|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||atc facility : lga|
|Altitude||msl bound lower : 17000|
msl bound upper : 17000
|Controlling Facilities||artcc : zny|
|Operator||common carrier : air carrier|
|Make Model Name||B737-500|
|Operating Under FAR Part||Part 121|
|Navigation In Use||Other |
|Flight Phase||climbout : intermediate altitude|
|Route In Use||enroute airway : zny|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 260|
flight time total : 15000
flight time type : 1310
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Qualification||pilot : instrument|
pilot : commercial
|Anomaly||aircraft equipment problem : critical|
other anomaly other
|Independent Detector||other flight crewa|
|Resolutory Action||flight crew : declared emergency|
Flight xyz lga to hou may/xx/98. Climbing out of lga, we received an intermediate leveloff at 17000 ft. Since the FMC had previously failed, the autothrottles were not engaged. We were manually adjusting the throttles as needed for the various flight modes. The left autoplt was engaged, and when it pitched over to acquire 17000 ft, the airspeed began building very rapidly. I (captain) was flying, so I pulled both throttles back to mid position. I was looking at the N1 gauges as I did so, and I noticed that #2 N1 did not reduce from its climb setting of 91%. The first officer remarked the airspeed was in the 320-330 KT range. I pulled the #1 throttle back to keep the airspeed in limits. The first officer told ATC that we had a problem and we wanted to stay at 17000 ft while we evaluated it. The first officer radioed ewr maintenance for assistance. We made several attempts to regain control of the engine (turned off the power management computers, tried engaging the autothrottles, looked for circuit breakers to pull, etc -- all without result), but could not. I declared an emergency and we reversed course for ewr. Neither the QRH nor the flight manual had any procedure for this problem. We rejected anything that involved a restart due to the fact that the engine was at such a high power setting. Had the engine been at an intermediate power setting, or down towards idle, we might have tried a restart. ATC gave us a descent clearance. We tried descending at a shallow angle with the speed brake out and #1 engine at idle to see if we could keep the airspeed within limits. It became apparent that as we descended into the thicker air, the airspeed would soon be bumping up against the maximum limit. I told the first officer to open the QRH to the 'engine fire/failure/separation' checklist and to prepare to shut the engine down so we could descend at a more reasonable speed. We ran the checklist, shutting down the #2 engine. It was a noisy, 'aggressive' shutdown, in that there was a lot of yaw. I told the passenger what had happened and what we were doing and that we were heading back to ewr (I had already told the lead flight attendant). We made an uneventful landing at ewr. Callback conversation with reporter revealed the following information: the reporter stated there was no control over this engine except to shut it down. The reporter said it was not a case of the thrust lever being frozen since the lever moved smoothly in manual and the autothrottle system moved it forward and aft. The reporter stated maintenance did not report the corrective action taken but suspects possible main fuel control failure.
Original NASA ASRS Text
Title: A B737-500 IN CLB AT 17000 FT DECLARED AN EMER AND DIVERTED DUE TO #2 ENG PWR STUCK AT 91% AND REQUIRING INFLT ENG SHUTDOWN.
Narrative: FLT XYZ LGA TO HOU MAY/XX/98. CLBING OUT OF LGA, WE RECEIVED AN INTERMEDIATE LEVELOFF AT 17000 FT. SINCE THE FMC HAD PREVIOUSLY FAILED, THE AUTOTHROTTLES WERE NOT ENGAGED. WE WERE MANUALLY ADJUSTING THE THROTTLES AS NEEDED FOR THE VARIOUS FLT MODES. THE L AUTOPLT WAS ENGAGED, AND WHEN IT PITCHED OVER TO ACQUIRE 17000 FT, THE AIRSPD BEGAN BUILDING VERY RAPIDLY. I (CAPT) WAS FLYING, SO I PULLED BOTH THROTTLES BACK TO MID POS. I WAS LOOKING AT THE N1 GAUGES AS I DID SO, AND I NOTICED THAT #2 N1 DID NOT REDUCE FROM ITS CLB SETTING OF 91%. THE FO REMARKED THE AIRSPD WAS IN THE 320-330 KT RANGE. I PULLED THE #1 THROTTLE BACK TO KEEP THE AIRSPD IN LIMITS. THE FO TOLD ATC THAT WE HAD A PROB AND WE WANTED TO STAY AT 17000 FT WHILE WE EVALUATED IT. THE FO RADIOED EWR MAINT FOR ASSISTANCE. WE MADE SEVERAL ATTEMPTS TO REGAIN CTL OF THE ENG (TURNED OFF THE PWR MANAGEMENT COMPUTERS, TRIED ENGAGING THE AUTOTHROTTLES, LOOKED FOR CIRCUIT BREAKERS TO PULL, ETC -- ALL WITHOUT RESULT), BUT COULD NOT. I DECLARED AN EMER AND WE REVERSED COURSE FOR EWR. NEITHER THE QRH NOR THE FLT MANUAL HAD ANY PROC FOR THIS PROB. WE REJECTED ANYTHING THAT INVOLVED A RESTART DUE TO THE FACT THAT THE ENG WAS AT SUCH A HIGH PWR SETTING. HAD THE ENG BEEN AT AN INTERMEDIATE PWR SETTING, OR DOWN TOWARDS IDLE, WE MIGHT HAVE TRIED A RESTART. ATC GAVE US A DSCNT CLRNC. WE TRIED DSNDING AT A SHALLOW ANGLE WITH THE SPD BRAKE OUT AND #1 ENG AT IDLE TO SEE IF WE COULD KEEP THE AIRSPD WITHIN LIMITS. IT BECAME APPARENT THAT AS WE DSNDED INTO THE THICKER AIR, THE AIRSPD WOULD SOON BE BUMPING UP AGAINST THE MAX LIMIT. I TOLD THE FO TO OPEN THE QRH TO THE 'ENG FIRE/FAILURE/SEPARATION' CHKLIST AND TO PREPARE TO SHUT THE ENG DOWN SO WE COULD DSND AT A MORE REASONABLE SPD. WE RAN THE CHKLIST, SHUTTING DOWN THE #2 ENG. IT WAS A NOISY, 'AGGRESSIVE' SHUTDOWN, IN THAT THERE WAS A LOT OF YAW. I TOLD THE PAX WHAT HAD HAPPENED AND WHAT WE WERE DOING AND THAT WE WERE HDG BACK TO EWR (I HAD ALREADY TOLD THE LEAD FLT ATTENDANT). WE MADE AN UNEVENTFUL LNDG AT EWR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THERE WAS NO CTL OVER THIS ENG EXCEPT TO SHUT IT DOWN. THE RPTR SAID IT WAS NOT A CASE OF THE THRUST LEVER BEING FROZEN SINCE THE LEVER MOVED SMOOTHLY IN MANUAL AND THE AUTOTHROTTLE SYS MOVED IT FORWARD AND AFT. THE RPTR STATED MAINT DID NOT RPT THE CORRECTIVE ACTION TAKEN BUT SUSPECTS POSSIBLE MAIN FUEL CTL FAILURE.
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.