Correction to This Article
In print editions and some online versions of this story, the company General Atomics was misidentified as Global Atomics.

NTSB Cites Lax Safety Controls, Pilot Error in Ariz. Drone Crash

Pilot failure to follow a checklist and lax oversight by Customs officials led to the crash of a $6.5 million Predator-B drone, NTSB investigators said.
Pilot failure to follow a checklist and lax oversight by Customs officials led to the crash of a $6.5 million Predator-B drone, NTSB investigators said. (By Gary Williams -- Getty Images)
By Del Quentin Wilber
Washington Post Staff Writer
Wednesday, October 17, 2007

Sophisticated computer systems on a 10,000-pound unmanned drone were no match for its pilot's failure to follow a checklist when confronted with a computer glitch.

The mistake set off a chain of events that led the $6.5 million Predator-B to smash into the Arizona desert near Nogales, Ariz., the National Transportation Safety Board concluded yesterday. The NTSB also cited poor oversight by Customs and Border Protection officials as a factor in the April 2006 crash.

It was the first accident involving an unmanned vehicle that the NTSB investigated, and board members said they hoped their findings would prod government officials and the industry to regulate the growing use of drones in civil airspace.

"This is historic," said Mark V. Rosenker, NTSB chairman. "We want to get it early before we, in fact, have a critical mass of these devices flying in the nation's airspace. We are just learning how to regulate them."

He called the safety and oversight lapses in the crash "disturbing."

The crash occurred when the Predator-B was flying along the Mexican border, with its sophisticated cameras and electronics equipment scanning for illegal immigrants. The drone was built and operated by General Atomics under a contract with the federal government.

The pilot, an employee of General Atomics, was flying the drone Libby Airfield in Sierra Vista, Ariz., about 60 miles away, when the problems started about 3:30 a.m., NTSB investigators said.

The pilot's computer console locked up, investigators said. He started to transfer control to a backup console used by Customs agents to operate the drone's cameras but did not follow a checklist that required him to make sure the engine controls on the second console matched the ones he had been using.

Because the second console's controls were in the fuel shut-off position, investigators said, the Predator-B's engine quit when control was switched.

The pilot, who did not understand why his plane kept descending, turned off ground communication with the drone to trigger its automatic emergency responses, according to investigators. Under such conditions, the plane should have climbed to 15,000 feet and circled above a designated spot until communication was reestablished. But without engine power, the plane crashed.

The pilot told investigators that he didn't follow the checklist because he was in a hurry, said Pam Sullivan, an NTSB investigator.

Under Customs guidelines, the pilot did not have enough hours on the Predator-B to fly the plane without an instructor in the room, and the instructor was in another building, Sullivan said.

Board members found that Customs officials did not do a proper job of overseeing operations of the drone by General Atomics. They also found that General Atomics and Customs did not do enough to investigate past computer lockups.

Customs officials did not reply to e-mails and phone messages seeking comment. General Atomics also did not respond to inquiries.

The Federal Aviation Administration grants government agencies and companies the right to operate drones on a case-by-case basis. Through last month, the FAA had granted 55 such certificates this year and had a backlog of 35.

Steven R. Chealander, a board member and former Air Force pilot, said that regulators and operators need to ensure that proper procedures are followed in drone operations because pilots may not realize the consequences of their actions if they are not in a cockpit. "You have to change the mind-set from someone operating a computer Game Boy to being the pilot of an aircraft," Chealander said.

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