Rudder loss—Mach 1.7—FL440

British Airways Concorde (G-BOAF) rudder damage at FAST (Farnborough Air Sciences Trust)—©2017 Joseph May/Slipstream Photography

Nearing their destination of Sydney Australia, enroute from Christchurch New Zealand, the flight crew (as well as the 100 passengers) of British Airways Concorde G-BOAF (9 years in service) felt a bird strike-like thud while traversing the Tasman Sea at Mach 1.7 and passing through 44,000 feet.

But there are no birds at FL440 and instruments indications were normal. But there was that thud? Possibly an engine surge? The flight continued as all appearances were that nothing definitively concerning had occurred. Sydney was as close as Christchurch was at their position so the flight continued as planned.

More input occurred upon deceleration in preparation for landing when a definite and stronger vibration onset occurred near Mach 1.3—so Number 4 engine was idled as its indications were a bit different in relation to the other three.

No positive effect, though.

Speed was further reduced by retarding the remaining throttles. No effect and vibration continued.

Speed was further reduced to Mach 1 with the vibration becoming variable though handling was unaffected.

Upon landing the story readily became apparent. The majority of the upper rudder had been lost due to skin panel delimitation which exposed the underlying honeycomb support structure which ultimately caused loss of the majority of the upper rudder.

A failure of maintenance but a victory for engineering.

Failure was due to improper riveting and water sealing (though the specifications were difficult to attain)—hence corrosion and subsequent delimitation. The victory was the redundant two piece rudder design with the upper and lower rudders structurally independent of each other.

Aircraft Accident Report 6/89: Report on the Accident to Concorde 102 G-BOAF, over the Tasman Sea, about 140 nm east of Sydney, Australia on 12 April 1989, ISBN 0 11 550942 9, 19 pp.