EMB ERJ 145 ER/LR
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Flight Crew Returned To Departure Airport; General Maintenance Action
Manuals; Aircraft; Chart Or Publication; Human Factors; Procedure
Aircraft had the Nose Gear Sliding Tube Seals replaced during 3rd Shift [Midnights] due to a leaking strut pilot report. Third Shift to First Shift Turnover was to reinstall the previously repaired nose strut and sliding tube seals back into the Nose Gear Assembly. About three hours into the 1st Shift [Dayshift]; we started where 3rd Shift left off in the Turnover. I; as Inspector X; inspected Aircraft Maintenance Technician (AMT) X in doing this procedure in accordance with Embraer Maintenance Manual 32-20-08; Page 417; [which was] our Turnover point from 3rd Shift. We finished the task and aircraft was returned to service. First flight; Aircraft had an air turnback due to after takeoff; an 'AIR/LDG IND' on EICAS [message appeared] as Landing Gear selected 'Up'. Override functioned properly; gear was 'Down' and 'Locked' for landing. Aircraft returned to field with no other incident. My understanding was the Aircraft was returned to the hangar for a Gear Swing and discrepancy was duplicated. Teardown of nose gear strut and removal of sliding tube assembly and seals revealed and found Centering Upper Cam 90-degrees out. Reference Non-Routine Work Card (NRWC) turnover; discrepancy found after my shift had ended. Embraer Manual does not call out for a Gear Extension and Retraction Check; or a Weight on Wheels (WOW) Operational Check after a nose strut sliding tube seal replacement or full service of Nose Landing Gear (NLG) strut. Turning the nose wheels to one side; then selecting Gear 'Up' while on jacks would be a check to see if the Centering Cam functions properly. My suggestion would be to advise the Manufacturer of this problem and revise the current Work Card to perform these procedures. [Our] Air Carrier could also generate a Quality Control (QC) Alert stating a Gear Extension and Retraction Check and or WOW Operational Checks will be performed until Embraer Manuals are updated or revised. Complete nose strut servicing should also have a Gear Extension and Retraction Check to prevent similar occurrences happening in the future.
I; as Mechanic Y [3rd Shift]; was assigned the task of repacking the nose strut on an Embraer aircraft. I had completed the task in accordance with Maintenance Manual 32-20-08; up to Step-2p of that Maintenance Manual. I had repacked the Nose [Sliding Tube] to the point of ready to assemble back into the [Nose] Gear; which is where I turned over the job. When I returned to work the next day; I was told about the event. It is my understanding that the [Nose] Gear was assembled and operationally checked in accordance with the correct manual and found to be good. When the aircraft was taking off; it is my understanding that the [Nose] Gear would not retract. When the aircraft was taken out of service; it was found to have the Upper Cam 90-degrees out of alignment. When assembling the Nose Gear with the gear sleeve on; it is hard to notice the upper cam; to notice [see] what position the upper cam is in. When doing this task the Maintenance Manual does not direct you to perform extension and retraction of the gear which might of found this discrepancy prior to aircraft release.
Two Inspectors and two Mechanics were involved with the Nose Landing Gear (NLG) Sliding Tube seals replacement and installation on an EMB-145 aircraft that required an air turnback after takeoff.