Narrative:

Air carrier X being vectored by st louis approach for runway 30L at lambert. Approach asked us if we had the airport in sight. We confirmed we had the airport in sight. Approach pointed out traffic on a parallel approach for runway 30R which we also had in sight. Approach told us to descend to 2500 ft, turn to heading 320 degrees and started to clear us for the approach when communication was lost mid sentence. If we continued on the 320 degree heading we would have conflicted with the parallel traffic. We tried twice to re-establish contact with approach with no luck. I turned the aircraft on the approach to avoid a conflict and we called the tower that we were on the approach and he said 'continue.' we continued the approach and learned that the problem was a B747 in position on runway 30L and had some passenger get out of their seats so he could not start his takeoff roll. Tower called us and said this wasn't going to work and gave us a climb to 2500 ft and a heading for the missed approach. No conflict occurred but looking back on the situation I am not sure that I should have departed 2500 ft and started the approach. I believe the reason for the lost communication was that tower was talking to approach about the problem with the B747.

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Original NASA ASRS Text

Title: ACR X GAR DUE TO OCCUPIED RWY.

Narrative: ACR X BEING VECTORED BY ST LOUIS APCH FOR RWY 30L AT LAMBERT. APCH ASKED US IF WE HAD THE ARPT IN SIGHT. WE CONFIRMED WE HAD THE ARPT IN SIGHT. APCH POINTED OUT TFC ON A PARALLEL APCH FOR RWY 30R WHICH WE ALSO HAD IN SIGHT. APCH TOLD US TO DSND TO 2500 FT, TURN TO HDG 320 DEGS AND STARTED TO CLR US FOR THE APCH WHEN COM WAS LOST MID SENTENCE. IF WE CONTINUED ON THE 320 DEG HDG WE WOULD HAVE CONFLICTED WITH THE PARALLEL TFC. WE TRIED TWICE TO RE-ESTABLISH CONTACT WITH APCH WITH NO LUCK. I TURNED THE ACFT ON THE APCH TO AVOID A CONFLICT AND WE CALLED THE TWR THAT WE WERE ON THE APCH AND HE SAID 'CONTINUE.' WE CONTINUED THE APCH AND LEARNED THAT THE PROB WAS A B747 IN POS ON RWY 30L AND HAD SOME PAX GET OUT OF THEIR SEATS SO HE COULD NOT START HIS TKOF ROLL. TWR CALLED US AND SAID THIS WASN'T GOING TO WORK AND GAVE US A CLB TO 2500 FT AND A HDG FOR THE MISSED APCH. NO CONFLICT OCCURRED BUT LOOKING BACK ON THE SIT I AM NOT SURE THAT I SHOULD HAVE DEPARTED 2500 FT AND STARTED THE APCH. I BELIEVE THE REASON FOR THE LOST COM WAS THAT TWR WAS TALKING TO APCH ABOUT THE PROB WITH THE B747.

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.