What happened
On July 28, 2016, at approximately 17:00 UTC, a Beechcraft A-36 Bonanza, registration SP-KTZ, was performing local flight operations at a private airfield in Niemstów, Poland. Following the second flight of the day, the pilot attempted to land the aircraft. While the cockpit indicators suggested that the nose gear was properly extended and locked, the gear failed to remain secured after the aircraft's tail was raised. Although the nose gear initially emerged from the bay, it failed to lock into position, leading to a collapse. The aircraft was subsequently moved to a hangar for assessment.
The impact caused extensive damage to the aircraft, including the destruction of the propeller blades, the nose gear bay doors, and the lower engine cowling. Additionally, the engine required a specialized inspection due to the violent stoppage caused by the propeller strike.
The investigation
An investigation was conducted by the aircraft owner, with a technical inspection performed by the company Helitec from Oppin, Germany. The technical examination focused on the structural integrity of the landing gear assembly. The inspection revealed significant excessive play between the bushings and the landing gear suspension pins on the fuselage, as well as within the nose gear scissor bushings.
Findings
- The primary cause of the incident was operational wear within the landing gear components.
- The wear was accelerated by the aircraft's frequent use of unpaved airfields, which subjected the landing gear kinematics to increased mechanical loads during taxiing.
- This increased stress led to the accelerated degradation of the pins and bushings in the nose gear linkage.