized to arrive at a safe
flight condition. The initial speed influences the magnitude of the
heating rate. The type abort trajectory also influences the abort
heating rates, but of more importance it determines the time required
for descent, and thus, the total abort heat load. If we utilize a
thermo/structural system in which an external aluminum skin is used as
a heat sink the required skin thickness is determined by the total abort
heat load. The chart illustrates these effects for the case where the
initial structural temperature is 250°F prior to the cooling system
failure requiring the abort and a limit on the structural temperature
rise of 200°F. The dominating effect of the type abort trajectory used
is evident. With this type of heat sink (unprotected aluminum skin)
approach, limitations may be required on maximum test Mach number. This
Mach number limitation will be a function of the ability of the aircraft
to pull high g's during abort and the ability to accommodate vertical
fin weight. The fin design cost was based on the use of 0.08 inch thick
skins.
/MCDONNEL.L. AIRCRAFT COMPANY
128
REPORT MDC A3265 20 JANUARY 1975
SPE·ED AND DESCENT TRAJECTORY DETERMINE
SKIN THICKNESS
0.8 r-------,.--------,--------r----r------,
HIGH LID DESCENT
0.6 1--------+------4-------J.-..~---~
ALUMINUM FIN DESIGN WITH 0.08 SKIN LOW LID
THICKNESS O.4~--~-~----~--~~DESCENT-~~ I
INCH STRUCTURAL MINIMUM CONSIDERATIONS HEATING
DESCENT 0.2 1------:(--{---+-----~-----+---'\-7oC..--___1
---- - --- - -~ - --- ---- ------
o~-------~--------~~--------~--------~ 2 3 4 5 6
MACH NUMBER GP74·'039-87
_CDONNELL AIRCRAFT CO_PANV
129
REPORT Moe A3265 20 JANUARY 1975
COOLING SYSTEM ELEMENTS
The active cooling system was assumed to be contained in the pay
load bay. The system arrangement shown is one of several arrangements
that could supply the required cooling capacity. The illustrated ap
proach utilizes supercritical hydrogen, stored in a vacuum jacketed
tank, as the heat sink. Another approach, using normal boiling point
hydrogen at subcritical pressures and a pump to deliver hydrogen to the
heat exchanger, could also be utilized. It is estimated that either
approach would result in about the same order of magnitude cost. The
major elements of the integrated system exhibited on the chart are the
cooled fin, the coolant distribution lines, the tank containing the hy
drogen heat sink, the coolant pump package, and the coolant-to-hydrogen
heat exchanger. The heat exchanger design concept will fall within the
category of critical technology.
MCDONNELL AIRCRAFT COMPANY
130
REPORT MDe A3265 20 JANUARY 1975
COOLING SYSTEM ELEMENTS
ACTIVELY COOLED
FIN
1
I J
~ ____ ~~J~L / - /
\ ~4 ____ ------PAYLOAD-BAY----------~·\
HYDROGEN TANK
\ HEAT SOURCE TO MAINTAIN
PRESSURE I
VALVE AND REGULATOR
PRESSURE-RELIEF VALVE
,...-- ----~ACCUMULATOR
~ ~ \ ~PUMP & MOTOR
I I
HEAT EXCHANGER
131
--
BASICT SPEED BRAKE
I , COOLANT
RETURN
~COOLANT , SUPPLY ,
-----.--.' HYDROGEN
- VENT/DUMP
GP74-1039-2
MCDONNIELL AIRCRAFT COItIIPANY
REPORT Moe A3265 20 JANUARY 1975
ACTIVE COOLING SYSTEM SCHEHATIC
This chart shows a representative schematic with all the elements
integrated into a functional system. Mechanical, electro-mechanical
and electronic components are all required. One of the more critical
items, in terms of'required research and development, is the coolant
to-hydrogen heat exchanger. Obtaining the required heat transfer with
out coolant freezing, and designing to accommodate thermal stresses,
while maintaining reasonable weight and volume are prime areas of con
cern. It is estimated that the total integrated lleating rate over the
entire fin surface is approximately 560 BTU/sec, at Uach 6 and a dy
namic pressure of 1000 PSF, and would require a heat exchanger volume
of 3 ft 3 with a weight of llO lb. Approximately 88 lb of hydrogen
heat sink is required. Operation at lower dynamic pressures at Mach
6 or reducing the maximum cruise Mach number would of course reduce
these values.
