MQ-9 drone crash caused by failed navigation system

Rennett Stowe/via Flickr
July 4, 2014

The Air Force says multiple communication and navigation failures lead to the crash of an MQ-9 Reaper drone, piloted by the Syracuse-based 174th Air National Guard wing. No one was hurt when the multi-ton aircraft plummeted into the lake 12 miles offshore, late last year.

Agamemnon Crassidis, professor of mechanical engineering at RIT and the academic director of upstate New York’s private drone research alliance, NUAIR, said GPS and internal navigation system failures on drones are their most common issue.

"I’m assuming what happened was, once it’s lost its location, it caused the drone to go into an emergency mode and it looks like those emergency system backup modes failed as well," said Crassidis.

The drone’s backup autopilot is designed to steer away from populated areas. But Crassidis says with navigation systems down, some luck may have factored into the drone still being over water when it went down.

"In terms of the sensor not being able to locate the position, then essentially the unmanned aircraft system had no idea where it was and... we got lucky it didn’t crash into a populated area," said Crassidis.

The Air Force says a bad right turn while on autopilot sent the drone into an unrecoverable flat spin. Crassidis said a drone under computer control is only as good a flyer as the sensors it has on board.

"If that sensor fails, the autopilot has no chance," said Crassidis.

An Air Force review board released its report on the crash this week. It ruled there was no pilot error in the accident and the drone had passed a pre-flight inspection.

The MQ-9 had been in the air on a training mission for about two hours when it encountered problems. It was just over 15 minutes from error to crash impact.