What happened
On September 26, 2014, a Piper PA-34 Seneca, registration SP-GKA, was performing its second landing of a series on runway 30 at the Dęblin airport (EPDE). Immediately after the nose gear made contact with the concrete runway, the landing gear spontaneously retracted into the fuselage. The crew reported that all landing gear indicators were functioning correctly prior to landing, showing that the gear was properly extended and locked with three green lights.
The sudden retraction caused the nose of the aircraft to strike the runway, resulting in damage to the forward fuselage, the nose gear bay cover, and both propellers. The impact caused the engines to stop abruptly. After the nose of the aircraft was lifted, the nose gear extended and locked into position. Following approval from the authorities, the aircraft was moved to a hangar.
The investigation
An investigation was conducted by the operator. During subsequent repair work performed by Aero-Modlin sp. z o.o., it was discovered that the landing gear mounting node on the forward fuselage bulkhead had lost its rigidity and exhibited signs of fatigue damage. The forward bulkhead itself also showed similar fatigue characteristics. Repairing this damage required a special repair procedure; however, the Type Certificate holder had not responded to inquiries regarding the repair at the time of the report, though there were suggestions regarding the permanent withdrawal of the aircraft from service.
The investigation noted that SP-GKA was a 1974 model and was the first aircraft of its type operated in Poland. Over its 40-year service history, the aircraft had experienced several similar incidents involving spontaneous nose gear retraction, the first occurring in the summer of 1976. This pattern was likely linked to the aircraft's extensive use on grass and unpaved airfields, particularly during its early years of operation in Poland.
Findings
- The primary cause of the incident was structural fatigue resulting from operational wear and tear.
- The landing gear mounting assembly and the forward bulkhead had suffered from fatigue-related degradation.