MCDONNEL.L. AIRCRAFT COMPANY
132
-,
SUPERCRITICAL HYDROGEN AT
15 ATM PRESSURE
PRESSURE RELIEF VALVE
r , , , , L-
VACUUM SHELL TANK
REPORT Moe A3265 20 JANUARY 1975
ACTIVE COOLING SYSTEM SCHEMATIC
TO AI RCRAFT POWER -( -=--= = = ::i1 TO PILOT OFF/ON SWITCH ========--,-..,,1
CONTROL
ACCUMULATOR .:::::{:::. II III PUMP/MOTOR ::::I}:: II III
PACKAGE
~-CONTROL
_--t-----~COOLANT
TO FIN
BYPASS VALVE
METHANOL/WATER COOLANT TO HYDROGEN HEAT EXCHANGER
~--·VENT ---PRESSURE REGULATOR AND FLOW CONTROL VALVE GP74-1039-1
MCDONNELL AIRCRAFT COMPANY
133
REPORT Moe A3265 20 JANUARY 1975
FAILURE DETECTION SYSTID1
Features of the selected type of failure detection system are
exhibited by this chart. The sensing elements utilize a eutectic
salt mixture. Melting of the eutectic, at the set point temperature,
changes resistance of the element and thereby changes the magnitude
of a voltage signal to the control unit. Dual sensing elements are
used to prevent false warnings due to element shorts. The selected
set point temperature is 265°F. The sensing elements are positioned
at a location where the normal operating temperature is adequately
below set point temperature. Loss of cooling results in temperature
rise, a signal to the control unit, which in turn provides a pilot
warning of loss of fin cooling. The sensing elements run through
the length of the fin and an overtemperature condition at any point
would be sensed. The FDS control unit requires input power to be in
working order and, therefore, would require connection to an essen
tial electrical power supply.
MCDONNELL AIRCRAFT COMPANY
134
REPORT MDe A3265 20 JANUARY 1975
FAILURE DETECTION SYSTEM
INCONEL TUBING 0.089 0.0. (0.064 1.0.)
VOIDS BETWEEN TUBING, CERAMIC AND NICKEL CORE ARE SATURATED WITH A EUTECTIC SALT MIXTURE
POROUS ALUMINUM OXIDE CERAMIC 0.0540.0.,0.034 1.0.
COOLANT TUBE
ALUMINUM SKIN -1: ~CONT~ DUAL SENSING
UNIT ELEMENTS PI LOT II (SET POINT 265°F)
l-~ \I WARNING L -=: AIRCRAFT POWER
135
GP74-1039-33
IIIICDONNELL ~AFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
COST AND SCHEDULE SUMMARY
This chart presents a summary of the active cooling system flight
experiment cost and schedule. As shown, the program cost is propor
tioned to four major program facets. The first is overall program
management, interface coordination and control, and documentation.
The remaining three are: Phase I - Design, Development and Test;
Phase II - Tooling, Fabrication and Assembly; and Phase III Flight
Testing. Each of these facets of the program will be covered in
greater detail in following charts. Total cost of the program is
estimated at approximately $5.8 million. The duration is 31 months.
MCDONNELL AIRCRAFT COIWPANY
136
REPORT MDe A3265 20 JANUARY 1975
COST AND SCHEDULE
SUMMARY
ACTIVITY YEARS FROM GO-AHEAD
1 2 3
PROGRAM MANAGEMENT, INTERFACE COORDINATION I
AND CONTROL, DOCUMENTATION
DESIGN, DEVELOPMENT AND TEST I
(PHASE I)
TOOLING, FABRICATION AND 1
ASSEMBL Y (PHASE II)
FLIGHT TESTING (PHASE ill) I
TOTAL COST*
*Constant 1974 Dollars
COST*
326,000
3,397,000
1,856,000
198,000
5,777,000
G P74-1 039-9
MCDONNELL AIRCRAFT COMPANY
137
REPORT Moe A3265 20 JANUARY 1975
PHASE I, DESIGN DEVELOPMENT TESTING
In the following charts we will review in more de
tail the significant elements of Phase I which effect
the d~sign, development and test costs.
ItIICDONNELL AIRCRAFT COItIIPANY
138
REPORT Moe A3265 20 JANUARY 1975
PHASE I
DESIGN, DEVELOPMENT AND TESTING
GP74-1039-35
MCDONNELL AIRCRAFT COMPANY
139
REPORT Moe A3265 20 JANUARY 1975
NO COST DESIGN INFORMATION/ITEMS
Part of the cost basis is the assumption that cer
tain design information/items are available to the ex
periment contractor at "no cost". The items listed, at
authorization to proceed with the experiment, would be
expected to be supplied in a timely manner.
