What happened
On October 20, 2003, at approximately 16:45 local time, a Cessna 172-RG, registration EC-HHX, departed from Badajoz Airport for a scheduled one-hour instructional flight. The aircraft was operated for flight training purposes with an instructor and a student pilot on board.
Following the completion of the training maneuvers, the crew returned to the airport for landing. During the landing approach, the pilot experienced intense vibrations originating from the nose gear. In an attempt to mitigate the forces on the nose wheel, the pilot applied elevator input to maintain a nose-up attitude. While this initially suppressed the vibrations, the reduction in airspeed caused a proportional increase in the load applied to the nose gear.
As the aircraft slowed, the vibrations returned and could no longer be controlled through aerodynamic means. Shortly thereafter, the nose gear fork failed, causing the nose wheel to detach from the assembly. The aircraft subsequently rested on the nose gear components and slid along the runway for several meters before coming to a halt. The impact of the nose gear failure caused the propeller to strike the pavement, resulting in damage to both the propeller and the nose gear assembly. Both occupants were uninjured and evacuated the aircraft independently.
The investigation
The investigation focused on the structural integrity of the nose gear fork, which featured a double-lug configuration designed to hold the wheel axle. Physical examination of the fork revealed that both lugs had fractured. The fracture surfaces showed significant machining/abrasion marks caused by the friction generated while the aircraft slid on the runway, which prevented a detailed metallurgical analysis of the initial failure point.
Investigators noted that the wheel, axle, and associated retaining hardware remained undamaged, confirming that the wheel only detached because the fork itself had failed. The pilot's report of heavy vibrations prior to the detachment was a key factor in reconstructing the sequence of events.