What happened
On June 29, 2015, a Piper PA-23, registration HK912, was conducting an aerial photography mission over the Sogamoso River region in Colombia. The flight, operated by Aviones Publicitarios de Colombia S.A.S., was monitoring electrical power lines. After completing the mission, the crew requested landing clearance from the Yariguies (SKEJ) tower.
During the final approach to runway 22, the aircraft struck the top of a tree. The impact caused the aircraft to slide across the terrain, eventually striking the airport's perimeter fence. The aircraft sustained severe structural damage, including the loss of both wings and significant deformation of the fuselage and landing gear. Despite the impact, the pilot, co-pilot, and technical operator were all uninjured and were able to evacuate the aircraft on their own. No post-impact fire occurred.
The investigation
The GRIAA investigation focused on the mechanical state of the engines and propellers, as well as the maintenance history of the aircraft. While the engines themselves were found to be in normal operating condition, investigators identified a critical failure in the right engine's propeller governor.
Technical inspections revealed that during a previous overhaul of the propeller governors, a component known as the rack had been installed backward. Because the components passed subsequent functional tests, this error remained a latent defect until the failure occurred during the approach. The investigation also examined the oversight provided by the subcontracted maintenance workshop (TAR) and the operator's safety management implementation.