What happened
On October 29, 2023, a Pilatus Porter PC-6/B2-H4, registration OB-1600, operated by Aero Andino Survey S.A.C., departed Pucallpa for a cargo flight to Breu. The flight crew consisted of the pilot in command and a co-pilot undergoing instruction.
During the flight, the pilot requested a lower cruising altitude of 5,500 feet due to heavy cloud cover. While maneuvering to avoid Brazilian airspace near the Sawawo community, the aircraft encountered a weather front characterized by significant turbulence, forcing a further descent. Approximately five minutes before reaching the destination, the crew experienced a loss of engine power. Despite attempts to adjust the throttle, there was no response. The pilot disconnected the fuel controls and feathered the propeller in preparation for an autorotation and impact.
The aircraft crashed approximately 2.29 nautical miles from the Breu aerodrome. The co-pilot lost consciousness during the impact and regained it later that night to activate the ELT. The pilot in command was found unconscious among the wreckage and later pronounced deceased. The co-pilot was rescued the following day and transported to a clinic in P/ucallpa.
The investigation
The CIAA investigation focused on the engine failure hypothesis. Technical assistance was provided by the manufacturer, Pilatus Aircraft LTD, and Pratt & Whitney Canada. Investigators coordinated the transport of the engine to Pucallpa for examination. The engine, a PT6A-27, was disassembled, and photographic evidence of the affected areas was collected. Specifically, investigators examined the power turbine (PT) blades, which were sent to laboratories in Canada for analysis. The investigation also included a review of the maintenance history for both the aircraft and the engine.