What happened
On 4 August 2008, a Beech Baron, registration N23659, was performing a private flight from Jersey to Guernsey for the purpose of inspecting engine cylinders for corrosion. During the return leg of the flight, the aircraft commander sat in the right seat, while a prospective purchaser, an experienced pilot but not current on this specific type, occupied the left seat.
Upon arriving at Guernsey Airport, the aircraft performed a standard approach to Runway 2 and a normal touchdown. Following the touchdown, the pilot in the left seat attempted to assist by raising the flaps. However, he mistakenly manipulated the landing gear lever, moving it to the UP position. Although the commander immediately attempted to reset the lever to the DOWN position, the retraction sequence had already been initiated. As a result, the aircraft sank onto the runway, and the nose and right main landing gear partially retracted. The aircraft veered toward the right side of the runway and came to a stop at the runway edge. There were no fatalities and no injuries to the two occupants.
The investigation
The investigation focused on the mechanical operation of the landing gear and the human error involved in the lever manipulation. It was established that the aircraft's landing gear system included a weight-on-wheels protection system. This system relies on microswitches on the main landing gear oleos that prevent the gear handle from being moved to the UP position when the gear is compressed. However, investigators found that because the oleo was not compressed at the moment the error occurred, this safety protection was not active.
Findings
- The pilot in the left seat mistakenly operated the landing gear lever instead of the flap lever.
- The pilot's error was driven by an assumption that the lever positions in the Beech Baron were identical to another aircraft type he frequently flies.
- The weight-on-wheels protection system failed to prevent the retraction because the landing gear oleo was not compressed at the time of the error.