The US Federal Aviation Administration has developed a rudimentary set of ground rules for the certification and operation of "small" unmanned air vehicles in civilian airspace. The work comes in advance of an Aviation Rulemaking Committee (ARC) the FAA plans to launch in early 2008 to develop recommendations for how the vehicles can be safely integrated into the national airspace system.
The ARC report, in parallel with the output an FAA-internal safety management panel, will then form the basis for a proposed rulemaking covering certification and flight requirements and operations for small UAVs, says Bruce Tarbert, the FAA's UAV team lead for national airspace system integration. Tarbert says the rule, which would likely become a new section of the FAA regulations, could be published as early as July 2009.
Developed by Mitre with input from John Hansman and Roland Weibel of the Massachusetts Institute of Technology, the ground rules would limit aircraft flying in densely populated urban areas to a weight of 1.8kg (4lb) or less and a maximum altitude of 400ft (120m). For all other areas, the aircraft would be required to weigh less than 15.9kg and fly at or below 1,200ft above the ground.
Both classes of aircraft would be limited to airspeeds of 40kt (75km/h)) or less, piloted by FAA-certificated pilots who would have to keep the vehicles at least 4.8km (2.6nm) from charted airports. Rather than carrying on-board collision avoidance features, the vehicles would be likely to use "outboard" collision avoidance - ground-based pilots having line-of-sight contact and direct control over the vehicle (one pilot for each aircraft).
The overall system would be FAA-certificated, although most likely using "non-traditional" standards. Operators would have to notify the FAA of incidents involving fatalities, serious injuries or significant property damage.
Mitre and MIT developed the recommendations by investigating the probability of ground and mid-air collisions with civilian aircraft, using a safety threshold of one fatality per every 10 million flight hours, according to Mitre.
Currently a UAV operator can gain access to civilian airspace through a certificate of authorisation or the issuance of an experimental airworthiness certificate, both of which have operational mitigations to ensure safety. Tarbert says the FAA approved 100 certificates of authorisation last year and 60 so far this year. The agency approved 14 experimental certificates this year and has 10 more in the queue, he adds.
Tarbert cautions that the Mitre system description is a "starting point" for the ARC work, and will likely mature with stakeholder input.