MCDONNEL.L. AIRCRAFT COMPANY
140
REPORT MDe A3265 20 JANUARY 1975
NO COST DESIGN INFORMATION/ITEMS
• STRUCTURAL DESIGN CRITERIA/DESIGN LOADS AND STIFFNESS REQUIREMENTS
• AIRCRAFT TRAJECTORY/AERODYNAMIC CHARACTERISTICS
• DRAWINGS/TOOLING ADEQUATE TO DESIGN/CONSTRUCT STRUCTURAL SPLICE WITH BASELINE FIN MOUNTING
., DRAWINGS/TOOLING ADEQUATE TO INTERFACE WITH BASELINE SPEED BRAKE DESIGN
o AERODYNAMIC HEATING CHARACTERISTICS DUE TO SPEED BRAKE UTILIZATION AT HIGH SPEED
o THERMAL DESIGN OF SPEED BRAKE HINGE STRUCTURE AND BASELINE FIN SUPPORT STRUCTURE
., INTERFACE CONTROL DOCUMENTATION GP74-1039-37
MCDONNELL AIRCRAFT COIfIfPANV
141
REPORT Moe A3265 20 JANUARY 1975
INTERFACE CONTROL DOCUMENTATION
Interface control documentation, in the form of draw
ings, specifications, and reports, containing information
adequate to define any special design requirements will be
a vital program element. It is an absolute fundamental
that the aircraft contractor, as well as the experiment
contractor, be aware of, and plan for accommodation of, any
planned experiments if minimum cost is to be achieved. The
type information expected to be available is listed on the
chart.
MCDONNELL AIRCRAFT COMPANY
142
REPORT MDe A3265 20 JANUARY 1975
INTERFACE CONTROL DOCUMENTATDON
INFORMATION ADEQUATE TO DEFINE DETAILS OF:
• EXPERIMENTS PAYLOAD BAY - ROUTING/MOUNTING
• COCKPIT DESIGN/CONSOLES - ACS AND FDS INTERFACE
• TOTAL ENVIRONMENTS - TEMPERATURE, PRESSURE, HUMIDITY, ACCELERATION, VIBRATION, DEFLECTIONS, ACOUSTICAL LOADS
• BETWEEN FIN AND PAYLOAD BAY
• PAYLOAD BAY
• BETWEEN PAYLOAD BAY AND COCKPIT
• COCKPIT
• AIRCRAFT POWER SYSTEMS
• AVAILABLE HYDROGEN VENT/DUMP PROVISIONS
• CARRIER AIRCRAFT INTERFACE WITH X-24C
• ONBOARD INSTRUMENTATION SYSTEM AND PROVISIONS FOR ADDITIONAL INSTRUMENTATION
• FLIGHT TEST FACILITY INSTRUMENTATION SYSTEM GP74-1039-38
MCDONNELL AIRCRAFT COIfIfPANY
143
REPORT MDe A3265 20 JANUARY 1975
DESIGN, DEVELOPMENT AND TESTING TASKS
Six major program tasks are identified here for the design, development and testing phase of the active cooling system flight experiment. A brief description of each task was written in order to provide a proper basis for cost estimation.
Task 1 - Program }lanagement, Interface Coordination and Control, and Program Documentation - extends throughout the program. Personnel assigned to this task would be the prime contact to provide NASA with visibility to the program. In addition to technical management and control of budgets and schedules, their responsibilities would include coordination and control, both internal and external, of interface requirements and program documentation.
Task 2 - Preliminary Design - starts with the "no-cost" information provided at authorization to proceed and culminates, five months later, in the design freeze of a final design concept for the experiment. This concept would be arrived at by means of a series of layout drawings and trade studies, backed by technical analysis, aimed at optimization of the experiment to meet program objectives.
Task 3 - Procurement Specifications - would cooling system and the failure detection system. worthiness qualification of these elements would fications.
be written and released for the active Technical requirements for flight-
be included in the procurement speci-
Task 4 - Shop Drawings - would be created using as a basis the final layout drawings from the preliminary design task. Full release of these drawings would occur fifteen months after authorization to proceed. The low cost approach to this design function previously discussed would be followed.
Task 5 - Technical Design Analysis - would be made of the thermo-structural functional systems to analytically verify the design adequacy of the experiment. major efforts would involve strength and thermodynamic analyses.
and The
Task 6 - Development Testing and Planning - would be conducted throughout the predelivery phases of this program. This task involves developing and coordinating the test plans, conducting the tests and evaluating the results.
