Incident: Philippine Airlines A333 at Sydney on Jul 17th 2008, takeoff without clearance, B737 crossing runway
By Simon Hradecky
The crew had been planning and prepared a departure from runway 34L. While taxiing to the runway, air traffic control inquired whether the crew could accept a departure from runway 25. The crew recalculated the performance and accepted runway 25, however, underestimated the shortened taxi time and the impact on their briefing. While taxiing on taxiway Golf, the crew reported ready for departure and was cleared to line up runway 25 and hold, fly heading 240. The takeoff clearance however was withheld, as a Boeing 737 was cleared to cross the runway at taxiway Bravo. That reason however was not provided to the Airbus crew. The Boeing was on a different radio frequency, so that the Airbus crew was not aware of the Boeing at all. |
A Philippine Airlines Airbus A330-300, registration RP-C3333 performing flight RP212 from Sydney,NS to Melbourne,VI (Australia), was cleared to line up departure runway and hold, but the crew commenced takeoff despite another (unspecified) Boeing 737 crossing the runway.The Australian Transportation Safety Board was investigating the incident and came out with this report. PHOTO by Flickr.
The Airbus crew read back their clearance, however without the "and hold" portion, the tower controller did not challenge the missing hold.
The aircraft lined up runway 25 and commenced the takeoff without having received the takeoff clearance. A tower controller saw the aircraft moving and instructed the crew to hold position, which was queried by the crew. The controller then instructed the crew to cancel the takeoff, to which the crew reacted and aborted the takeoff. The Sydney ground radar showed, that the airplane had reached a maximum speed of 29 knots. The Airbus subsequently vacated the runway and returned to the holding point, where a takeoff clearance was issued. The aircraft departed without further incident.
The Australian Manual of Air Traffic Services (MATS) required, that controllers should issue traffic information as appropriate and should advise crew of the "nature of obstructions if it is not apparent", when aircraft are delayed by the traffic situation.
The ICAO Procedures for Air Navigation Services specified, that a departure instruction may be combined with a takeoff clearance, however did not provide the option to combine a departure instruction with the line up clearance.
The MATS however permitted the combination of a departure instruction with the line up clearance.
The ATSB said, that the combination of the departure instruction with the line up clearance provided an ambiguity to the flight crew, who were not used to hear such a combination. The inclusion of the reason for the delayed takeoff clearance could have reduced the likelihood of a misunderstanding by the crew. The controller did not challenge the missing "and wait" in the readback missing another opportunity to remove any ambiguity. Instead of "stop immediately" the controller issued a "hold position" instruction, which was not understood by the crew so that they questioned what was being said. ATC phraseology should be clear, concise and unambiguous and should reflect international practises and standards where possible, especially with regards to instructions to international aircraft and in safety critical situations.
The flight crew was distracted with departure preparations and provided themselves with little time to brief and comprehend the change to their departure. Had the crew not put themselves under that pressure, they may have been less distracted and may have correctly comprehended the ATC instructions. When the crew was instructed to line up and hold runway 25 combined with the departure instruction to fly heading 240, the crew erroneously took this as a takeoff clearance. The confusion was amplified by the departure instruction, which had only been heard together with a takeoff clearance before.
Air Services Australia, responsible for providing Air Traffic Control, reviewed their procedures to bring them in line with the ICAO standards. The necessary changes to MATS will commence in the August 2009 release. (avherald.com)
The aircraft lined up runway 25 and commenced the takeoff without having received the takeoff clearance. A tower controller saw the aircraft moving and instructed the crew to hold position, which was queried by the crew. The controller then instructed the crew to cancel the takeoff, to which the crew reacted and aborted the takeoff. The Sydney ground radar showed, that the airplane had reached a maximum speed of 29 knots. The Airbus subsequently vacated the runway and returned to the holding point, where a takeoff clearance was issued. The aircraft departed without further incident.
The Australian Manual of Air Traffic Services (MATS) required, that controllers should issue traffic information as appropriate and should advise crew of the "nature of obstructions if it is not apparent", when aircraft are delayed by the traffic situation.
The ICAO Procedures for Air Navigation Services specified, that a departure instruction may be combined with a takeoff clearance, however did not provide the option to combine a departure instruction with the line up clearance.
The MATS however permitted the combination of a departure instruction with the line up clearance.
The ATSB said, that the combination of the departure instruction with the line up clearance provided an ambiguity to the flight crew, who were not used to hear such a combination. The inclusion of the reason for the delayed takeoff clearance could have reduced the likelihood of a misunderstanding by the crew. The controller did not challenge the missing "and wait" in the readback missing another opportunity to remove any ambiguity. Instead of "stop immediately" the controller issued a "hold position" instruction, which was not understood by the crew so that they questioned what was being said. ATC phraseology should be clear, concise and unambiguous and should reflect international practises and standards where possible, especially with regards to instructions to international aircraft and in safety critical situations.
The flight crew was distracted with departure preparations and provided themselves with little time to brief and comprehend the change to their departure. Had the crew not put themselves under that pressure, they may have been less distracted and may have correctly comprehended the ATC instructions. When the crew was instructed to line up and hold runway 25 combined with the departure instruction to fly heading 240, the crew erroneously took this as a takeoff clearance. The confusion was amplified by the departure instruction, which had only been heard together with a takeoff clearance before.
Air Services Australia, responsible for providing Air Traffic Control, reviewed their procedures to bring them in line with the ICAO standards. The necessary changes to MATS will commence in the August 2009 release. (avherald.com)
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