What happened
On July 18, 2002, at 14:08 local time, a Beechcraft Queen Air 88, registration EC-HML, was performing a test flight for airworthiness certification at Cuatro Vientos Airport in Madrid. During the takeoff roll on runway 28, the aircraft reached rotation and climbed to approximately 20 meters before experiencing a sudden and simultaneous loss of power in both engines.
The co-pilot, acting as the pilot flying, responded by cutting power to both engines, extending the landing gear, and bringing the aircraft back to the ground. The impact occurred with the nose gear extended and the main gear in transition. The aircraft traveled approximately 3/4 of the runway length before exiting the pavement, sliding for about 300 meters (with 150 meters occurring off-runway) on the nose gear and partially extended main gear, with the rear fuselage contacting the ground. All four occupants—the two pilots, an engineer, and a DGAC inspector—were uninjured.
The investigation
The CIAIAC examined the fuel system, the engines, and the crew's pre-flight procedures. The investigation confirmed that the fuel loaded from two different sources was suitable for service. The aircraft's fuel system was analyzed, noting that it lacks any common component between the two engines that could cause a simultaneous failure. Post-accident inspections of the engines, fuel filters, and lines showed no mechanical defects or impurities.
Functional tests were conducted following the accident. When the fuel selector valves were moved to the "closed" position, the engines lost power and stopped within approximately 9 seconds. When the valves were moved to the "crossfeed" position, the engines experienced a power drop at roughly 14 seconds and stopped completely after about 22 seconds. This mirrored the behavior observed during the accident.
Findings
- The investigation established that the simultaneous loss of power was caused by the interruption of fuel supply due to the fuel selector valves being left in the crossfeed position.
- The crew failed to correctly complete the pre-takeoff checklist, which requires setting the selectors to the "inner tank" position.
- The error was likely exacerbated by the crew performing a rolling takeoff rather than stopping at the runway threshold, which may have diverted their attention from cockpit instrument monitoring to external surroundings.