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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
© 2009 Lockheed Martin Corporation
Structural Prognostics and Health Management (SPHM)
for the F-35 Lightning II
Michael R. Woodward
Principal EngineerF-35 Chief Engineer’s Office
Lockheed Martin Aeronautics Company
2009 Aircraft Structural Integrity Program (ASIP) Conference
December 1-3, 2009
Jacksonville, FL
DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.
Robert J. Burt
DirectorF-35 Structures Development
Lockheed Martin Aeronautics Company
JC (Carl) McConnell
Senior Staff EngineerF-35 Structures Development
Lockheed Martin Aeronautics Company
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
UK(138 STOVL)
United States - 2443
Italy
(131)
Netherlands(85)
Turkey(100)
Canada(80)
Australia(100)
Norway
(56)
Denmark(48)
Potential FMS Customers
Scope – F-35 Users
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 SPHM Effort Supports 3 Aircraft Types
F-35C CV
Span . . . . . . . . . . . . . . . . . . . . . . . . 43 ft / 13.11 m
Length . . . . . . . . . . . . . . . . . . . . . 51.4 ft / 15.67 m
Wing area . . . . . . . . . . . . . . . . . . 668 ft2 / 62.06 m2
Combat radius (internal fuel) >600 n.mi / 1,111 km
Range (internal fuel) . . . . . >1,200 n.mi / 2,222 km
F-35B STOVL
Span . . . . . . . . . . . . . . . . . . . . . . . 35 ft / 10.67 m
Length . . . . . . . . . . . . . . . . . . . . 51.2 ft / 15.61 m
Wing area . . . . . . . . . . . . . . . . . . 460 ft2 / 42.7 m2
Combat radius (internal fuel) >450 n.mi / 833 km
Range (internal fuel) . . . . . . ~900 n.mi / 1,667 km
F-35A CTOL
Span . . . . . . . . . . . . . . . . . . . . . . . . 35 ft / 10.67 m
Length . . . . . . . . . . . . . . . . . . . . . 51.4 ft / 15.67 m
Wing area . . . . . . . . . . . . . . . . . . 460 ft2 / 42.7 m2
Combat radius (internal fuel) >590 n.mi / 1,093 km
Range (internal fuel) . . . . . ~1,200 n.mi / 2,222 km
Convention
Take-
Off and
Landing
Short
Take-
Off and
Vertical
Landing
Carrier
Variant
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 SPHM Data
Collection/Processing/Assessment
• Deployment Scenarios
– USAF/USN/USMC
• Continental US
• Carrier Deployment
• Austere Forward Deployment
• Foreign Base Deployment
– Non-US Users (Partners/FMS)
• Data Collection/Processing/ Assessment Scenarios
– US Users
• JSF Program Task
• US Service Task
– Non-US Users (Partners/FMS)
• JSF Program Task
• Sovereign Task
SPHM Data
Collection/Processing/Assessment
F-35 SPHM Data Collection/Processing/Assessment Architecture
Accommodates Diverse Deployment Scenarios
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 ASIP Status
Interpretation and
Evaluation of Test
Results
Durability AnalysisSelection of Materials
Climatic TestsDamage Tolerance AnalysisNondestructive Inspection
Program
Force Management UpdatesIndividual Aircraft Tracking
(IAT) Program Development
Damage Tolerance
Tests
Stress AnalysisCorrosion Prevention &
Control Program (CPCP)
Aircraft Structural RecordsLoads/ Environment Spectra
Survey (L/ESS) Development
Durability TestsDesign Chemical/Thermal
Environment Spectra
Durability & Damage
Tolerance Control
Program
ASIP ManualForce Structural
Maintenance Plan (FSMP)
Flight TestsDesign Service Loads
Spectra
Structural Design Criteria
Loads/Environment Spectra
Survey (L/ESS)
Strength Summary &
Operating Restrictions
(SSOR)
First Flight
Verification Ground
Tests
Loads AnalysisDesign Service Life &
Design Usage
Individual Aircraft Tracking
(IAT) Program
Certification AnalysesStatic TestMaterial and Joint
Allowable Testing
ASIP Master Plan
Force Management
Execution
Certification & Force
Management
Development
Full Scale
Testing
Design Analysis &
Development Testing
Design Information
Task VTask IVTask IIITask IITask I
Complete In Work Planned
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
T
T/2
t/2
tAssumed Initial
Design Flaw
Assumed In-service
Inspectable Flaw
(Time to critical flaw length)
Critical flaw size
Initial inspection time
Maintenance Action Flaw Size
(Initial Inspection)
Maintenance Action
Flaw(2)
Mandatory Repair
Flaw(1)
(Reinspection Interval)
Flight Hours
Flaw Size
Notes:
1. Mandatory Repair Flaw: Largest flaw
size allowed by the structural part before
a maintenance action is required for
repair.
