What happened
On May 1, 1999, a Beech B36TC (registration D-EHHA) was conducting a recreational flight from Dortmund to Groningen Airport Eelde. During the approach to runway 23, the pilot reported engine problems, stating the engine had stopped with a loud bang. While attempting to manage the emergency, the pilot switched the fuel selector to the right tank and set the electric fuel pump to the 'HI' position.
As the aircraft descended, witnesses observed dark smoke trailing from the engine. The aircraft struck several obstacles, including a tree, an antenna, a house roof, and garden poles, before coming to rest in a grassy field approximately 700 meters from the runway threshold. The impact caused the right main landing gear to collapse and resulted in the separation of the engine, the nose gear, and the outer portion of the right wing. The three occupants survived the accident, with only one minor injury reported.
The investigation
The investigation focused on the engine's performance and the fuel management procedures used during the emergency. Investigators examined the engine, propeller, and fuel system components. While the mechanical fuel pump and the electric pump were found to be functioning correctly, the investigation noted that the spark plugs were black and sooted, a condition consistent with a rich fuel-air mixture.
Analysis of the fuel levels indicated that the left tank was empty at the time of the engine failure. The pilot had failed to follow the 'before landing' checklist, which requires selecting the fullest tank. Furthermore, the investigation looked into the use of the auxiliary fuel pump in the 'HI' position, noting that the engine manufacturer's data confirms that reducing throttle while the pump is in 'HI' leads to excessive power loss.
Findings
- The pilot was unaware that the left fuel tank was nearly empty at the start of the approach.
- The pilot did not follow the prescribed checklist to select the fullest tank prior to landing.
- The engine stopped due to fuel starvation.
- In an attempt to restart the engine, the pilot incorrectly set the electric fuel pump to the HI position instead of LO.
- The use of the 'HI' setting created an excessively rich fuel-air mixture, causing significant power loss that prevented the pilot from maintaining the necessary glide path.