> our title:

Malfunction, Operator Error Caused Predator Crash

> original title:

MQ-1B Predator Accident Report Released

(Source: US Air Force Air Combat Command; issued Nov. 13, 2013)

LANGLEY AIR FORCE BASE, Va. --- An MQ-1 B Predator propeller-system malfunction, and the ground aircrews' misinterpretation of instrument readings, led to the crash of the aircraft approximately 11 nautical miles west of Creech Air Force Base, Nev., May 13, 2013, according to an Air Combat Command Abbreviated Accident Investigation Board report released today.

The aircraft and its aircrew were assigned to the 11th Reconnaissance Squadron at Creech AFB, Nev. When the accident occurred, the aircraft was participating in an eight-hour training mission, which included four separate ground crews.

The Abbreviated Accident Investigation Board President found by clear and convincing evidence that the cause of the mishap was a variable-pitch-propeller system failure. A cable that provides electrical current to the system's servomotor was found to have produced _inconsistent electrical current. This lack of electrical power eventually put the aircraft into a thrust deficient situation from which it could not recover.

Additionally, the board president found evidence that misinterpreted instrument readings by the aircrew substantially contributed to the mishap. While the aircrews were checking the propeller pitch angle hourly during their required operations checks, they focused on the fact that the propeller pitch angle was within a normal range, rather than recognizing that the number was stagnant over a period of time. The aircrews' misinterpreted instrument readings caused them to incorrectly assume that the propeller pitch was functioning properly.

The aircraft and one M-36 training missile were destroyed on impact, with a loss valued at approximately $4.5 million. There were no injuries or damage to private property.