What happened
On 7 June 2008, a PA 18-150 aircraft, registration SE-FYK, was conducting a training flight at Nyckelsjön, near Vängsö airport, to renew a seaplane flying authorization. During the takeoff roll on the lake, the pilot applied full engine power, causing the aircraft to plow through the water with a high nose attitude. In an attempt to get the floats to plane, the pilot moved the control column forward, only to discover that the column was locked in the full rearward position.
Although the instructor ordered an immediate abort, the aircraft lifted from the water and climbed several meters in a nose-high attitude. The instructor took control to correct the flight path, but the aircraft subsequently descended and struck the water surface nose-first. The impact occurred in approximately 1.5 meters of water. The aircraft ended up vertical on the lake bottom before tipping over onto its wings. Both occupants escaped the substantially damaged aircraft uninjured and reached the shore by swimming and wading.
The investigation
The investigation established that the pilot had relied on memory rather than reading the official checklist during the pre-flight phase. Consequently, the pilot failed to verify that the ailerons and rudder had full and free movement. To highlight this oversight, the instructor intentionally locked the control column in its rearmutmost position during the takeoff roll.
Findings
- The pilot's failure to use the checklist resulted in an unverified control surface movement.
- The instructor's use of a control column lock to emphasize a safety risk was an unsuitable measure that directly caused the accident.
- Strong wind gusts and waves on the lake allowed the aircraft to lift off before reaching a proper planing attitude.
- Communication difficulties via the aircraft intercom prevented the pilot from receiving the instructor's command to abandon the takeoff in time.