flight testing the x-48c conference... · copyright © 2012 boeing. all rights reserved, government...

Copyright © 2012 Boeing. All rights reserved, Government Purpose Rights.

Engineering, Operations & Technology | Boeing Research & Technology Blended Wing Body | X- 48C

X-48C_Template.ppt | 1

Flight Testing the X-48C Advancing the BWB Concept

Michael Kisska X-48C Project Manager

(714) 896-1464

AIAA Southern California Aerospace Systems and Technology Conference

May 4, 2013




-33%

Conventional Aircraft Blended Wing Body

Wetted Area Comparison

Fuselage 23,000 ft2 22,000 ft2

Wing 12,000 ft2 6,000 ft2

Propulsion 4,000 ft2 1,200 ft2

Empennage 5,000 ft2 500 ft2

Total 44,000 ft2 29,700 ft2

1/3 less wetted area than conventional configuration

Why BWB? - Aerodynamic Efficiency




Span loading

Non-lifting vs lifting fuselage

Independent vs integrated wing box

Payload distributed normal vs parallel to wing

Ideal circular vs flat pressure vessel

Conventional Aircraft Blended Wing Body

Aerodynamic Lift

Pressure Loads

Why BWB? - Structural Efficiency




BWB Technology Development Background

Low-Speed Wind

Tunnel Test

BWB 450-1L Low-Speed

Wind Tunnel Test

Piloted

Simulation

X-48B Built

BWB-17 Flight

Control Testbed

High-Speed Wind

Tunnel Test (NTF)

Finite Element

Analysis

Computational

Fluid Dynamics

High-Speed Wind

Tunnel Tests (NTF)

Structures Panel Fab Free-Flight Test

5% Model

X-48B Wind Tunnel

Test (30x60)

1997 1998 1999 2000

2001 2004 2005 2006

2007

PRSEUS Structure HS Wind Tunnel Test

(AEDC 16T)

X-48B Flight Test

2010 2012 2013

X-48C Wind Tunnel

Test (30x60)

X-48C Flight Test PRSEUS CoLTS

Test Article




8.5% Dynamically Scaled X-48B BWB

Vehicle Characteristics

Wing Span 20.4 ft

Wing Area 100.5 ft2

Maximum Weight 523 lbs

Static Thrust 162 lbs

Maximum Airspeed 118 kts

Maximum Altitude 10,000 ft MSL

Load Factor Limits +4.5 g’s to -3.0 g’s

Flight Duration 30 minutes + 5 minute reserve




X-48B Low Speed Vehicle




Definition of Test Flight Blocks

Block 1: Flights 1-11

Slats EXT


Slats RET

Block 3: Flights 21-34, 44-56, 59-61, 67-70

Slats EXT

Block 4: Flights 35-43, 57-58, 62-66, 71-72

Slats RET

En

ve

lop

e E

xp

an

sio

n

PID / Stalls /

Engine Out

Maneuvering

Block 5: Flights 73-75, 77

Slats EXT

Block 6: Flights 76, 78-80

Slats RET Departure Limiter

Assaults / Turning

Stalls

Currently moving

forward Single

Surface PID and

additional RTSM

Maneuvers to fly

on Recycle Decks




X-48B Flight Test Program – Success!

Project initiated in 2002

Airplanes designed by Boeing, built by Cranfield Aerospace, and operated at NASA Dryden

Objective to prove that flight characteristics of a BWB are as robust as current transports

1st Flight on July 20, 2007

80 flights completed in Phase 1 Program

Completed all flight test conditions originally planned - met expectations

Final Report submitted on May 28, 2010

Aircraft underwent a detailed airworthiness inspection and heavy maintenance

12 additional test fights NASA Phase 1.5 experiments conducted in 4Q10 – 92 flights completed

Phase 1.5 Completed on Nov 25, 2010

Several NASA Authored AIAA Papers presented in 2011




X-48B Preliminary Flight Test Results

Extremely maneuverable in roll

Aircraft very closely matches sim for up/away flight (and landing)

Flight control design is very robust

Both Slat EXT and Slat RET stalls successful

• Controllable to 3 degrees beyond CLmax

Departure limiter assaults highly successful!

