An accident investigation board found that a remotely piloted MQ-1B Predator that was intentionally crashed into an uninhabited area of the U.S. Central Command area of responsibility on May 27, 2015, suffered an engine failure due to loss of coolant.
At the time of the accident, the aircraft was flying a classified combat support mission in the U.S. CENTCOM AOR.
The board president identified interference as a main factor that contributed to the mishap. According to the investigation report, the crew learned the engine was overheating and began running the associated checklist for addressing the problem. Simultaneously, the pilot in coordination with the mission commander, decided to return the aircraft to base so the checklist was not completed. This interference forestalled the sensor operator from manually turning on the cooling fan as per the checklist instructions.
The pilot also did not verify that the fan was on, so it remained in the automatic position the entire flight, never turning on sufficiently, according to the investigation. By the time the engine stopped working, the aircraft was unrecoverable, so the pilot was told to fly it into the ground, according to the report. The wreckage was not recovered
The aircraft and crew were assigned to the 20th Reconnaissance Squadron, an associate unit at Whiteman Air Force Base, Mo., under the 432nd Wing at Creech AFB, Nev. The total loss to the U.S. Government is estimated at $2.8 million. There were no additional injuries or damages to other government or private property.
The full report can be seen here.
Source: US Air Force