MCDONNELL AIRCRAFT COMPANY
144
REPORT MDe A3265 20JANUARY 1975
DESIGN, DEVELOPMENT AND TEST TASKS
1 PROGRAM MANAGEMENT - INTERFACE COORDINATION AND CONTROL - PROGRAM DOCUMENTATION
2 PRELIMINARY DESIGN STRUCTURAL LAYOUTS - EQUIPMENT/ELECTRICAL/SUBSYSTEM LAYOUTS
TRADE STUDI ES - ANALYSIS
3 PROCUREMENT SPECIFICATIONS ACTIVE COOLING SYSTEM - FAILURE DETECTION SYSTEM
4 SHOP DRAWINGS
5 TECHNICAL DESIGN ANALYSIS THERMODYNAMICS - STRENGTH - WEIGHTS - SYSTEM DESIGN
6 DEVELOPMENT TESTING AND PLANNING ELEMENT TESTS - SUBCOMPONENT TESTS - PURCHASE PART TESTS - FLIGHT WORTHINESS TESTS - FLIGHT TESTS
GP74-1039-39
MCDONNELL AIRCRAFT COItIIPANY
145
REPORT Moe A3265 20 JANUARY 1975
PHASE I, D, D & T COST AND SCHEDULE SUMMARY
As shown, Phase I will cover a time span of 23 1/2 months. Total man-hours and
cost for this phase are estimated as 66,590 hours and $3,560,000, respectively. The
cost item shown as CFE is procurement cost for the active cooling system and failure
detection system and total $1,700,000. Additional procurement cost are accrued in
Phase II.
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
146
MCDONNEL.L. AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
PHASE I DESIGN, DEVELOPMENT AND TEST COST
AND SCHEDULE SUMMARY ACTIVITY MONTHS FROM GO-AHEAD
12345678 910111213141516171819202122232~251262 2812!l 30 31 MANHOURS COST*
ATP ~~
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, PROG RAM DOCU M E NT AT I 0 N __________ I=*:!=!:=!=;:;::!=!:~;:::;::;::;:~=:;::;:::;:~:::::=~
TASK 2 - PRELIMINARY DESIGN ______ ~ DESIGN FREEZE _____________________________ ,,{>-
TASK 3 - PROCUREMENT SPECS
ACTIVE COOLING SYSTEM__________ )-FAILURE DETECTION SYSTEM ___________ ~)-
EVALUATE PROPOSALS _____________ _ ___ ~}
SE lECT VENDORS____________________ -\---? 9,O~.J~OO% TASK 4 - SHOP DRAWINGS______________ _ __ _
TASK 5 - TECH. DESIGN ANALYSIS___ J-h=~=:=~*::Q'). APL'S RELEASED______________________ _1. -I-{> PLACE PO'S_~ _____________________ ~ _________________ I_.Q.
TASK 6 - DEVELOPMENT TESTING AND PLANNING
TEST PLANS____________________________ }o.
ELEMENT & SUBCOMP. TESTS _____ - -f --- -.I. l i /I I I ~ PURCHASE PARTS TESTS ------------ - -r -i-r - IA
FLIGHT WORTHINESS TESTS ------- - -+ -T -y-~- __ 1 __ - --1-- - - -- - -- -~~D! *Constant 1974 Dollars
Information contained herein is privileged Or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (bl. 5 USC 552, Do not disclose outside recipient organization of U.S. Government.
PHASE I TOTALS
147
5,850
8,740
7,210
10,790
8,210
25,790
66,590
163,000
243,000
201,000
301,000
229,000
2,423,000
( 1,700,000)
CFE
3,560,000
GP74 103940
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
PHASE II, TOOLING, FABRICATION AND ASSEMBLY
The following charts will present a more detailed revieVl of the elements of
Phase II Vlhich effect the tooling, fabrication and assembly costs.
MCDONNEILIL AIRCRAFT CONfPANY
148
REPORT Moe A3265 20 JANUARY 1975
PHASE n
TOOLING, FABRICATION AND ASSEMBLY
GP74-1039-45
MCDONNELL AIRCRAFT COMPANY
149
REPORT MDe A3265 20 JANUARY 1975
TOOLING, FABRICATION AND ASSEMBLY TASKS
The sub-tasks identified for the Phase II effort are listed on this chart. The
second phase of the experiment program includes tool design and fabrication, manufacture
of detail parts, assembly into subcomponents, and finally the actively cooled fin
structural assembly. Necessary instrumentation components will be installed during the
manufacturing process. Subsystems will be received and checked. In addition, sus
taining engineering support will be required during this period for timely change of
drawings and suggested repairs or modifications, if required.
