Aircraft and Flight Details
The aircraft involved was a Reims Cessna F172N Skyhawk, registration G-BFTX, manufactured in 1978. It was powered by a single Lycoming O-320-H2AD piston engine. The flight was a private local sortie from a private grass airstrip at Clipgate Farm, Denton, Kent. The pilot, aged 63, held a Private Pilot's Licence with 237 total flying hours, including 30 hours on type. His recent experience included 2 hours in the previous 90 days and 0 hours in the last 28 days. One passenger, the pilot's son, was also on board.
History of the Flight
The weather at the time was good: surface wind from 200° at 10 to 15 kt, visibility 24 km, scattered stratus cloud between 2,000 and 3,000 feet, and an outside air temperature of 20°C. The aircraft's mass was 93 kg below the maximum authorised takeoff mass.
After completing the pre-flight inspection and fuel check, the aircraft was started and taxied to the threshold of Runway 20, which measured 480 metres long by 30 metres wide. The surface was mown grass, with open areas of long grass on each side. Power checks were carried out satisfactorily. With the carburettor air set to cold and mixture set to fully rich, full throttle was applied and the take-off run commenced. The flaps were set to 10° and the aircraft accelerated normally. The pilot recalled announcing "50 KNOTS" and gently easing back on the control column, with the aircraft lifting off at the normal point on the runway, adjacent to the aircraft parking area.
After approximately 30 metres, the aircraft sank back onto the runway as if the wind had dropped. The pilot decided to abandon the takeoff in accordance with his pre-arranged procedure. He closed the throttle and applied maximum braking, noting that the windsock appeared to be hanging straight down. The aircraft veered to the right into the longer grass, which the pilot expected to assist with deceleration as he had experienced previously. The landing gear wheels appeared to be locked and the aircraft skidded across the surface, slowly veering left under the influence of full left rudder in a deliberate attempt to enter a crop field to the left. The turn could not be tightened and the aircraft struck an earth bank at the southern boundary of the airstrip at about 10 kt, breaking off the nose landing gear and probably stopping the engine. The aircraft then slowly nosed over and inverted, leaving the two occupants hanging by their seat harnesses.
The pilot carried out the emergency shut down drills from memory before he and his passenger released themselves, exiting by their normal doors. Persons on the site came to their assistance but both were uninjured.
Analysis
The pilot concluded that the aircraft, having lifted off gently, encountered a reduction in the surface wind and lost airspeed, which caused the aircraft to sink back onto the runway. With limited distance available, the lack of wheel 'grip' due to the grass surface, and locked wheels, he was not able to turn or stop the aircraft before it struck the hedge-covered earth bank.
Damage
The aircraft sustained extensive damage to the airframe and engine.