What happened
On 23 August 2017, a Piper PA-32R-301T, registration N414AG, was conducting a private flight from Retford (Gamston) Airport to Bagby (Thirsk) Airfield. While flying approximately 1,900 ft agl near York, the pilot encountered heavy rain and Instrument Meteorological Conditions. During this period of intense precipitation, the engine suddenly stopped and the propeller began to windmill.
The pilot attempted several troubleshooting steps, including switching fuel tanks, activating the electric fuel pump, and adjusting the mixture, but the engine failed to restart. After establishing a glide, the pilot selected a landing site in a field approximately 5 miles south of Linton-on-Ouse Airfield. During the descent, the pilot declared an emergency with RAF Linton-on an Ouse.
Upon approaching the field, the pilot configured the aircraft for landing. Although the initial touchdown on the wet grass was relatively gentle, the aircraft struck a line of trees and bushes. The impact caused the right wing and landing gear to detach, and the left wing sustained damage. The aircraft skidded across the field and came to a halt near a pond. The pilot, who sustained no injuries, was able to exit the aircraft without difficulty.
The investigation
Technical inspections of the engine following the accident revealed that the paper air filter element was swollen and puffy, a condition indicating it had been heavily saturated with water. When the filter became wet, it impeded the necessary airflow to the engine. Engineers noted that replacing the filter allowed the engine to run normally. The investigation also considered the use of the alternate air source, which bypasses the primary filter.
Findings
- The engine failure was caused by the saturation of the paper air filter element with water during heavy rain, which restricted airflow to the engine.
- The pilot did not select the alternate air source before the primary air intake became blocked by the wet filter.
- The aircraft was equipped with a turbo-charged engine that lacked carburettor heat control, a feature that might have otherwise allowed for bypassing the filter via air intake adjustment.