ARP94910 Origins – Project Definition & Approval

1. SAE A-6 Project A-6A3-08-1Aerospace Recommended Practice - ARP94910Aerospace- Flight Control Systems - Design, Installation and Test of, Military Unmanned Aerial Vehicles, Specification Guide

2. ARP94910 Origins – Project Definition & Approval • In 2007 the A-6 Systems panel completed AS94900 – Aerospace Standard for FCS for Military Manned Aircraft • Spec released July 6, 2007 adopted by DoD to replace MIL-F-9490 November 5, 2007 • Version of the AS for UA’s suggested and informally polled in industry to mixed results • The US Navy, Army and Air Force expressed support which justified initiating the project • May 2008, A-6 Steering Council approved project • But as an Aerospace Recommended Practice, not an Aerospace Standard • Explicitly confined to vehicle subsystem (ground station and data links not included) • Targeting late 2009 for a draft ARP ACGSC Meeting 102 15-17 Oct 2008

3. Project Sponsored by the SAE A-6A3 Flight and Utility Control Systems Panel • A-6A3 “Systems” Panel Officers • Ian Halley, Chairman and Co Sponsor • Boeing Phantom Works • Dave Flavell, Vice Chairman and Co Sponsor • Moog Inc • Floyd Fazi, Secretary and ASD Liason • Lockheed Aeronautics ACGSC Meeting 102 15-17 Oct 2008

4. Moving Forward with the ARP • AS94900 is written for manned military aircraft. Implicit premise that total loss-of-control should an exceedingly rare event rather than an occasionally acceptable event. • At least for some UAS’s to date, occasional losses seem to be acceptable in today’s climate. Some would claim even frequent losses are acceptable in certain circumstances. • AS94900 may serve as a basis for developing the ARP, but clearly not all requirements in AS94900 are applicable to all UA’s. Some UA requirements are missing all together. • If manned aircraft loss-of-control criteria are not technically or economically achievable for some classes of UA’s, what should our expectations be? Thoughts which follow are VERY preliminary and subject to change. Your feedback encouraged ! shawn.donley@navy.milwilliam.facey@navy.mil ACGSC Meeting 102 15-17 Oct 2008

5. From Weibel & Hansman, MIT, May 2005(with F-18 data added) Unmanned Aircraft1 Accidents/ 100,000 hr • Global Hawk (4 accidents)* 168 • RQ-2A Pioneer 363 • RQ-2B Pioneer 139 • Predator RQ-1A* 43 • Predator RQ-1B* 31 Manned Military Aircraft1,3 • F-16 3.5 • F-18 2.8 Manned Civil/ Commercial Aircraft Accident Rates (2003)2 • General Aviation 6.7 • General Aviation (Fatal) 1.4 • Part 121 Scheduled & Unscheduled 0.313 • Part 121 Scheduled & Unscheduled (Fatal) 0.012 Data Spans 5 Orders of Magnitude ! Unclear What Percentage of Losses are Due to Flight Controls Sources: 1.) National Defense Magazine, May 2003 2.) NTSB Press Release, March 22, 2004 3.) NAVAIR System Safety, August 2008 *Total Operational Hours < 100,000 : Predator (65,000 hr); Global Hawk (2,500 hr) ACGSC Meeting 102 15-17 Oct 2008

6. What Does the Customer Expect a UA to Do After a FCS Failure ? • Need to answer this question before we can generate a useful ARP. • Answer depends on the characteristics of the UA (size, cost, range), its mission and its operating area. • Perhaps trying to answer this question provides a framework for linking ARP flight control recommendations to UA behavioral expectations. • Applicability of an ARP paragraph would depend upon expectations for post-failure behavior. ACGSC Meeting 102 15-17 Oct 2008

7. Proposal Develop a Concept of “Types” of UA FCS Post-Failure Behavior • Applicability of an ARP paragraph would depend upon FCS Type • If “Type” is the wrong name, pick another one • Brute-force redundancy may not be the best or only answer • for smaller UA’s, it may be impossible or cost prohibitive • Definitions of behavior and comments are very preliminary • Have purposely avoided trying to assign a PLOC number to each Type since I don’t trust these numbers, and because management focuses on them as absolutes when they are not • If PLOC numbers become unavoidable, recommend considering “Probability of Containment” requirement to augment PLOC • Probability of containment is the probability that the UA will not stray outside pre-defined geographical coordinates ACGSC Meeting 102 15-17 Oct 2008

