What happened
On June 22, 2023, a pilot operating a Tecnam P2008-JC, registration SP-MGT, departed from Szymanów (EPWS) for a planned navigation flight. During the return to the airfield, the pilot executed a standard approach and landed on runway 14L. While the landing itself was performed correctly, the aircraft's nose gear strut failed upon touchdown, causing the nose wheel to detach and the strut to break. The impact resulted in damage to the nose gear strut, the propeller, and the lower engine cowlings. The pilot was able to exit the aircraft without any injuries.
The investigation
Investigators examined the fractured components of the nose gear strut, which is a closed-section steel structure designed to be airtight to prevent internal corrosion. The inspection revealed significant corrosion on the internal surfaces and parts of the fracture surface. Because the internal environment should only contain trace amounts of oxygen from the welding process, the presence of extensive corrosion indicated that a micro-crack had formed much earlier, allowing air and moisture to enter the strut.
Further analysis of the structural damage showed that the forks of the nose wheel were severely deformed, the forks had been bent away from the console at the bolted connection, and the nose wheel axle was excessively bent. These physical deformations, combined with the nature of the fractures, indicated that the component had been subjected to high loads during previous landings on the grass runway.
Findings
- The primary cause of the incident was a progressive crack in the nose gear strut that expanded under repeated loading following an initial, undetectable fracture.
- The structural integrity of the strut had been compromised by internal corrosion, which was made possible by a pre-existing leak in the closed section.
- The frequent use of grass runways at the airfield contributed to the high-load environment.
- The high proportion of flight training operations (approximately 90% of local operations) increased the frequency of high-stress landing cycles.
Safety action
Following the investigation, it was proposed that training sessions be conducted for pilots and maintenance personnel. These sessions focus on improving pre-flight inspection methodologies, specifically regarding the detection of cracks in the nose gear strut, with particular attention to welded joints.