History of the Flight
The pilot arrived at Compton Abbas Airfield in the early afternoon intending to fly to Kemble Airfield for a fly-in. Due to poor weather at Kemble, he waited. After the weather improved, he carried out a pre-flight inspection and placed items in the rear cockpit. At about 1410 UTC, he booked out and stated he would perform aerobatics over the airfield before departing. After engine start, he requested a radio check and advised an eight-minute aerobatic display overhead. The air-to-ground radio asked other traffic to remain clear. The aircraft took off from Runway 26 and was seen making an inverted pass along the runway, then pulling up for manoeuvres north of the airfield. Observers said the aircraft remained clear of cloud.
After a few minutes, the aircraft pulled into a vertical climb followed by a stall turn. The pilot then radioed "display complete" and said he was departing to Kemble. He immediately pulled into a second vertical climb. At the top, as he began a stall turn, the aircraft entered a spin. It performed about four rotations before hitting the ground. A fire started on impact and burned intensely. Local fire service arrived 15 minutes after the emergency call.
Meteorological Conditions
Surface wind was 250°/18–20 kt, visibility more than 10 km, QNH 1026 mb. A pilot report indicated broken cloud at 2,300 ft amsl north of Compton. Compton Abbas elevation is 810 ft, with high ground two miles north at 910 ft. This gave a general cloudbase around 1,500 ft agl, confirmed by several pilots airborne at the time.
Witness Evidence
Multiple witnesses on and off the airfield saw a spin or spiral through three or more turns with little variation or recovery signs. None could clearly recall the direction of the final stall turn or spin rotation. The engine was heard at high power during the vertical climb and reduced to idle before impact.
Pilot Experience
The pilot learned to fly in 1975 and flew regularly. In April 1999, he joined a group owning two Yakovlev aircraft. The group required aerobatic training and stall/spin recovery training for anyone flying aerobatics. Members who hadn't flown one of the aircraft in 28 days needed a dual check flight. The pilot completed eight hours of dual aerobatics training in the Yak-52, including basic aerobatics and normal spin recoveries. His wife thought he attended a residential aerobatics course in 2000, but no record existed. His last logbook entry was 29 June 2000 (13 months before the accident). There was no indication of training in flat spin recoveries.
In October 2000, he applied for a provisional Display Authorisation and reportedly practiced manoeuvres, prepared a sequence, and lowered practice height. Other pilots considered his approach cautious and methodical. The CAA recommends pilots seeking a DA should have a mentor; there was no indication he had progressed to that stage.
On the day before the accident, he practiced aerobatics in the accident aircraft, observed by another group member. He appeared to have difficulty completing stall turns successfully.
He usually wore a parachute and helmet, with some parachute experience. His parachute was usable down to 1,000 ft agl.
Aircraft Information
The Yak-52 is a low-wing, two-seat tandem aircraft with all-metal fuselage and fabric-covered control surfaces. Solo flight was from the front cockpit. The aircraft had been based in the UK, initially as LY-ALM (Lithuanian) then as RA44546 (Russian). If issued a UK Permit to Fly, modifications would have been required, all concerning rear cockpit equipment.
It was refuelled with 66 litres of aviation gasoline the day before and not flown again. Normal practice was to fill to 120 litres, which would have kept CG within limits.
The Yak-52 recovers from a normal spin using standard technique, losing 300–400 ft per turn. In a spin with pitch attitude less than 45°, height loss per turn is less but rotation rate higher and recovery more difficult. A Yak Club editorial noted that mishandling a stall turn can lead to a flat spin, which may take up to four rotations to recover, with high stick forces possibly giving an impression of jammed controls.
Engineering Investigation
The aircraft struck the ground upright, left wing and nose low. Impact angle was initially estimated at 30° nose down, but later examination showed it was steeper, about 45° but less than 60°. Ground marks and damage confirmed low horizontal velocity and a left-hand spin at impact. The propeller was turning with very low engine power. The aircraft caught fire and was extensively burned, especially the cockpit. From burned residue, no personal items or bags were found that could have affected balance or controls. Damage indicated high vertical speed, causing wings to break at landing gear positions. Flaps were retracted. Flying control cables were connected. Due to fire damage, it was not possible to determine if any control restriction occurred. Aircraft logbook showed routine inspections since October 1998 with no significant technical problems.
Discussion
The pilot likely stowed the aircraft cover and flight log in the rear cockpit. He wore a parachute, but with only about 500 ft of altitude available, it could not have been used successfully. The radio call stating departure to Kemble followed by another aerobatic manoeuvre raised several possible explanations, but none seemed more likely than a deliberate decision to perform one more manoeuvre. The Yak-52 can have difficult spin characteristics; the manoeuvre attempted was one the pilot had found difficult before, and if mishandled could result in a flat spin with limited recovery space.