Narrative:

February; 2010 I worked a turn around (T/a) check on a dc-9 on the gate in ZZZ with another technician. I wiped down the landing gear struts per the seasonal requirement of a transit check. When I wiped down the nose strut I noticed that the nose gear torque link assembly had what seemed to be more than usual side play. We also had a right-hand nose tire that was worn to the tread reinforcing cord in one spot. I am aware that in-service limits can make the appearance of excessive wear; but in fact are in-limits. Before the aircraft departed ZZZ I did a 30-day history check of air traffic area chapter 32-00 and found no reference to nose gear vibrations. With that; we completed the work and the aircraft departed on time. When I returned to our office I decided to educate myself on what the in-service limits are for the torque link assembly. A practice I do any time I have not dealt with a particular subject for a length of time. I retrieved the computerized maintenance program reference for the dc-9A-32-21-04. That is where I found the 0.010' maximum in-service limit for the torque link to landing gear end play. I discussed this with my lead and decided to call maintenance control and solicit another opinion; still not sure that I had found a real problem. He found and read to me a nose wheel vibration log page from 41-days prior and quoted from that log page a manual reference and dimensions. I attempted and was unable to retrieve maintenance manual (MM) reference chapter 32-21-02 in our computer system.the dimensions quoted to me were beyond the maximum allowable of the above manual reference that I had found. When I questioned this in a second phone call to maintenance control and said that per the log page he quoted to me; it appeared to be out of tolerance. But the aircraft was not recording any vibration issues in the last 30 days. With that the maintenance controller said he had to hang up and stop the aircraft in ZZZ1. He also stated the aircraft was not scheduled to overnight at a maintenance station. Approximately 30-minutes later he called my lead and informed him and myself that I should file a report. He insinuated that I had knowingly dispatched an non-airworthy aircraft. This could not be farther from the truth.due to the fact I constantly re-educate myself on manual procedures and the fact that manuals change all the time; I make it a practice to review manuals when I encounter something I have not seen for awhile. The maintenance controller assigned a log page and stopped the aircraft in ZZZ1. This log page was also written indicating that I knowingly dispatched the aircraft with a problem. Again not the case. The aircraft was sent to the hanger and both upper and lower toque links and the related bushings on the gear were replaced. The log page stated the clearance was out of limits but the dimensions where not listed. Given that the aircraft was operating without a vibration issue; the end play was not currently an operational issue and was not in danger of imminent failure. From a service check observation; without a scheduled inspection of that torque link; I don't believe I could have made a determination of serviceable condition. My diligence following up after the fact is the only reason this ever came to light.

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Original NASA ASRS Text

Title: A Line Mechanic reports about his efforts to address a possible out of limits nose landing gear torque link assembly side play on a DC-9-30 aircraft. Changes in their computerized Maintenance Program references contributed to the confusion. Maintenance Controller called aircraft back to the gate at a downline station during Taxi-out.

Narrative: February; 2010 I worked a Turn Around (T/A) check on a DC-9 on the gate in ZZZ with another Technician. I wiped down the landing gear struts per the seasonal requirement of a Transit Check. When I wiped down the nose strut I noticed that the Nose Gear Torque Link assembly had what seemed to be more than usual side play. We also had a right-hand nose tire that was worn to the tread reinforcing cord in one spot. I am aware that In-Service Limits can make the appearance of excessive wear; but in fact are In-limits. Before the aircraft departed ZZZ I did a 30-day history check of ATA Chapter 32-00 and found no reference to nose gear vibrations. With that; we completed the work and the aircraft departed on time. When I returned to our office I decided to educate myself on what the In-Service Limits are for the Torque Link assembly. A practice I do any time I have not dealt with a particular subject for a length of time. I retrieved the computerized Maintenance program reference for the DC-9A-32-21-04. That is where I found the 0.010' Maximum In-Service Limit for the Torque Link to landing gear end play. I discussed this with my Lead and decided to call Maintenance Control and solicit another opinion; still not sure that I had found a real problem. He found and read to me a nose wheel vibration Log page from 41-days prior and quoted from that Log page a Manual reference and dimensions. I attempted and was unable to retrieve Maintenance Manual (MM) reference Chapter 32-21-02 in our computer system.The dimensions quoted to me were beyond the Maximum allowable of the above Manual reference that I had found. When I questioned this in a second phone call to Maintenance Control and said that per the Log page he quoted to me; it appeared to be out of tolerance. But the aircraft was not recording any vibration issues in the last 30 days. With that the Maintenance Controller said he had to hang up and stop the aircraft in ZZZ1. He also stated the aircraft was not scheduled to overnight at a Maintenance station. Approximately 30-minutes later he called my Lead and informed him and myself that I should file a report. He insinuated that I had knowingly dispatched an non-airworthy aircraft. This could not be farther from the truth.Due to the fact I constantly re-educate myself on Manual Procedures and the fact that Manuals change all the time; I make it a practice to review Manuals when I encounter something I have not seen for awhile. The Maintenance Controller assigned a Log page and stopped the aircraft in ZZZ1. This Log page was also written indicating that I knowingly dispatched the aircraft with a problem. Again not the case. The aircraft was sent to the hanger and both Upper and Lower Toque Links and the related bushings on the gear were replaced. The Log page stated the clearance was out of limits but the dimensions where not listed. Given that the aircraft was operating without a vibration issue; the end play was not currently an operational issue and was not in danger of imminent failure. From a Service Check observation; without a scheduled Inspection of that Torque Link; I don't believe I could have made a determination of Serviceable condition. My diligence following up after the fact is the only reason this ever came to light.

Data retrieved from NASA's ASRS site as of April 2012 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.