Development, Certification, and Flight Testing of an OPA for UAS FTT Development and Training at NTPS 2013 SFTE/SETP Flight Test Symposium Evolution of Flight Testing from Manned Vehicles to UAVs 1
Overview Introduction NTPS C-150 OPA ~ System Overview ~ Ground Testing ~ Flight Testing ~ Certification and Limitation Reduction RPV/CDV FTT Development ~ Specific FTTs ~ Outcomes and Observations Current RPV Flight Test Courses Lessons Learned 2
National Test Pilot School Only SETP recognized civilian test pilot school Educate and train TPs and FTEs to successfully plan, execute, and report on flight test programs Year long professional course and master s degree program Scheduled and on-demand short courses Underlying philosophy of flight testing is continually reinforced 3
RPV Short Course Background NTPS began offering a two-week RPV flight test short course in 2006 Initially RPV FTT demonstrations were limited to simulation In order to enhance the realism and value of training it was necessary for NTPS to acquire a platform 4
C-150 OPA Overview Why an OPA? ~ Operate from KMHV ~ Operate within the NAS ~ No significant weather or range lim. Standard Cessna 150L (N18531) Cloud Cap Piccolo II Autopilot ~ Integrated 900MHz C 2 Datalink ~ Integrated GPS/INS ~ Air Data Input ~ Payload Interfaces Autopilot Control ~ Elevator ~ Aileron ~ Throttle 5
Ground Control Element OPA Command Path Optionally Piloted Aircraft 6
OPA System Block Diagram Flight Control Subsystem Ground Control Element Payload Sensor Subsystem Sensors 7
Command Directed Vehicle (CDV) Control Modes Command Loops Active PFD Autonomous Flight Plans Active Moving Map 8
Remotely Piloted Vehicle (RPV) Control Modes Stability Augmented Control ~ Vertical Rate ~ Bank Angle ~ Throttle Position Full Authority Override ~ Elevator Position ~ Aileron Position ~ Throttle Position 9
Sensor Payload Subsystem Dedicated 5.8GHz Datalink Forward Looking EO Sensor ~ GCS Situational Awareness Cloud Cap TASE200 Gimbal ~ FLIR Long Wave IR Sensor ~ Sony Color EO Sensor ~ Integrated with Piccolo II Sensor Control from GCS ~ Joystick ~ Active Real Time Display ~ Geo-Referenced ~ Multiple Tracking Modes 10
Sensor Gimbal GCS Interface 11
OPA Control Room Integration Ground Control Station OPA TM/Control Room Student Sensor Operator Student GCS Pilot Safety Pilot FTE FTE Instructor TC FTE Systems Instructor Designated GCS IP FTE TM Support FTE 12
FAA Airworthiness Certification Optionally Piloted Aircraft (OPA) Experimental Research and Development NTPS Letter of Deviation Authority Permits School Operations Current Critical Limitations ~ Minimum System Operating Altitude 50ft AGL ~ Safety Pilot Required Onboard (Sense-and-Avoid) ~ Designated GCS Instructor Required for each Mission ~ Restricted Operating Area 13
FAA Airworthiness Certification 14
Ground Testing Pitot-static instrument calibration Motor controller optimization Surface calibration SIL/HIL Simulation Aileron Calibration Graph Sensor variable validation RF spectrum analysis Simulator 15
Flight Test Schedule ID Test Title Hours Date FT 01 In-flight Sensor Variable Validation 0.9 6/6/2011 FT 02 0.5 6/15/2011 FT 02.a 0.6 6/16/2011 FT 02.b 1.0 6/17/2011 Airborne Communications FT 02.c 1.1 6/21/2011 FT 02.d 0.6 6/22/2011 FT 02.e 0.5 6/23/2011 FT 03 Smooth Controllable Flight 1.6 7/1/2011 FT 03.a Inflight Motor Controller Optimization (Aileron) 1.1 7/8/2011 FT 03.e Inflight Motor Controller Optimization (Elevator) 0.9 7/8/2011 FT 3G Communications Testing 1.2 7/28/2011 FT 04 1.0 7/18/2011 FT 04.a Refine Autopilot Gain Settings (Aileron) 1.0 7/25/2011 FT 04.b 1.3 8/5/2011 FT 05 1.4 8/8/2011 FT 05.a Refine Autopilot Gain Settings (Elevator) 1.5 8/10/2011 FT 05.b 1.6 8/12/2011 FT 06 Refine Autopilot Gain Settings (Throttle) 1.6 8/23/2011 FT 07 Refine Autopilot Gain Settings (Longitudinal Control - Airspeed) 1.7 8/25/2011 FT 08 Refine Autopilot Gain Settings (Longitudinal Control - Altitude) 1.5 8/31/2011 FT 09 Refine Autopilot Gain Settings (Heading) 1.5 9/2/2011 FT 10 Control Authority and Limit Confirmation (Aileron) FT 11 Control Authority and Limit Confirmation (Elevator/Throttle) 1.6 9/7/2011 Control Authority and Limit Confirmation (Elevator/Throttle FT 12 Aileron) FT 13 Track Navigation Logic FT 14 Failure State Testing (Airborne) 1.5 9/27/2011 FT 15 Command Directed and RPV flight 1.6 10/18/2011 Total: 28.8 Number of Flights 24 16
