Release Number: 031913
3/21/2013 - LANGLEY AIR FORCE BASE, Va. -- An
MQ-1B Predator propellor malfunction led to the crash of the aircraft
in a non-residential area in Afghanistan Oct. 26, 2012, according to an
Air Combat Command abbreviated accident investigation board report
released March 13.
The mishap crew and mishap remotely piloted aircraft were assigned to
the 432d Wing at Creech Air Force Base, Nevada. When the accident
occurred, the crew was flying a surveillance mission out of Jalalabad
Air Base, Afghanistan.
According to the report, the crew received a high temperature caution
message, indicating a problem with the variable pitch propeller, roughly
10 hours into the mission. Eventually, the propellor failed in a manner
that only allowed movement to a lower propeller-pitch angle. While
attempting to resolve the problem, the mishap pilot momentarily
commanded the propeller pitch to an angle that produced reverse thrust,
and the system would not accept commands to return the propeller to a
higher pitch angle. The resulting loss of forward thrust prevented the
aircraft from returning to base. The pilot was then directed to crash
the aircraft because it would not be able to reach a suitable landing
The accident investigation board president found by clear and convincing
evidence, the cause of the mishap was a combination of mechanical
failure of the propeller motor and unneccessary movements of the
propeller pitch control lever by the mishap pilot. Additionally, the
board president found by a preponderance of evidence that incorrect and
insufficient checklist guidance, reinforced by incorrect simulator
training, substantially contributed to the mishap.
The aircraft and one air-to-ground AGM-114 Hellfire missile were
destroyed on impact. The loss is valued at approximately $4.6 million.
There were no injuries or damage to government or private property.