8. How Should the Vehicle Respond After a Flight Control Failure (For purposes of this table, FCS includes Nav Sensors such as GPS/INS, but not data links) ACGSC Meeting 102 15-17 Oct 2008

9. FCS “Type” Continued ACGSC Meeting 102 15-17 Oct 2008

10. What Sets Required FCS Type • Required “Type” is some function of: Vehicle + Payload Cost, Mission, Operating Area, Kinetic Energy, Weapons carriage ? • Change any parameter and the required “FCS Type” may change • Operating Area may be bigger driver than Mission (although related) • Need some definitions of “Operating Area” • Not strictly an airspace classification • Change the Operating Area and the FCS may no longer be suitable • Need to adopt a taxonomy for UA Categories • Use 2007 DoD UAV Roadmap ? • Make “mission creep” difficult without reconsideration of FCS applicability and safety. • Break the habit of assuming “small = throw-away” • Even an insect will try to save itself when injured ACGSC Meeting 102 15-17 Oct 2008

11. UA Categories From DoD 2007 UAV Roadmaphttp://www.acq.osd.mil/usd/Unmanned%20Systems%20Roadmap.2007-2032.pdf ACGSC Meeting 102 15-17 Oct 2008

12. Operating Area/Mission Considerations Preliminary Definitions of Operating Areas Note: No attempt (yet) to marry these up with NAS definitions or FAA Notice 07-01 ACGSC Meeting 102 15-17 Oct 2008

13. Notional Relationship of FCS Type to UA Category and Operating Area • Baseline FCS Type Could be Adjusted Up for: • Shipboard operations • Aerial refueling capability • Weapons carriage • Payload classification • Active structural load control • Swarming ops (multiple UA’s in same airspace) ACGSC Meeting 102 15-17 Oct 2008

14. Summary • Aerospace Recommended Practice rather than a Spec • Challenge of accepting some vehicle losses without compromising safety to people and property • Challenge of encompassing large range of UA sizes, cost, missions, etc • Smaller UA’s may be able to utilize flight control failure accommodation strategies that are considered too risky, immature or unconventional for manned aircraft • Volunteers needed to help develop the ARP ACGSC Meeting 102 15-17 Oct 2008

15. Backup Charts

16. Definition of a UAV From STANAG 4671 • UAV • An aircraft which is designed to operate with no human pilot on board and which does not carry personnel. • Moreover a UAV : • Is capable of sustained flight by aerodynamic means, • Comment: Is jet lift considered “by aerodynamic means?” • Is remotely piloted or automatically flies a pre- programmed flight profile, • Is reusable, • Is not classified as a guided weapon or similar one shot device designed for the delivery of munitions. ACGSC Meeting 102 15-17 Oct 2008

17. ARP94910 Origins – SAE A-6 and Panel A-6A3 • Systems Panel Place in A-6 ACGSC Meeting 102 15-17 Oct 2008

18. ARP vs AS • Aerospace Recommended Practice rather than an Aerospace Standard because, “although the FCS technology employed for UAs is mature, the application is not” • Definitions from the SAE “Aerospace Council Organization and Operating Guide, 6th Revision, February 2006 • AS - Aerospace Standard - These Technical Reports contain specific performance requirements and are used for: (1) design standards, (2) parts standards, (3) minimum performance standards, (4) quality, and (5) other areas conforming to broadly accepted engineering practices or specifications for a material, product, process, procedure, or test method. • ARP - Aerospace Recommended Practice - These Aerospace Technical Reports are documentations of practice, procedures, and technology that are intended as guides to standard engineering practices. Their content may be of a more general nature, or they may propound data that have not yet gained broad acceptance. ACGSC Meeting 102 15-17 Oct 2008

