|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : cle|
|Altitude||agl bound lower : 0|
agl bound upper : 0
|Controlling Facilities||tracon : sat|
|Operator||common carrier : air carrier|
|Make Model Name||Medium Large Transport, Low Wing, 2 Turbojet Eng|
|Flight Phase||climbout : takeoff|
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Qualification||pilot : flight engineer|
pilot : instrument
pilot : commercial
|Experience||flight time last 90 days : 210|
flight time total : 3000
flight time type : 350
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Anomaly||aircraft equipment problem : critical|
other anomaly other
|Independent Detector||other flight crewa|
|Resolutory Action||flight crew : declared emergency|
flight crew : rejected takeoff
Takeoff runway 23L cle, power advanced by captain. Takeoff power set on both sides and slight EPR fluctuation noted on #2 gauge. Immediate decision made to abort to a speed slightly below 60 KTS. Abort procedures followed normally and aircraft stopped with normal effort. Upon discussion of EPR anomaly, decided that instruments may have been misinterpreted or that needle movement may have been caused by throttle movement by captain. Upon hearing my questioning the engine indications the captain aborted immediately before further evaluation of other parameters could take place, and we therefore thought the best course of action would be to run the engine in a less critical time. Engine run to approximately 1.8 EPR at pad and all indications normal. Returned for takeoff. Good spool and power advanced normally to takeoff thrust. After approximately 80 KTS I noticed small fluctuations in the N1 gauge for #2 and x-chked it against a slightly fluctuating EPR abort made again at 110 KTS (V1 112) and returned to gate. Aircraft was very light for this flight and so accelerated very rapidly on both takeoff attempts. It was very difficult to thoroughly note parameters, but I believe on the first attempt the EPR fluctuated by about +/-.05 and on the second by +/-.03, with only a flutter of north, around 93%. I commend the captain for his quick decisions to abort when I raised even the question of something being wrong. Upon return to gate, aircraft parked on taxiway for approximately 20 mins for brake cooling, gear assembly checked by maintenance, and then aircraft taxied to gate.
Original NASA ASRS Text
Title: ACR MLG TKOF ABORT DUE ENGINE POWER FLUCTUATION BEFORE V1.
Narrative: TKOF RWY 23L CLE, PWR ADVANCED BY CAPT. TKOF PWR SET ON BOTH SIDES AND SLIGHT EPR FLUCTUATION NOTED ON #2 GAUGE. IMMEDIATE DECISION MADE TO ABORT TO A SPD SLIGHTLY BELOW 60 KTS. ABORT PROCS FOLLOWED NORMALLY AND ACFT STOPPED WITH NORMAL EFFORT. UPON DISCUSSION OF EPR ANOMALY, DECIDED THAT INSTRUMENTS MAY HAVE BEEN MISINTERPRETED OR THAT NEEDLE MOVEMENT MAY HAVE BEEN CAUSED BY THROTTLE MOVEMENT BY CAPT. UPON HEARING MY QUESTIONING THE ENG INDICATIONS THE CAPT ABORTED IMMEDIATELY BEFORE FURTHER EVALUATION OF OTHER PARAMETERS COULD TAKE PLACE, AND WE THEREFORE THOUGHT THE BEST COURSE OF ACTION WOULD BE TO RUN THE ENG IN A LESS CRITICAL TIME. ENG RUN TO APPROX 1.8 EPR AT PAD AND ALL INDICATIONS NORMAL. RETURNED FOR TKOF. GOOD SPOOL AND PWR ADVANCED NORMALLY TO TKOF THRUST. AFTER APPROX 80 KTS I NOTICED SMALL FLUCTUATIONS IN THE N1 GAUGE FOR #2 AND X-CHKED IT AGAINST A SLIGHTLY FLUCTUATING EPR ABORT MADE AGAIN AT 110 KTS (V1 112) AND RETURNED TO GATE. ACFT WAS VERY LIGHT FOR THIS FLT AND SO ACCELERATED VERY RAPIDLY ON BOTH TKOF ATTEMPTS. IT WAS VERY DIFFICULT TO THOROUGHLY NOTE PARAMETERS, BUT I BELIEVE ON THE FIRST ATTEMPT THE EPR FLUCTUATED BY ABOUT +/-.05 AND ON THE SECOND BY +/-.03, WITH ONLY A FLUTTER OF N, AROUND 93%. I COMMEND THE CAPT FOR HIS QUICK DECISIONS TO ABORT WHEN I RAISED EVEN THE QUESTION OF SOMETHING BEING WRONG. UPON RETURN TO GATE, ACFT PARKED ON TXWY FOR APPROX 20 MINS FOR BRAKE COOLING, GEAR ASSEMBLY CHKED BY MAINT, AND THEN ACFT TAXIED TO GATE.
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.