History of the Flight
The pilot, who also owned the helicopter, kept it outside at a private site near Manchester Airport. He planned a local pleasure flight in the Macclesfield area, intending to return after about an hour. Manchester ATC recorded the takeoff at 1517 UTC and cleared the pilot to fly south-west. The helicopter remained flying north of Macclesfield. At 1519 UTC, ATC advised the pilot of another helicopter, G-CKCK, an Enstrom 280FX, taking off from a nearby site. The pilot of G-RIDL replied he would descend to 200 ft and had the other helicopter in sight, but the pilot of G-CKCK did not see G-RIDL.
Witness Observations
Shortly before the accident, witnesses saw G-RIDL flying at a height between 500 and 1,000 ft, circling near the crash site. One witness heard a noise described as a "bang" or "clatter" and saw the helicopter rock from side to side. The engine continued sounding normal, but the helicopter slewed so that its nose pointed left of the direction of travel. Other witnesses saw it descending and heard the engine running. People near the accident site heard a "struggling" noise and then a heavy thud. The helicopter was found on its side in a field.
Accident Site and Initial Examination
The first ground contact was a shallow scrape with two angled slash marks consistent with the tail rotor blades striking the ground while rotating. The helicopter was on a heading of approximately 147° magnetic. The tail rotor gearbox and both blade roots detached and were found nearby. A third mark indicated the right skid striking the ground. The final mark came when a main rotor blade struck the ground, rotating the fuselage 180° around the rotor head and landing on its right side. The helicopter came to rest 53 metres from the first ground mark. There was no evidence of contact with trees or overhead cables.
Examination Findings
The left magneto (TCM S4LSC-200) exhibited corrosion. The right magneto (TCM S4LSC-204T) was also identified. The magneto switch was found in the off position, but it was later confirmed that emergency services had turned it from both to off during rescue. The carburettor heat selector was off, though it could not be determined if it was moved after the accident. The clutch circuit breaker was not mentioned as having been pulled. The helicopter was not equipped with a crash-protected recorder. A GPS receiver was recovered but its internal battery had insufficient charge to maintain track data. Radar data from Manchester Airport captured the ground track but not altitude, as the transponder altitude reporting was not enabled.
No definitive probable cause was stated by the investigation. Evidence suggested the pilot may have been attempting a precautionary landing and that the tail rotor contacted the ground, leading to loss of control. Corrosion in the left magneto could have caused increased engine vibration and noise, possibly prompting the pilot to attempt such a landing.