What happened
On 27 December 2012, a COMCO-ICARUS C42 FB microlight, registration EI-ETU, was attempting a local flight from Carrickbrack Airfield in Letterkenny, Co. Donegal. During the takeoff roll, the aircraft traversed an area of wet and soft grassland. Although the pilot noted the initial roll seemed normal, the aircraft encountered patches of longer, soft ground that impeded its progress.
As the aircraft continued its takeoff run, the pilot realized the takeoff was taking longer than anticipated. Despite recognizing that the aircraft was approaching a boundary hedgerow, the pilot did not abort the maneuver. The aircraft eventually became airborne only 63 meters from the boundary. In an attempt to clear the trees at the airfield edge, the pilot maneuvered between two trees, but the starboard wing-tip struck a holly tree. The aircraft then impacted a nearby field from a height of approximately 15 feet. Both the pilot and the passenger escaped the substantial damage to the aircraft without injury.
The investigation
The AAIU investigation focused on the ground conditions and the pilot's decision-making during the takeoff. Investigators found that the airfield, while a wide open area, featured a surface of wet and soft grassland with visible tyre rutting.
Technical examinations of EI-ETU revealed no mechanical failures. However, the investigation noted that a recent propeller balancing procedure had been performed earlier in the month. The pilot suggested he may have underestimated how this adjustment, combined with the degraded ground surface, would affect the aircraft's performance during the takeoff and climb-out phase.
Findings
- The takeoff roll was extended due to the aircraft passing through wet and soft ground.
- The pilot continued the takeoff despite the degraded surface conditions, leading to a late liftoff.
- The aircraft lacked sufficient height to clear the boundary trees after the delayed rotation.
- The use of an uncompacted, non-standard runway strip increased the risk of unpredictable performance.