What happened
On November 29, 2000, a Siai Marchetti S.205-20/R, registration I-IBAG, departed from Rome Urbe airport for a local flight with two passengers on board. After completing several touch-and-go maneuvers, the pilot attempted a final landing. During the landing roll, the pilot applied the brakes, which caused the nose gear to fail to remain in the fully extended position. This resulted in the aircraft pitching forward, causing the propeller and the lower engine cowling to strike the runway. The aircraft came to a stop on the runway, and all three occupants exited the aircraft without assistance; no injuries were reported.
The investigation
The ANSV investigation focused on the mechanical state of the landing gear and the flight dynamics during the landing phase. Physical examination of the aircraft revealed damage to the propeller, engine cowling, exhaust pipes, and a VHF antenna, as well as permanent deformation of the nose gear extension/retraction mechanism rod.
Technical testing revealed that the nose gear was not reaching its locked down position. Investigators discovered that the preload spring adjustment was out of limits (62 mm instead of the specified 5able 56±1 mm). Furthermore, a maintenance error was identified: an unauthorized washer had been placed between the bolt head and the control rod, which restricted the necessary movement of the sleeve. This created a hidden unsafe condition that prevented the gear from properly locking.
Findings
- The primary cause was a non-compliant adjustment of the nose gear mechanism, which prevented the gear from locking in the down position.
- A contributing factor was an abnormal load placed on the nose gear, likely caused by a heavy landing or a late flare, which forced the gear out of its unlocked state.
- The pilot, while highly experienced in general aviation, had not flown this specific aircraft type within the 90 days preceding the accident.
- The presence of an unapproved washer in the gear mechanism acted as a latent mechanical defect.