Lesson objective - to discuss Reliability, Maintainability, Supportability, and Safety

1. Lesson objective - to discuss Reliability, Maintainability, Supportability, and Safety Expectations - You will understand the issues (benefits and penalties) associated with UAV supportability and safety.

2. Why Consider Supportability? • Operations & Support and Safety are Key Cost Drivers for the Overall UAV System • Operations & Support (O&S) Represent the Largest Percentage of the Life Cycle Cost (LCC) • Reliability & Maintainability Attributes of the Air Vehicle Drive Support Manpower • - Affordability Issues Due to High Attrition Rates Constrain UAV Market Penetration (Military and Civilian) • O&S and Safety Issues Need to be Seriously Addressed During Pre-Concept Design • It is Not Something That Can be Delayed • You Get What You Pay For

3. Definitions • Reliability • The probability that an item can perform its intended function for a specified interval under stated conditions. • Mean Time Between Failures (MTBF) (ususally in terms of flight hours) • Failure Rate (failures per unit time) • Probability (expressed as a decimal or percentage) • Tasks and Responsibilities During Pre-Conceptual Design* • Allocations • Predictions • Functional Failure Modes & Effects Analysis • Design Reviews • Trade Studies * For purposes of this course, a discussion of the reliability issues and your proposed approach will suffice

4. Definitions • Maintainability • The measure of the ability of an item to be retained or restored to a specified condition when maintenance is performed by personnel having specified skill levels, using prescribed procedures and resources, at each prescribed level of maintenance and repair. • Mean Time to Repair – average of repair times • Maintenance Manhours Per Flight Hour • Crew Size – Average number of individuals required to accomplish the maintenance action • Tasks and Responsibilities During Pre-Conceptual Design* • Allocations • Predictions • Time Line Analyses (Combat Turns, etc.) • Design Reviews • Trade Studies * For purposes of this course, a discussion of maintainability issues and your proposed approach will suffice

5. Definitions • Supportability • The degree to which system design characteristics and planned logistics resources, including manpower, meet system requirements. • Direct Maintenance Manpower per Aircraft • Logistics Footprint (# transport aircraft sorties to deploy squadron’s support equipment, manpower and spares) • Mission Capable Rate • Not Mission Capable Supply (NMCS) Rate • Tasks and Responsibilities During Pre-Conceptual Design* • Define Support (Maintenance & Supply) Concept • Estimate Manpower; Sortie Generation Rates • Define Deployment Concept & Predict Logistics Footprint • Trade Studies * Requirements for this course underlined

6. Support Locations Main Base Forward Base Emergency Base

7. Contractor Organic http://www.fas.org/man/dod-101/sys/ac/row/cl-327.htm http://www.fas.org/irp/program/collect/predator.htm Support Concept

8. IOC Predictions Assessments What Kinds of R&M Analyses Are Expected in Pre-Conceptual Design? Acquisition & Life Cycle Phases OT&E Concept & Technology Development System Development & Demonstration Operations & Support Production & Deployment R&M Data Sources & Techniques Parametric Estimates Supplier Predictions • Weight • Parts Count • Surface Area • Duty Cycle • Sortie Length Component Tests Integration Tests • Part Stress • Environ Mod & Sim • Thermal Surveys • FMEA/FMECA • PHM Mod & Sim • Virtual Human M&S Flight Test • Durability Tests • Growth Tests • Qual Tests Field Data • M Demos • Surges • Environmental Extremes • Military Maintainers • End Users & Maintainers • Production Configuration R&M Predictions Fidelity Increase with Design Fidelity

9. What Is It About UAVs That Affects Supportability? • Micro, Mini, or Larger? • Proximity to Ground • Interface with Loading Equipment • Access to Daily Servicing Points • Engine Removal • Transportation / Deployment Considerations • Hangar Space • Refueling Times / Turnaround Times • Storage vs. Flying • Deployment Timelines • Optempo • Crew Sizes • Weapons • Self-Sufficiency • Contractor Logistics Support Considerations • Infrastructure Size CONOPS Basing

10. What Is It About UAVs That Affects Supportability? Endurance • Airframe Life • Inspection Criteria • Consumables • Redunancy / Mission Reliability • Autonomous Refueling vs. Sizing for Range • Deployment of Ground Stations • LOS vs. BLOS Comms • Mission Planning for Satellite Coverage • Coordination with ATC • Coordination with Ground Crews • Design for Testability • How Much Redundancy Can You Afford? • How Much Safety Analysis Can You Afford? • Approach to Support Ground Segment Cost / Fleet Size

11. Air Vehicle Eliminates Man-Rated Systems Man-Rated Systems Are Eliminated • Crew Station • Instruments • Cockpit Structure / Boarding Ladders • Canopy • Ejection Seat / Escape Provisions • Throttle/Control Stick/Rudder Pedal • Control Panels • Crew Station Environmental Controls • Heating/Cooling • Pressurization • Defog • Oxygen System • LOX or OBOGS • Regulator • Emergency/Survival Equipment • O&S Cost Reduction of 8% in Personnel Alone! • No Egress Shop • Eliminate Survival Skill • Smaller, Less Costly ECS • No LOX Consumables • Less Support Equipment

