What happened
On April 4, 2015, at approximately 13:00 UTC, a Piper PA-34-200, registration PR-FLM, was conducting a local flight instruction session at Florianópolis Airport (SBFL) in Brazil. The aircraft was occupied by an instructor, a student pilot, and a passenger.
The flight proceeded normally through the first two touch-and-go maneuvers. However, during the third approach, while the student pilot had confirmed the nose gear was down and locked, the nose gear unexpectedly retracted upon touchdown. The instructor reported feeling a strong vibration through the nose gear at the moment of contact, followed by a sudden nose-down movement. The aircraft's nose and propellers struck the runway, causing the plane to slide approximately 250 meters before coming to a halt. All three occupants escaped without injury, though the aircraft sustained substantial damage to the engines, propellers, fuselage, and nose gear.
The investigation
CENIPA investigators examined the nose gear actuator mount bracket and found that a failure had occurred in one of the mounting holes. The investigation revealed that the hole was ovalized and its dimensions were irregular, failing to meet the specifications outlined in Piper Aircraft Service Bulletin (SB) No. 1123C. This discrepancy prevented the nose gear from properly locking in the extended position.
Technical analysis of the component by the Department of Aerospace Science and Technology (DCTA) determined that the fracture was a typical result of an overload failure. No evidence of corrosion or material fatigue was found. Additionally, the investigation noted that the aircraft had experienced a nose gear tire blowout during a training flight just two days prior. The investigation also identified that the presence of the passenger on this instructional flight violated the flight school's internal regulations.
Findings
- The nose gear actuator mount bracket failed due to an overload.
- The mounting hole in the bracket was ovalized and out of tolerance with the manufacturer's Service Bulletin.
- Maintenance failures contributed to the condition of the component.
- The aircraft had a recent history of nose gear-related issues (a tire blowout two days prior).
- The student pilot was performing his first flight in an aircraft with retractable landing gear.