Narrative:

On may/xx/97, flight xyz was en route from AAA climbing through FL250 when the crew felt a vibration in the throttle quadrant. The #1 engine filter bypass light came on 30 seconds after the quadrant shake, then shut down. The crew declared an emergency and returned safely to AAA. #1 engine serial number YYYY was removed and sent to XXX for tear down. The tear down analysis revealed that the oil supply line for #2/3 bearing was not positioned in the lower pressure box. The tube was partially bent and distorted. All oil was flowing back to the gear box and not to the #2/3 shaft bearings. The engine seized due to oil starvation. Air carrier records indicate that engine serial number YYYY was in ZZZ for in-shop work. All maintenance records indicate that ZZZ maintenance personnel installed the gear box on may/xa/97. Air carrier maintenance manual task oriented document requires an air pressurization check of the bearing pressure feed line and system. The pressure check insures the mechanic that the #2/3 oil pressure line is installed correctly. It appears that ZZZ personnel did not follow appropriate manual procedures for repair. The task oriented document requires a specific training and qualification for gear box replacement. The training and qualification indicates that ZZZ maintenance personnel assigned to engine serial number YYYY were not qualified to change the gear box on may/xa/97. Maintenance performance of this type is contrary to air carrier maintenance manual procedures and the FARS.

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Original NASA ASRS Text

Title: A B737-200 AT FL250 DECLARED AN EMER AND DIVERTED DUE TO A SEIZED #1 ENG CAUSED BY AN IMPROPERLY INSTALLED ACCESSORY DRIVE GEAR BOX.

Narrative: ON MAY/XX/97, FLT XYZ WAS ENRTE FROM AAA CLBING THROUGH FL250 WHEN THE CREW FELT A VIBRATION IN THE THROTTLE QUADRANT. THE #1 ENG FILTER BYPASS LIGHT CAME ON 30 SECONDS AFTER THE QUADRANT SHAKE, THEN SHUT DOWN. THE CREW DECLARED AN EMER AND RETURNED SAFELY TO AAA. #1 ENG SERIAL NUMBER YYYY WAS REMOVED AND SENT TO XXX FOR TEAR DOWN. THE TEAR DOWN ANALYSIS REVEALED THAT THE OIL SUPPLY LINE FOR #2/3 BEARING WAS NOT POSITIONED IN THE LOWER PRESSURE BOX. THE TUBE WAS PARTIALLY BENT AND DISTORTED. ALL OIL WAS FLOWING BACK TO THE GEAR BOX AND NOT TO THE #2/3 SHAFT BEARINGS. THE ENG SEIZED DUE TO OIL STARVATION. ACR RECORDS INDICATE THAT ENG SERIAL NUMBER YYYY WAS IN ZZZ FOR IN-SHOP WORK. ALL MAINT RECORDS INDICATE THAT ZZZ MAINT PERSONNEL INSTALLED THE GEAR BOX ON MAY/XA/97. ACR MAINT MANUAL TASK ORIENTED DOCUMENT REQUIRES AN AIR PRESSURIZATION CHK OF THE BEARING PRESSURE FEED LINE AND SYS. THE PRESSURE CHK INSURES THE MECH THAT THE #2/3 OIL PRESSURE LINE IS INSTALLED CORRECTLY. IT APPEARS THAT ZZZ PERSONNEL DID NOT FOLLOW APPROPRIATE MANUAL PROCS FOR REPAIR. THE TASK ORIENTED DOCUMENT REQUIRES A SPECIFIC TRAINING AND QUALIFICATION FOR GEAR BOX REPLACEMENT. THE TRAINING AND QUALIFICATION INDICATES THAT ZZZ MAINT PERSONNEL ASSIGNED TO ENG SERIAL NUMBER YYYY WERE NOT QUALIFIED TO CHANGE THE GEAR BOX ON MAY/XA/97. MAINT PERFORMANCE OF THIS TYPE IS CONTRARY TO ACR MAINT MANUAL PROCS AND THE FARS.

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.