Computer-Related Incidents with Commercial Aircraft

A330, landing difficulties, Melbourne, Australia, 27 August 2001

27 August 2001

Synopsis On a flight from Adelaide, the A330 aircraft experienced approach and landing difficulties while manually landing. A first landing attempt resulted in a bounce and a go-around. The second landing attempt involved bouncing, but the aircraft was successfully brought to a halt.

The transition of the digital flight control law from "flight mode" to "flare mode" is controlled inter alia by readings from the radio altimeters. It was determined that the radio altimeter antennas were wet, which resulted in "out of range" signals and that no transition to flare mode had occurred. The manufacturer advised that the aircraft had been landed during flight test without a transition to flare mode, but that this situation required a different handling technique than would be required for non-fly-by-wire aircraft.

Reverse-thrust and spoiler deployment were unavailable. Analysis determined that this was because the logic conditions for deployment of either were not met. This is reminiscent of the 1993 Lufthansa Warsaw runway overrun accident.

The Air Safety Occurrence Report of the incident is available on the ATSB WWW site.

Thank you to John Sampson for advising me of this incident.