Narrative:

While holding #1 for takeoff at taxiway B for runway 25L at las vegas, tower cleared company flight Y for takeoff on runway 25L (they were position and hold runway 25L). After company flight Y answered tower, we (flight X) were cleared position and hold runway 25L. Before I realized my parking brake was set, I advanced power on one engine to check for a takeoff warning and due to the brakes set, I received 1 or 2 beeps before the brakes were released. This occurred at the same time my first officer repeated position and hold on tower frequency. Company flight Y, which had started their takeoff roll, aborted due to a takeoff warning horn. Was this coincidence or did they abort after hearing a beep on tower frequency during our position and hold readback? This I don't know, but it's possible this was the cause. Ensuring the brakes are released next time would prevent this. If, in fact, the other aircraft aborted for a horn beep over the radio, the only way to prevent this in the future would be for all company warning horn checks to be done prior to depressing the microphone switch.

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Original NASA ASRS Text

Title: B737-300 CREW HAD A TKOF WARNING HORN SOUND AT THE SAME TIME THEIR RADIO COM MIKE WAS KEYED. AN ACFT ON TKOF ROLL MAY HAVE ABORTED TKOF AFTER HEARING THE WARNING HORN ON THEIR RADIO HEADSETS.

Narrative: WHILE HOLDING #1 FOR TKOF AT TXWY B FOR RWY 25L AT LAS VEGAS, TWR CLRED COMPANY FLT Y FOR TKOF ON RWY 25L (THEY WERE POS AND HOLD RWY 25L). AFTER COMPANY FLT Y ANSWERED TWR, WE (FLT X) WERE CLRED POS AND HOLD RWY 25L. BEFORE I REALIZED MY PARKING BRAKE WAS SET, I ADVANCED PWR ON ONE ENG TO CHK FOR A TKOF WARNING AND DUE TO THE BRAKES SET, I RECEIVED 1 OR 2 BEEPS BEFORE THE BRAKES WERE RELEASED. THIS OCCURRED AT THE SAME TIME MY FO REPEATED POS AND HOLD ON TWR FREQ. COMPANY FLT Y, WHICH HAD STARTED THEIR TKOF ROLL, ABORTED DUE TO A TKOF WARNING HORN. WAS THIS COINCIDENCE OR DID THEY ABORT AFTER HEARING A BEEP ON TWR FREQ DURING OUR POS AND HOLD READBACK? THIS I DON'T KNOW, BUT IT'S POSSIBLE THIS WAS THE CAUSE. ENSURING THE BRAKES ARE RELEASED NEXT TIME WOULD PREVENT THIS. IF, IN FACT, THE OTHER ACFT ABORTED FOR A HORN BEEP OVER THE RADIO, THE ONLY WAY TO PREVENT THIS IN THE FUTURE WOULD BE FOR ALL COMPANY WARNING HORN CHKS TO BE DONE PRIOR TO DEPRESSING THE MIKE SWITCH.

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.