What happened
On June 23, 2007, a Piper PA-34-200T Seneca II, registration D-GANN, was conducting a VFR training flight near the Avigliana lakes. The flight, operated by Turin Flying Institute, included an instructor and two student pilots. After performing various maneuvers, including stalls and turns, the crew proceeded to land at Torino Aeritalia.
The instructor reported that the approach was normal, with the landing gear correctly configured and the green extension lights illuminated. The aircraft touched down on its main gear in a nose-high attitude. However, as the pilot lowered the nose to transition for the landing roll, the nose gear failed to support the weight of the aircraft. This caused the nose and propellers to strike the runway surface. Following a short excursion, the aircraft came to a stop on the grass beside the runway. All three occupants were unharmed and evacuated the aircraft safely.
The investigation
The ANSV investigation focused on why the nose gear failed to lock despite the cockpit indicators showing the gear as extended and locked. Technical examination revealed that the support bracket for the nose gear actuator had failed. The investigation determined that the actuator had extended beyond its intended limit, causing a deformation of the bracket. This deformation moved the drag link pivot out of the over-center position, preventing the nose gear leg from locking. Notably, the green indicator light remained functional because it was linked to a switch on the bracket that was not affected by the mechanical failure of the locking mechanism itself.
Findings
- The primary cause of the gear failure was the structural failure of the nose gear actuator support bracket.
- The investigation identified two potential contributing factors that could have caused the actuator to over-extend and damage the bracket: a hydraulic pump malfunction or the extension of the landing gear at speeds exceeding the permitted limits.