History of the Flight
The aircraft, operated by a private pilot, departed from Thruxton Airfield at approximately 1430 hrs on 3 December 2000 with three passengers. The pilot had been authorised for a one-hour local flight. Radar data showed the aircraft tracking north, manoeuvring near the White Horse landmark, then heading east and south-east. At around 1502 hrs, the aircraft was at 4,200 feet altitude. Witnesses reported that the aircraft deviated from normal flight, rolling and pitching while descending, with engine noise increasing then stopping. Pieces of structure were seen falling, including about a third of the left wing. The main wreckage was found in woods near Warren Farm, Lambourne, Berkshire.
Meteorology
A meteorological aftercast indicated surface wind 170°/12 kt, 4,000 feet wind 210°/35 kt, visibility 30 km, with 2 okta cumulus at 2,500 feet and 1 okta stratocumulus at 5,000 feet. Witnesses reported small amounts of cloud and a brisk wind. The aircraft was observed in clear air throughout.
Aircraft Information
The aircraft was a Piper PA-28R-200-2 Cherokee Arrow II, serial number 1974, with a 200 HP Lycoming IO-360-CIC engine and a two-bladed constant-speed propeller. It had accumulated approximately 4,000 total flight hours. The most recent annual inspection was performed about 30 hours before the accident. The take-off weight was estimated just below the maximum of 2,650 lb, with centre of gravity within limits.
Occupants and Injuries
The pilot, aged 29, held a UK Private Pilot's Licence with an IMC rating and had 224 flying hours (203 on type). The three passengers included a work colleague (also an aircraft maintenance engineer), the colleague's seven-year-old daughter, and the colleague's adoptive brother. Seating positions could not be determined due to impact disruption, but the child was found in the rear cabin area. All four occupants died from multiple injuries; toxicology showed no alcohol, drugs, or disease in the pilot.
Wreckage and Examination
The aircraft was destroyed. Examination revealed that the first failure was the outer section of the left wing, which failed under download. No pre-existing defects were found in the wing structure or flight controls. No evidence of atmospheric turbulence or a need for an evasive manoeuvre was identified. The investigation concluded that a manoeuvre resulting from unintentional and unusual control inputs by either the pilot and/or the front seat passenger, sufficient to overload the wing structure, was the most likely cause of the wing failure.
Analysis and Conclusions
The analysis found that within five seconds of deviating from straight and level flight, the aircraft suffered structural failure. The break-up sequence began with the left wing outer section failing in download. The aircraft's pitch behaviour and control forces were analysed, but no single specific manoeuvre sequence could be determined. The report concluded that the wing failure was most likely caused by control inputs that exceeded the structural limits.