UAVs will not be able to fill their potential unless the regulations governing their use in civil airspace change

Proponents of the unmanned air vehicle (UAV) are keen to describe a future in which pilotless aircraft deliver mail overnight, monitor political troublespots, patrol borders in search of drug smugglers and serve as high-flying, long-endurance surrogates for telecommunications spacecraft.

But before these new missions can be accomplished routinely in the 21st century, aviation officials around the world will have to resolve the thorny regulatory issues that continue to limit the UAV industry's growth.

Little progress can be reported on this controversial issue, but several groups are spearheading efforts to develop international regulations that would allow the regular operation of UAVs over desolate and populated areas alike, the key to unlocking their commercial potential.

Ready for business

Meanwhile, although "enabling technologies" are being tested that could offer the required safety margins, NASA says several of the slow-flying research aircraft it has developed over the past five years are "ready for business", performing a variety of high-altitude, long-endurance earth science and commercial missions.

One pioneering manufacturer has stepped forward formally to seek civil certification of a UAV, effectively forcing the Federal Aviation Administration to face the issue.

While most UAV flights are conducted within special use airspace, the FAA will occasionally allow flights within certain controlled airspace, but only with the vehicle on a tight leash. Accidents sometimes occur, however, as in October 1999, when Aurora Flight Sciences' Perseus B UAV crashed on a highway near Barstow, California, after leaving NASA's Dryden Flight Research Center. It suffered moderate damage when it came down in the east-bound lanes, skidded across the median and came to rest in the westbound lanes. No one on the ground was hurt.

Andre Clot, a director of the UK's Remote Services, which is developing the Global Explorer long-endurance civil UAV, says: "It must be accepted that the operating environment is hostile to their presence and that little or no accommodation to their operational capabilities is forthcoming. The designers, manufacturers and operators are all constrained by an operating regime developed for manned aircraft."

All sides agree on the main issue facing government aviation authorities about operation of UAVs in civil airspace, namely the need for a safety standard that is equivalent to those applied to manned aircraft. What aspects of UAVs are different from manned aircraft and how might these differences affect certification requirements?

There are two significant resources of risk: the absence of real-time control capability in the event that the UAV loses its control link with the ground and the absence of a "see-and-avoid" capability. Does "detect-and avoid" capability offer the equivalent level of safety?

Creation of a government/industry support group in 1998 to work with the FAA in developing procedures for the operation of UAVs in civil airspace should increase the momentum in the USA. Meantime, the efforts of the US-based Association for Unmanned Vehicle Systems International, which has been re-named the International Association for Unmanned Systems (IAUS), are being mirrored in Europe.

IAUS, which has worked with the FAA for years to create regulatory standards that would enable UAVs to operate safely in US airspace, says: "The regulatory process remains incomplete, and it is likely that technological development will continue to outpace creation of regulatory criteria and operational procedures. This deficiency is beginning to affect adversely the growth potential of the UAV commercial and civil industry-Failure by industry and the FAA to address these issues in a timely manner could very well threaten the American UAV industry's position in these emerging commercial and civil markets."

The European Unmanned Vehicle Systems Association and the UK's Unmanned Aerial Vehicle Systems Association (UAVS) exist to promote UAVs and serve as focal points for work with their respective aviation authorities. UAVS, for example, has formed three technical committees to help the UK's Civil Aviation Authority resolve key issues about design qualification and certification requirements, airspace policy and air traffic management, and frequency allocation issues. The UK group is producing a concept of operation for civil UAVs, and last May it participated in the first joint industry/government working session to set a course for the work of UAVS' committees.

The FAA has no regulations governing routine civil operations of UAVs in US airspace, but the rulemaking process is under way - albeit at a snail's pace. Little has been accomplished since 1996 when a UAV Aviation Rulemaking Advisory Committee made a number of recommendations. Among other things, the group of outside aviation experts recommended that vehicle operators be licensed pilots; that UAV operations outside line-of-sight to the operator should be conducted under instrument flight rules to ensure separation; and that collision-avoidance equipment "in lieu of conventional see-and-avoid, would provide an equivalent level of safety".

No timeline has ever been established for regulatory action, with FAA officials saying that nothing could happen until a manufacturer sought a type certification for a UAV. In late 1998, however, California-based AeroVironment, which built the Pathfinder, Centurion and Helios solar-powered aircraft for NASA, made just such a request so that the Helios could routinely operate in civil airspace offering telecommunications relay.

The company reports "upfront and straightforward discussions" with the FAA on its request, but could not say when the type certificate would be issued. FAA sources say, however, that the application is bogged down in the bureaucracy with the legal, flight standards and aircraft certification offices at loggerheads. George Donohue, who until recently directed the FAA's research and development efforts, says: "The FAA doesn't have a clue on how to rule on this certification issue-It will take a substantial amount of courage to go into uncharted policy waters. I don't see the FAA doing it right now-not for a long time."

Pressure mounts

But pressure is mounting to allow use of UAVs outside restricted airspace. A US State Department disaster relief expert sees a future for low-speed, long-duration air vehicles in performing remote sensing and telecommunications relay in the aftermath of natural disasters. Larry Roeder is organising a "Peacewing" experiment this summer in Kenya in which the Helios would be applied to disaster work. He says such aircraft could assist in disaster recovery management via the Global Disaster Information Network.

Meanwhile, the US Air Force's UAV Battlelab at Eglin AFB in Florida has successfully tested the civil traffic alert and collision avoidance system (TCAS) on a surrogate UAV, showing that they could fly safely in non-military airspace outside the current rules. Project officials say TCAS should be installed in the military's General Atomics Predator and Northrop Grumman Global Hawk UAVs, since they could prevent a mishap with commercial traffic if normal flight separation procedures break down. Looking to the future, there are several air traffic management initiatives, such as free flight and automatic dependent surveillance - broadcast, that could make it easier for manned aircraft and UAVs to co-exist peacefully.

Source: Flight International