What happened
On August 15, 2014, an Ayres Thrush agricultural aircraft, registration TG-BIF, was performing aerial spraying operations in the area of Finca El Caobanal, located in the municipality of Guanagazapa, Escuintla, Guatemala. While the aircraft was in straight and level flight, the pilot reported hearing a loud, unusual noise coming from the engine. This was immediately followed by a sudden and complete loss of engine power.
The engine failure caused the aircraft to descend rapidly. Due to the low altitude and the low airspeed at the time of the failure, the pilot was able to exit the aircraft without physical injuries. The aircraft's tubular structural design provided a survivable space during the impact, and the pilot was assisted by ground personnel following the crash.
The investigation
The DGAC/UIA investigation focused on the mechanical condition of the engine and the accuracy of its maintenance records. Investigators examined the engine, which had been installed on July 1, 2014, with a total time of 6,960.6 hours since its last repair.
Upon inspection of the engine, investigators found evidence of high-velocity internal impacts and fractures within the turbine compressor wheels and the power section, which were attributed to material fatigue. Furthermore, the investigation scrutinized the maintenance logs. While the engine had undergone a repair and test run documented via FAA Form 8130-3, the investigators found that the engine's total time exceeded the required time between overhaul (TBO) of 4,000 hours, and there was no documented evidence of a major overhaul having been performed to reset this interval.