12. Crew Station Benefits • Equipment Moved Into Ground Control Station • Flight Instruments / Information • Displays • Data Recording • Reduced Environmental Qualification Testing • No High “g” Testing Required • Reduced Vibration Requirement (Maybe) • No High Altitude Testing • Increased Reliability • Some Equipment 2-5 Times More Reliable • Less Manpower Required for Maintenance • Cheaper to Implement Redundancy

13. Weapons Loading / Engine Removal • Proximity to Ground For Most UCAVs Complicates Weapons Loading • Innovative Loading Schemes Can Mitigate Restricted Access • Consider Hoists; Alternate Lifting Devices • X-45 Demo Uses Weapons Dolly and Ejectors Mounted on Weapon • Robotic Loading May Help • Considered By Navy for Ships • Engine Removal Also Challenging • Drop Down or Lift Out? • Existing SE Sufficient?

14. Deployment and Transportation • Storable UAVs Can Be Airlifted in Individual Storage Containers • USAF UCAV Concept is to Deploy via C-17 (See Demo Below) • Autonomous Aerial Refueling and/or Rearming May Allow Self-Ferry

15. Endurance Benefits • Pilot Physical Limitations Limit Effective Sortie Length • Endurance UAV Sortie Durations May Approach 48-60 Hours! • Ground Operators Can Work in Shifts • UAVs Have Potential to Remain Aloft Indefinitely • Requires Autonomous Refueling Technology • 4 to 5 UCAVs Can Displace 24 Manned Fighters in 24-Hour CAP • Longer Sorties Mean Less Wear and Tear • Cycle-Related Fatigue and Duty Cycles Reduced • 80% of Fighter Failures are Constant on a Per-Sortie Basis • Maintenance Manhours Per Flight Hour Reduction • Knee in Curve at Approximately 24 Hour Sortie Length This Study Assumed A Similar Level of Maintainability

16. Long Endurance MeansFewer Sorties Per Flight Hour • Assumes 80% of Failures are Constant on a Per Sortie Basis • Manpower Eventually Reduces to a Constant to Retain a Minimum Number of Personnel of Each Specialty for All Shifts MFTBM1 - Mean Flight Time Between Maintenance (Inherent) MMH/FH - Maintenance Manhours Per Flight Hour This Study Assumed A Similar Level of Maintainability

17. Endurance Benefits • Pilot Physical Limitations Limit Effective Sortie Length • Endurance UAV Sortie Durations May Approach 48-60 Hours! • Ground Operators Can Work in Shifts • UAVs Have Potential to Remain Aloft Indefinitely • Requires Autonomous Refueling Technology • Longer Sorties Mean Less Wear and Tear • Cycle-Related Fatigue and Duty Cycles Reduced • 80% of Fighter Failures are Constant on a Per-Sortie Basis • Maintenance Manhours Per Flight Hour Reduction • Knee in Curve at Approximately 24 Hour Sortie Length

18. Ground Handling Options • Preprogrammed Routes Using dGPS • Accurate, Hands-Off • Requires Site Survey, Detailed Mission Planning • Likely Requires Deconflicted Ops with Other Aircraft • Remote Control By Ground Crew • Good Ground Situational Awareness • Adds Complexity to Air Vehicle Design • Remote Control By Ground Operator • Good Ground Situational Awareness • Minimal Impact on Manpower • Hardware Intensive • Needs On-Board Camera

19. Redundancy Considerations • Redundancy Exists for 3 Reasons: • Safety • Survivability • Mission Reliability • Consider Life Cycle Cost Sensitivities • Maintenance Savings vs. Increased Loss of Aircraft • Consider Mission Reliability Requirements • For Flight Critical Systems (failure = crash): • Generally required to fail operational/fail safe (at a minimum) • Triplex Redundancy is Most Cost-Effective on $/Flight Hour Basis • Extremely High Reliability (>10,000 hrs MTBF) or Extremely Low Cost (<$1000/Channel) Are Required for Dual Redundancy to Be Cost Effective • For Mission Critical Systems (mission fails or degraded) • Generally required to fail operational (albeit degraded) • Typically back-up most mission critical systems (radios, GPS, etc)

20. Redundancy Cost Trades Module Cost/Channel: $18,400 Average Repair Cost: $6000 Average Sortie Duration: 4 .5 Hours UAV Unit Cost: $10 Million Critical Failure Rate: 1/3 of MTBF Trade Studies Will Determine Level of Redundancy

21. Training Concept • Manned Aircraft Pilots Maintain Proficiency By Flying • Require Minimum of 30 Flight Hours/Month • Most Flight Hours In Lifetime are for Training • UAV/UCAV Operator Interface Is Unique • Actual vs. Simulated Flight Similar • Keep UCAV In Storage Until War • Reduced Spares/Consumables • Reduced O&S Costs • Note – this ConOps is changing as we speak

