Narrative:The flight had departed London at 11:37 for Innsbruck and had just passed the Mike NDB near Munich at FL210 when it lost control. The Viscount crashed onto the Nürnberg-München highway in a slightly nose-down attitude and broke up on impact.
Probable Cause:PROBABLE CAUSE: "The accident is attributable to the fact that the aircraft's electrical power supply failed in cruising flight - possibly without the generator warning lights illuminating or illuminating distinctly - which meant that during the subsequent descent, which had to be carried out by instruments because of the weather, the vital instruments for indicating the flight attitude showed increasingly incorrect readings and failed completely after the gyros had stopped rotating.
Under these conditions it was unavoidable for the aircraft to get into uncontrolled flight attitudes, in which it was subjected to severe loading. These loads exceeded the ultimate load and led to structural failure.
Following the fracture of the wings and elevator and when the crew came into visual contact with the ground, it was no longer possible to exert any decisive control over the flight path.
It has not been possible to determine with certainty the cause of failure of the electrical system. It may be assumed, however, that a fault occurred in the DC generator control circuit. Faults had occurred repeatedly in the electrical supply system without their true cause being discovered." (HMSO CAP 354)
Loss of control
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from London-Heathrow Airport to Innsbruck-Kranebitten Airport as the crow flies is 966 km (604 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Networks opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.