Overall, the aircraft flies extremely well…




NASA N+2 – X-48C Inspiration…




X-48C Low Emission Concept Evolution

Twin AMT Titan

turbojet engines

mounted further

forward on the

centerbody Inboard Vertical

Stabilizers –

Revised Elevon 1

Winglet Rudders

removed –

conventional

wingtips

Revised VMS

Flight Control

Software

X-48B

X-48C




X-48C Flight Test Vehicle

12

Description:

The X-48C is a modification of the X-48B

designed to investigate the stability and control

of the “Low Emissions Concept” BWB

configuration.

Goals/Objectives:

To aerodynamically characterize the revised

BWB configuration to validate the vehicle’s

simulation model. Characterization will be

assessed via dynamic maneuvers flown at

multiple CGs including: PID, SHSL, Stalls,

Doublets and Frequency Sweeps while

simultaneously verifying the revised elements

of the vehicle’s control laws.

Success will be achieved when the vehicle’s

flight envelope is defined.

Project Schedule - Key Milestones/Deliverables:

Initial Design

and Sizing

Studies

Design for WT

Testing Vehicle

Engineering

and Fab of Flit

Components

1st Flight

8/7/12

2010 2009 2008 2011 2012 2013

Complete

Flight Testing

Issue Final

Report in Q2

Complete WT

Testing and

Issue Report




Validating Critical Flight Control Technology

Intend to characterize the X-48C flight envelope

B-2

pre-stall

a limit CL

a

BWB

post-stall

a limit

Performance gain –

reduced wing area

and weight

CM Stable Unstable

Increased challenge to maintain control in unstable post-stall region

Controllable in

post-stall region




X-48C in Langley Full Scale Tunnel – Aug. 2009

14




SPT15 Engine Development




AMT Titan Engine Installation

ECU

Fuel Pump

Engine CMD

PumpV

Throttle

CMD

Sensor

output

Thrust FCC

Fuel Flow

Propulsion

System




First Flight! August 7, 2012




X-48C 2012-2013 Milestones

2012

Jan X-48C “Mass Correct” Vehicle Assembled

Jan GVT/SMI successfully Completed

Mar Engine Mapping & Software Development

Apr First Flight VMS Software Released

May First Flight Readiness Review

Aug First Flight

Aug-Sep eRCCA

10/9/12 Successful Return to Flight

Oct-Dec Flights 3-13 (Envelope Expansion)

2013

Jan Return to Flight - Flight 14

Jan-Apr Flights 14-26

April Completion of Flight Testing

Note: Continued work planned throughout 2Q13 to complete flight testing, document and publish Final Report




Definition of Test Flight Blocks


Slats EXT


Slats RET

Block 3: Flights 25-

Slats EXT


Slats RET

En

ve

lop

e E

xp

an

sio

n

PID / Stalls /

Engine Out

Maneuvering

Block 5:

Slats EXT

Block 6:

Slats RET Departure Limiter

Assaults / Turning

Stalls

Due to time constraints,

Block 4 maneuvers were

performed immediately

after Block 2 in order to

eliminate the additional

configuration change.




X-48C Preliminary Flight Test Results

Remains extremely maneuverable in roll

Aircraft again very closely matches sim for up/away flight (and landing)

First Cut flight control design is very robust – but further gains could be realized with future software roll…

Both Slat EXT and Slat RET stalls successful

• Controllable to 2 degrees beyond CLmax…but CLmax was higher with the X-48C configuration

Overall, the data related to the configuration appears to be encouraging and merits additional study…




Poster Child!




Additional Images Featured in Print




And Finally…Pop Culture Icon!




And Chase Mascot!

flight testing the x-48c conference... · copyright © 2012 boeing. all rights reserved, government...

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