22. Next Subject • Review of RM&S Functions • UAV & UCAV RM&S Considerations • Supportability Attributes • Subsystem Considerations • Manpower • O&S Cost • UAV Safety Lessons Learned

23. UAV and Drone Experience Mishaps Per 100,000 Flight Hours Fighter* 4.5 Manned QF-106 Drones* 130 Unmanned QF-106 Drones* 70 Pioneer UAV** 167 Hunter UAV** 140 Predator UAV** 27 *Class A Cumulative Mishap Rate, 1997 **Loss Rate (non-combat) • Primary Cause of Drone Mishaps is Old Age and Structural Integrity • Primary Causes of UAV Mishaps: • Non-Aviation Qualified Parts (Pioneer & Hunter) • Inadequate Emergency Procedures Training / Lack of Concurrency • Lack of Redundancy in Flight Critical Systems • Inadequate Testing & Configuration Control

24. Attrition Cost Comparison Lower Unit Cost Does Not Necessarily Mean Lower Life Cycle Cost! … and there’s a reason! Cost Per Vehicle $25-50M $200K $1.0M $3.0M Losses Per 100K Flt. Hrs. 5.0 7.0 167 27 Typical Fighter General Aviation Low Cost UAV High Cost UAV Global Hawk Goal is 10 per 100K Flight Hours

25. m of n ? ? ? UAV Lessons Learned • Carefully Weigh Risk When Considering Redundancy • Establish Acceptable Mission Reliability Goals • Trade Cost of Redundancy vs. Reduced Attrition • Affordability is Usually Achieved at Higher Risk • Recognize UAV/UCAV Mishap Rates Will Probably Exceed Manned Tactical Aircraft Mishap Rates • As a Minimum, Consider Redundancy for: • Data Links • Flight Controls • Propulsion System Controls • Utilize Mil-Spec or Commercial Aviation-Grade Parts • Already Qualified for Operating Environment (Temperature, Altitude, Vibration, EMI, etc.) • Better Reliability • May Obviate Need for Expensive Qualification Testing • Expensive for a Reason

26. UAV Lessons Learned • Use Qualified Test Pilot During Testing • Understands Aerodynamics & Engineering • First Responsibility is to Save Aircraft • Trained to React to Unexpected Events • Place Increased Emphasis on Operator-Vehicle Interface • Provide Adequate Fault Annunciation to Operator • Must Be Immediately Recognized • Should Indicate Appropriate Operator Response • Consider Operator Workload In Emergency Conditions • Consider Operator Skill Level (Pilot, Novice, etc.) • Segregate Houskeeping & Maintenance Functions from Flight Ops Functions • Train Emergency Procedures! (Especially for Flight Test) • Adequately Test Hardware Prior to First Flight • End-to-End Comms Loop (Including AV Antenna Multipath) • Hardware-In-the-Loop Testing is Critical

27. UAV Lessons Learned • Software Configuration Control • Hazard Analysis Should Include Software Hazards • A Software Change is a Configuration Change! • Utilize Software-In-The-Loop Testing • Automate Repetitive Functions to Alleviate Operator Fatigue and Improve Safety • Plan Adequate Schedule for Software Test

28. How to Achieve Reliability • Simplification – Fewer parts means less things to fail • Standardization – Quality and tolerances all match • Stress/Strength Derating – Particularly for avionics • Function Isolation – Improved mission reliability • Packaging Design – Hermeticity, vibration isolation, etc. • Redundancy – Judicious use! • Producibility and Tolerance Evaluation – Quality issue • Local Environment Evaluation – Avoid “hot” spots • Sensitivities – Trade studies • Drift and Degradation – Design for it or test for it • Development – Test, test, test • Reliability Design Checklists – Lessons learned

29. Empirical Analysis of Reliability Trends Historical Trend 10.0 7-9 5.0 3.0 EW = 30Klb EW = 20Klb MFHBF (Inherent ) 1.0 • TREND: Reliability Doubles Every 15 Years • Newer Technologies • Improved Manufacturing Processes (Quality) • Increased Emphasis on Design for RM&S 0.1 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Year of Initial Production Delivery

30. UAV maintenance personnel Parametric Data Shows Manpower Requirements are a Function of Aircraft Speed, Weight (EW + Wpay) and Type • UAV Comparison • - Global Hawk fits overall manpower parametric • - Predator falls well outside other aircraft norms • Use this parametric to estimate maintenance manpower required for your design projects Predator Global Hawk

31. Homework • Assess RMSS for your project (1) What redundancy levels do you think are appropriate the following subsystems • - Flight control computer • - Air vehicle up link • - Payload down link (2) From the internet, Janes or other sources pick a UAV that you think is closest to your project UAV - What are the maximum speed and empty and payload weights? (3) Estimate the number of personnel required to maintain it Submit your homework via Email to Egbert by COB next Thursday. Document all calculations