What happened
On April 20, 2018, at approximately 7:00 a.m., a Piper PA-25-235 performing agricultural spraying operations crashed in the community of Ranchito, La Vega, Dominican Republic. The aircraft, registration HI-632, had departed from a spraying strip in Sabana Rey to apply agricultural inputs to a rice plantation.
During the flight, the pilot noticed the smell of burning wires. Shortly thereafter, the engine began to fail and eventually shut down completely. The pilot performed an emergency landing in a rice field. The pilot, the sole occupant, sustained minor injuries, and was able to evacuate the aircraft on his own. The aircraft sustained significant damage, including the loss of the left landing gear and deformation of the left wing.
The investigation
The CIAA investigation focused on the mechanical failure of the engine and the maintenance history of the aircraft. Investigators examined the engine compartment and discovered evidence of a short circuit in the battery area. Specifically, the insulation on the cables for both magnetos had overheated and melted, causing the wires to make contact and interrupt the electrical continuity required for engine operation.
Technical inspections also reviewed the maintenance records of the operator, AEROSER-S.R.L. The investigation established that the electrical failure was a result of a lack of adequate observation by the company's maintenance personnel during routine inspections.