Introduction
On 2 August 2008, a Piper PA38-112 aircraft, registration OK-IWB, operated by Piper OK a.s., was involved in an accident at Zbraslavice Airport (LKZB). The pilot was the sole occupant and was not injured, but the aircraft sustained damage.
Flight History
Earlier that day, the pilot completed three supervised flights at his home base in Roudnice nad Labem to renew currency. He then departed solo at 08:05 UTC as the second aircraft in a two-ship formation bound for Zbraslavice. The total flight duration to the accident was 45 minutes.
Accident Sequence
During the landing flare at Zbraslavice, the pilot reported that the wing flaps retracted from the "2" position to the "1" position without manual input. The indicated airspeed at that moment was 70 knots. The pilot attempted a go-around by applying power and pulling back on the control column, but the attempt was unsuccessful. He then continued the landing rollout, exited the runway, and shut down the engine.
Damage and Injuries
The pilot was not injured. The aircraft damage included a ruptured fuselage skin near the nose landing gear attachment, bent engine mount reinforcement, and a shifted powerplant. The propeller blades were undamaged. No other property damage occurred.
Investigation Findings
Post-accident examination revealed no pre-existing technical defects in the flap control system. Functional tests of the flap lever and its detent mechanism performed on-site were satisfactory. The most recent maintenance (50/100/annual inspection) had been completed on 18 July 2008 at 3003:45 airframe hours; the accident flight occurred at 3040:58 hours.
The pilot held a valid private pilot license and medical certificate. Weather conditions were suitable for the flight. The aircraft was within weight limits and operated within flap extension limits.
Pilot Characteristics
The pilot was described as having a stocky build. In the left seat, the flap control lever was positioned close to his right leg. When the flaps were set to position 2, the lever contacted his thigh.
Conclusions
The accident investigation did not determine a definitive cause. No technical fault was found in the flap system. It is considered possible that the pilot's right leg inadvertently contacted the flap lever, causing it to move from position 2 to position 1, and that the lever was not fully secured in the selected position. The pilot managed the critical phase within his training and aircraft capabilities.
No safety recommendations were issued.