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Medium large transport on takeoff roll, at 80 KTS flap warning horn sounded. Flight crew aborted takeoff.
| Attributes | |
| ACN | 106644 |
| Time | |
| Date | 198903 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : dca |
| State Reference | VA |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | climbout : takeoff other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 100 flight time total : 10000 flight time type : 1500 |
| ASRS Report | 106644 |
| Events | |
| Anomaly | aircraft equipment problem : critical |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : rejected takeoff |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Aborted takeoff runway 35 due to takeoff warning horn sounding and voice saying, 'flaps.' this occurred at approximately 80 KTS. Flaps had been set and verified prior to taking the runway, and warning did not sound when both throttles were advanced to test the system. Warning did not occur when throttles were initially advanced--but sounded at about 80 KTS. After clearing the runway, the flaps were again visually checked to be set properly. The flaps were set using the dial-a-flap to a setting of 18.4. After conferring with maintenance and securing a new load plan, a subsequent takeoff was made using the standard 15 degree flap detent, ie, no dial-a-flap. This takeoff was uneventful. The problem appeared to be with the dial-a-flap system, because even though the flaps were properly set, the warning system activated at about 80 KTS. A further problem is, 'why the system activated at 80 KTS?' why not during the test or when throttles advanced for takeoff? Reporter stated he has used the dial-a-flap system many times. This was the first time it had not worked properly. Maintenance found nothing wrong with the system and speculated it was a one time fluke. It may be that some small adjustment was edgy enough to cause the one time electrical malfunction.
Original NASA ASRS Text
Title: MLG ON TKOF ROLL, AT 80 KTS FLAP WARNING HORN SOUNDED. FLT CREW ABORTED TKOF.
Narrative: ABORTED TKOF RWY 35 DUE TO TKOF WARNING HORN SOUNDING AND VOICE SAYING, 'FLAPS.' THIS OCCURRED AT APPROX 80 KTS. FLAPS HAD BEEN SET AND VERIFIED PRIOR TO TAKING THE RWY, AND WARNING DID NOT SOUND WHEN BOTH THROTTLES WERE ADVANCED TO TEST THE SYS. WARNING DID NOT OCCUR WHEN THROTTLES WERE INITIALLY ADVANCED--BUT SOUNDED AT ABOUT 80 KTS. AFTER CLRING THE RWY, THE FLAPS WERE AGAIN VISUALLY CHKED TO BE SET PROPERLY. THE FLAPS WERE SET USING THE DIAL-A-FLAP TO A SETTING OF 18.4. AFTER CONFERRING WITH MAINT AND SECURING A NEW LOAD PLAN, A SUBSEQUENT TKOF WAS MADE USING THE STANDARD 15 DEG FLAP DETENT, IE, NO DIAL-A-FLAP. THIS TKOF WAS UNEVENTFUL. THE PROB APPEARED TO BE WITH THE DIAL-A-FLAP SYS, BECAUSE EVEN THOUGH THE FLAPS WERE PROPERLY SET, THE WARNING SYS ACTIVATED AT ABOUT 80 KTS. A FURTHER PROB IS, 'WHY THE SYS ACTIVATED AT 80 KTS?' WHY NOT DURING THE TEST OR WHEN THROTTLES ADVANCED FOR TKOF? RPTR STATED HE HAS USED THE DIAL-A-FLAP SYS MANY TIMES. THIS WAS THE FIRST TIME IT HAD NOT WORKED PROPERLY. MAINT FOUND NOTHING WRONG WITH THE SYS AND SPECULATED IT WAS A ONE TIME FLUKE. IT MAY BE THAT SOME SMALL ADJUSTMENT WAS EDGY ENOUGH TO CAUSE THE ONE TIME ELECTRICAL MALFUNCTION.
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.