Classified documents and video obtained by the Der Spiegel have revealed a near collision between a small Luna reconnaissance drone operated by the Bundeswehr and an Ariana Airbus A300 airliner over Kabul in August of 2004. The Ariana flight was carrying 100 passengers.

The report comes as German Defense Minister Thomas de Maizière faces another drone scandal over the purchase of the "Euro Hawk," a long-range surveillance drone that was found to be too dangerous to operate in European airspace because it lacked a collision-avoidance system.

Officials of EMT, the company that manufactures the Luna drone, told Der Spiegel that the Airbus had flown into restricted airspace where the drone was operating, but the tower at Kabul's airport was not aware of the restriction.

The risk of collisions with manned and other unmanned aircraft is a major concern that the Federal Aviation Administration is trying to address as it works to meet a Congressional mandate to "integrate" drones "into the national airspace." And it's the reason for the cancellation of Germany's Euro Hawk program, a €600 million Euro contract with Northrop Grumman that was killed after five years because it failed to gain certification to operate over Europe.

Getting an air-worthiness certificate from the European Aviation Safety Agency would require improvements to the Euro Hawk's collision-avoidance system that would require an additional €250 million to €600 million, according to a government report—along with "incalculable technical, temporal, and financial risks."