Piper PA-28R-201T Turbo Cherokee Arrow III, G-JMTT
The commander was planning to return to Andrewsfield Airfield, Essex, from Oban Airport after a weekend of touring with his family. The weather was poor and the commander (who was not IMC or instrument rated) said to the Air/Ground operator at Oban that he would depart “to have a look at the weather” and then return to Oban if it was not suitable. The aircraft departed Oban at 1035 hrs and the Air/Ground operator lost sight of it shortly thereafter due to the poor visibility as it headed west at approximately 1,000 ft amsl. The commander subsequently transmitted to Oban that he was changing to the en-route ATC frequency. Nothing was subsequently heard from the aircraft by any other ATC agency. The wreckage of the aircraft was discovered the following day in the hills, 9 nm south of Oban Airfield, by a farmer. No technical fault with the aircraft was found apart from evidence of a pre-impact failure of the vacuum pump which would have caused the Attitude Indicator to become unreliable. The characteristics of the final flight path, particularly the high airspeed, the rapid descent and the rate of turn, were consistent with a loss of control following spatial disorientation in IMC. The vacuum pump failure, the commander’s lack of instrument flying training and his apparent high blood alcohol level, all contributed to the spatial disorientation. This report contains four Safety Recommendations relating to the maintenance of vacuum pumps.