History of Flight
The aircraft, a Piper PA-28-161 Cherokee Warrior II (registration G-BTID), was departing from Runway 08 at Eaglescott Airfield on a training flight back to Exeter Airport. It had arrived from Exeter earlier and been shut down for about 20 minutes. On board were the student pilot (who was two-thirds through his PPL course), an instructor, and a passenger. Weather was good with clear skies and a variable surface wind of two to three knots. Runway 08 has an estimated upslope of about 1° and consists of short dry grass on firm subsoil.
The takeoff used the full runway length with full power applied against the brakes and flaps retracted. Normal checks were completed and engine speed was observed at full RPM. The student was handling. After brake release, the aircraft initially accelerated slowly then gathered speed normally. About halfway down the runway, the ASI indicated 45 kt. After another 100 metres, it reached 50 kt but then seemed to stop accelerating, though engine instruments showed full power.
The instructor considered rejecting the takeoff but delayed to check airspeed again, then concluded insufficient runway remained to stop. He took control, selected 10° of flap, and applied back pressure. The aircraft pitched up, became airborne, and began climbing. Seconds later, a 'thud' occurred as the left main landing gear struck a wooden post next to a gate in the boundary hedge, 115 metres beyond the runway end. The aircraft descended rapidly, crossed a road, and landed in a field. On touchdown, it swung left due to landing gear damage. The instructor used rudder to maintain directional control, then retarded throttle and mixture. As it slowed, it veered further left and came to a halt upright, facing 90° to the takeoff direction. The occupants exited normally, uninjured. There was no fire. Damage included the left main landing gear, left wing, and stabilator.
Aircraft Performance
Before the flight, the instructor briefed the student to complete pre-flight planning for the flights to Eaglescott and back before departing Exeter. However, both calculated performance for the Eaglescott takeoff due to time constraints. Using the UK Supplement to the Pilot's Operating Handbook (POH), they computed a Take Off Distance Required (TODR) of 446 metres. The declared Take-Off Run Available (TORA) for Runway 08 is 600 metres. Subsequent re-calculation gave a TODR of 868 metres and a take-off run required to lift off of 657 metres. The UK Supplement figures assume full throttle, flaps retracted, and a take-off safety speed of 64 kt.
Analysis
The instructor attributed the accident to incorrectly calculated take-off performance figures and delaying his decision to reject the takeoff until it was too late. The reason for the apparent reduction in acceleration at 50 kt is unclear. Runway 26 had been used earlier; it's possible the light variable wind presented a tailwind component during the takeoff roll.
The company issued a notice reminding all instructors to base performance calculations on approved charts, and stressed that students, especially in the PA-28-161, must be familiar with the UK supplement as the sole source for take-off and landing data.
This was the instructor's first flight from Eaglescott; he had three prior experiences from short airstrips in the PA-28-161. After the accident, the company required him to complete further training before instructing on that type from short field runways.