Narrative:

Working in ind in the balance check hangar on medium large transport aircraft, I had routine work cards requiring servicing the main landing gear upstop dampers. I followed the job card step by step to the point of getting the upstop dampers to the proper dimension required for installation. After installation of both dampers, the paperwork has no provision of an operational check of the upstop dampers. The only thing a mechanic or an inspector can do is compress the damper by hand, as noted on the initial inspection on the job card, which has no specifics on how much resistance should or shouldn't be on the dumper piston. I have had this job card before and have had no problems with the servicing of the dampers. Evidently the aircraft departed the field and had a left gear unsafe warning when attempting to retract the gear and had to return to the field. I think that the servicing paperwork should include a provision to perform an operational check of the upstop dampers by doing a gear extension and retraction. By doing the job as it's written now, only leaves doubt in your mind that the damper will perform as it should. To correct the problem line maintenance resvced the left main upstop damper and performed an operational check by extending and retracting the gear leaving no unknowns about the operation of the upstop damper.

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Original NASA ASRS Text

Title: FLC OF AN MLG ACR ACFT RETURNED TO LAND AFTER THE LNDG GEAR DID NOT RETRACT COMPLETELY DURING THE FIRST FLT AFTER A LNDG GEAR MAINT REPAIR.

Narrative: WORKING IN IND IN THE BAL CHK HANGAR ON MLG ACFT, I HAD ROUTINE WORK CARDS REQUIRING SVCING THE MAIN LNDG GEAR UPSTOP DAMPERS. I FOLLOWED THE JOB CARD STEP BY STEP TO THE POINT OF GETTING THE UPSTOP DAMPERS TO THE PROPER DIMENSION REQUIRED FOR INSTALLATION. AFTER INSTALLATION OF BOTH DAMPERS, THE PAPERWORK HAS NO PROVISION OF AN OPERATIONAL CHK OF THE UPSTOP DAMPERS. THE ONLY THING A MECH OR AN INSPECTOR CAN DO IS COMPRESS THE DAMPER BY HAND, AS NOTED ON THE INITIAL INSPECTION ON THE JOB CARD, WHICH HAS NO SPECIFICS ON HOW MUCH RESISTANCE SHOULD OR SHOULDN'T BE ON THE DUMPER PISTON. I HAVE HAD THIS JOB CARD BEFORE AND HAVE HAD NO PROBS WITH THE SVCING OF THE DAMPERS. EVIDENTLY THE ACFT DEPARTED THE FIELD AND HAD A L GEAR UNSAFE WARNING WHEN ATTEMPTING TO RETRACT THE GEAR AND HAD TO RETURN TO THE FIELD. I THINK THAT THE SVCING PAPERWORK SHOULD INCLUDE A PROVISION TO PERFORM AN OPERATIONAL CHK OF THE UPSTOP DAMPERS BY DOING A GEAR EXTENSION AND RETRACTION. BY DOING THE JOB AS IT'S WRITTEN NOW, ONLY LEAVES DOUBT IN YOUR MIND THAT THE DAMPER WILL PERFORM AS IT SHOULD. TO CORRECT THE PROB LINE MAINT RESVCED THE L MAIN UPSTOP DAMPER AND PERFORMED AN OPERATIONAL CHK BY EXTENDING AND RETRACTING THE GEAR LEAVING NO UNKNOWNS ABOUT THE OP OF THE UPSTOP DAMPER.

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.