MCDONNELL AIRCRAFT COMPANY
150
REPORT MDe A3265 20 JANUARY 1975
TOOLING, FABRICATION AND 'ASSEMBLY TASKS
• TOOL DESIGN
• TOOL FABRICATION
• PARTS FABRICATION
• SUBASSEMBLY
• STRUCTURAL ASSEMBLY
• INSTRUMENTATION INSTALLATION
• SYSTEMS INSTALLATION
• PREPARATION AND SHIP
(TASK 7) GP74-1 039-47
MCDONNE ...... AIRCRAFT C~.-ANY
151
REPORT Moe A3265 20 JANUARY 1975
TOOLING, FABRICATION AND ASSEMBLY COST AND SCHEDULE SUMMARY
The time span of this program phase is 18 months with completion 24 months after
program ATP. Estimated man-hours are 39,570 and cost of $1,954,000 are accrued
during this phase. Material costs are only $40,000 while procurement cost total
$870,000.
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b). 5 USC 552_ Do not disclose outside recipient organization of U.S. Government.
152
MCDONNELL AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
PHASEll TOOLING, FABRICATION AND
ASSEMBLY COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 12345678 91Dl112131415161718192021~232425~272829JD31 MANHOURS
ATP -<>
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, P R OG R AM DOC U M E NT AT ION _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____ t=;:::;::::::;:::!::;::;=!=:;::!:=;:;::!::::;~:::;::::::;~
TASK 7 - TOOLING, FABRICATION AND ASSEMBLY ____________________________________ ~~::::!:::!=!:=;::;::;:::!=:!::=;~~:::;::;~
" MATERIALS ORDERED _______________________ - -. u
TOOL DESIGN & FABRICATION ____ _ __ _ ____ __ ).
FABRICATION & SUBASSEMBLY .__ _L~~::::!=:!=!:::;::!::!:~~). ALL CFE RECEIVED __________________ ---- ____ - -- - ---- - -- - ---- - -- - . .0-FINAL ASSEMBLY, SYSTEMS AND INSTRUMENTATION
A
INSTALLATION ------------------------ -r --- --T -r -r- - ---- - -- - - I PREPARATION ANDSHIP _________ .__ _ __ _ ____ _ __ _1. ___ 1. _____ .co-
*Constant 1974 Dollars PHASE H TOTALS
3,510
36,060
(9,050)
(7,134)
(4,756)
39,570
COST*
98,000
1,856,000
(40,000)
(235,000)
(165,000)
(870,000)
(110,000)
(15,000)
1,954,000 GP74 103948
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (bl, 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
MCDONNELL AIRCRAFT COMPANY
153
L
REPORT MDC A3265 20 JANUARY 1975
PHASE III, FLIGHT TEST
The third, and last, phase of the experiment programs is flight test of the
integrated active cooling system. After the complete experiment package is received
the tes t aircraft \vill have the basic vertical fin replaced by the experiment fin.
The onboard experiment systems will then be installed and exercised during familiar
ization of flight test personnel. Following charts presents elements of Phase III
which influence program costs.
MCDONNELL AIRCRAFT COMPANY
154
REPORT Moe A3265 20 JANUARY 1975
PHASE m
FLIGHT TEST
155
GP74-1039-4~
MCDONNELL AIRCRAFT COItIIPANV
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST OBJECTIVES
The overall objective of this experimental program is to demonstrate an integrated
"fail-safe" actively cooled structure and active cooling system within the total
flight and operational environment. The stated objective offers important opportunities
for the advancement of hypersonic cruise aircraft if the fail-safe abort approach can
be fully demonstrated. The specific objectives and flight test plans are structured to
assure adequate investigation of these opportunities.
MCDONNELL AIRCRAFT COMPANY
156
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST OBJECTIVES
DEMONSTRATE AN INTEGRATED "FAIL-SAFE" ACTIVELY COOLED STRUCTURE - ACTIVE COOLING SYSTEM WITHIN THE TOTAL
ENVIRONMENT
• DEMONSTRATE ACTIVELY COOLED ALUMINUM STRUCTURE
• DEMONSTRATE ACTIVE COOLING SYSTEM WITH HYDROGEN HEAT SINK
• DEMONSTRATE FAILURE DETECTION SYSTEM WITH WARNING TO TAKE
CORRECTIVE ACTION
NORMAL FLIGHT OPERA TION
ABORT FLIGHT CONDITIONS
GROUND OPERA TIONS GP74-1039-50
MCDONNEL.L. AIRCRAFT COMPANY
157
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST PLAN
This chart illustrates a suggested approach to meeting the flight test objectives.
