What happened
On September 16, 2017, at approximately 14:47 LMT, a Moravan/Zlin Z-142, registration SP-ASM, departed from the Sobienie-Jeziory airport (EPSJ) for a flight carrying a pilot and one passenger. Shortly after takeoff, during the initial climb phase, the engine began to malfunction, accompanied by the emission of black smoke.
At an altitude of approximately 50 to 100 meters AGL, the pilot initiated a left turn to avoid trees located in the flight path. During this maneuver, the aircraft rapidly lost altitude. The aircraft entered a stall at low altitude and struck the ground in a nearly flat attitude in an agricultural field approximately 800 meters from the eastern threshold of the runway. The impact caused the landing gear to detach and significant damage to the forward fuselage. Both the pilot and the passenger sustained serious injuries and were evacuated by emergency services.
The investigation
The PKBWL investigation focused on the technical condition of the engine and the pilot's emergency procedures. Investigators examined the engine components and found evidence of internal corrosion. The investigation also reviewed the aircraft's maintenance logs, noting that the aircraft had been used very sporadically, with only about 17 hours of flight time recorded between 2008 and 2017. Furthermore, the investigation analyzed the available flight manual, which lacked detailed emergency procedures for engine failures specifically during the takeoff phase.
Findings
- The primary cause of the accident was the failure to follow engine maintenance requirements specified in the manufacturer's documentation and the aircraft's individual maintenance program.
- The engine failure was caused by the failure and subsequent destruction of the compressor wheel bearing due to inadequate lubrication and progressive corrosion.
- The aircraft entered a stall during the final phase of the emergency landing.
- Contributing factors included the sporadic use of the aircraft with long periods of inactivity, inconsistencies between available maintenance documentation, and terrain features (uneven ground and ditches) that were unfavorable for an emergency landing.