What happened
On 12 February 2018, a Beechcraft F33A Bonanza, registration OO-XXX, was conducting a flight near Stokrooie, Belgium. During the flight, the aircraft experienced a sudden restriction in air induction, which led to fuel starvation and a subsequent loss of engine power. Because the aircraft was operating at a low altitude, the pilot had limited time and terrain options to manage the emergency. The aircraft ultimately impacted the ground, resulting in two fatalities.
The investigation
Investigators from the AAIU(Be) examined the wreckage and the aircraft's systems to determine the sequence of events. The examination focused on the engine, the airframe, and the fuel system. The investigation established that the engine suffered from a restriction in the air induction, which triggered the fuel starvation. The team also analyzed the impact sequence and the bank angle of the aircraft prior to hitting the ground. Additionally, the investigation looked into the aircraft's maintenance history, specifically regarding the fuel selector valve and any Supplemental Type Certificates (STC) applied to the airframe.
Findings
- The primary cause of the engine power loss was a restriction in the air induction which led to fuel starvation.
- The low altitude of the flight significantly reduced the time available for the pilot to troubleshoot the engine and limited the available landing sites.
- The investigation noted that the fuel selector valve design, while compliant with older certification standards, lacked modern safeguards to prevent inadvertent operation.
- The use of older certification standards via STCs may have prevented the implementation of more modern, safer flight control layouts.