I/O Error with a Difference
A RYANAIR flight with 144 passengers and crew on board narrowly avoided a crash-landing at Knock Airport last March after both pilots became distracted with the aircraft’s computer system while attempting to land the plane.
Details of what air accident investigators described as "a serious incident" only emerged yesterday with the publication of an official report into the event.
It revealed that a ground impact warning system was triggered on board the aircraft after it began a rapid descent on an approach to Knock Airport. The report concluded that a collision with the ground was "marginally avoided."
"The captain and flight officer were so engrossed in trying to re-programme the [aircraft’s computer] that they both lost their critical situational awareness for a time," said the official report.
The incident happened when the pilot of the aircraft had to abandon an approach to Knock Airport after breaking through cloud cover and realising that the plane was just 400ft above ground level.
A report by the Department of Transport’s Air Accident Investigation Unit showed that the pilot had intended to descend only to the recommended limit of 1,300ft before circling the airport to land.
Instead, the aircraft had descended dangerously below that limit as Knock Airport is situated on a plateau at 665ft above sea level.
Data provided by radar equipment showed the aircraft was descending at the speed of 2,200 feet per minute — three times the normal speed for approaches to airports.
The incident occurred on board a Ryanair Boeing 737-800 aircraft on a flight between London Gatwick and Knock Airport on March 23 last. There were 138 passengers and six crew.
The AAIU report found that confusion arose among the cockpit crew about which direction to approach the runway at Knock Airport for a landing.
It claimed uncertainty about weather conditions at Knock by both the captain and his assistant officer had impaired their decision-making.
The two pilots were also hampered by the fact that several navigational aids were unavailable at the time due to improvement works being carried out at the airport.
However, the AAIU noted that information about the unavailability of such navigational aids had not been conveyed to the Ryanair flight crew by the airline.
The AAIU also acknowledged that a widely used professional manual containing information on approaches to all airports had not been updated to reflect the ongoing works at Knock.
The cockpit crew were also distracted by the fact they were trying to input information on an extra navigational aid, which had recently come into operation, into the aircraft’s computer at a time when they should have been concentrating on their visual approach.
"The work overload meant that normal routine checks were not carried out and there was no questioning of the developing situation by either pilot," said the AAIU report.
It concluded that the flight crew had contravened Ryanair’s own standard operating procedures by descending below 1,300ft to circle the airport.
Ryanair was also criticised for failing to report the incident until 12 days after it occurred. Such a delay was "unacceptable" and contrary to aviation regulations, said the AAIU.
Last night, a Ryanair spokesperson said the company had assisted and co-operated fully with the AAIU report and had accepted and implemented all of its recommendations.