What happened
On September 30, 2004, a Piper PA-23-250, registration EC-CAC, was performing a scheduled aerial photography flight departing from Cuatro Vientos Airport in Madrid. The aircraft was operated by Servicios Politécnicos Aéreos, S. A., and was carrying a crew of two: the pilot and a photographer.
During the takeoff roll on runway 28, approximately 200 meters into the run, the pilot felt the aircraft pass over a slight bump and heard a metallic sound. This was immediately followed by vibrations and a sudden nose-down pitch, causing the propellers to strike the runway surface. The pilot attempted to abort the takeoff by reducing engine power and applying aerodynamic controls to raise the nose, while simultaneously cutting the fuel, magnetos, and master switch. Despite these efforts, the nose of the aircraft continued to scrape along the asphalt.
To prevent a potential fire caused by friction, the pilot steered the aircraft toward the unpaved shoulder using light braking. The aircraft eventually came to a stop 1,430 meters from the runway threshold, with the right wheel resting on the runway edge marker. Fuel had leaked from the wing vents, prompting emergency services to apply foam to prevent ignition. The two occupants evacuated the aircraft safely.
The investigation
The investigation focused on the mechanical failure of the nose gear and the subsequent sequence of events. Investigators examined the wreckage and the runway surface, noting that the nose gear tire had burst, leaving debris on the runway. The inspection of the nose gear revealed that the drag arm had partially broken, and the remaining arm was bent. The propellers sustained significant damage, with one blade losing its tip and the other being bent by contact with the pavement.
Upon inspecting the tire, investigators identified a specific pattern of damage. While most marks on the tire moved from the outer edges toward the center, a distinct cut was found originating from the center and extending toward the edges. This specific morphology suggested a different origin for this particular damage. Furthermore, a search of the runway was conducted, but no foreign object debris (FOD) was found that could have caused the puncture during the takeoff roll.
Findings
- The primary cause of the accident was the burst of the nose gear tire.
- The tire failure led to the nose gear dragging on the runway, which caused the structural damage to the landing gear and the subsequent impact of the propellers with the ground.
- The specific damage pattern on the tire suggests the failure may have been caused by a pre-existing cut or defect.
- Since the pre-flight inspection revealed no abnormalities, the damage to the tire likely occurred during taxiing to the runway.