British Mediterranean Airways - Incidents and Accidents

Incidents and Accidents

On 31 March 2003 a British Mediterranean Airbus A320 was involved in a serious incident while approaching Addis Ababa Airport, Ethiopia. The pilots were unaware of a significant discrepancy in the aircraft flight management system position caused by the sole navigational beacon transmitting erroneous data. This same beacon was also being used to navigate the approach. The crew executed a go-around, the Enhanced Ground Proximity Warning System (EGPWS) "TERRAIN AHEAD, PULL UP" audio warning was triggered too late to be of any help, and later analysis showed that the aircraft passed within 56ft of terrain at its closest point. The AAIB determined that improper maintenance of the ADS VOR Beacon had allowed water ingress causing the erroneous signal, which should have been detected by monitoring equipment, but this had been disconnected during construction work. Also, the Airbus EGPWS design relied on the same positional information as navigation system.