NTSB Cites Wide Range of Safety Issues in First Investigation of Unmanned Aircraft Accident

The National Transportation Safety Board today issued a total of 22 safety recommendations to address what NTSB Chairman Mark V. Rosenker said were "a wide range of safety issues involving the civilian use of unmanned aircraft.


Washington, D.C. - As a result of its first investigation of an accident involving an unmanned aircraft (UA), the National Transportation Safety Board today issued a total of 22 safety recommendations to address what NTSB Chairman Mark V. Rosenker said were "a wide range of safety issues involving the civilian use of unmanned aircraft."

The safety recommendations approved by the Board stemmed from the April 25, 2006, accident in which a turboprop- powered Predator B operated on a surveillance mission by the United States Customs and Border Protection (CPB) crashed in a sparsely populated residential area near Nogales, Arizona. No one on the ground was injured; the remotely piloted 66- foot wingspan aircraft was substantially damaged.

The Safety Board determined that the probable cause of the accident was the pilot's failure to use checklist procedures when switching operational control from a console that had become inoperable due to a "lockup" condition, which resulted in the fuel valve inadvertently being shut off and the subsequent total loss of engine power, and a lack of a flight instructor in the Ground Control Station.

At the Board meeting, the NTSB highlighted several areas of particular interest including: the design and certification of the unmanned aircraft system; pilot qualification and training; the integration of UAs into the air traffic management system; and audio records of all UA operations- related communications.

"This investigation has raised questions about the different standards for manned and unmanned aircraft and the safety implications of this discrepancy," said Rosenker. "Why, for example, were numerous unresolved lock-ups of the pilot's control console even possible while such conditions would never be tolerated in the cockpit of a manned aircraft?"

Expressing concerns about how manned and unmanned aircraft will share the same airspace, Chairman Rosenker said, "The fact that we approved 22 safety recommendations based on our investigation of a single accident is an indication of the scope of the safety issues these unmanned aircraft are bringing into the National Airspace System."

The Safety Board's investigation also revealed that the pilot was not proficient in the performance of emergency procedures, which led to the accident. "The pilot is still the pilot, whether he is at a remote console or on the flight deck," said Rosenker. "We need to make sure that the system by which pilots are trained and readied for flight is rigorous and thorough. With the potential for thousands of these unmanned aircraft in use years from now, the standards for pilot training need to be set high to ensure that those on the ground and other users of the airspace are not put in jeopardy."

On the issue of UA operations-related communications, the Safety Board noted that there is no equivalent of a cockpit voice recorder at the pilot's control console and that the pilot's communications with air traffic controllers and others were not recorded. To enhance the efficacy of future investigations of UA incidents and accidents, the NTSB recommended that the Federal Aviation Administration (FAA) require all conversations, including telephone conversations between unmanned aircraft pilots and air traffic control, other UA pilots, and other assets that provide operational support to unmanned system aircraft system operations, be recorded and retained.

Among the additional safety recommendations sent to the FAA are:

This content continues onto the next page...

We Recommend