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
5
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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
titud
e (1
000’
s ft
MSL
)
Mach
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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
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
0
10
20
30
40
50
0 0.5 1 1.5 2
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
00
0’s
ft
MSL
)
Mach
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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
”…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)
-4
-2
0
2
4
6
8
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12
-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
0
2
4
6
8
10
12
-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
titud
e (1
000’
s ft
MSL
)
Mach
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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
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
10
20
30
40
50
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?