Event Summary
On June 19, 2000, at 16:56 UTC, a Piper PA-34-200, registration I-MIMU, operated by PANAIR C.A.M. srl, was on a training flight from Catania Fontanarossa to Palermo Punta Raisi. During approach, after extending the landing gear, all three green landing gear indicator lights illuminated, but the red transit light remained on. To verify the gear extension, the crew performed two low passes over the control tower. The tower controller visually confirmed that the gear appeared to be fully extended. The aircraft then landed on runway 02 with full flaps. During the landing roll, the nose wheel retracted, causing the aircraft's nose to contact the runway and slide for approximately 100 meters before coming to a stop. The pilots were uninjured. The aircraft sustained damage to the propeller blades, lower engine cowling, nose gear well, and forward doors.
Investigation Findings
The investigation was initially opened by the Italian Ministry of Transport and Navigation and later transferred to the National Agency for Flight Safety (ANSV). Technical examination of the nose landing gear revealed that the nose wheel, fork, shock absorber, and trunnion assembly were in good condition overall. However, the stop limits cast into the shock strut showed significant deformation on both sides, consistent with forced ground maneuvers that subjected the nose wheel to extreme angular travel. The support truss was undamaged, and both the emergency release system and hydraulic system functioned properly. The lower support of the steering flange exhibited a clear fracture. Due to tension from the steering cables, the fractured flange had shifted from its horizontal position to an upward orientation. This displacement caused the movable rail attached to the steering flange to separate from the fixed rail. It is presumed that the spherical pin of the landing gear, during retraction, exited the rails through the resulting gap and became lodged in a nearby reinforcement gusset, locking the gear at approximately 60 degrees of extension. This condition prevented the gear from fully locking in the down position.
Probable Cause
The ANSV determined the probable cause to be prior over-steering of the nose wheel at the departure airport, which led to structural damage that prevented the gear from locking during landing.