What happened
On August 12, 2004, a Beechcraft C90A departed from Werneuchen, Germany, on a chartered flight to Vilshofen. The aircraft was carrying two crew members and six passengers. Shortly after takeoff, the landing gear was retracted. During this phase of flight, a passenger notified the crew that the wing fuel caps had been left open.
In response, the crew decided to abort the departure and return to the airfield. The pilot initiated a right-hand turn at an altitude of approximately 100 meters. During the maneuver, the crew discussed what they perceived to be insufficient engine performance and airspeed. As the aircraft attempted to reposition for landing, the flaps were set to the "Approach" position and the landing gear was extended. This configuration increased aerodynamic drag, contributing to a loss of airspeed. The aircraft's stall warning horn sounded intermittently before becoming constant. The aircraft eventually impacted a field approximately 200 meters east of runway 26. The impact resulted in five serious injuries and one minor injury among the passengers, while the aircraft sustained heavy damage.
The investigation
The BFU investigation examined the aircraft's maintenance history, the crew's actions, and the fuel system design. Investigators analyzed radar data and Cockpit Voice Recorder (CVR) audio to reconstruct the flight path and cockpit communications. The investigation also reviewed the pre-flight procedures and the meteorological conditions at the time of the accident.
Findings
- The fuel caps, which had been opened in preparation for refueling, were not closed prior to departure.
- The pre-flight inspection was inadequate, as it failed to identify the open fuel caps.
- The pilot's decision to execute a spontaneous turn was made without maintaining the necessary visual contact with the runway.
- The crew likely perceived a loss of power due to the fuel escaping from the wing tanks; however, the aircraft's fuel system design prevented fuel from flowing from the nacelle and inner wing tanks through the filler necks, meaning an engine failure was not an immediate threat.
- The aerodynamic stall occurred because the pilot executed a steep turn at low altitude while the aircraft was in a high-drag configuration (gear and flaps extended) and at a high takeoff weight.
Safety action
No specific safety recommendations were recorded in the provided source material.