Colorado Aviation Accidents & Incidents

Note: This case was reclassified from an accident to an incident as a result of applicable revisions to 49 Code of Federal Regulations Part 830.2, as amended at 75 FR 51955, Aug. 24, 2010. The case was previously identified under accident number DEN08FA130.


HISTORY OF FLIGHT

On July 28, 2008, at 1231 mountain daylight time, an experimental Raytheon Cobra, unmanned aircraft system (UAS), N601RN, sustained substantial damage when it collided with a stadium light pole while maneuvering for a pre-programmed landing near Colorado Springs, Colorado. The aircraft was registered to and operated by Raytheon Missile Systems Advanced Programs of Tucson, Arizona. There were no injuries to persons on the ground. Visual meteorological conditions prevailed for the Title 14 Code of Federal Regulations Part 91 test flight, and no flight plan was filed. The aircraft had departed from a paved road paralleling one of the athletic fields on the grounds of the United States Air Force Academy at 1208, and was returning to that location when the accident occurred.

The purpose of the flight was to test the system before demonstrating the Cobra to Air Force Academy staff. The staff at the Air Force Academy wanted to evaluate the aircraft's potential as part of an advanced airmanship curriculum course on UAS for the cadets. Prior to the flight, the Raytheon flight test team surveyed the road, the athletic fields, and the terrain north and south of the takeoff area. They then programmed the Global Positioning System (GPS) flight profile waypoints into the autopilot.

The aircraft underwent a preflight and systems tests. The aircraft's engine was started at 1206. It was also at this time that the aircraft's left wing-mounted camera was activated, which recorded the 25 minute, 5 second flight. Following automatic and manual engine run ups, the aircraft was taxied to a position on the road from which the command for an automatic takeoff was entered. The aircraft took off to the north and climbed to 8,000 feet above mean sea level (msl) or 1,000 feet agl. It then turned east to enter a counter clockwise, east-to-west rectangular flight pattern profile over the athletic fields north of the Air Force Academy's cadet area, as programmed. The aircraft then climber to 9,000 feel msl (2,000 feet agl) and continued the rectangular patterns.

The Cobra UAS performed several rectangular patterns over the athletic field with no problems noted. Part of the demonstration showed that the UAS could fly on its pre-programming in the event of a "lost-link" or loss of signal between the ground station and the aircraft.

After the aircraft had performed all of its maneuvers, it entered a north upwind leg for a right hand traffic pattern. The aircraft made several patterns at 8,000 and 7,600 feet before it was descended on the downwind leg for landing. The south-to-north landing pattern was set up so that a downwind to dogleg, dogleg to base, and base to final pattern would be flown. Du