Computer-Related Incidents with Commercial Aircraft

The Tokyo-London A340 FMGS Problem

30 June 1994

Synopsis This incident attained Page 1 of the British daily newspaper The Independent when the report was published. The BBC also reported on it in the news on 15 March 1995. An Airbus A340 aircraft on a scheduled flight from Tokyo to London experienced intermittent failure of navigational and flight-status information on one or another of the EFIS diplays en route to London. When being sequenced for approach to Heathrow, the airplane displayed an odd reaction to an autopilot command (it went the `long way round' to capture a heading) and abrupt and undesired manoeuvering while attempting to capture the ILS (the localiser and glideslope). They came in on a radar surveillance approach, the pilots having lost faith in their on-board equipment to assure them a safe approach and landing. While the incident brought to light some problems with the ILS broadcast (the aircraft encountered a `false lobe'), the British CAA considered the problems with the A340 flight management computers severe enough that they asked the JAA (Joint Aviation Authority, which has major responsibility for coordinating the certification of civil transports in Europe) if they were aware of such problems during certification.

The original AAIB incident report, AAIB Bulletin No: 3/95.

A340 shenanigans by Les Hatton;
Re: A340 incident by Peter Ladkin and John Rushby;

A slight change... by Ric Forrester via Dave Horsfall refers to the same incident.