What happened
On 6 February 1958, a de Havilland Ambassador (registration G-ALZU) operated by British European Airways (BEA) was involved in a serious accident during its landing at Munich Riem Airport. The aircraft was performing a scheduled passenger service when it encountered difficult surface conditions on the runway. During the landing roll, the aircraft failed to decelerate as expected, leading to an excursion from the runway.
The investigation
The investigation involved a detailed re-examination of the circumstances surrounding the accident, incorporating evidence from both the German Federal Office of Aviation and the Royal Aircraft Establishment at Farnborough. A significant portion of the inquiry focused on the physical properties of the runway surface at the time of the event. Specifically, investigators analyzed the effects of slush and its impact on the braking effectiveness of the aircraft.
Technical assessments included the application of results from slush drag tests performed on the Ambassador type. These tests were designed to determine how much additional drag and resistance are produced by accumulated slush on a runway surface and how such conditions influence the stopping distance of heavy propeller-driven aircraft.
Findings
- The primary factor in the accident was the presence of slush on the runway surface at Munich Riem Airport.
- The investigation established that the accumulation of slush significantly altered the braking performance of the G-ALZU.
- Testing conducted at Farnborough provided empirical evidence regarding the drag characteristics of the de Havilland Ambassador when operating in slush-covered environments.
- The interaction between the aircraft's tires and the slush layer contributed to the inability to maintain the runway centerline and stop within the available distance.