July 02--Air Force officials said that GPS and guidance system malfunctions led to the crash of a multimillion-dollar MQ-9 Reaper drone into Lake Ontario in November.
The resulting failures sent the 10,500-pound aircraft descending in a clockwise spiral at 5,000 feet per minute, with crews unable to change its course.
"I can't recover it," the aircraft's unnamed pilot said, according to an Air Combat Command Accident Investigation Board report released Tuesday.
The Reaper drone from the 174th Attack Wing, Syracuse, crashed Nov. 12, about 12 miles from the lake's eastern shore and 35 miles from Fort Drum's Wheeler-Sack Army Airfield, where it took off at 10:42 a.m. The aircraft was traveling in approved airspace during a routine intelligence, reconnaissance and surveillance training exercise at the time of the crash, and had passed its preflight inspection that morning without issue.
About 12:45 p.m., a crew at Hancock Field Air National Guard Base, near Syracuse, noticed a series of warnings indicating a partial failure in one of the MQ-9's onboard satellite-led GPS and inertial navigation systems, leading it to show incorrect information about its pitch, roll and location.
As a result, the Syracuse-based crew started an emergency backup mission to return the aircraft to Fort Drum. As the aircraft flew back to the post, it lost connection to its remote pilots multiple times.
At 12:58 p.m., as crews from the post attempted to gain control of the aircraft, the Reaper's third navigational unit failed, and the aircraft's backup control module did not switch to another, functioning system.
Seconds later, a preprogrammed right turn inverted the aircraft and sent it into a spin. Two and a half minutes later, at 1:01 p.m., the Reaper hit the lake, being destroyed on impact.
A majority of the aircraft's pieces were lost, the report said, with some washing ashore, such as a vertical tailpiece and part of its landing gear. The Air Force estimated the value of the aircraft at $10.6 million.
The guidance system faced multiple issues in the weeks leading up to the crash. The report said that there were two "separate but similar discrepancies" with the guidance system on the aircraft on Oct. 28 and Nov. 6, with the former incident leading the unit to stop communicating with its satellite.
On both occasions, the report said, the failing guidance units were removed and replaced by maintenance personnel.
Human error was determined not to have played a role in the crash.
The crash was the first for the unit with the aircraft since it began using Fort Drum's airfield in October 2011. The unit grounded its remaining drones for several weeks after the crash, but they resumed flying at the end of November.
A recent Washington Post report indicated some safety concerns about drones, counting 418 crashes for unmanned aircraft from September 2001 to the end of 2013.
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