Investigation
After the crash, an investigative team from the UK Department for Transport Air Accidents Investigation Branch attended the scene in co-operation with Strathclyde Police. The wreckage of the helicopter was removed to Farnborough for further forensic investigation. Pilots operate under strict regulations, and are expected in the case of helicopters under CAA rules to undertake a competency test every year, and renew their licenses every five years — not to do so is illegal. It later emerged that McRae had not undertaken a competency check as required in March 2006, and that effectively his license had expired in February 2005. A CAA spokesman commented "The investigators must determine why he (McRae) hasn't kept up to date with his documentation. There is no suggestion that Mr McRae was not a competent pilot.”
The final report into the accident was published on 12 February 2009. In it, the AAIB did not reach a definite conclusion as to the cause of the accident, stating instead that "the helicopter crashed in a wooded valley while manoeuvring at high speed and low height. It was intact prior to impact, and the available evidence indicated that the engine was delivering power. The cause of the accident was not positively determined. Although no technical reason was found to explain the accident, a technical fault could not be ruled out entirely. However, it is more likely that the pilot attempted a turning manoeuvre at low height, during which the helicopter deviated from his intended flight path; whether due to the pilot encountering handling difficulties, misjudgement, spatial disorientation, distraction or a combination of such events. There were indications that the pilot had started a recovery but, with insufficient height in which to complete it, the helicopter struck trees in the valley and crashed, killing all four occupants."