Narrative:

We were cruising a FL370 and were instructed to slow to 250 KTS. Passing through 260 KTS we experienced a compressor stall in the #1 engine and it went to idle. We requested and were given FL330 by ATC. At this point I (first officer) assumed flying duties and the captain and so worked on the problem. On-line maintenance was contacted and they suggested shutting down and restarting the #1 engine. At the same time ATC cleared us to cross the hayed intersection at FL190. I advised the captain, armed FL190 and initiated a descent. The captain and the engineer ran the in-flight engine shutdown and in-flight engine restart procedures. It should be noted that on this type of aircraft a power source change to the #1 or #3 AC bus results in the autoplt dropping off and the flight director reverting to a basic mode (heading hold and vertical speed). Any altitude armed or navigation modes are lost. At about FL250 the #1 engine restarted and it's generator automatically began pwring the #1 AC bus. (A power source change from the tie bus that had been pwring it.) the autoplt dropped off and I reengaged it and reset the appropriate navigation mode. However, I forgot to rearm the altitude. At about FL200 I returned control to the captain telling him that we were to cross hayed at FL190. I do not think that a 1000 ft call was made. At about FL189 the captain noticed that we had flown through our assigned altitude and returned to FL190. Maximum deviation from FL190 was about 300 ft. Although we did not feel that the pullup was very abrupt, 1 flight attendant reported a slight ankle injury from the pullup. The rest of the flight proceeded uneventfully to destination. Yes, the engine worked normally for the remainder of the flight, although the company did change the engine that night. My most important comment is this: all of the way from FL250 to our level off I had the uneasy feeling that something was not right. I think that I attributed it to uncertainty over the engine but it was really something else. One of the danger signals stressed in our CRM (cockpit resource management) training falls under the title of ambiguity - conflicting signals or the gut feeling that something is just not right. I had the feeling that I had missed something but did not voice my concern to the other crew members. That is one mistake that I will never make again. If the 'little voice inside my head' is saying something is not right, I will ask for help in resolving the problem. Another contributing factor is the fact that the aural alert on the altitude alert only sounds after you are through the altitude. It does not sound approaching the altitude. Other aircraft that I have flown sound about 700 ft prior to reaching the preset altitude. An aural alert might have diverted our attention from discussion or thoughts about the engine back to the task of flying. Finally, I think that it was poor judgement on my part to give control of the aircraft back to the captain so close to a level off altitude. I think that if I had stayed in control to FL190 I might have noticed the unarmed altitude in time. As it was, I gave the aircraft back to him and diverted my attention to preparing for the approach. Control changed should be limited to several thousand feet from assigned altitudes, and if they are necessary closer to an assigned altitude I will be more careful about 'staying in the loop' until the level off maneuver is complete.

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Original NASA ASRS Text

Title: ACFT EQUIP PROB MALFUNCTION CREATES AN ALT BUST AND FLT ATTENDANT PERSONAL INJURY.