The maximum Mach capability would be dependent upon the fin capacity to survive abort
heating. Varying the skin thickness of the fin to increase start of abort Mach number
would have very little impact on program cost. It is possible, with better definition
of the aircraft lee-side flow field, that skin thicknesses on the order of 0.080 in.
could survive a Mach 6 abort.
MCDONNELL AIRCRAFT COMPANY
158
FLT
1
2
3
4
5
6
7
8
9
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST PLAN ~,
-TEST CONDITIONS TEST CONDITIONS
M = 2 - HIGH DYN PRESS. ACS FUNCTIONAL DEMONSTRATION AND DEMONSTRATE STRUCTURAL INTEGRITY
M = 3 - MED DYN PRESS. ACS AND FDS FUNCTIONAL DEMONSTRATION MANEUVER ABORT TECHNIQUE DEMONSTRATION
M = 4 - MED DYN PRESS. ACS FUNCTIONAL DEMONSTRATION
M = 5 - MED DYN PRESS. ACS FUNCTIONAL DEMONSTRATION
M = 6 - MED DYN PRESS. ACS FUNCTIONAL DEMONSTRATION
M = 6 - MED DYN PRESS. ACS FUNCTIONAL DEMONSTRATION
M = 6 - HIGH DYN PRESS. ACS FUNCTIONAL DEMONSTRATION
M = 6 - HIGH DYN PRESS. ACS AND FDS FUNCTIONAL DEMONSTRATION MANEUVER ABORT TECHNIQUE DEMONSTRATION
M = 6 - HIGH DYN PRESS. SAME AS 8 PLUS DEMONSTRATION OF REUSE
Note: Scheduled Maintenance/Ground Operation Provides Servicing/Maintainability Data GP74-1039-53
MCDONNELL AIRCRAFT COMPANY
159
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST INSTRUMENTATION
Approximately 45 instrumentation measurands are required as a minimum.
Thermocouples, pressure transducers and strain gages would be installed during
manufacture of the subsystems and calibrated after final experiment installation.
The instrumentation would be designed to be compatible with the airborne instru
mentation recorder and telemetry system in the X-24C.
MCDONNELL AIRCRAFT COMPANY
160
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST INSTRUMENTATION
. • STRAIN GAGES - 6 - VERIFY PREDICTED FIN OVERALL
LOADS AND DISTRIBUTIONS
,~ • ACCELEROMETER -1 {TRI-AX} - VERIFY LOAD FACTORS
AND VIBRATION ENVIRONMENT
• THERMOCOUPLES (FIN) - 20 - VERIFY STRUCTURAL TEMPERATURES - MAGNITUDE AND DISTRIBUTIONS
• THERMOCOUPLES {ACS} - 9 - VERIFY COOLANT TEMPERATURES, HYDROGEN TEMPERATURES
9 PRESSURE TRANSDUCERS - 9 - VERIFY SYSTEM PRESSURES, COOLANT AND HYDROGEN FLOW RATES
G P 74-1 039-54
MCDONNELL AIRCRAFT COMPANY
161
REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST TASKS
The tasks in which the experiment contractor would be involved during Phase III are
listed on the chart. The first of these tasks would be pre-installation experiment
checkout to insure that all experiment hardware is received at the flight test location
ready to be installed. The experiment will then be installed in the X-24C. This
involves mating all experiment elements to the test aircraft. The experimental fin
will be spliced to the basic structure, subsystems will be installed and all required
interfaces installed and mated. The final assembly of all experiment elements will then
be checked. This will include functional testing of the cooling system, a check of the
failure detection system, checks of structural splices and instrumentation checkout.
Experiment contractor support will be provided during the test program on a "as required"
basis.
MCDONNELL AIRCRAFT COMPANY
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REPORT MDe A3265 20 JANUARY 1975
FLIGHT TEST TASKS
• PRE-INSTALLATION EXPERIMENT CHECKOUT
• INSTALL EXPERIMENT IN X-24C
• EXPER1MENT CHECKOUT • STRUCTURAL SPLICES
• ACTIVE COOLING SYSTEM
• FAILURE DETECTION SYSTEM
• INSTRUMENTATION
• PROVIDE SUPPORT AND ANALYSIS AS REQUIRED GP74-1039-105
MCDONNELL AIRCRAFT COMPANY
163
REPORT MDe A3265 20 JANUARY 1975
BASIS FOR PHASE III COST
Again, assumptions must be made to establish a basis for costing Phase III.
These assumptions are presented on the chart.
