Narrative:

Right engine lost ability to control low pressure variable stator vane with thrust changes. Warning message on CRT indicated this fact and advised 'do not modulate thrust' to crew during descent and approach. On short final, thrust was modulated by autothrust and compressor stall created engine spool down. During descent and approach, engine thrust increase and decrease at level off altitude occurred normally with similar EPR/temperature, and RPM indications on both engines. Unlike several other spurious warning messages, this warning message did not reset and remained active. The crew reported the request for maintenance action to the destination operations, but failed to consult the cockpit operating manual which recommended disconnecting autothrust and manually synchronizing power settings. Such action probably would have prevented the thrust modulations and corresponding engine stall. This action could have prevented the engine stoppage while airborne. Callback conversation with reporter revealed the following information: engine spool down and compressor stall occurred below 1000 ft. Reporter attributes the engine shutdown to the engine working harder with aircraft in landing confign, gear and flaps extended. ECAM message stated not to modulate thrust (with the compressor vane fail), but the flight crew left autothrottles on. During the descent, all engine parameters were normal, however, until on final approach, post flight inspection revealed that improper maintenance had been performed by a previous company and incorrect spacers had been installed on the engines. Within 1 month the other engine from the same aircraft had recurring overtemps on takeoff. Both engines have been removed and repaired. Reporter's company had recently started flying the A320 and were still using the airbus manuals. Of interest to note are the 2 graphics from separate major acrs enclosed with this report and the difference in procedures for the 'engine compressor vane' problem. This reporter does say that the book procedure they had was to disconnect the autothrottles, but because the ECAM actions didn't call for that, they didn't do it. It should also be noted that the engine compressor vane procedure is different because the engines installed are different, the one with no action procedure is the cfm 56-5a1 and the other with action items is the iae V2527-A5.

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Original NASA ASRS Text

Title: ACFT EQUIP PROB -- COMPRESSOR VANE FAIL ENG SHUTDOWN.

Narrative: R ENG LOST ABILITY TO CTL LOW PRESSURE VARIABLE STATOR VANE WITH THRUST CHANGES. WARNING MESSAGE ON CRT INDICATED THIS FACT AND ADVISED 'DO NOT MODULATE THRUST' TO CREW DURING DSCNT AND APCH. ON SHORT FINAL, THRUST WAS MODULATED BY AUTOTHRUST AND COMPRESSOR STALL CREATED ENG SPOOL DOWN. DURING DSCNT AND APCH, ENG THRUST INCREASE AND DECREASE AT LEVEL OFF ALT OCCURRED NORMALLY WITH SIMILAR EPR/TEMP, AND RPM INDICATIONS ON BOTH ENGS. UNLIKE SEVERAL OTHER SPURIOUS WARNING MESSAGES, THIS WARNING MESSAGE DID NOT RESET AND REMAINED ACTIVE. THE CREW RPTED THE REQUEST FOR MAINT ACTION TO THE DEST OPS, BUT FAILED TO CONSULT THE COCKPIT OPERATING MANUAL WHICH RECOMMENDED DISCONNECTING AUTOTHRUST AND MANUALLY SYNCHRONIZING PWR SETTINGS. SUCH ACTION PROBABLY WOULD HAVE PREVENTED THE THRUST MODULATIONS AND CORRESPONDING ENG STALL. THIS ACTION COULD HAVE PREVENTED THE ENG STOPPAGE WHILE AIRBORNE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: ENG SPOOL DOWN AND COMPRESSOR STALL OCCURRED BELOW 1000 FT. RPTR ATTRIBUTES THE ENG SHUTDOWN TO THE ENG WORKING HARDER WITH ACFT IN LNDG CONFIGN, GEAR AND FLAPS EXTENDED. ECAM MESSAGE STATED NOT TO MODULATE THRUST (WITH THE COMPRESSOR VANE FAIL), BUT THE FLC LEFT AUTOTHROTTLES ON. DURING THE DSCNT, ALL ENG PARAMETERS WERE NORMAL, HOWEVER, UNTIL ON FINAL APCH, POST FLT INSPECTION REVEALED THAT IMPROPER MAINT HAD BEEN PERFORMED BY A PREVIOUS COMPANY AND INCORRECT SPACERS HAD BEEN INSTALLED ON THE ENGS. WITHIN 1 MONTH THE OTHER ENG FROM THE SAME ACFT HAD RECURRING OVERTEMPS ON TKOF. BOTH ENGS HAVE BEEN REMOVED AND REPAIRED. RPTR'S COMPANY HAD RECENTLY STARTED FLYING THE A320 AND WERE STILL USING THE AIRBUS MANUALS. OF INTEREST TO NOTE ARE THE 2 GRAPHICS FROM SEPARATE MAJOR ACRS ENCLOSED WITH THIS RPT AND THE DIFFERENCE IN PROCS FOR THE 'ENG COMPRESSOR VANE' PROB. THIS RPTR DOES SAY THAT THE BOOK PROC THEY HAD WAS TO DISCONNECT THE AUTOTHROTTLES, BUT BECAUSE THE ECAM ACTIONS DIDN'T CALL FOR THAT, THEY DIDN'T DO IT. IT SHOULD ALSO BE NOTED THAT THE ENG COMPRESSOR VANE PROC IS DIFFERENT BECAUSE THE ENGS INSTALLED ARE DIFFERENT, THE ONE WITH NO ACTION PROC IS THE CFM 56-5A1 AND THE OTHER WITH ACTION ITEMS IS THE IAE V2527-A5.

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.