What happened
On 23 February 2020, a Ryan PT-22 aircraft, registration N53018, was conducting a private cross-country flight from Clermont-Ferrand Auvergne airport to Brioude Beaumont aerodrome. The aircraft was occupied by a pilot in the rear seat and one passenger in the front seat.
Shortly after departing, the pilot flew at a low altitude over the Issoire Le Broc aerodrome. While the aircraft was in level flight, the engine suffered a sudden shutdown. This loss of power led to a loss of control, and the aircraft descended in a steep, nose-down attitude, ultimately colliding with the ground in a field near Beaulieu. The impact resulted in two fatalities and the destruction of the aircraft.
The investigation
The investigation examined the wreckage, the engine components, and security camera footage from a nearby location. Analysis of the video recording confirmed that the aircraft was in level flight before black marks—indicative of smoke or oil spray—appeared behind the plane. Shortly thereafter, the aircraft began a descent that transitioned into a steep nose-down attitude prior to impact.
Investigators examined the engine, a Kinner R-56, and found that the oil tank was empty. The investigation focused on the seal between the engine's accessory section and the engine casing. This seal, which had been in place since at least 1977, showed signs of failure. Additionally, the engine's highest cylinder showed significant piston erosion and a blocked control rod, which were attributed to a lack of lubrication.
Findings
- A failure of the seal between the accessory section and the engine casing caused a gradual oil leak.
- This leak was not detectable by the pilot during the flight but resulted in the emission of smoke and the eventual depletion of engine oil.
- The lack of engine lubrication caused the engine to seize and shut down.
- The engine shutdown occurred at a low altitude, leaving the pilot with insufficient time or altitude to manage the descent and regain control before the aircraft struck the ground.