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Air carrier medium large transport takeoff abort because of uneven engine spool up and loss of aircraft control.
| Attributes | |
| ACN | 198935 |
| Time | |
| Date | 199201 |
| Day | Sun |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : tus |
| State Reference | AZ |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | climbout : takeoff other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time total : 9000 |
| ASRS Report | 198935 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi |
| Experience | flight time last 90 days : 150 flight time total : 9700 flight time type : 1300 |
| ASRS Report | 198897 |
| Events | |
| Anomaly | aircraft equipment problem : less severe other anomaly |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : regained aircraft control flight crew : rejected takeoff |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Taxi out from the gate to runway 11L was routine, all checklists were completed. Upon receiving takeoff clearance, as the aircraft entered the runway, power was advanced. The #1 engine was slow to accelerate. When positive acceleration on #1 engine was observed, the toga button on the autothrottle system was engaged. The #2 engine accelerated rapidly while the #1 engine continued to lag. The aircraft yawed violently to the left, and the takeoff was aborted. We taxied back to the ramp, and an appropriate logbook entry was made. Supplemental information from acn 198897: the yaw induced by asymmetrical thrust resulted in minor runway excursion with left main and nose gear exiting runway briefly. Returned to gate and inspected -- no damage. Factors related to incident are the characteristically slow acceleration of engines and frequent dissimilar rates of acceleration between left and right engines. This particular engine was abnormally slow to accelerate. Contributing factor also was very low gross weight of aircraft at takeoff.
Original NASA ASRS Text
Title: ACR MLG TKOF ABORT BECAUSE OF UNEVEN ENG SPOOL UP AND LOSS OF ACFT CTL.
Narrative: TAXI OUT FROM THE GATE TO RWY 11L WAS ROUTINE, ALL CHKLISTS WERE COMPLETED. UPON RECEIVING TKOF CLRNC, AS THE ACFT ENTERED THE RWY, PWR WAS ADVANCED. THE #1 ENG WAS SLOW TO ACCELERATE. WHEN POSITIVE ACCELERATION ON #1 ENG WAS OBSERVED, THE TOGA BUTTON ON THE AUTOTHROTTLE SYS WAS ENGAGED. THE #2 ENG ACCELERATED RAPIDLY WHILE THE #1 ENG CONTINUED TO LAG. THE ACFT YAWED VIOLENTLY TO THE L, AND THE TKOF WAS ABORTED. WE TAXIED BACK TO THE RAMP, AND AN APPROPRIATE LOGBOOK ENTRY WAS MADE. SUPPLEMENTAL INFO FROM ACN 198897: THE YAW INDUCED BY ASYMMETRICAL THRUST RESULTED IN MINOR RWY EXCURSION WITH L MAIN AND NOSE GEAR EXITING RWY BRIEFLY. RETURNED TO GATE AND INSPECTED -- NO DAMAGE. FACTORS RELATED TO INCIDENT ARE THE CHARACTERISTICALLY SLOW ACCELERATION OF ENGS AND FREQUENT DISSIMILAR RATES OF ACCELERATION BTWN L AND R ENGS. THIS PARTICULAR ENG WAS ABNORMALLY SLOW TO ACCELERATE. CONTRIBUTING FACTOR ALSO WAS VERY LOW GROSS WT OF ACFT AT TKOF.
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.