ACR WDB CROSSED ACTIVE RWY WITHOUT CLRNC.

Narrative

AT XA20 LCL TIME ON LAST 7/THU/88; OUR ACFT LANDED ON THE LAX RWY 24R. WE ENTERED TXWY 75V; CROSSED RWY 24L AND DIRECTED TO THE PARKING SPOT OF THE S SIDE OF ARPT THROUGH TXWYS U. WE COULD WELL ESTABLISH A COM WITH THE GND CTL ON THE N SIDE OF 50 YD LINE USING THE N SIDE GND FREQ. HOWEVER; WHEN WE SWITCHED IT TO THE S ONE ON TXWY 49M; WE COULD NOT DO WELL BECAUSE WE WERE IN THE BUSY TIME ZONE. THEREAFTER; BY AN INSTRUCTION FROM THE GND CTLR; WE MADE A LEFT TURN TO TXWY J AND CAME TO HALT AT TXWY 47J. THEN THEY SEEMED TO GIVE US AN INSTRUCTION: 'CONTINUE E...;' BUT WHICH WAS INAUDIBLE; BUT HESITATING WHAT TO DO; WE HEARD IT AS IF WE WERE INSTRUCTED TO MAKE A RIGHT TURN. WE TRIED TO CONFIRM THEIR INSTRUCTION W/O RECEIVING THEIR QUICK RESPONSE; BUT THEY SEEMED TO GIVE US AN INSTRUCTION: 'CONTINUE...;' AS IF THEY RESPONDED TO OUR INQUIRY. WHEN WE WANTED TO BRING THE ACFT HDG TO TXWY 47J; IT SEEMED TO US THAT THEY GAVE US AN INSTRUCTION TO MOVE AHEAD BECAUSE OF THE FOLLOWING TFC AND THEN TO 'CONTINUE.' AT THAT TIME; OUR ACFT NOSE SECTION PUSHED OUT TO THE RWY EDGE AND WE TOOK AN INSTRUCTION 'CONTINUE' IN THE MEANING OF A CLRNC OF RWY XING WHICH WAS ISSUED UNDER AN AGREEMENT BTWN THE GND CTL AND THE TWR CTL; AND THEN ATTEMPTED TO CROSS THE RWY W/O SWITCHING THE GND FREQ TO THE TWR ONE AND ALSO CONFIRMING AN INSTRUCTION; 'CLR CROSS...' IMMEDIATELY THEREAFTER; WE WERE TOLD THAT THEY ISSUED NO CLRNC OF RWY XING. I BELIEVE THIS INCIDENT IS ATTRIBUTABLE TO THE FOLLOWING: NOTWITHSTANDING ATC INSTRUCTION WAS INAUDIBLE BECAUSE COM WAS IN A POOR CONDITION WITH INTERFERENCE; ETC; WE ATTEMPTED TO PROCEED WITH OUR OPS WITH MY POOR JUDGEMENT. ON THE OTHER HAND; I WOULD LIKE TO ASK THE GND CTLR FOR ISSUING A CLEAR INSTRUCTION USING A SHORT WORDING EXPRESSING ACTION SUCH AS STOP; HOLD; TAXI; GO; ETC; FOLLOWED BY FLT NUMBER. IN VIEW OF THIS INCIDENT; I REFLECT ON MY CONDUCTS; WHICH WE WILL CHANGE TO THE FOLLOWING LESSONS IN FUTURE: DO NOT ACT BY A JUDGEMENT CONVENIENT TO ONESELF; DO NOT MOVE BUT WAIT FOR THE NEXT INSTRUCTION WHEN AN INSTRUCTION WAS INAUDIBLE ON THE GND FULL OF TFC; AND CONFIRM AN INSTRUCTION--WAITING FOR A CONDITION WITH COM POSSIBLE. SUPPLEMENTAL INFO FROM ACN 90943: WE VAINLY TRIED TO GO BTWN THE VERY BUSY ATC COM FOR OUR CONFIRMATION AS POSSIBLE. THERE WAS NO ROOM FOR ESTABLISHING COM. WE OPERATED THE ACFT NOTWITHSTANDING NONE OF OUR 3 CREWMEMBERS CONFIRMED AN INSTRUCTION: 'CLR CROSS...' THIS IS THE MOST IMPORTANT PROB. LESSONS: DO NOT MAKE HASTE; DO NOT MOVE WHEN INAUDIBLE; ADVISE THE CAPT TO CONFIRM ONCE AGAIN; NEVER MAKE SUCH SPEECH AND BEHAVIOR AS TO PUZZLE THE CAPT; TRY TO COM BY THE CAPT'S ORDERS AND DARE TO SAY; 'WAIT A MOMENT; PLEASE!'