Narrative:

During the approach briefing, I said that if we landed on runway 25L at lax I expected to exit on txwys K or M and hold short of runway 25R until we were explicitly cleared to cross. I also indicated that once cleared to cross, I would expect to taxi across taxiway B and turn left onto taxiway C unless directed otherwise, then via the north route, right turn on taxiway Q, hold short of taxiway D, then as assigned to the gate. We landed on runway 25L, cleared the runway onto taxiway K, and were directed to hold short of runway 25R, and stay with the tower. Tower then cleared us to cross runway 25R, cross (or pass, I don't remember which word was used) behind an airbus eastbound on taxiway B, and contact ground control. At that time, the airbus was between txwys M and K, and was the last of several eastbound aircraft on taxiway B. I set my taxi speed so that I would pass safely behind the airbus after he crossed in front of us (this was somewhat slower than I normally would have crossed the runway). Since tower told me to go behind the airbus and taxiway B had just been used for eastbound aircraft, I assumed that tower wanted me to join taxiway C, even though he hadn't specified that. As we crossed the runway, frequency congestion did not allow us to question tower as to which taxiway he wanted us on. I told the first officer I would take C8 to taxiway C, turn left on taxiway C, and hold there until ground control gave us further instructions. The ground control frequency was congested, and by the time ground control called us back, we were turning from C8 onto taxiway C. Ground control issued the instructions to taxi via: txwys B, C10, C, north route. The first officer read back the instructions verbatim. The instructions didn't make sense to me, since I was already on taxiway C and I've never been instructed to taxi wbound on taxiway B in over 30 yrs of experience at lax. I slowed further, rechked the taxi diagram, and confirmed that we had already joined taxiway C earlier than ground control had instructed us. As the frequency was too congested to question ground control at that point and we were already on taxiway C with no traffic conflict apparent, I decided to continue slowly ahead on taxiway C. I felt that it would cause more of a problem if I stopped and waited for clarification than if I continued the short distance to C10. Ground control did not call us back, and I did not bring up the issue because I felt that it would have contributed negatively to the frequency congestion. Although I caused no conflict that I am aware of and ground control's instructions were received too late for us to be able to comply, I realize that we did not comply with those instructions. Reviewing fom page operations-51, (after landing taxi procedure) I believe that I complied with the intent of that section, as I had to turn wbound onto either taxiway B or taxiway C for the aircraft's tail to be clear of runway 25L, and had I chosen taxiway B, it was likely that I could cause a conflict. Bottom line: my expectations, briefing, experience, and the tower's phraseology led me to believe that I should continue to taxiway C. Ground control wanted me on taxiway B, and communications (both us and ATC) were not timely enough to clarify ground's intent before I was committed to turning onto taxiway C. If I had it to do all over again, I would read back the tower's runway crossing instructions and immediately ask if he wanted us to join taxiway B or taxiway C. While this would have added to the frequency congestion, it would have clarified the situation for all concerned. This would also have complied with far 91.123 (compliance with ATC clrncs and instructions. A -- when a pilot is uncertain of an ATC clearance, that pilot shall immediately request clarification from ATC), and aim 5-5-2.a.3.

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Original NASA ASRS Text

Title: B757 LNDG LAX CROSSED RWY 25R ONTO TXWY C IN LIEU OF THE TXWY B CLRNC THE GND CTLR SUBSEQUENTLY ISSUED.

