Human Factors of Remotely Piloted Aircraft Alan Hobbs San Jose State University/NASA Ames Research Center
Nogales Predator Accident
Emerging Issues 1.Transfer of risk 2.Teleoperation 3.Air traffic considerations 4.Transfer of control 5.The control station 6.Maintenance
Transfer of Risk UA collides with people or property on ground Other airspace user collides with UA
Public Tolerance of Risk Involuntary exposure Unfamiliar Radioactive waste Commercial aviation Skateboards Lead paint Pesticides Trampolines Water fluoridation Automobile accidents Smoking Nuclear weapons Familiar Voluntary exposure Genetically modified organisms Paul Slovic, 2000
Flight Termination Manned vs unmanned mindset Information requirements
Teleoperation Reduced perceptual cues Potential for reduced situational awareness Control/consequence incompatibility Latencies Link management
The Loop Human-in-the-loop – Manual – Via automation Human-on-the-loop Human-out-of-the-loop
Capability of on-board automation HOOTLHITL HOTL
Capability of on-board automation HOOTLHITL HOTL
Capability of on-board automation HOOTLHITL HOTL
Capability of on-board automation HOOTLHITL HOTL
Teleoperation + Automation “After take-off the unmanned aircraft began an uncommanded bank to the left. It then impacted the ground at full power in a nose down attitude approximately 60 feet from the launch site. Testing after the accident indicated that the ground station computer was running slow and the software was locking up. The computer was changed and the system returned to normal status”.
Automation Automation surprise Automation complacency Mode awareness & mode errors Engagement & workload Workarounds Data entry errors – Tunes out small errors – May increase probability of large errors
Teleoperation + Automation
Air Traffic Lack of out-the-window view Timeliness of response? Autonomous collision avoidance? Lost link? Impact on ATC workload and efficiency Voice latencies
Transfer of Control Between control stations, between consoles within control station, crew change, link change Complicating factors: – Off-duty crew may leave workplace – Geographical separation – High potential for mode error – Long duration flights
Transfer of Control
1 3 2
Control Stations
70 years of cockpit design experience ignored Inadequate feedback to crew on system state Multi-mode controls and displays Difficult to read fonts and colors Placement of critical controls next to non- critical controls Reliance on text displays Display proliferation
IFF transponder “IDENT” 1. Remove right hand from control stick 2. Move curser to tracker display 3. Click on TOOLS menu 4. Scroll to IFF 5. Click to open IFF window 6. Click “IDENT” button 7. Click “APPLY” Curser is accessed by trackball and Left/Right buttons Note: In manned aircraft, the pilot response to ATC-directed “IDENT” command is one step: 1. Push a button.
Fuel Heat Inhibit Disable / EnableF9 Turning on the fuel heat system. Note: This switch labeling has been changed to: “Fuel Heat: ON / OFF” On-screen menu items refer to Function Keys for control.
Human Factors in UAS Maintenance
UAS Maintenance Diverse skill and knowledge requirements Lack of direct feedback on aircraft performance Repetitive assembly and handling Maintenance while missions underway Lack of documentation Salvage decisions Maintenance and fault diagnosis of IT systems
Maintenance and Fault Diagnosis of IT Systems Ill-defined faults Consumer hardware and software Laptop use discipline
Maintenance and Fault Diagnosis of IT Systems “The desktop computer, which was serving as the ground control system, locked up while the unmanned aircraft was in flight. The only alternative was to re-boot the computer, and this took about two to three minutes before command- and-control was reestablished. The unmanned aircraft’s flight path, however, was already uploaded so there was no effect on the flight.”
Final thoughts Public perceptions may matter more than “equivalent level of safety” We need to get it right from the start We need to apply old lessons, and learn new ones There is an acute need to learn from UAS incidents and accidents