Synopsis
A Beech 76 Duchess, registration G-OADY, sustained damage to its propellers, engines, nose landing gear doors, forward bulkhead, and nose cone during a training flight at Doncaster Sheffield Airport on 30 April 2008. The aircraft was conducting touch-and-go circuits under the supervision of an instructor. The student pilot, an experienced military pilot with 2,230 hours PIC but only three hours on type, was practicing multi-engine rating. The weather was fine, the runway dry, and visibility good.
History of the Flight
The flight departed Leeds Bradford Airport at 0825 hrs and flew to Sheffield Doncaster Airport. The student pilot and instructor began routine visual circuit training with touch-and-go landings. The instructor briefed the student to keep his hands on the control column and throttles while the instructor retracted flaps and reset switches, then call "flaps up" to commence takeoff. The first circuit was completed successfully.
On the second circuit, after touchdown and during the ground roll, the instructor said, "I'll tidy up the aircraft." The student immediately removed his hand from the throttles and moved the landing gear selector switch to the up position. Both instructor and student recognized the error and returned the switch to down. The main gear remained down and locked, but the nose gear retracted. The front of the aircraft dropped, causing propeller blade tips to strike the ground. The aircraft slid on its nose, veering slightly left, and came to rest left of the runway centerline. The air traffic controller observed the retraction, activated emergency services, and directed a landing helicopter to execute a missed approach. The instructor reported the accident by radio.
Safety Protection System
The Beech 76 is equipped with a safety retraction switch designed to prevent inadvertent gear retraction on the ground. This switch is triggered by a pitot pressure sensor that deactivates the hydraulic pump circuit when airspeed is below 59 to 63 kt. During the ground roll, the aircraft's speed remained above this threshold, so the protection was not active. The student's action was described as a "reflex" reaction, a known human factors issue termed an 'inadvertent slip.' The non-standard callout by the instructor may have acted as a trigger. The training centre amended briefings to emphasize a speed check below 40 kt before flap retraction.