Aircraft and Pilot Information
The aircraft involved was a Piper PA-32-260 Cherokee Six, registration G-RAYE, manufactured in 1966. It was powered by a single Lycoming O-540-E4B5 piston engine. The private flight was operated by the pilot, who held a Private Pilot's Licence and was 53 years old. He had accumulated 329 total flying hours, of which 201 were on type, with 37 hours in the last 90 days and 32 hours in the last 28 days.
Flight and Weather
The flight originated from Humberside Airport, Lincolnshire, and was returning to Panshanger Airfield, Hertfordshire. En route, the pilot obtained the Luton weather report from the Automatic Terminal Information System (ATIS), which indicated surface wind from 170° varying between 130° and 270° at 11 kt. The pilot joined the circuit at Panshanger on right base for Runway 29, a grass runway with 788 metres (2,585 feet) of landing distance available. Although it was not raining at the time, the runway surface was wet.
Approach and Landing
During the final approach, the pilot noticed an aircraft taxiing on the runway and requested it vacate; it taxied off to one side. Trees on short final for Runway 29 led the pilot to be mindful of potential windshear effects. The combination of anticipating windshear and a possible tailwind resulted in the aircraft floating along the runway before touching down approximately halfway along it with a relatively high groundspeed.
Outcome
The pilot applied brakes, but deceleration was minimal. Approaching the end of the runway, he attempted to slew the aircraft to the side. The aircraft continued off the end of the runway and slid into a raised hedge and ditch on a heading about 60° to the right of the landing direction. Substantial damage occurred to the port wing and landing gear. The pilot, who was wearing a lapstrap and shoulder strap, was uninjured. He shut down the aircraft and vacated normally with fire services in attendance.
Performance Guidance Note
The General Aviation Safety Sense Leaflet 7B 'Aeroplane Performance' published on the Civil Aviation Authority website provides guidance that wet grass, and particularly very short wet grass, may increase the landing ground run by up to 60%, and a tailwind of 10% of the lift-off speed of an aircraft may increase landing distance by 20%.