The Mentor's owner, a private pilot, had flown over 1,000 hours in it since acquiring it in 1983. He suffered from a benign but gradually progressing condition called essential tremor-excessive involuntary shaking of the head and hands - and the medications he took to control it, Klonopin and Inderal, together with some "unusual behavior" that he had displayed "during operation of an aircraft," had led to his FAA medical certificate being suspended in 1996. In 2000 he had applied again for a medical, reporting that he was now taking only the cholesterol-lowering drug Lipitor. He also stated that he did not suffer from any neurological disorders, though his essential tremor was alluded to in the "Notes" section of the application. The third-class medical certificate was issued, but withdrawn a week later when his blood tests came back with an abnormally elevated glucose level that suggested possible diabetes. He had not subsequently applied for an aviation medical. Despite the pilot's having lost his medical certification, he continued to maintain his airplane and probably to fly it at least occasionally. The engine, which was majored in 1996, had clocked 118.6 hours when the last annual was performed in September 2001. It is unclear how many, if any, of these hours were flown by the owner, but he could have continued to fly as long as he had another pilot aboard.