Narrative: WE WERE CRUISING A FL370 AND WERE INSTRUCTED TO SLOW TO 250 KTS. PASSING THROUGH 260 KTS WE EXPERIENCED A COMPRESSOR STALL IN THE #1 ENG AND IT WENT TO IDLE. WE REQUESTED AND WERE GIVEN FL330 BY ATC. AT THIS POINT I (FO) ASSUMED FLYING DUTIES AND THE CAPT AND SO WORKED ON THE PROB. ON-LINE MAINT WAS CONTACTED AND THEY SUGGESTED SHUTTING DOWN AND RESTARTING THE #1 ENG. AT THE SAME TIME ATC CLRED US TO CROSS THE HAYED INTXN AT FL190. I ADVISED THE CAPT, ARMED FL190 AND INITIATED A DSCNT. THE CAPT AND THE ENGINEER RAN THE INFLT ENG SHUTDOWN AND INFLT ENG RESTART PROCS. IT SHOULD BE NOTED THAT ON THIS TYPE OF ACFT A PWR SOURCE CHANGE TO THE #1 OR #3 AC BUS RESULTS IN THE AUTOPLT DROPPING OFF AND THE FLT DIRECTOR REVERTING TO A BASIC MODE (HDG HOLD AND VERT SPD). ANY ALT ARMED OR NAV MODES ARE LOST. AT ABOUT FL250 THE #1 ENG RESTARTED AND IT'S GENERATOR AUTOMATICALLY BEGAN PWRING THE #1 AC BUS. (A PWR SOURCE CHANGE FROM THE TIE BUS THAT HAD BEEN PWRING IT.) THE AUTOPLT DROPPED OFF AND I REENGAGED IT AND RESET THE APPROPRIATE NAV MODE. HOWEVER, I FORGOT TO REARM THE ALT. AT ABOUT FL200 I RETURNED CTL TO THE CAPT TELLING HIM THAT WE WERE TO CROSS HAYED AT FL190. I DO NOT THINK THAT A 1000 FT CALL WAS MADE. AT ABOUT FL189 THE CAPT NOTICED THAT WE HAD FLOWN THROUGH OUR ASSIGNED ALT AND RETURNED TO FL190. MAX DEV FROM FL190 WAS ABOUT 300 FT. ALTHOUGH WE DID NOT FEEL THAT THE PULLUP WAS VERY ABRUPT, 1 FLT ATTENDANT RPTED A SLIGHT ANKLE INJURY FROM THE PULLUP. THE REST OF THE FLT PROCEEDED UNEVENTFULLY TO DEST. YES, THE ENG WORKED NORMALLY FOR THE REMAINDER OF THE FLT, ALTHOUGH THE COMPANY DID CHANGE THE ENG THAT NIGHT. MY MOST IMPORTANT COMMENT IS THIS: ALL OF THE WAY FROM FL250 TO OUR LEVEL OFF I HAD THE UNEASY FEELING THAT SOMETHING WAS NOT RIGHT. I THINK THAT I ATTRIBUTED IT TO UNCERTAINTY OVER THE ENG BUT IT WAS REALLY SOMETHING ELSE. ONE OF THE DANGER SIGNALS STRESSED IN OUR CRM (COCKPIT RESOURCE MGMNT) TRAINING FALLS UNDER THE TITLE OF AMBIGUITY - CONFLICTING SIGNALS OR THE GUT FEELING THAT SOMETHING IS JUST NOT RIGHT. I HAD THE FEELING THAT I HAD MISSED SOMETHING BUT DID NOT VOICE MY CONCERN TO THE OTHER CREW MEMBERS. THAT IS ONE MISTAKE THAT I WILL NEVER MAKE AGAIN. IF THE 'LITTLE VOICE INSIDE MY HEAD' IS SAYING SOMETHING IS NOT RIGHT, I WILL ASK FOR HELP IN RESOLVING THE PROB. ANOTHER CONTRIBUTING FACTOR IS THE FACT THAT THE AURAL ALERT ON THE ALT ALERT ONLY SOUNDS AFTER YOU ARE THROUGH THE ALT. IT DOES NOT SOUND APCHING THE ALT. OTHER ACFT THAT I HAVE FLOWN SOUND ABOUT 700 FT PRIOR TO REACHING THE PRESET ALT. AN AURAL ALERT MIGHT HAVE DIVERTED OUR ATTN FROM DISCUSSION OR THOUGHTS ABOUT THE ENG BACK TO THE TASK OF FLYING. FINALLY, I THINK THAT IT WAS POOR JUDGEMENT ON MY PART TO GIVE CTL OF THE ACFT BACK TO THE CAPT SO CLOSE TO A LEVEL OFF ALT. I THINK THAT IF I HAD STAYED IN CTL TO FL190 I MIGHT HAVE NOTICED THE UNARMED ALT IN TIME. AS IT WAS, I GAVE THE ACFT BACK TO HIM AND DIVERTED MY ATTN TO PREPARING FOR THE APCH. CTL CHANGED SHOULD BE LIMITED TO SEVERAL THOUSAND FEET FROM ASSIGNED ALTS, AND IF THEY ARE NECESSARY CLOSER TO AN ASSIGNED ALT I WILL BE MORE CAREFUL ABOUT 'STAYING IN THE LOOP' UNTIL THE LEVEL OFF MANEUVER IS COMPLETE.

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.