2 fatalities

1999-06-30: Beechcraft 99 Airliner (D-IBEX) — NightExpress Luftverkehrs — Liege, Belgium

Liege, BelgiumLanding (descent or approach)

On June 30, 1999, a Beechcraft 99 Airliner (registration D-IBEX) operated by NightExpress Luftverkehrs was involved in an aviation accident near Liege, Belgium during landing or approach. 2 people were killed. Investigators recorded the probable cause as: The sequential failure of both engines was driven by mechanical fatigue in the right engine and subsequent overstressing of the left engine, compounded by improper emergency communication and a decision to continue flight on one engine. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781204282Data APIEditorial standards

A cargo flight operating from Luton to Frankfurt crashed in a wooded area near Seraing following the sequential failure of both engines.

What happened

During a nighttime cargo operation, an aircraft flying from Luton to Frankfurt experienced a critical mechanical failure. While cruising at 11,000 feet, the right engine suffered a malfunction, prompting the crew to shut it down. Approximately four minutes later, the left engine also failed.

Following the loss of the first engine, the crew issued a Pan-Pan alert and received clearance to divert to Liege-Bost Bierset Airport. While being vectored for an approach to runway 23L, the aircraft entered an uncontrolled descent after passing through 4,000 feet. The plane crashed in a forested region near Seraing, roughly 8.3 km southeast of the airport. The impact destroyed the aircraft, and both pilots were killed.

Findings

Investigations revealed that the initial failure was caused by the breakage of a turbine blade in the right engine, which resulted from abnormal wear due to a missing seal on the inner guide vane drum. Following this shutdown, the captain chose to continue the flight on a single engine, a decision that violated company regulations and placed extreme stress on the remaining engine. This high-power demand contributed to the subsequent failure of a compressor turbine blade in the left engine.

Communication errors also played a significant role in the accident. The crew transmitted a Pan-Pan call rather than a Mayday, which led air traffic controllers to believe the situation was a medical emergency rather than an engine failure. Consequently, the controller directed the aircraft on a longer approach procedure for runway 23L instead of a more direct cross-traffic emergency procedure. By the time the urgency of the engine loss was realized at 4,000 feet, the aircraft was too low and too far from the runway to land safely. Additional contributing factors included poor visibility due to nighttime conditions and a lack of initiative by the crew to resolve the situation.

Probable cause

The sequential failure of both engines was driven by mechanical fatigue in the right engine and subsequent overstressing of the left engine, compounded by improper emergency communication and a decision to continue flight on one engine.