|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||airport : wsss.airport|
|Altitude||agl single value : 0|
|Controlling Facilities||tower : pdx.tower|
|Operator||common carrier : air carrier|
|Make Model Name||B747-400|
|Operating Under FAR Part||Part 121|
|Flight Phase||ground : taxi|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
observation : company check pilot
oversight : pic
|Experience||flight time last 90 days : 75|
flight time total : 11000
flight time type : 1500
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Anomaly||incursion : runway|
non adherence : clearance
|Independent Detector||other controllera|
|Resolutory Action||none taken : detected after the fact|
|Consequence||faa : reviewed incident with flight crew|
|Problem Areas||ATC Human Performance|
Flight Crew Human Performance
On taxi out from wsss en route vhhh nearing the departure end of runway 20C ground asked 'would we be ready when we reached the runway.' the first officer responded 'yes' and we were told to contact tower. Initial contact to the tower was; 'air carrier X ready in sequence.' the next transmission from the tower was 'position runway 20C.' the first officer responded 'position 20 center.' as we taxied onto the runway the tower cleared us for an 'immediate' takeoff. Not long after being airborne we were asked why we had entered the runway (or words to that effect). Again at altitude; we were switched to what must have been a frequency not normally used by wsss control and asked essentially the same question. We replied that we had been cleared into 'position' and I asked for a telephone number to contact them upon reaching vhhh. After a couple of calls to wsss control; I was eventually told that upon initial contact the tower had said 'good morning; air carrier X hold short of runway 20 center.' we had responded 'position runway 20 center' and the tower had said nothing in response. Regarding human factors; to me; the instruction 'position' like the instruction 'line up and wait' are unique to international flying and different enough from the instruction 'position and hold' (that both the first officer and I are used to) that I immediately hear the difference and pause to make sure I know what is wanted. It seems unlikely that both I and the first officer would have confused the words 'hold short' with the non standard (to us) phrase 'position.' equally unlikely would be the first officer's response to the words 'hold short' with the word 'position' that he rarely uses. If anything; he would most likely have said 'position and hold' which would have contradicted the information from the phone conversation with wsss control. I'm at a loss to explain this situation. Though the remainder of the flight was uneventful; the anxiety over this situation was apparent. Wsss control said they would report this directly to our company.
Original NASA ASRS Text
Title: B747-400 ENTERS THE RWY AT WSSS WITHOUT CLRNC DUE TO CONFUSION REGARDING TERMINOLOGY.
Narrative: ON TAXI OUT FROM WSSS ENRTE VHHH NEARING THE DEP END OF RWY 20C GND ASKED 'WOULD WE BE READY WHEN WE REACHED THE RWY.' THE FO RESPONDED 'YES' AND WE WERE TOLD TO CONTACT TWR. INITIAL CONTACT TO THE TWR WAS; 'ACR X READY IN SEQUENCE.' THE NEXT XMISSION FROM THE TWR WAS 'POS RWY 20C.' THE FO RESPONDED 'POS 20 CTR.' AS WE TAXIED ONTO THE RWY THE TWR CLRED US FOR AN 'IMMEDIATE' TKOF. NOT LONG AFTER BEING AIRBORNE WE WERE ASKED WHY WE HAD ENTERED THE RWY (OR WORDS TO THAT EFFECT). AGAIN AT ALT; WE WERE SWITCHED TO WHAT MUST HAVE BEEN A FREQ NOT NORMALLY USED BY WSSS CTL AND ASKED ESSENTIALLY THE SAME QUESTION. WE REPLIED THAT WE HAD BEEN CLRED INTO 'POS' AND I ASKED FOR A TELEPHONE NUMBER TO CONTACT THEM UPON REACHING VHHH. AFTER A COUPLE OF CALLS TO WSSS CTL; I WAS EVENTUALLY TOLD THAT UPON INITIAL CONTACT THE TWR HAD SAID 'GOOD MORNING; ACR X HOLD SHORT OF RWY 20 CTR.' WE HAD RESPONDED 'POS RWY 20 CTR' AND THE TWR HAD SAID NOTHING IN RESPONSE. REGARDING HUMAN FACTORS; TO ME; THE INSTRUCTION 'POS' LIKE THE INSTRUCTION 'LINE UP AND WAIT' ARE UNIQUE TO INTL FLYING AND DIFFERENT ENOUGH FROM THE INSTRUCTION 'POS AND HOLD' (THAT BOTH THE FO AND I ARE USED TO) THAT I IMMEDIATELY HEAR THE DIFFERENCE AND PAUSE TO MAKE SURE I KNOW WHAT IS WANTED. IT SEEMS UNLIKELY THAT BOTH I AND THE FO WOULD HAVE CONFUSED THE WORDS 'HOLD SHORT' WITH THE NON STANDARD (TO US) PHRASE 'POS.' EQUALLY UNLIKELY WOULD BE THE FO'S RESPONSE TO THE WORDS 'HOLD SHORT' WITH THE WORD 'POS' THAT HE RARELY USES. IF ANYTHING; HE WOULD MOST LIKELY HAVE SAID 'POS AND HOLD' WHICH WOULD HAVE CONTRADICTED THE INFO FROM THE PHONE CONVERSATION WITH WSSS CTL. I'M AT A LOSS TO EXPLAIN THIS SITUATION. THOUGH THE REMAINDER OF THE FLT WAS UNEVENTFUL; THE ANXIETY OVER THIS SITUATION WAS APPARENT. WSSS CTL SAID THEY WOULD RPT THIS DIRECTLY TO OUR COMPANY.
Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.