2. Maintenance Action Flaw size
(reinspection) is not always equal to
mandatory repair flaw size as shown in
this figure.CTOL Fracture Critical Inspections
T
T/2
t/2
tAssumed Initial
Design Flaw
Assumed In-service
Inspectable Flaw
(Time to critical flaw length)
Critical flaw size
Initial inspection time
Maintenance Action Flaw Size
(Initial Inspection)
Maintenance Action
Flaw(2)
Mandatory Repair
Flaw(1)
(Reinspection Interval)
Flight Hours
Flaw Size
Notes:
1. Mandatory Repair Flaw: Largest flaw
size allowed by the structural part before
a maintenance action is required for
repair.
2. Maintenance Action Flaw size
(reinspection) is not always equal to
mandatory repair flaw size as shown in
this figure.CTOL Fracture Critical Inspections
T
T/2
t/2
t
Assumed In-service
Inspectable Flaw
(Unfactored Time to crack intiation)
Critical flaw size
Initial inspection time
(Reinspection Interval)
Flight Hours
Flaw Size
STOVL & CV Maintenance Critical & Normal Controls Inspections
T
T/2
t/2
t
Assumed In-service
Inspectable Flaw
(Unfactored Time to crack intiation)
Critical flaw size
Initial inspection time
(Reinspection Interval)
Flight Hours
Flaw Size
STOVL & CV Maintenance Critical & Normal Controls Inspections
F-35 Structural Health Management
Strategies
• Designed to Support
Various Damage
Accumulation and
Management
Approaches
– Crack Growth and
Crack Initiation at
Specified Control
Points
– Flight Parameter-
based Load
Equations
– PHM Sensor-based
Load and Stress
Equations
F-35 SPHM Strategy Accommodates All User Approaches
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 PHM Architecture
Air Vehicle On-Board
Health Assessment
Air Vehicle/Support System
Interface
ALGS &
Off-Board PHM
• SPHM Processing:− L/ESS− IAT− Conditional Events
• Generate Reports• Store/DistributePHM Information
• Determine Maintenance Requirements
Mission Critical
PHM Data
Displays and Controls
.
Portable Maintenance
Aid (PMA)
Flight Critical
PHM Area
Managers
PVI
TO Data,
Status, Consumables, Stores
Off-Board Diagnostics
Health/Service Info
Database
AV PHM
Area Manager
Fault
Accommodation
Status via
ICAWS
Portable Memory Device
(PMD)
Propulsion
Mission
Systems
Structures
Vehicle
Systems
Crash Data
RecorderNVM
Maintenance
Vehicle
Interface
• Fleet Decision Support
•Maintenance Planning
Products:
Structural PHM Data/Information
Activities:
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
Elements of F-35 SPHM
• Loads/Environment Spectra Survey (L/ESS)
– Monitoring Actual A/C Usage
– Comparing Actual A/C Usage to Baseline Usage
– Generating Updated Baseline Usage Spectra and Environments
• Individual Aircraft Tracking
– Determination of Individual A/C Damage for Actual Usage vs. Baseline
Usage
• Conditional Event Reporting and Analysis
– Conditional Event Reporting
• On-board Detection and Reporting of Structural Overloads
– For Example –Wing Root Bending Moment/Shear
– Conditional Event Analysis
• Off-board Confirmation and Refinement of Conditional Event
• Mapping of Conditional Event Maintenance Tasks Based to Event
Type(s) and Magnitude(s)
F-35 SPHM System Supports ASIP Task V
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 SPHM ConOps/Tempo
AVPHM System - On A/C
On A/C Data
- Maneuver Time History
- Discrete Parameter Time
History
- SPHM Gage Data
- Conditional Event Data
- Configuration Data
...
