> our title:

Coolant, Software Caused Predator Crash

> original title:

MQ-1B Predator Accident Report Released

(Source: US Air Force; issued July 10, 2014)

LANGLEY AFB, Va. -- An MQ-1B Predator coolant-system malfunction, and an error by the aircraft's digital control system, led to a forced landing of the aircraft in the Mediterranean Sea Jan. 17, 2014, according to an Air Combat Command abbreviated accident investigation board report released today.

The aircraft and its aircrew were assigned to the 18th Reconnaissance Squadron at Creech AFB, Nev. When the accident occurred, the aircraft was conducting a routine intelligence, surveillance and reconnaissance mission, which included three separate ground crews. The aircraft and associated special mission equipment were destroyed on impact. The loss is valued at approximately $4.6 million. There were no injuries or damage to private property.

The board president found, by clear and convincing evidence, that the cause of the mishap was a loss of coolant due to an undetermined failure in the coolant system. Additionally, the board president determined that a substantially contributing factor was the aircraft's digital control system incorrectly enriching the fuel-to-air mixture, negating the crew's attempts to reduce fuel flow and improve engine performance.

After running the applicable emergency checklists multiple times and consulting with the on-duty instructor pilot in the ground control station, the ground crew realized the aircraft could not make it to the divert airfield within the existing altitude and distant constraints, and guided the aircraft into a forced landing in the water.