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Large Crowd Surveillance UAV. International Aircraft Design Team - Spring 2008. International Design Team. Aircraft Design projects since 1997 Virginia Tech and Loughborough University International collaboration Communication: Video Conferences E-mail Project Management Websites
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Large Crowd Surveillance UAV • International Aircraft Design Team - Spring 2008
International Design Team • Aircraft Design projects since 1997 • Virginia Tech and Loughborough University • International collaboration • Communication: • Video Conferences • E-mail • Project Management Websites • MSN, Skype • Various Competition wins and awards from NASA General Aviation Design competitions.
Requirements RELIABILITY“1 or fewer uncontrolled crashes per 100,000 hrs of operation” • Cruise Speed: 50 knots • Top Speed: 70 knots • Range: 15 nautical miles • Endurance: 8 hours (minimum) • Service Ceiling: 10,000 ft (half fuel) • Operational Altitude: 2000 - 3000 ft • Minimum Turn Rate: 6 degrees/sec • Climb Rate: 200 ft/min (sea level) • MTOGW: 300 lb • Payload: 45 lb desired • Noise Levels: < 50 dBA at 200 ft • 10 knot crosswind landing capability • Conventional landing within a 50 ft by 250 ft
Importance of Reliability • Airworthiness and Safety of Flight • Is it safe to fly overhead in large crowd situations ? • Is it expendable? • Is it capable of performing to specifications? • Acceptance • UAV restrictions due partly to unreliable systems • Key to winning confidence of FAA to regulate UAV flight • Lower long-term costs of UAVs • Increased availability of UAVs for missions
Definition of Reliability • Reliability according to the DoD • “The ability of a system to perform its mission without failure, degradation, or demand on the support system.” • Mean Time Between Failure (MTBF) • Period of time a repairable system/component will perform between failures • Mean Time To Failure (MTTF) • Same as MTBF, but for non-repairable systems • What is aircraft failure? • Failure to return to base
Current UAV Reliability F-16 (Manned) Mishap Rate: 3.5 per 100,000 hours
Improving Reliability RQ-5/MQ-5 Hunter http://www.designation-systems.net/dusrm/m-155.html MQ-9 Predator http://www.airforce-technology.com/projects/predator/predator6.html • Methods • Redundant Systems • Backup Systems • Scheduled Maintenance • Diversification • Implications • Cost • Weight • Increase in maintenance responsibilities
Summary of Key Reliability Issues • Engine/Propulsive Failure • Control/Communication Failure • Structural Failure • Human (Ground Crew) Error • Methodology Used • -Propulsion/Autopilot – Fault Tree Analysis • -Structure – Joint Probability Distribution Function (PDF)