PMD Cartridge
Process Data
- L/ESS
- IAT
- Conditional Event
Define Maintenance
- Conditional Event
- Per FSMP
Transfer data to ALIS
Ground Station – Unit Level
•Ground Station Data
Synchronized with
Accumulated Data on ALIS
•Generate/Distribute Fleet
Usage Reports
•Reprocess Data if Required
•Raw A/C Data
Transferred to Data
Warehouse
ALIS
SME Review
- L/ESS Assessment
- IAT Assessment
- FSMP Update
- IAT Update
-Fleet Management
Recommendations
Data Warehouse
Long Term Storage
of Raw A/C Data
Daily Weekly
Data >5 Years Old
3-6 Months
Fleet Management
Update
-Usage Update
-Life Update
Initial - 8000 FH
Updates ~ 5 Y
ConOps/Tempo Consistent with Traditional ASIP Practice
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 L/ESS – Usage Data Recording
• Over 150 Parameter Time Histories Captured
– Strain Gauge Data
– Accelerations (Rotational & Translational)
– Velocities & Rates (Rotational & Translational)
– Air Data System Parameters (AOA, Mach No., Altitude, etc)
– Control Surface Deflections
– Stores Configurations & Masses
– Fuel Tank States
– Engine Parameters
– Miscellaneous Discrete Parameters (Weight-on-Wheels,
Door Positions, etc)
Unprecedented Aircraft Usage Data Capture
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
• Evaluated Data Reported
– Peak-Valley Tables
– From-To Tables
– Exceedence Curves
– Range Pair Tables
– A/C Sortie Data
– Control surface position changes (All Surfaces)
– Nz and NzW
– Bending Moments (Fuselage, Wing Root, Wing
Mid-Span, Horizontal Tail and Vertical Tail)
– Time at Mach-Altitude-Weight
– Time in qbar-AOA ranges
– Takeoff and Landing Gross Weight Bands
– On Ground Nz
• Redundant On-board Storage Assures
Sufficient Data Capture in Event of Data
Download Failure
F-35 L/ESS Evaluation
F-35 L/ESS Supports ASIP Task V with High Quality Data
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 IAT Approach
• External Loads Sources– A/C State Parameters are used to calculate Airframe Maneuver Loads, Landing Loads, Taxi, Take-Off and other Ground Handling Loads
• Utilizes same Load Relationships as in L/ESS
– Direct Measurement – SPHM Sensors
• Stress– Algorithms calculate Stress as a Function of External Load for Individual Control Points
– Algorithms Developed using Appropriate Regression Techniques
• Accounts for Flight Control Law related discontinuities via piecewise continuity
• Damage– Calculated for Critical Structural Details and Generic Algorithms Sensitive to Individual External Loads
– Calculations are Consistent with Variant Specific Design Criteria
• Crack Growth
• Crack Initiation
F-35 IAT Program Encompasses All Services Tracking Methods
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 IAT Control Point Selection and
Verification
• Initial F-35 SDD IAT Control Point List
– Locations Distributed to Capture Major Load Parameters
– Locations in Critical Load Paths
– Low Margin/Limited Life Locations
– Locations to Capture Discrete Load Sources
• Updated Following completion of Full-scale Ground and Flight Tests
– Result of Final Certification Analysis – Updated Loads
– Result of Test Findings
• IAT Algorithm Verification
– Regression Accuracy:
• Maximum Dependent Variable Error
• Correlation Coefficient
– Damage Calculation Accuracy:
• Design Baseline Life versus IAT Algorithm Based Life (Using Design Spectrum Endpoints)
• Design Baseline Life versus IAT Algorithm Based Life (Using Simulated A/C Parameter Time Histories)
• The Performance of IAT Models will be Monitored throughout the Life of the Program
• Problems will be Identified and Corrected as Necessary
F-35 Control Point List Supports Task V Activities
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 IAT – SPHM Sensors
• Load Source Monitored
• All Variants – Center Fuselage Bending, Wing Root Bending/Shear, Vertical Tail Bending/Shear, Horizontal Tail Bending, Flaperon Bending, Forward Fuselage Bending, Aft Fuselage Bending
• CV – Launch Bar Axial, Wingfold Shear
• SPHM Sensors Data Acquisition Rate Sufficient to Detect Dynamic
Response
• Present on All A/C
Rear Spar Outboard Flaperon Hinge – LH
Fwd Fuse Bending (Upper Sill Longeron)
Center Fuse Bending (Lower Keel Longeron)
LH VT Shear Attachment
LH HT Actuator Lug
LH Aft Fuse Kicked Keel
LH VT Bending Attachment