19. Revised Approved Scope • Approved by SAE A-6 Steering Council, May 2008; • Revised by “Customer TOR” Meeting Sept 3, 4, Warrendale, PA • “This document will provide a comprehensive guide to the specification of the general performance, design, test, development and quality assurance requirements for the Flight Control System (FCS) of a military Unmanned Aircraft (UA). It will recognize the levels of FCS capability required for UAs of differing size, function and operational strategy. (Prior emphasis on categorization removed) Specific focus areas will include flight safety and the integration of the FCS with other systems and subsystems, such as the electrical and hydraulic systems. (reference to “See and Avoid” removed) It will address the integration with the up-link and down-link of the command loop but not the specification of these links or the design of the associated Control Station, both of which will customarily be separately specified by the procuring activity. It will be similar in structure to the new standard for manned military aircraft, AS94900.” ACGSC Meeting 102 15-17 Oct 2008

20. Draft Terms of Reference for Working Group • WG Mission • Produce an aerospace standard that provides recommended practices for the specification of the Flight Control System (FCS)of a military Unmanned Aircraft (UA). The document will be titled “ARP94910 Aerospace- Flight Control Systems - Design, Installation and Test of, Military Unmanned Aerial Vehicles, Specification Guide”. • Document to be Based on: • The document shall be closely related to the new standard for the FCS of manned military aircraft, AS94900. That Aerospace Standard (AS) takes the form of a specification whereas ARP94910 will be a guide to the writing of a specification. ACGSC Meeting 102 15-17 Oct 2008

21. Draft Terms of Reference for Working Group (Cont’d) • Document Structure and Scope • The document shall be: • An ARP rather than an AS • A guide to the specification of the FCS for the UA and not for the entire UAS • Applicable to the FCS capability required for the range of UAs covered by figure A.4 in the DOD 2007 roadmap. There will be a limit to the smallest size covered to be decided on kinetic energy and other grounds. • A comprehensive guide to the specification of the general performance, design, test, development and quality assurance requirements of the FCS. • Similar in structure, scope and depth to AS94900. • Performance oriented: • guiding the specification of the FCS performance requirements, the design of the FCS and its subsystems, and of its integration with the vehicle, and not specific architectural approaches. • A guide to the specification of the design and manufacture of the FCS components. • A guide to the documentation, testing, verification, validation and other quality assurance requirements of the FCS. ACGSC Meeting 102 15-17 Oct 2008

22. Draft Terms of Reference for Working Group (Cont’d) • Document Emphases • The ARP will pay particular attention to: • The definition of a UA flight control system. • The definition of a range of FCS capability. (Ref. to UA categories deleted) • Flight safety, including the definition of minimum acceptable capability following failure and the associated probability. • Integration of the FCS with other systems and subsystems within the UAS. • (Ref. to impact of “Detect, Sense and Avoid” deleted.) ACGSC Meeting 102 15-17 Oct 2008

23. Draft Terms of Reference for Working Group (Cont’d) • Requirements Assessment • Many national and international bodies are currently working to define suitable airworthiness requirements to allow the certification of UASs for flight within the non-segregated, controlled national airspaces of participating countries. In support of these efforts, several Standards Development Organizations (SDOs) are producing aerospace standards, currently mostly for UASs rather than for UAs. The WG will track these airworthiness and standards efforts and the ARP will incorporate the relevant portions of the UA flight control requirements and recommendations that result from them. References for these requirements and recommendations will be cited. (See Appendix to the TOR document - Documents of Interest.) ACGSC Meeting 102 15-17 Oct 2008

24. From STANAG 4671 What Constitutes a UAV Flight Control System ? • Flight control system • The flight control system comprises sensors, actuators, computers and all those elements of the UAV System, necessary to control the attitude, speed and flightpath (trajectory) of the UAV. • Comment: Navigation sensors (GPS, INS, other) are part of FCS for ARP94910 purposes • Comment: Data Links are not part of FCS for our purposes • The flight control system can be divided into 2 parts: • Flight control computer – A programmable electronic system that operates the flight controls in order to carry out the intended inputs. • Flight controls – sensors, actuators and all those elements of the UAV System (except the flight control computer), necessary to control the attitude, speed and flightpath of the UAV. • Comment: Not sure we need to make this distinction for the APR • Flight controls can further be defined as: • Primary flight control – Primary flight controls are those used in the UAV by the flight control system for the immediate control of pitch, roll, yaw and speed. • Secondary flight control - Secondary controls are those controls other than primary flight controls, such as wheel brakes, spoilers and tab controls. • Comment: Useful definitions for the ARP ACGSC Meeting 102 15-17 Oct 2008

