What happened
On 19 December 2007, a private flight involving a Lambada UFM-11, registration EI-DGP, experienced a runway excursion at Abbeyshrule Airfield, Co. Longford. During the landing roll on runway 10, the pilot noticed the aircraft veering toward the right side of the tarmac. In an attempt to correct this, the pilot applied significant left rudder. This input caused the aircraft to swing sharply to the left, leading it to depart the paved surface and travel onto adjacent rough ground, eventually coming to a stop approximately 6 metres from the runway edge.
The weather at the time of the incident was sunny with calm wind conditions. Following the excursion, the pilot successfully shut down the fuel and ignition systems and exited the aircraft without injury. There were no injuries to the pilot during the event.
The investigation
The investigation focused on the mechanical impact of the excursion and the pilot's control inputs. Upon exiting the runway, the aircraft's nose gear assembly sustained damage when the wheel impacted the rough terrain. Specifically, the steering fork of the nose wheel bent rearwards. This deformation caused the wheel spats to rub against the grass as the aircraft moved to a halt. Additionally, the wooden propeller blades sustained severe damage after making contact with the ground.
Investigators examined the construction of the nose wheel fork, noting that the design includes a specific weak point intended to fracture during an overload to protect the aircraft's composite skin. In this instance, however, the tube did not fracture but instead bent under the abnormal loads encountered during the excursion.
Findings
- The pilot was operating under a valid Student Pilot Licence.
- The aircraft departed the runway due to a loss of directional control during the landing phase.
- Over-correction with the rudder in response to an initial rightward deviation caused the aircraft to swing left and leave the paved surface.
- The damage to the Lambada UFM-11 was caused by the nose steering fork being subjected to abnormal loads during the excursion.