164
REPORT MDe A3265 20 JANUARY 1975
BASIS FOR FLIGHT TEST COSTS
• FINAL INSTALLATION OF EXPERIMENT PACKAGE AND CHECKOUT AT EAFB
• GROUND TESTS AND DATA ANALYSIS PRIOR TO FIRST FLIGHT
• X-24C AIRCRAFT FLOWN AND MAINTAINED BY NASA
• TEST FACILITIES/RANGE SUPPORT PROVIDED BY NASA
• DATA COLLECTION BY X-24C RECORDER/TELEMETRY SYSTEM
• DATA REDUCTION BY NASA
• MINIMUM CONTRACTOR SUPPORT
• 9 FLIGHTS AT 3 PER MONTH RATE
• LH~ AND ASSOCIATED EQUIPMENT AVAILABLE AT EAFB
o NO REFURBISHMENT OF EXPERIMENT HARDWARE GP74-1039-51
MCDONNELL AIRCRAFT COMPANY
165
REPORT Moe A3265 20 JANUARY 1975
FLIGHT TEST COST AND SCHEDULE SUMMARY
Duration of the flight test phase was assumed to be 7 months, concluding at the
end of 31 months from experiment ATP. The estimated total man-hours and cost are
9,420 hours and $263,000, respectively. It was assumed that support for the actual
flight test would average 720 man-hours per month for the three month period. This is
equivalent to 4 to 5 men and may be slightly low.
Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b), 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
166
MCDONNELL AIRCRAFT COMPANY
REPORT Moe A3265 20 JANUARY 1975
PHASE m FLIGHT TEST COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 1 2 3 4 5 6 7 8 9 10 1112 13 14 15 16 17 181920 21122 23 24 2526127 28129 30 31 MAN HO U RS COST*
ATP i~
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL
PROGRAM DOCUMENTATION ----------- ---- -J-- - -- - ---- - -- - ---- ---- ---- - -- - ----TASK 8 - FLIGHT TEST. ___________________ ..1._ __ _ ____ _.I.. h=~~~l!').
DELIVERY OF EXPERIMENT ________________________________________________ .~).
LH2 SYSTEM FINAL CHECKOUT
2,340
7,080
AND INSTALLATION IN X-24C _____ -r ----- ---- ----- ----- ---T ---- ---f- ---- --~). } FINAL EXPERIMENT CHECKOUL_ T -J + -+ -_J
1 __ ----- -11---- - ..1._ - ---- ~>-
FLIGHT TEST - 9 FLTS@3/MO------------r-l-r-----r------r--------- ________ '--'r!---'-"""'Ii""..... ~~~~ ~~ j ANAL VSIS AND EVALUATION------ +- ----- -__ J __ J -- -- ---- -- ---- ----- ---'--1- =r ,.I AVERAGet
PROGRAM COMPLETE. _______________ -- - ---- - ---- - J J -----f-I---- --- --- -J---M~
*Constant 1974 Dollars PHASE In TOTALS 9,420
65,000
198,000
97,000
(101,000)
263,000
GP74 1039·55 Information contained herein is privileged or confidential information of McDonnell Douglas Corporation and exempt from public disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
MCDONNELL AIRCRAFT COMPANY .
167
REPORT Moe A3265 20JANUARY 1975
PROGRAM COST AND SCHEDULE SUMMARY
The total active cooling system flight experiment cost and schedule are summarized
on this chart along with the total manhours involved. The program spans a total of
31 months, approximately 115,580 manhours would be required and the rough order of
magnitude cost is $5.8 million, given in constant 1974 dollars.
I nformation contained herein is privi leged or confidential information of McDonnell Oouglas Corporation and exempt from public disclosure under subsection (b), 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
168
MCDONNELL AIRCRAFT COMPANY
REPORT MDe A3265 20 JANUARY 1975
PROGRAM COST AND SCHEDULE SUMMARY
ACTIVITY MONTHS FROM GO-AHEAD 1234567 8 910111213141516171B19202122232425262728~3031 MANHOURS
ATP ~}
TASK 1 - PROGRAM MANAGEMENT, INTERFACE COORD AND CONTROL, PROG RAM DOCUM E NT A TI ON . ________ .I=*:~~~~~::::;::*=*=:=*=***=*=*=~~=:=~=**=**~
PHASE I - DESIGN, DEVELOPMENT AND TEST. _____________ . ____________________ I=*:~~~~~~~~~:;::;::;::;~~~""
PHASE II _ TOOLING, FABRICATION AND ASSEMBLY ___________________________ -r --- --- ~
PHASE ill - FLIGHT TEST________________ ____ _ ____________________________ ~~~~O'Jo
*Constant 1974 Dollars PROGRAM TOTALS
11,700
60,740
36,060
7,080
115,580
COST*
326,000
3,397,000
1,856,000
198,000
5,777,000 GP74 103960 Information contained herein is privileged
or confidential information of McDonnell Douglas Corporation and exempt from pub· lic disclosure under subsection (b). 5 USC 552. Do not disclose outside recipient organization of U.S. Government.
