Incident Overview
On 22 May 2023, a Cessna C-172RG, registration SP-WLF, operated by OKL PANS in Chełm, was conducting training flights at Depułtycze Królewskie airfield (EPCD). The crew consisted of an instructor and a student pilot. During the first traffic pattern, after the third turn, the student moved the landing gear lever to the down position. The instructor visually confirmed the right main gear was extended, but the student noted the left main gear was not down. A "Gear Fault" message appeared on the primary flight display. The crew attempted both normal and emergency gear extension procedures multiple times. They performed a low pass over the runway, and the flight director confirmed the left main gear was hanging in an incorrect position. After further attempts to manually lock the left main gear, the crew decided to land without the landing gear on the grass runway. Following a trial approach to runway 36L, they executed a full circuit and landed safely at 13:38 UTC. The crew evacuated the aircraft without injury.
Cause
The investigation determined the cause of the incident was a fracture of the mounting fitting of the hydraulic actuator for the extension and retraction system of the left main landing gear.
Contributing Factors
Two factors were identified as contributing to the incident:
- Accelerated operational wear of the actuator due to the aircraft's use in flight training, resulting in a higher number of landing gear extension/retraction cycles compared to normal operations.
- Maintenance oversights, including infrequent inspections of the landing gear actuators for cracks relative to the aircraft's training usage, and the application of a crack detection method different from that specified in the aircraft maintenance program.
Safety Actions
The training organization implemented a preventive measure: before conducting flights on the Cessna 172RG, it obtains from the aircraft owner information about recent actuator inspections and any occurrence of hard landings on that aircraft, and then decides whether to proceed with flights.