B-767 loses navigation over Atlantic
The US Airways flight had to dump fuel and divert to Shannon after a complete navigation failure.
US Airways flight AWE-711 was en route from Zurich to Philadelphia on 25 May, and was ~200km W of the Irish coast when the navigation problem was reported.
At about 1340 BST, the Boeing 767-200 crew contacted Shannon ATCC to report that they had no navigation systems. It was decided that the flight should be diverted back to Shannon.
Around 11,000lb (5,000kg) of fuel had to be dumped before a safe landing was made at Shannon at around 1500 BST.
After inspection, the flight was cancelled and the 110 passengers and crew were accommodated in hotels in Limerick and Clare overnight. It was the third time this month that a US Airways flights had to divert to an Irish airport - previous problems had been due to crew illness.
The B-767 flight management system (FMS) is based on 3 inertial measurement units (IMUs), of which at least 2 must have failed to cause such a diversion.
Details from the The Irish Times below . .