History of the Flight
The aircraft, a Piper PA-38-112 Tomahawk (G-BMXL), departed Wycombe Air Park at 1810 hrs on 31 May 2005 for an aerial inspection of a newly prepared farm strip near Chepstow, Monmouthshire. The pilot and passenger, both members of the aircraft's owner group, conducted two visual circuits with low go-arounds, flown by the passenger. The pilot then took control for a third circuit intended to be the last before returning to Wycombe. As the pilot applied full power to go-around, the engine began to run roughly, with a perceived reduction in power though maximum rpm was indicated. The pilot reduced power and landed on the farm strip uneventfully, with no further abnormal engine indications. Fuel had been checked before departure at approximately 76-78 litres, total capacity 121 litres. The pilot had used carburettor heat regularly and changed fuel tanks at least twice.
After landing, the pilot inspected the engine and aircraft, finding no apparent faults except a slight oil quantity anomaly attributed to uneven ground. The aircraft was prepared for departure with flaps set to one notch as per the Pilot's Operating Handbook for soft or short field takeoff. Two power checks were conducted during taxi, and a final power check before takeoff. Carburettor heat was used according to procedures. Engine indications were normal, and the aircraft accelerated normally down the strip, which initially sloped downward. As the aircraft neared the bottom of the slope, it achieved 55-60 kt and became airborne normally. However, the engine immediately ran roughly again, and the pilot sensed a sink. After a brief attempt to raise the nose, the apparent power loss persisted, and the aircraft sank back. The pilot aborted the takeoff and closed the throttle. The aircraft landed heavily on the upward sloping part of the strip, bounced at least once, passed through a boundary fence into a field, and collided with a calf, which later had to be destroyed. The propeller was turning when the aircraft passed through the fence but had stopped by the time it came to rest. The pilot performed a normal shutdown (including raising flaps) and both occupants vacated via doors. The aircraft suffered substantial damage and was later written off.
Aircraft Inspection
Photographic evidence and examination by the AAIB at the maintenance organisation revealed substantial damage. The aircraft came to rest upright, left main gear missing, left wing contacting the ground, heading about 30° left of takeoff heading, 130 m beyond the fence. Witnesses noted a lack of obvious ground marks. Both wings sustained leading edge damage, worst on the left wing outboard end. The left wing tip showed abrasion and scoring on its rear underside, with the rear section detached. The right wing had cracked wing tip assembly and outboard aileron damage. Both wing skins were buckled, though most upper skin damage was attributed to cattle in the field. The left main undercarriage detached due to two retaining bolt failures. A cracked frame at the rear fuselage base of the fin indicated heavy load through the tail skid. The centre carry-through spar was buckled. The port tail plane had a large hole in both skins at mid-span. One propeller blade was bent backwards about 20° from mid-span; the other undamaged, with only small burrs on the tip and one witness mark. Both flaps had minor buckling. There were no obvious signs of the reported engine problems; spark plugs showed no sooting or fouling. Fuel was present; 69 litres were drained before recovery. The aircraft had a history of verbal reports of intermittent rough running engine from group members, but no factual data or maintenance records supported this; the maintenance company was unaware of these reports.
Farm Strip
The strip spanned three fields used for cattle grazing, with parts of two tree lines removed. The surface was generally rough or very rough, with uneven ground and small rocks from removed trees. Strip orientation 07/25, main takeoff direction 066°M, initially 085°M. The landing strip length was 315 m; takeoff available length 495 m. The field beyond the fence held cattle at the time. The strip was on undulating ground: significant downward slope for about 350 m from takeoff point, then upward to the end fence, then sloping away in the overshoot field. Ends approximately level, gradual fall from left to right in takeoff direction. Mean field elevation 475 ft amsl. Large trees in the westerly field dictated the angled initial takeoff run. Strip width about 50 m, defined by gaps in tree lines.
Pilot Experience
The pilot held a Private Pilot's Licence, age 50, with 104 total flying hours (4 on type, last 90 days: 5 hours, last 28 days: 4 hours). He had learned to fly on Warrior aircraft and recently converted to the PA-38. He had some strip operations experience in the USA but no formal training. The passenger had about 160 hours fixed-wing and 60 hours rotary-wing, with limited recent fixed-wing experience. The pilot and passenger had not flown together before and had only a broad idea of each other's experience. The passenger had originally intended to visit the strip with an instructor or the group leader but instead approached the pilot on the day.
Witness Observations
Two witnesses observed the takeoff. They saw the passenger conducting two low approaches earlier. During the accident takeoff, the aircraft lifted off approximately halfway down the strip, climbed normally to 25-30 ft, then rolled left, and veered left to right. No unusual engine noises or ground strike were heard or seen.
Meteorological Information
En-route weather from RAF Brize Norton reported calm, good visibility, no significant cloud. At the accident area, conditions were similar with negligible surface wind. The Met Office indicated a 2,000 ft gradient wind of about 280°T at 5-10 kt, suggesting a surface wind of about 250° at 5 kt.