History of the Flight
On 25 May 2004 at 0720 UTC, a Piper PA-34-200T Seneca II (registration G-BOUL) was preparing for a local training sortie at Oxford (Kidlington) Airport. The commander briefed the student pilot, who had approximately 20 hours on type, for the flight. The student had already started the engines and completed pre-start checks before the commander arrived, in accordance with local procedures. The weather was fine and dry with light winds.
The Collision
The PA-34 was parked in a line of similar aircraft, with the taxiway immediately ahead at 90 degrees. Beyond the taxiway was a line of parked PA-28 aircraft facing the same direction. Apron space was limited but all aircraft were in their normal positions marked by yellow lines, and the apron surface was free from contamination. Local taxi procedures required a right turn onto the uni-directional taxiway centerline.
Due to a misunderstanding, taxiing commenced without ATC clearance. The student released the parking brake and checked the toe brakes while moving forward. The commander delayed his own brake check because of the confined space. As the student began the right turn, the commander's notepad and pen fell to the floor, and he leaned forward to retrieve them. While doing so, he was unable to monitor the student's actions, although he thought the turn felt and sounded normal. Almost immediately, a loud bang was heard; the student had failed to negotiate the turn, and the PA-34's port wing struck the fin of a parked PA-28. The collision rotated the PA-28 90 degrees anti-clockwise and caused substantial damage to the PA-34's left outer fuel tank leading edge, left outer wing skin, and wing rear spar fuselage attachment bracket.
Turn Technique
The student applied right rudder and reduced power on the right engine while increasing power on the left. He felt the aircraft reluctant to turn with full right rudder and increased left engine power. At first, he thought the aircraft would clear the PA-28, but when it became apparent it would not, there was insufficient time to stop. The commander later considered that the student had used little or no wheel braking, which would account for the modest turn and the speed of events. The commander ruled out any possibility that he may have fouled the rudder or brakes while leaning forward.
Conclusion
The commander concluded that he was distracted at a critical stage and was unable to monitor his student's handling of the turn.