Mitigating Risk at the Mitigating Risk at the Edge of the EnvelopeEdge of the Envelope

Capt Benjamin E GeorgeCapt Benjamin E George40 FLTS, Eglin AFB40 FLTS, Eglin AFB

Revising Basic Aircraft Revising Basic Aircraft Limit Test ProceduresLimit Test Procedures

TIS-1166 Loads Test

F-16C # 83-1123 RUDDER & FLAPERON FAILURE (FY90)

Bad things happen to good airplanes…

0

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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2

FF--16 CSFDR Operational Employment16 CSFDR Operational EmploymentAl

titud

e (1

000’

s ft

MSL

)

Mach

35%

14%

32%

7%

.02%

.04%

1.8%

.83%

0.0000%

0.0000%

0.0007%

9%

0.0013%

Basic Aircraft Limit (BAL)Basic Aircraft Limit (BAL)Process Action Team (PAT)Process Action Team (PAT)

►►CharterCharter:: Fundamentally examine and review Fundamentally examine and review how the 46 TW conducts BAL tests and how the 46 TW conducts BAL tests and identify the best test practices that meet ACC identify the best test practices that meet ACC requirements while minimizing risk to aircraft requirements while minimizing risk to aircraft and aircrewand aircrew

Stores Certification ProcessStores Certification ProcessACC (User Need)

SEEK EAGLE

40 FLTS

46 MX

LM Aero

F-16 Systems Group

Flutter

Separation

Loads

CFP

S&C / HQ

RequirementsRequirements

AnalysisAnalysis

CertificationCertification

Flight TestFlight Test

BAL PAT Member

BAL Risk Mitigation StrategiesBAL Risk Mitigation Strategies

1) Eliminate the BAL certification requirement1) Eliminate the BAL certification requirement

2) Modify test design to reduce the number of 2) Modify test design to reduce the number of BAL test pointsBAL test points

3) Minimize BAL risk exposure by making BAL 3) Minimize BAL risk exposure by making BAL test points as efficient and safe as possibletest points as efficient and safe as possible

Compatibility Flight ProfilesCompatibility Flight ProfilesAl

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Mach

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MIL-HDBK-244A and MIL-HDBK-1763:”…subject aircraft-store combination to maximum symmetrical

and unsymmetrical load factors at max allowable airspeed.”

Maneuver Set

-1g Roll L/R

-3g BSPO

6g Roll L/R

9g WUT

Throttle Chop

Speed Soak

Eliminate BAL RequirementEliminate BAL RequirementStrategy 1

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ACC (User Need)

SEEK EAGLE

40 FLTS

Fighter Aircraft C2 Fighter Aircraft C2 Enhancement PodEnhancement Pod(FACE)(FACE)

BAL CertificationBAL Certification800 KCAS / 2.05 M800 KCAS / 2.05 M9/9/--3 g Symmetric3 g Symmetric6/6/--1 g 1 g UnsymmetricUnsymmetric

Revisiting Revisiting CFPsCFPsA

ltit

ude

(1

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ft

MSL

)

Mach

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”…subject aircraft-store combination to maximum symmetricaland unsymmetrical load factors at max allowable airspeed.”

Maneuver Set

-1g Roll L/R

-3g BSPO

6g Roll L/R

9g WUT

137137800 KCAS / 5k

1992171.8M / 30k

1821871.4M / 30k

165197.9M / 30k

194207.9M / 15k

6-g1-g

Max Roll Rate (deg/sec)Airspeed /

Altitude

-4

-2

0

2

4

6

8

10

12

-8-6-4-202468

0.9 M / 15k / 6 g

2φ&rar =

nz

at

ar

φ&&rat = φ&&φ&

Wingtip Store Inertial LoadsWingtip Store Inertial Loads(6g Right Roll)(6g Right Roll)

nz

(g’s

)

ny (g’s)

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-2

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-8-6-4-202468

1.8 M / 30k / 6 g0.9 M / 15k / 6 g

2φ&rar =

nz

at

ar

φ&&rat = φ&&φ&

-4

-2

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2

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6

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-8-6-4-202468

1.8 M / 30k / 6 g1.8 M / 30k / 1 g0.9 M / 15k / 6 g

Station 1 Station 9

Modified Modified CFPsCFPsAl

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1g Roll Only

9g WUT Only

9g WUT / -3g BSPO Only

Reduces BAL Exposure by a factor of 6!

-1g Roll L/R

-3g BSPO

6g Roll L/R

9g WUT

Strategy 2

Max Efficiency / Min Risk ExposureMax Efficiency / Min Risk Exposure

► Pre/Post-mission high-speed MX inspectionsNew NDI procedures for key structural areas?

► Test Aircraft Usage ReviewAirframe equivalent age analysis

► High-speed test planning toolsFlight Path Angle & Energy Height analysisEnergy height IADS plots in Control RoomDive recovery analysis

Strategy 3

Energy Height PlanningEnergy Height PlanningA

ltit

ude

(1

00

0’s

ft

MSL

)

Mach

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0.8 1 1.2 1.4 1.6 1.8 2

600KCAS

500 KCAS

400 KCAS

90,000 ft

40,000 ft

Energy Height

700

KCAS

50,000 ft

60,000 ft

70,000 ft

80,000 ft30

0 KCA

S

800

KCASV MAX γ = -25°

PS= -375 ft/

sec

BAL Risk Mitigation StrategiesBAL Risk Mitigation Strategies

1) Eliminate the BAL certification requirement1) Eliminate the BAL certification requirement

2) Modify test design to reduce the number of 2) Modify test design to reduce the number of BAL test pointsBAL test points

3) Minimize BAL risk exposure by making BAL 3) Minimize BAL risk exposure by making BAL test points as efficient and safe as possibletest points as efficient and safe as possible

Conclusions & Lessons LearnedConclusions & Lessons Learned

►►BAL Risk MitigationBAL Risk Mitigation

►►Periodic Review of AssumptionsPeriodic Review of Assumptions

►►Process Action Team MakeProcess Action Team Make--upup

Questions?Questions?