Air carrier flight crew has takeoff warning horn on fast taxi. Reset and checked everything that wou...

Attributes
ACN	129881
Time
Date	198911
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hou
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 270 flight time total : 12000 flight time type : 10000
ASRS Report	129881
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

When 'cleared into position and hold,' we were told to be ready for an immediate as an aircraft was clearing and one was on final. I used a little more power to taxi than usual to expedite and got the takeoff warning horn. I reset the speed brake handle and checked all other indicators which would cause the warning. The throttles were advanced and retarded quickly beyond the warning range and the horn did not sound. We assumed resetting the speed brake had corrected the problem. Immediately after checking the horn we were cleared for takeoff. As I was about to call V1 (about 125 KTS), the horn began to sound again. I told the first officer to continue the takeoff. I quickly rechked the indicators and speed brake down and called 'rotate.' this may have kept us on the runway an additional moment, but I wanted to anticipate any roll if the flaps were wrong, and be ready to take the aircraft. The takeoff was normal and the horn stopped as the wheels left the runway. During taxi-in at destination, we checked the horn in all configns, and it worked when it was supposed and didn't when it shouldn't. We tried every combination. Again during taxi-out for the next leg we did the same and no problem. The subsequent leg was normal. This was an medium large transport which seems to have a lot of electrical gremlins at times. Technically we were right at or just short of V1, but I feel that a high speed abort would have been much more dangerous than continuing, given recent aircraft accident history. By rechking everything and then taking off, I feel we were much safer than than aborting, with about 5 KTS to go to V1, when I was 99% sure it was a false warning. Earlier we had also gotten a false confign warning, which would not repeat with this aircraft the same day 2 flts earlier. I feel that the hard rule about aborting prior to V1,'period,' should be carefully reviewed given recent accident history.

Original NASA ASRS Text

Title: ACR FLT CREW HAS TKOF WARNING HORN ON FAST TAXI. RESET AND CHECKED EVERYTHING THAT WOULD CAUSE SUCH A WARNING. PROCEEDED WITH TKOF. JUST PRIOR TO V1, HORN SOUNDED AGAIN. QUICKLY CHECKED AND CONTINUED TKOF.

Narrative: WHEN 'CLRED INTO POS AND HOLD,' WE WERE TOLD TO BE READY FOR AN IMMEDIATE AS AN ACFT WAS CLRING AND ONE WAS ON FINAL. I USED A LITTLE MORE PWR TO TAXI THAN USUAL TO EXPEDITE AND GOT THE TKOF WARNING HORN. I RESET THE SPD BRAKE HANDLE AND CHKED ALL OTHER INDICATORS WHICH WOULD CAUSE THE WARNING. THE THROTTLES WERE ADVANCED AND RETARDED QUICKLY BEYOND THE WARNING RANGE AND THE HORN DID NOT SOUND. WE ASSUMED RESETTING THE SPD BRAKE HAD CORRECTED THE PROB. IMMEDIATELY AFTER CHKING THE HORN WE WERE CLRED FOR TKOF. AS I WAS ABOUT TO CALL V1 (ABOUT 125 KTS), THE HORN BEGAN TO SOUND AGAIN. I TOLD THE F/O TO CONTINUE THE TKOF. I QUICKLY RECHKED THE INDICATORS AND SPD BRAKE DOWN AND CALLED 'ROTATE.' THIS MAY HAVE KEPT US ON THE RWY AN ADDITIONAL MOMENT, BUT I WANTED TO ANTICIPATE ANY ROLL IF THE FLAPS WERE WRONG, AND BE READY TO TAKE THE ACFT. THE TKOF WAS NORMAL AND THE HORN STOPPED AS THE WHEELS LEFT THE RWY. DURING TAXI-IN AT DEST, WE CHKED THE HORN IN ALL CONFIGNS, AND IT WORKED WHEN IT WAS SUPPOSED AND DIDN'T WHEN IT SHOULDN'T. WE TRIED EVERY COMBINATION. AGAIN DURING TAXI-OUT FOR THE NEXT LEG WE DID THE SAME AND NO PROB. THE SUBSEQUENT LEG WAS NORMAL. THIS WAS AN MLG WHICH SEEMS TO HAVE A LOT OF ELECTRICAL GREMLINS AT TIMES. TECHNICALLY WE WERE RIGHT AT OR JUST SHORT OF V1, BUT I FEEL THAT A HIGH SPD ABORT WOULD HAVE BEEN MUCH MORE DANGEROUS THAN CONTINUING, GIVEN RECENT ACFT ACCIDENT HISTORY. BY RECHKING EVERYTHING AND THEN TAKING OFF, I FEEL WE WERE MUCH SAFER THAN THAN ABORTING, WITH ABOUT 5 KTS TO GO TO V1, WHEN I WAS 99% SURE IT WAS A FALSE WARNING. EARLIER WE HAD ALSO GOTTEN A FALSE CONFIGN WARNING, WHICH WOULD NOT REPEAT WITH THIS ACFT THE SAME DAY 2 FLTS EARLIER. I FEEL THAT THE HARD RULE ABOUT ABORTING PRIOR TO V1,'PERIOD,' SHOULD BE CAREFULLY REVIEWED GIVEN RECENT ACCIDENT HISTORY.

Data retrieved from NASA's ASRS site as of August 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.

Air carrier flight crew has takeoff warning horn on fast taxi. Reset and checked everything that would cause such a warning. Proceeded with takeoff. Just prior to V1, horn sounded again. Quickly checked and continued takeoff.