Flight Testing Advanced Unmanned Aircraft Michael McDaniel - AIR Naval Air Systems Command NAS Patuxent River, MD, USA DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Advanced Unmanned Aircraft High level of automation –e.g. Global Hawk These aircraft are not simply remotely operated manned aircraft –Unconventional controls No direct control of flight control surfaces Command output, not method –Many tasks automated Takeoff, landing, emergency procedures Testing carries significant challenges –Especially early flights DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Major Test Challenges Loss of communications Loss of control Subsystem failures in flight Range safety Crew resource manangement Risk management for early flights *All screens are simulated DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Loss of Communications – Challenge Loss of command & control link between aircraft and ground station Management of concerns –Program leadership –Range safety –Airspace controlling authority DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Loss of Communications – Response Use redundant links –Example: Standard Global Hawk procedure is to use 2+ links If lost-communications procedures are tested in flight, have a method to recover comms –May want special software to tell airplane to ignore a working link for test Design to operate without link –Example: Global Hawk has lost-communication actions in mission plan Understand response of system –Loss of communications does not mean out-of-control Brief all participants beforehand –Including program managers, range personnel, airspace authorities Prevent panic responses DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Loss of Control - Challenge Software failure Airplane loses navigation solution –Leaves test range Can be serious risk DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Loss of Control - Response Build a good Systems Integration Laboratory (SIL) –Must use flight hardware –Exercises all functions in simulated flight environment –High demand item Need to have at least 1 year in advance May want multiple SILs Test all software functions and possible failures in SIL Test on ground –Taxi tests Do not fly until you are certain software is thoroughly tested –Example: Global Hawk program has 30,000+ flight hours, has never lost an aircraft due to flawed software May need range safety destruct system for early flights DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Range Safety - Challenge Reduce risk to acceptable level –Overflight of populated areas –Airspace –Flight termination systems Minimize impact on other test activities Many range safety personnel unfamiliar with unmanned aircraft DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Range Safety - Response Early engagement –Identify no-fly areas –Explain system operation in detail Practice ground handling –Tying up runways is a major issue –GHMD operations clear runway quickly Smart planning –Avoid no-fly areas –Stay in test airspace May need to limit winds aloft DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Range Safety - Response GHMD Mission Plan segment for NAS Patuxent River Winds aloft limits for FL500 DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Range Safety - Response Flight termination system (destruct system) –Balance risks FTS adds one risk to reduce risk from out-of-control flight When guidance & control is proven, FTS is greater risk Remove FTS at that point DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Crew Resource Management - Challenge Manage flight crew and test team communications –Get critical information quickly Test team has more information than pilot –Keep lines of communication clear Inform pilot Don’t overwhelm pilot DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Crew Resource Management - Response Crew = Pilot + other flight crew + test team If test team is > 5-7 people, have a hierarchy –Guidance & Control, Structures, ECS, etc. –Multiple engineers for each discipline –One engineer speaks for that discipline One person talks to the pilot & chase aircraft –Anyone can break in if aircraft is threatened Manage terminology –Have one term for aircraft destruction, use only for that purpose Train before flight –Formal CRM training –Simulated flights if possible –Example: Prior to 1 st flight, the ACTD Global Hawk test team did ~5 simulated flights with simulated emergencies DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Risk Management for Early Flights - Challenge Risk management –Technical –Programmatic Exploration of control envelope Chase aircraft DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Risk Management for Early Flights - Response Gradual test program –Manage risk Risk tolerance in early tests < risk tolerance later in program –Expand command envelope in manner similar to flight envelope Example: Early ACTD Global Hawk test program –1 st flight: Fully preprogrammed –2 nd flight: On-track override commands –3 rd flight: Off-track override commands Test in the SIL, then test in taxi, then test in flight Test team must control test program –Program pressure to fly before safe must be resisted DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Risk Management for Early Flights - Response Define RTB criteria beforehand –Lay out abort criteria –Write them down –Use if needed Know the limits of the aircraft –Can affect RTB Example: ACTD Global Hawk first flight –Unable to get gear locked up –Test team knew gear speed limit >Vne for airframe –Pressed with mission successfully Chase aircraft –Brief mission plan and contingencies –May need multiple chase aircraft for different portions of flight Example: Early ACTD Global Hawk test program F-16 for climb (ROC~5,000 ft/min) T-39 for landing (approach speed ~120 KCAS) DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Conclusion Unmanned aircraft will make up a large part of future flight testing High levels of automatic operation pose special challenges Challenges can be met with flexible planning and good test discipline DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,

Questions? DISTRIBUTION STATEMENT A: Approved for public release; Distribution is unlimited. 20 October 2009,