Aircraft and Flight Details
The aircraft involved was a Cessna U206A Super Skywagon, registered G-ATLT, manufactured in 1966. It was powered by a single Continental Motors Corp IO-520-F piston engine. The flight was conducted as aerial work for parachuting, with one pilot on board and no passengers. The commander held a Private Pilot’s Licence and was 66 years old, with 1,330 hours total flying experience, including 382 hours on type.
Accident Narrative
On 23 July 2011 at 0815 UTC, the aircraft was landing on Runway 06 at Grindale Airfield, near Bridlington, Yorkshire. The runway was a close-mown grass strip approximately 500 m long and 30 m wide, surrounded by ground crop. The surface wind was from 340° at 10 kt. The pilot reported that a stand of trees near the runway generated turbulence over the threshold.
The pilot landed deeper into the runway than intended and found the braking action to be poor or negligible on the wet grass surface. As the end of the runway approached, the pilot turned the aircraft to the left and it slid sideways. The right main landing gear slipped off the end of the runway surface into the crop, which at that point was about one foot lower than the runway. During the sideways movement, the right wing contacted the ground with sufficient force to cause damage to its outer section.
Damage
The accident resulted in damage to the right wing outer main spar and associated wing structure.
Pilot’s Conclusion
The pilot concluded that the accident was the result of windshear, turbulence, and the wet grass surface.
Additional Information
The AAIB bulletin referenced CAA General Aviation Safety Sense leaflet 7, which states that wet grass can increase the landing distance required by 35%, and very short grass may increase required distances by up to 60%.