25. Draft Terms of Reference for Working Group (Cont’d) • Requirements Assessment • Many national and international bodies are currently working to define suitable airworthiness requirements to allow the certification of UASs for flight within the non-segregated, controlled national airspaces of participating countries. In support of these efforts, several Standards Development Organizations (SDOs) are producing aerospace standards, currently mostly for UASs rather than for UAs. The WG will track these airworthiness and standards efforts and the ARP will incorporate the relevant portions of the UA flight control requirements and recommendations that result from them. References for these requirements and recommendations will be cited. (See Appendix to the TOR document - Documents of Interest.) ACGSC Meeting 102 15-17 Oct 2008

26. Tech – Categories- Roadmap Table A.1 Table A.1 Alignment of UAS Categories with FAA Regulations UAS (Cat III). Capable of flying throughout all categories of airspace and conforms to Part 91 (i.e., all the things a regulated manned aircraft must do including the ability to S&A). Airworthiness certification and operator qualification are required. UASs are generally built for beyond LOS operations. Examples: Global Hawk, Predator UAS (Cat II). Nonstandard aircraft that perform special purpose operations. Operators must provide evidence of airworthiness and operator qualification. Cat II UASs may perform routine operations within a specific set of restrictions. Example: Shadow UAS (Cat I). Analogous to RC models as covered in AC 91-57. Operators must provide evidence of airworthiness and operator qualification. Small UASs are generally limited to visual LOS operations. Examples: Raven, Dragon Eye. The JUAS COE has since further divided these three categories into six categories, as shown in Figure A.4. ACGSC Meeting 102 15-17 Oct 2008

27. Domestic Use UAS “Levels” From DoD UAV 2007 Roadmap ACGSC Meeting 102 15-17 Oct 2008

28. Combination, Courtesy of Mr. R. Burton ACGSC Meeting 102 15-17 Oct 2008

29. UAS Stds and Airworth. – Stds Devel Orgs (SDOs) • SDOs from DoD roadmap 2007 & UAV Forum, see updated Table below • Also, in Europe, EUROCAE and ETSI are working standards ACGSC Meeting 102 15-17 Oct 2008

30. UAS Stds and Airworth. – Stds Released & in Work • RTCA • 3 MASPS in work – top level and not duplicative • ASTM • 11 released, 12 in work • 5 of these 23 are relevant but not duplicative • SAE ASD AS-4 & GPD G-10 • 8 released – top level or training and not duplicative • AIAA • 1 released – terminology, superseded by ASTM spec • EUROCONTROL • 1 released – list of UAS standards needed, of interest but not duplicative ACGSC Meeting 102 15-17 Oct 2008

31. UAS Stnds and Airworth. – Airworthiness Bodies & Docs • NATO FINAS USAR • STANAG 4671 Airworthiness – draft form but highly relevant (See 4.) • NATO NNAG & JAPCC • Two released STANAGs, one in work, one flight plan – of interest but not believed to be relevant • FAA • Two released procedural cert. docs - Controlling UAS cert through CoA and Exp Certificate • ICAO • Study Group Report – Guidance for state UAS regulation • EASA • Certification policy doc • DoD • MIL-HDBK-516 –Rev B includes UASs– relevant check lists but no numbers • US Army • UAV Airworthiness procedural document • UK MoD • Design & airworthiness DEF STAN doc. – relevant but overtaken by STANAG? ACGSC Meeting 102 15-17 Oct 2008