MCDONNELL AIRCRAFT COMPANY
169
REPORT MDe A3265 20 JANUARY 1975
CRITICAL TECHNOLOGY AND LONG LEAD TIME ITEMS
Two major problems have been identified as falling within the category of critical
technology and/or long lead time items. The first is the development of the cooling
system coolant-to-hydrogen heat exchanger. Preventing coolant freezing while main
taining high heat transfer capability with low weight and volume requirements will
present a challenge. The second is attachment of the FDS sensing elements to the fin
surface material. Good thermal contact along the total length of the element will be
required, and element spacing will be critical. While not listed as a critical area on
the chart another area which would benefit from some immediate effort is definition of the
best type of abort maneuver. Our preliminary studies indicate high lift, low lift-
to-drag descents are excellent trajectory candidates. However, data is required to
define fin heating during high angle-of-attack operation.
MCDONNELL AIRCRAFT COMPANY
170
REPORT MDe A3265 20 JANUARY 1975
CRITICAL TECHNOLOGY AND LONG LEAD TIME ITEMS
• ACTIVE COOLING SYSTEM COMPONENTS
. . • FAILURE DETECTION SYSTEM SENSING ELEMENT
ATTACHMENT
GP74-1039-58
MCDONNELL AIRCRAFT COMPANY
171
REPORT Moe A3265 20 JANUARY 1975
X-24C PROGRAM IMPACT OF EXPERIMENT ACCOMMODATION
A number of items must be considered in the initial design of the aircraft if an
experiment of this type i"s to be accommodated. All interfaces and structural provisions
must be recogniz~d and defined. All special tool requirements must be defined and
included within the development plan. Aircraft weight and C.G. changes due to the
experiment package must be considered. A minimum cost experiment, and full flight
envelope capability requires full accommodation of the flight experiment in the basic
X-24C aircraft design.
MCDONNELL AIRCRAFT COMPANY
172
REPORT MDe A3265 20 JANUARY 1975
X-24C PROGRAM IMPACT OF EXPERIMENT ACCOMMODATION /
• INTERFACES AND STRUCTURAL PROVISIONS
• FIN/FUSELAGE SPLICE
• UTILIZE BASIC SPEED BRAKE AND ACTUATION
• PAYLOAD BAY CONTAINMENT OF ACTIVE COOLING SYSTEM
• ACTIVE COOLING SYSTEM INTERFACES
• FAI LURE DETECTION SYSTEM INTERFACES
• INSTRUMENTATION
• SPECIAL TOOLS
• FIN/FUSELAGE SPLICE
• FIN/SPEED BRAKE ATTACHMENT
• CONTROLS, WIRING, PLUMBING, SUBSYSTEM MOUNTS AND SUPPORTS
• BASIC AIRCRAFT DESIGN
• WEIGHT AND C.G. ENVELOPE GP74-1039-57
MCDONNELL AIRCRAFT COMPANY
173
REPORT Moe A3265 20 JANUARY 1975
POTENTIAL ADDITIONAL FLIGHT EXPERIHENTS
The active cooling system flight experiment as configured for this experiment
definition study will stand on its own as an experiment package. It is not dependent upon
other aircraft subsystem (other than power) or experimental packages. However," it
could, with very little redesign and cost, integrate with an integral LH2 tank experiment
or with a LH2 fueled scramjet experiment. An additional experiment, with high potential
payoff would be flight demonstration of insulated actively cooled structure. This could
be accomplished with the active cooling system experiment package with the fin accommo
dating add-on surface insulation packets. These bond-on insulation packets could be
configured to cover the leading edge and the surface of the fin. With the fin, and
cooling system, designed for the uninsulated surface heat loads risk to fin structure
would be low. Some additional cost would be required for the development of the bond-on
packets.
MCDONNELL AIRCRAFT COMPANY
174
REPORT Moe A3265 20 JANUARY 1975
POTENTIAL ADDITIONAL FLIGHT EXPERIMENTS
• INTEGRATE WITH INTEGRAL LH2 TANK EXPERIMENT
• INTEGRATE WITH SCRAMJET EXPERIMENT
• DEMONSTRATE INSULATED ACTIVELY COOLED STRUCTURE
GP74-1039-59
MCDONNEL.L. AIRCRAFT COMPANV
175