Incident
On 19 June 2000 at 16:56 UTC, a Piper PA-34-200, registration I-MIMU, operated by PANAIR C.A.M. srl on a training flight, was landing at Palermo Punta Raisi airport. During the approach, after the landing checks and gear extension, the three green landing gear indicator lights illuminated, but the red transit light remained on. To confirm gear extension, two flypasts over the tower were made, and the controller reported that the gear appeared extended. During the landing roll on runway 02 with full flaps, the nose gear retracted, causing the nose of the aircraft to skid for about 100 meters before coming to a stop.
Injuries and Damage
The instructor and student pilot sustained no injuries. The aircraft sustained damage to the propeller blades, lower engine cowling, nose wheel well, and forward doors.
Investigation Findings
Technical examination of the nose gear assembly revealed that the wheel-fork-shock absorber-trunnion assembly was in good condition. However, the stop lugs on the strut were found to be heavily forced to the right and left, indicative of previous forced ground maneuvers with the nose wheel at the limits of its angular travel. The support truss showed no damage. The emergency release system and hydraulic system functioned normally. The lower support of the steering flange was fractured; due to tension from the steering cables connected to the flange, the flange was no longer horizontal but tilted upward. This displacement caused the mobile rail connected to the flange to separate from the fixed rail. Through the resulting gap, the spherical pin of the gear likely came out of the rails during retraction and became jammed in a nearby reinforcement gusset, blocking the gear in an extended position at about 60°.
Probable Cause
The probable cause of the event was attributed to pre-existing over-steering of the nose wheel at the departing airport.