Incident Serious, DGCA Suspends Their Licences
Mumbai: The mystery behind the Mumbai-bound Jet Airways Boeing 737-800 veering off into soft ground at Riyadh airport last Friday has been solved. The pilots mistook a taxiway — pathways leading off the runway to parking bays — for a runway and attempted a takeoff.
Errors in runway identification are a serious issue. So much so, the US aviation regulator publishes a 45-page best practices guide to prevent errors. It advises pilots to stop the aircraft clear of any runway and seek ATC guidance when uncertain about their location in an airport.
Licences of both pilots have been suspended, said Lalit Gupta, joint director-general, Directorate General of Civil Aviation, on Monday. Pilots are generally de-rostered after any “incident”, pending investigation. The tougher decision points to the gravity of the incident. In 2000, a Singapore Airlines plane crashed after a similar mistake killing 81.
“The aircraft attempted takeoff from taxiway (K), parallel to takeoff-designated Runway (R33),’’ said a statement issued by Saudi Arabia’s Aviation Investigation Bureau on Sunday. It added that the visibility was high and there were no obstacles on the taxiway. “The aircraft accelerated with full takeoff power and exceeded the taxiway onto unpaved area…”
A Jet Airways spokesperson said: “The matter is currently under investigation and we cannot comment.” Last week, the airline said in a statement flight 9W 523 “departed the runway, following an aborted takeoff... All 142 guests and seven crew members safely evacuated”.
Experts are taken aback by the error. “What’s strange is that it occurred at night, when the white runway-edge lights and the blue taxiway lights are clearly visible. It’s not easy to mistake a runway for a taxiway at night,’’ said a senior instructor with a foreign airline.
Firstly, there are the runway markers: the piano key markings that indicate the threshold, the runway number and the white runway-edge lights. Most importantly, the runway centreline is indicated by 30m dashes with 20m gaps (illuminated when needed), while taxiway centrelines are a single, solid line, with blue taxiway-edge lights. Then there is the navigation display map in the cockpit and navigation aids like the localiser signals that indicate whether the aircraft has lined up along the correct runway.
The incident has raised questions, the ambit of which extends beyond the cockpit to include the role played by Riyadh airport officials and also Jet’s training standards and operational practices.
On May 28, Riyadh air traffic control had issued a permanent notice to pilots, controllers that a new taxiway K (Kilo) is functional. But the current aerodrome chart released by Saudi Arabia does not show taxiway K. Consequently, the Jeppesen airport chart, consulted by pilots, also does not show it.
“Airlines pay huge fees for Jeppesen charts, which are regularly updated. Had Saudi Arabia followed good aviation practices and published information about taxiway K, the charts would have had it and the Jet pilots would have been aware,” said a commander. The chart for Riyadh airport instead has a telling warning: “Use caution as unknown changes might exist.”
Unlike most major airports, the Riyadh airport does not have a surface movement radar, which would have indicated to the air traffic control that the Jet aircraft had entered a taxiway for takeoff.
Errors in runway identification are a serious issue. So much so, the US aviation regulator publishes a 45-page best practices guide to prevent errors. It advises pilots to stop the aircraft clear of any runway and seek ATC guidance when uncertain about their location in an airport.
A number of pilots TOI spoke to said Riyadh ATC is known to give “incomplete instructions”, that is they won’t spell out the taxiways to be taken to reach a particular bay or a runway.