Cessna 414 Chancellor G-BAOZ near Guiseley.

Prior to this incident, this aircraft had been registered to Northair Aviation Ltd, of Leeds-Bradford airfield, who then serviced and began to modify it in preparation for a charter flight to Pakistan by the United Nations. The role in Pakistan was described in newspapers as in "a communications and transport role". It was flown to Little Staughton and returned to Northair on 6th March 1980 in an all white colour scheme with just the UK registration lettering and "U.N." in black lettering on it. Part of this modification included the installation fuel tanks in the cabin area to give the aircraft a far greater range required for such a long ferry flight. The subsequent AAIB report stated that these modifications invalidated the British CAA certificate of airworthiness though various checks were made on the work carried out and despite not having passed the certificate of airworthiness it was deemed servicable to fly. It was then due to be flown to Pakistan on 24th March 1980.

During the morning of Sunday, 23rd March 1980 it was flown on an airtest by what would have been the pilot and engineer who would have flown it to Pakistan. It took off from Leeds-Bradford at 09.41hrs. Some air to air photographs of this aircraft were taken by another aircraft and the crew then undertook various checks of the aircraft, which was believed to include the testing of the fuel transfer from the cabin fuel tanks. At 10.53hrs the aircraft joined a left hand landing circuit at Leeds-Bradford. At 11.00hrs while turning to make a final approach the aircraft was seen to be flying slower than expected. It was thought that the pilot had made this turn slightly too late so that he had to make a steeper turn to line up with the runway approach than would normally have been expected. This, combined with the extending the undercarriage and a slow flying speed caused a stall. The pilot attempted to regain control but it dived into or close to a small area woodland near Upcroft Farm, a mile northeast of Guiseley and two miles from the end of the runway at Leeds-Bradford. It was destroyed by fire and sadly the pilot and engineer were killed.

Pilot - Captain Barry Patrick Thornhill. Aged 23. Burial location unknown.

Passenger (Ground Engineer) - Mr Paul Somers. Aged 22. Burial location unknown.