Having been firmly entrenched in modern military concepts of operations, unmanned air vehicles are slowly finding their way into civil airspace.

After a year-long study in collaboration with a consortium of 23 companies representing nine countries, Thales says it has identified four possible paths for addressing frequency spectrum needs and concerns for as part of the integration of military unmanned air systems with civilian air traffic.

The SIGAT study, or "Study on military frequency spectrum allocations for the Insertion into General Air Traffic of UAS", was aimed at defining and promoting a common European position for command and control radio frequencies for future military UAS integration in the European civil airspace.

"One of the major issues at the heart of UAS development today is the integration of these vehicles into civil airspace. We need to ensure proper segregation of existing air traffic and maintain a high level of safety for all airspace users to the standards of international civil aviation," says Pierre-Eric Pommellet, Thales senior vice-president in charge of defence mission systems.

While calling the SIGAT findings "decisive" and "a major outcome for European defence ministries" considering the technical and regulatory aspects of operating manned and unmanned aircraft in the same airspace, no details on the findings were released.

The technical aspects of how to best bring unmanned aircraft and general air traffic together over Europe is expected to be discusses at the next World Radiocommunication Conference in 2012.

The USA is only just embarking on its considerations of how to bring manned and unmanned systems together in civil airspace. The US Federal Aviation Administration and UAS-maker Insitu have struck a deal to study UAVs in civil airspace for the next two years.

Insitu, a wholly owned subsidiary of Boeing, will provide the FAA with two ScanEagle vehicles, two ground control systems, a launcher, SkyHook retrieval system and training materials worth around $1.6 million, plus the necessary training and support over the life of the agreement.

The FAA is expected to issue a notice of proposed rulemaking on UAS integrations in the first quarter of 2011. The agency has already accepted Insitu's recommendation of defining a "small UAS" as 25kg (55lb) or lighter, says Paul McDuffee, Insitu's vice-president of commercial business development.

While it looks like slow progress to some, the move to study integration is a major one for the FAA, which has long been reluctant to bring unmanned aircraft into civil airspace.

Fuel was added to the fire when, days after the FAA-Insitu announcement, the first UAV flying on a Texas-Mexico border security mission, a Predator B, lost communications with its pilot "which resulted in pilot deviation", according to US Customs and Border Protection.

The FAA and border patrol stopped UAV flights for six days for "additional training" of border patrol personnel. UAV flights over the border have since resumed.

Source: Flight International