Date: 201302
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Weather elements / visibility: Snow
Light: Night
Aircraft: B737-400
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Fan Reverser
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Time Pressure; Communication Breakdown; Situational Awareness
Second reporter function: Other / Unknown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Other Post Departure
Result: General Maintenance Action
Contributing factors: MEL; Logbook Entry; Human Factors; Aircraft; Procedure
Primary problem: Human Factors

Narrative: Event occurred at the gate. We were working the thrust reverser issue on Number 1 Engine at the time. During the check-out of the sync locks required for the reverser MEL; I noticed the bolts holding the feedback locking actuator bracket to the outboard upper locking reverser actuator on the reverser were slightly loose; allowing the bracket to move slightly. I took a mental note to check the torque of the bolts after we completed the reverser MEL. As you know this MEL is quite important to do correctly so I was focusing on it 100%. We continued on with the MEL procedures and when nearing completion I let our Lead know they were good to start boarding. I ran into a snag safety wiring the outboard turnbuckle and forgot about the actuator bolts until we were back in the break room. I figured the reverser was on MEL so they could be checked when the reverser was being repaired. I asked my Lead how to proceed and was told to add information to the MEL trouble-shooting section. I thought that was a good idea so I did. The bolts were only slightly loose and appear they had been that way for awhile. I feel safety of flight was never affected. The bracket is part of the actuator assembly so I feel this is directly related to a reverser MEL item. The next morning I looked the log page up in our Maintenance Tracking System to see what the fix was. It was then I noticed they cleared the MEL but there was no reference to the loose bolts. I immediately brought this issue to the attention of our Maintenance Supervisor. Trying to get the plane out with as little delay as possible; I went out to the plane and re-torqued the bolt as required. I determined there were no rigging issues as the bracket and actuator showed no sign of wear. The corrective action was performed on log page; thru flight.


Second narrative: A Line Aircraft Technician was working a B737-400 aircraft due to a report of gap in Number 1  reverser; the Line Technician noticed the upper thrust reverser actuator feedback cable bracket was loose due to attach bolts not being tight on the bracket. The Line Technician brought this to the attention of his Lead Mechanic. The Line Technician later stated that his Lead instructed him to include this discrepancy under the Troubleshooting tab in our Maintenance Tracking System computer for the original defect that was already on MEL 78-1A. The aircraft was previously released on MEL 78-1A. Aircraft was released with the thrust reverser on MEL with the loose bolts identified on the Troubleshooting tab in our Tracking System. The B737 aircraft arrived back in ZZZ on the same day for a Routine Overnight Check (RON). During the evening MEL 78-1A was worked and cleared. However; the loose bolts were not corrected during the RON work and the aircraft was released from Maintenance without ever correcting identified loose hardware. My Lead Technician brought to my attention that there was still a problem with the paperwork where these bolts had been identified in the Troubleshooting tab but were not looked at; or signed for; when the aircraft was released that morning. Lead [Mechanic] and Technician misunderstood the FAR requirements of application of MEL in conjunction with an open discrepancy with the applicable system. They believed that since the [Reverser] System was deactivated and would not be operated in flight; that they could also generate a discrepancy associated with the same system on the MEL paperwork. Had the Lead or the Technician notified me of the discrepancy and their intent to add [information] in the Maintenance Tracking System; I could have reviewed the paperwork and instructed them we could not release the aircraft with the paperwork configured that way. When the Supervisor reviews the logbook's top page; only the final sign-off is visible to check for compliance and balance [discrepancy close-out]. When information is added to the Troubleshooting tab in the Maintenance Tracking System; it is hidden during the review process unless that information is also printed from the Tracking program. I do not see a need to print this information if the procedures are followed and discrepancies are not added into the Tracking System. I called the graveyard technicians to ask if the work had been performed. I did not receive a phone call back until after the aircraft had been repaired. The B737 was inbound to ZZZ and due to arrive within 30 minutes of being notified of the event. When the aircraft arrived; I sent the originating Line Technician to inspect the aircraft where he found the bracket to still be loose. The Technician generated a [write-up] for the defect and corrected the problem; then released the aircraft. [Recommend] crew briefings and recurrent training on the intent of releasing aircraft on MEL and the requirements to identify discrepancies on individual and separate defect entries. [Extreme] cold. Complacency.


Synopsis: A Maintenance Supervisor; Lead Mechanic and Line Technician report a B737 Thrust Reverser on Number 1 Engine was placed on an MEL and later cleared. A secondary discrepancy for loose bolts holding the reverser feedback locking actuator bracket was missed; even though information had been entered in their Maintenance Tracking Computer System.