32. UAS Stnds and Airworth. - Summary • Two released ASTM standards and three in work are relevant • But not duplicative • Two regulatory docs relevant • STANAG 4671 (See next agenda section) • DEF STAN 00970 Part 9 (Rel. 2006. Emphasis now on the STANAG?) ACGSC Meeting 102 15-17 Oct 2008

33. NATO Airworthiness – Draft STANAG 4671 • DRAFT STANAG 4671 - UNMANNED AERIAL VEHICLE SYSTEMS - AIRWORTHINESS REQUIREMENTS (USAR) • “This document contains a set of technical airworthiness requirements intended primarily for the airworthiness certification of fixed-wing military UAV Systems with a maximum take-off weight between 150 and 20,000 kg that intend to regularly operate in non-segregated airspace. Certifying Authorities may apply these certification requirements outside these limits where appropriate.” • General. If a National Certifying Authority states that a UAV System airworthiness is compliant with STANAG 4671 (and any appropriate national reservations), then, from an airworthiness perspective, that UAV System should have streamlined approval to fly in the airspace of other NATO countries, if those countries have also ratified this STANAG. ACGSC Meeting 102 15-17 Oct 2008

34. Structure of ARP94910 • AS94900 Structure appears to be adequate for new ARP • Many updates needed to content of various sections • Need to incorporate guidance and navigation recommendations. • Need to incorporate contingency management recommendations. • Many references to pilot and crew station that need to be cleaned up • Many references to pilot controls that are no longer applicable or that need to be reworked to remotely piloted vehicle requirements. • Many references to other specifications (i.e. MIL-STD-1797, ADS-33E-PRF, MIL-F-83300) that may not support UAV requirements • Includes transient and ride quality requirements, do these need to be retained to cover the potential of carrying passengers? • Combat MEDVAC ACGSC Meeting 102 15-17 Oct 2008

35. Structure of ARP94910 1. SCOPE 2. REFERENCES 3. REQUIREMENTS 3.1 General System Requirements Applicable. 3.1.1 Safety and Operability Considerations Probably applicable but will require a re-write to remove references to pilot and AFCF. 3.1.2 Reliability Considerations May need to consider new vehicle classification. 3.1.3 Redundancy Considerations Probably applicable but may need to be rewritten to consider new vehicle classification 3.1.4 Maintainability Considerations Mostly applicable but needs rework to reference ground station, maintenance concepts and also needs to consider Contingency Management 3.1.5 Survivability Requirements Applicable but may need to consider new vehicle classifications. 3.1.6 Electromagnetic Interference (EMI) Limits Applicable ACGSC Meeting 102 15-17 Oct 2008

36. Structure of ARP94910 3.2 System Performance Requirements 3.2.1 General FCS Performance Requirement Needs to be reworked, includes references to other specifications that may not support UAV’s. 3.2.2 Primary FCS Requirements Applicable 3.2.3 Secondary FCS (SFCS) Applicable 3.2.4 Automatic Flight Control Function (AFCF) Performance Requirements Not applicable, need to consider how to include performance requirements related to navigation and guidance. 3.3 System Testability Requirements Mostly applicable but needs rework to reference ground station, maintenance concepts and also needs to consider Contingency Management 3.4 System Design Requirements Mostly applicable except section 3.4.5, Electrical FCS Design may need updating dependent on vehicle classification and mission. 3.5 Subsystem Design Requirements Applicable except section 3.5.8, Display and Annunciator Subsystem needs to be re-written to refer to the ground station operation. ACGSC Meeting 102 15-17 Oct 2008

37. Structure of ARP94910 3.6 Component Design and Fabrication Requirements All sections applicable except 3.6.7, Specific Component Requirements is not applicable, related to pilot controls 4. QUALITY ASSURANCE PROVISIONS 4.1 General Requirements Applicable 4.2 Analysis Requirements Applicable 4.3 Software Verification Applicable 4.4 Test Requirement Mostly applicable but may need updating dependent on vehicle classification and mission. 4.5 Qualification (Preproduction) Tests Mostly applicable but may need updating dependent on vehicle classification and mission. 4.6 Documentation Mostly applicable but may need updating dependent on vehicle classification and mission. ACGSC Meeting 102 15-17 Oct 2008