Wing Root BH 496 - LH
Wing Root – LH Shear
Wing Root – LH Bending
Rear Spar Outboard Flaperon Hinge – LH
Fwd Fuse Bending (Upper Sill Longeron)
Center Fuse Bending (Lower Keel Longeron)
LH VT Shear Attachment
LH HT Actuator Lug
LH Aft Fuse Kicked Keel
LH VT Bending Attachment
Wing Root BH 496 - LH
Wing Root – LH Shear
Wing Root – LH Bending
Wingfold Joint
Leading Edge - Shear
Wingfold Joint
Trailing Edge - Shear
Launch Bar Attach
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 IAT Output Reporting
• Download Summary
• Aircraft Sortie Usage
Summary
• Tracking Model Performance
Summary
• Individual Aircraft Control
Point IAT Summaries
• Fleet Comparisons
• Control Point Exceedance
Data
• Tracking Model Performance
and Status Data
• Maintenance Action Update
Periodic Updates of FSMP Provide Data for
Force Management Recommendations
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 Conditional Event Reporting
• Determine Structural Overloads On A/C Due to:
– Flight Maneuver
– Hard Landings
– Over-Speed Events
• Compare Measured Loads Against Allowable Envelopes
– Determine the load at specific locations on the airframe by consideration of aero, inertia and stores inertia loads
– Locations driven by unique loading environments
• Generate Health Report Code Unique to Event Type
FS270 Vertical
Bending Moment
Bending Moment and
Torsion and Torsion
Horizontal Tail
Bending Moment and
Torsion
Bending Moment and
Torsion
Vertical
Bending Moment
Wing Root CV Wing Fold
Vertical Tail
Wing Bending Moment
CER Notifies Users of the Event
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 Conditional Event Analysis
• CEA is the Off-board Assessment/Verification of CER
– CEA more Rigorous than CER
• Able to Localize Overload to Specific Structure
• Assessment of A/C Data Quality e.g. Did Overload
Occur Because of A/C Parameter Noise?
• CEA Initiation
– Upon HRC resulting from On-board Detection of a
Conditional Event
– Pilot Reported Event
• Determines Level of Severity
• Determines Maintenance Tasks based on Location and
Level of Severity
CEA Assures Appropriate Level of Maintenance is Performed
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 Conditional Event Maintenance
• Conditional Event Maintenance Encompasses
Maintenance/Inspection Tasks Required to Clear A/C for Flight
Following a Conditional Event
• Three Levels Defined
– Level 1 – Visual Inspection + Some NDI
– Level 2 – Level 1 + Additional Visual Inspection/NDI
– Level 3 – Level 2 + Ground A/C, Generate Action Request to
Have Subject Matter Expert Review/Resolution of Event
• Conditional Event Maintenance Generation
– Conditional Event Report – Engineering Source Data
– Maintenance Task Analysis
– Electronic Tech Data Implemented within ALIS
Required Maintenance a Function of Event and Event Magnitude
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
F-35 Task IV and V ASIP Activities
2009 2012 2013 2014 2015 2016 2017 201920182010 2011Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
1st Production A/C Deliveries
Flight TestSTOVL
CTOLCV
Program Milestones
OT&E
USMC IOC USAF IOC USN IOC
Durability TestSTOVL
CTOL
CV
Initial L/ESS
Initial IAT
Task IV ASIP ActivitiesInitial CER/CEA/CEM
L/ESS Update
IAT Update
CER/CEA/CEM Update
ALIS 2.0
Complete
ALIS 2.0
Deployed
Initial FSMPs FSMP Updates
Task V ASIP Activities
SPHM Data Processing
IAT/L/ESS/CER/CEA Status Reports
CTOL
19k FHCTOL Full Clear.
CTOL
82k FH
CTOL
223k FH
Initial Usage Updates (All Variants) Next Usage
Update 2022
AF-6 BF-6 CF-5
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
Summary
• F-35 SPHM Effort is Global in Nature
• System and Computational Architecture Designed for
Flexibility in Order to Meet the Fleet Management
Requirements of All Customers
• F-35 SPHM System Characterized By
– Distributed Processing to Address Varied A/C
Deployment Scenarios
– High Degree of Automation
–On-board and Off-board Computational Capability
Increase Data Availability and Quality
F-35 SPHM Provides the Right Data for ASIP Fleet
Managers World-wide
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F-35 Program Information
Non Export Controlled Information – Releasable to Foreign Persons
Public Information Release Authorization AER200911001
Questions?