Narrative: DURING THE APCH BRIEFING, I SAID THAT IF WE LANDED ON RWY 25L AT LAX I EXPECTED TO EXIT ON TXWYS K OR M AND HOLD SHORT OF RWY 25R UNTIL WE WERE EXPLICITLY CLRED TO CROSS. I ALSO INDICATED THAT ONCE CLRED TO CROSS, I WOULD EXPECT TO TAXI ACROSS TXWY B AND TURN L ONTO TXWY C UNLESS DIRECTED OTHERWISE, THEN VIA THE N RTE, R TURN ON TXWY Q, HOLD SHORT OF TXWY D, THEN AS ASSIGNED TO THE GATE. WE LANDED ON RWY 25L, CLRED THE RWY ONTO TXWY K, AND WERE DIRECTED TO HOLD SHORT OF RWY 25R, AND STAY WITH THE TWR. TWR THEN CLRED US TO CROSS RWY 25R, CROSS (OR PASS, I DON'T REMEMBER WHICH WORD WAS USED) BEHIND AN AIRBUS EBOUND ON TXWY B, AND CONTACT GND CTL. AT THAT TIME, THE AIRBUS WAS BTWN TXWYS M AND K, AND WAS THE LAST OF SEVERAL EBOUND ACFT ON TXWY B. I SET MY TAXI SPD SO THAT I WOULD PASS SAFELY BEHIND THE AIRBUS AFTER HE CROSSED IN FRONT OF US (THIS WAS SOMEWHAT SLOWER THAN I NORMALLY WOULD HAVE CROSSED THE RWY). SINCE TWR TOLD ME TO GO BEHIND THE AIRBUS AND TXWY B HAD JUST BEEN USED FOR EBOUND ACFT, I ASSUMED THAT TWR WANTED ME TO JOIN TXWY C, EVEN THOUGH HE HADN'T SPECIFIED THAT. AS WE CROSSED THE RWY, FREQ CONGESTION DID NOT ALLOW US TO QUESTION TWR AS TO WHICH TXWY HE WANTED US ON. I TOLD THE FO I WOULD TAKE C8 TO TXWY C, TURN L ON TXWY C, AND HOLD THERE UNTIL GND CTL GAVE US FURTHER INSTRUCTIONS. THE GND CTL FREQ WAS CONGESTED, AND BY THE TIME GND CTL CALLED US BACK, WE WERE TURNING FROM C8 ONTO TXWY C. GND CTL ISSUED THE INSTRUCTIONS TO TAXI VIA: TXWYS B, C10, C, N RTE. THE FO READ BACK THE INSTRUCTIONS VERBATIM. THE INSTRUCTIONS DIDN'T MAKE SENSE TO ME, SINCE I WAS ALREADY ON TXWY C AND I'VE NEVER BEEN INSTRUCTED TO TAXI WBOUND ON TXWY B IN OVER 30 YRS OF EXPERIENCE AT LAX. I SLOWED FURTHER, RECHKED THE TAXI DIAGRAM, AND CONFIRMED THAT WE HAD ALREADY JOINED TXWY C EARLIER THAN GND CTL HAD INSTRUCTED US. AS THE FREQ WAS TOO CONGESTED TO QUESTION GND CTL AT THAT POINT AND WE WERE ALREADY ON TXWY C WITH NO TFC CONFLICT APPARENT, I DECIDED TO CONTINUE SLOWLY AHEAD ON TXWY C. I FELT THAT IT WOULD CAUSE MORE OF A PROB IF I STOPPED AND WAITED FOR CLARIFICATION THAN IF I CONTINUED THE SHORT DISTANCE TO C10. GND CTL DID NOT CALL US BACK, AND I DID NOT BRING UP THE ISSUE BECAUSE I FELT THAT IT WOULD HAVE CONTRIBUTED NEGATIVELY TO THE FREQ CONGESTION. ALTHOUGH I CAUSED NO CONFLICT THAT I AM AWARE OF AND GND CTL'S INSTRUCTIONS WERE RECEIVED TOO LATE FOR US TO BE ABLE TO COMPLY, I REALIZE THAT WE DID NOT COMPLY WITH THOSE INSTRUCTIONS. REVIEWING FOM PAGE OPS-51, (AFTER LNDG TAXI PROC) I BELIEVE THAT I COMPLIED WITH THE INTENT OF THAT SECTION, AS I HAD TO TURN WBOUND ONTO EITHER TXWY B OR TXWY C FOR THE ACFT'S TAIL TO BE CLR OF RWY 25L, AND HAD I CHOSEN TXWY B, IT WAS LIKELY THAT I COULD CAUSE A CONFLICT. BOTTOM LINE: MY EXPECTATIONS, BRIEFING, EXPERIENCE, AND THE TWR'S PHRASEOLOGY LED ME TO BELIEVE THAT I SHOULD CONTINUE TO TXWY C. GND CTL WANTED ME ON TXWY B, AND COMS (BOTH US AND ATC) WERE NOT TIMELY ENOUGH TO CLARIFY GND'S INTENT BEFORE I WAS COMMITTED TO TURNING ONTO TXWY C. IF I HAD IT TO DO ALL OVER AGAIN, I WOULD READ BACK THE TWR'S RWY XING INSTRUCTIONS AND IMMEDIATELY ASK IF HE WANTED US TO JOIN TXWY B OR TXWY C. WHILE THIS WOULD HAVE ADDED TO THE FREQ CONGESTION, IT WOULD HAVE CLARIFIED THE SIT FOR ALL CONCERNED. THIS WOULD ALSO HAVE COMPLIED WITH FAR 91.123 (COMPLIANCE WITH ATC CLRNCS AND INSTRUCTIONS. A -- WHEN A PLT IS UNCERTAIN OF AN ATC CLRNC, THAT PLT SHALL IMMEDIATELY REQUEST CLARIFICATION FROM ATC), AND AIM 5-5-2.A.3.

Data retrieved from NASA's ASRS site as of July 2007 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.