What happened
On the morning of 27 September 2007, a Mainair Blade 912 microlight, registration G-CCFM, attempted to depart from a grass airstrip near Aghadoe, County Kerry. The pilot, accompanied by his son, was preparing for a private flight to Tullamore. As the aircraft accelerated along the runway, the pilot experienced a perceived loss of engine power.
In an attempt to manage the situation, the pilot immediately aborted the takeoff. However, the aircraft was unable to maintain sufficient speed to clear the end of the runway, subsequently running into a ditch. The impact with an embedded concrete pillar caused extensive damage to the airframe, including a twisted wing keel and a broken seat frame. While both occupants exited the wreckage unaided, the pilot sustained a broken wrist that ultimately led to his death several days later. The passenger escaped without injury.
The investigation
The AAIU investigation examined the aircraft's performance, the environmental conditions, and the mechanical state of the engine. Investigators noted that the Rotax 912-UL engine used in the aircraft is not aviation-certified and is subject to sudden stoppage. While the pilot reported a loss of power, the investigation established that the aircraft had indeed become airborne, suggesting that power was available at rotational speed.
Investigators also reviewed meteorological data and witness accounts. Observations from the local area indicated that recent frosts had been present. The investigation focused on how the aerodynamic properties of the wing might have been compromised by surface contamination.
Findings
- The pilot aborted the takeoff because the aircraft failed to reach the necessary climbing speed.
- Overnight frost on the wing surface likely disrupted the laminar airflow, significantly reducing lift and increasing drag.
- The resulting loss of aerodynamic performance was perceived by the pilot as a loss of engine power.