RPV/CDV FTT Development Standardized FTTs specifically designed for RPV/CDV not yet developed Diversity adds significant further complexity to the FTT development NTPS needed to develop FTTs to demonstrate during the RPV course Applied FTTs for manned aircraft to identify which transferred to RPV/CDV Initially focused strictly on P&FQ FTTs NTPS Volume X, Fixed Wing Flight Test Handbook, was used as the primary reference for the accepted manned fixed wing P&FQ FTTs 17
NTPS Volume X FTT Handbook 1. Position Error Correction 2. Cruise Performance 3. Engine Out Drag Polar 4. Glider Performance 5. Takeoff and Landing 6. Jet Cruise Performance 7. Climb and Level Acceleration 8. Turn Performance 9. Stall Speed Determination 10. Advanced Performance Maneuvers 11. Long Stat and Flight Path Stability 12. Maneuvering Flight Stability 13. Lateral Directional Static Stability 14. Trim Test 15. Engine Out (Vmca) 16. Roll Performance 17. Stall Characteristics 18. Prop Spin 19. Turboprop Spin 20. Turbojet Spin 21. Spin Chase 22. Dynamics 23. Closed Loop Handling Qualities 24. High Speed Taxi 25. Asymmetric Flying Qualities 18
GPS Method PEC FTT Position Error Correction ~ Best for airspeed position error ΔV pc ~ CDV Commanding Track vs. Hdg ~ RPV Directly Transfers Modified Tower Flyby ~ Best for altitude position error ΔH pc ~ CDV Commanding AGL (Laser Alt/DGPS) ~ RPV Unable to meet required precision/low Alt. CDV Combined PEC FTT ~ GPS for ΔVpc and mod. tower flyby for ΔHpc ~ No additional onboard instrumentation required Potential certification criteria related to measured static and total pressure errors 19
Dynamic Stability Baseline aircraft-powerplant combination could not be directly evaluated in CDV or RPV modes Directly injected commands through GCS Singlet/Doublet Inputs specified amp. and freq. Capable of extremely precise inputs Following input controls were fixed for a specified duration Terminate during maneuver autopilot resumes control at initial commanded condition 20
Flying Qualities Limited evaluation of RPV flying qualities Tasks focused on ISR mission Area of flight testing with the most significant differences from manned aircraft Anticipated to be the focus of future research UAV Flying Qualities Rating Scale ~ Developed by C. Cotting at Virginia Tech ~ Derived from Cooper-Harper ~ Rates mission effectiveness of UAS and sensor ~ Disturbance levels must be specified for task 21
Flying Qualities Evolution of Flying Qualities Analysis - Problems for a New Generation of Aircraft. Cotting, C., Virginia Polytechnic Institute and State University, 2010 22
Outcomes and Observations Many fundamental considerations and FTTs employed for the manned flight test are congruent for RPV/CDV Requires unique approaches to effectively execute CDV/RPV flight testing Different methods of control require significant differences in the required modification to manned FTTs Both CDVs and RPVs have advantages and disadvantages Primary issue with executing a particular FTT was the inability to maintain constant control position Benefit of flight test GCS application setting modes and sending inputs 23
Current RPV Courses Independent professional course RPV flight test module Two week RPV flight test short course scheduled twice yearly Short courses as requested by various organizations Students have been extremely satisfied with their experience ~ Prof. course students have requested further OPA implementation 24
Lessons Learned Onboard safety pilot was found to be invaluable ~ Significant reduction in the cost and time associated with flight testing ~ Rapid convergence to a stable optimized system ~ Reduces criticality level of malfunctions Optimized response is likely unsuitable for an OPA due to pilot comfort Special care should be given to defining and briefing GCS versus Safety Pilot knock-it-off criteria Knock-it-off execution is not trivial and needs to be planned and briefed An OPA flight test mission has been found to involve significantly more personnel than a manned aircraft flight test Additional considerations required due to the increased complexity of CRM Control room integration has significantly enhanced the learning experience 25
Questions? 26