Flight crew of an medium large transport air carrier aircraft on a ferry flight to return aircraft t...

Attributes
ACN	252692
Time
Date	199309
Day	Mon
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : abq
State Reference	NM
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zab
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 127 flight time total : 4150 flight time type : 1400
ASRS Report	252692
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

This aircraft was flown on a previous leg from dfw-sjc and had experienced a mild compressor stall on the right engine during takeoff from dfw. The engine recovered on its own, the automatic throttles never disengaged, and the flight was continued with all engine indications normal. As a precaution, maintenance performed a borescope inspection and replaced the pressure ratio control valve. A ground test run was done and above 1.90 EPR the engine consistently experienced compressor stalls. Due to limited maintenance, the company wanted the aircraft in dfw to do an engine change. We agreed to fly the aircraft only after insuring all 'legalities' were insured. Due to the light aircraft weight, no signs of engine damage (from the borescope inspection) and normal engine performance below 1.90 EPR, we felt it was safe to fly back to dfw. Takeoff was performed at reduced (alternate) thrust and climb to FL370 was normal. Approximately 90 mins into flight, with both engines operating at about 1.78 EPR, the right engine compressor stalled again and rolled back to about 1.50 EPR. Thrust on the right engine was reduced, a descent to FL240 accomplished and the left engine maintained a level cruise speed of mach .65 at about 1.90 EPR. We left the engine at near idle since it was running normally again. After radio contact was made with the maintenance coordinator, he again emphasized their desire to get the jet to dfw. Against my better judgement, the captain elected to continue the flight under these conditions and the return to dfw was uneventful. Looking back at the chain of events, we probably should have just let maintenance truck in a new motor, however our desire to get the airplane 'back on the line' and help maintenance out negatively affected our judgement. After experiencing the second compressor stall on the ferry flight home, I should have been more forceful about landing the airplane instead of overflying 2 suitable landing fields.

Original NASA ASRS Text

Title: FLC OF AN MLG ACR ACFT ON A FERRY FLT TO RETURN ACFT TO MAINT BASE EXPERIENCED SIMILAR ENG PROB WHICH CAUSED THE ORIGINAL OTS CONDITION AND NEED TO FERRY THE ACFT FOR MAINT. THE ACFT CONTINUED TO DEST ON REDUCED PWR UNEVENTFULLY.

Narrative: THIS ACFT WAS FLOWN ON A PREVIOUS LEG FROM DFW-SJC AND HAD EXPERIENCED A MILD COMPRESSOR STALL ON THE R ENG DURING TKOF FROM DFW. THE ENG RECOVERED ON ITS OWN, THE AUTO THROTTLES NEVER DISENGAGED, AND THE FLT WAS CONTINUED WITH ALL ENG INDICATIONS NORMAL. AS A PRECAUTION, MAINT PERFORMED A BORESCOPE INSPECTION AND REPLACED THE PRESSURE RATIO CTL VALVE. A GND TEST RUN WAS DONE AND ABOVE 1.90 EPR THE ENG CONSISTENTLY EXPERIENCED COMPRESSOR STALLS. DUE TO LIMITED MAINT, THE COMPANY WANTED THE ACFT IN DFW TO DO AN ENG CHANGE. WE AGREED TO FLY THE ACFT ONLY AFTER INSURING ALL 'LEGALITIES' WERE INSURED. DUE TO THE LIGHT ACFT WT, NO SIGNS OF ENG DAMAGE (FROM THE BORESCOPE INSPECTION) AND NORMAL ENG PERFORMANCE BELOW 1.90 EPR, WE FELT IT WAS SAFE TO FLY BACK TO DFW. TKOF WAS PERFORMED AT REDUCED (ALTERNATE) THRUST AND CLB TO FL370 WAS NORMAL. APPROX 90 MINS INTO FLT, WITH BOTH ENGS OPERATING AT ABOUT 1.78 EPR, THE R ENG COMPRESSOR STALLED AGAIN AND ROLLED BACK TO ABOUT 1.50 EPR. THRUST ON THE R ENG WAS REDUCED, A DSCNT TO FL240 ACCOMPLISHED AND THE L ENG MAINTAINED A LEVEL CRUISE SPD OF MACH .65 AT ABOUT 1.90 EPR. WE LEFT THE ENG AT NEAR IDLE SINCE IT WAS RUNNING NORMALLY AGAIN. AFTER RADIO CONTACT WAS MADE WITH THE MAINT COORDINATOR, HE AGAIN EMPHASIZED THEIR DESIRE TO GET THE JET TO DFW. AGAINST MY BETTER JUDGEMENT, THE CAPT ELECTED TO CONTINUE THE FLT UNDER THESE CONDITIONS AND THE RETURN TO DFW WAS UNEVENTFUL. LOOKING BACK AT THE CHAIN OF EVENTS, WE PROBABLY SHOULD HAVE JUST LET MAINT TRUCK IN A NEW MOTOR, HOWEVER OUR DESIRE TO GET THE AIRPLANE 'BACK ON THE LINE' AND HELP MAINT OUT NEGATIVELY AFFECTED OUR JUDGEMENT. AFTER EXPERIENCING THE SECOND COMPRESSOR STALL ON THE FERRY FLT HOME, I SHOULD HAVE BEEN MORE FORCEFUL ABOUT LNDG THE AIRPLANE INSTEAD OF OVERFLYING 2 SUITABLE LNDG FIELDS.

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.