An Inspector and a Mechanic reported a B757-200 aircraft's Nose Wheel Steering Tiller that would not center after landing. A rudder pedal steering Interconnect (input) rod was found disconnected.
Synopsis
An Inspector and a Mechanic reported a B757-200 aircraft's Nose Wheel Steering Tiller that would not center after landing. A rudder pedal steering Interconnect (input) rod was found disconnected.
Narrative
In February I was notified that there was going to be an investigation of an occurrence on a B757-200 aircraft; after landing; [when] the Nose Wheel Steering Tiller (handle) would not center when released. When [steering] input selected; Tiller stays in that position and will not return to Zero (0) index; [noted on] log page by pilot. I; as an Inspector; had been involved in the rigging of this system during a recent Heavy (8-C) Check. I and the Technician that worked on this system were told that a rod for the Rudder Interconnect had been found disconnected; item of detail in Aircraft Maintenance Manual (AMM) 32-51-00-835. This rod had been reconnected during our testing and the bolt and a self-locking nut was reinstalled during the work accomplished that I witnessed during the Heavy Check in January. The Nose Steering Cables in the left wheel well tunnel were adjusted and re-safetied per AMM 32-51-00; Step 'E'. Also the Rudder Interconnect rod was reinstalled per the [same] AMM procedures.The Nose Wheel Steering was checked per Work Cards. AMM 32-51-00 was used to comply with this work step and the Nose Wheel Steering Function as required. The Technician and I signed-off the Work Card Step. [With] my Quality Control (QC) stamp number being XXX; I was the last Inspector to see this process. I climbed into the left wheel well tunnel thru the Electronic Equipment (E/E) door to see that the steering cables were safetied. After exiting the E/E; I climbed a ladder to see that the rig pins and that the Rudder Interconnect rod; Item # 20; was installed and secured. [Again] in January; this rod was secured. Also the Nose Steering Cables were safetied and the Nose Wheel Steering functioned per the Work Card and the AMM. The Technician that corrected (signed-off) the pilot's log page [stated] that he performed rigging of the Nose Wheel Steering (NWS) System reference AMM 32-51-00 and all Operational Checks and Rig had checked good at that time. The aircraft was out of service for a few hours and is back in service. This is the events as I saw them on that day.A red streamer will be attached to any rods that are removed in the future and a Non-Routine [Write-up] will be written upon their removal; only to be signed-off after they are reconnected. Also; I will from this day forward use Torque Seal on all bolts and nuts that are reinstalled. All Maintenance will be documented on non-routines and work cards.
Second reporter narrative
Aircraft had a scheduled Nose Gear Remove and Replacement Work Card. All work was accomplished in accordance with the required references. The Steering and Nose Gear Piston Position (NGPP) System was adjusted and operationally checked; reference Aircraft Maintenance Manual (AMM) 32-51-00. All safeties; reconnection of required parts; and removal of rig pins were complied with; signed-off and were checked by the Inspection Department; before Inspection Department Final signature was given to Task Card. Installation of red streamers that will be seen outside of the fuselage; will be installed [in the future] on any items that require disconnecting and re-installation. Also; once work is accomplished; application of tamper proof torque seal will be used on all re-attached items. Also; a notation of torque seal application will be noted; dated; signed for by Technician and Inspector on all required aircraft work cards and non-routines.
NASA callback
Reporter stated the Rudder Pedal Input Rod to the Nose Wheel Steering System was found disconnected in the left nose tunnel of the B757-200 aircraft. If the Input rod is not connected; the nose wheel will not center; will not come back to the Zero index position on the Steering Wheel Tiller. The Input rod acts as a feedback mechanism that follows the rudder pedals.Reporter stated he was not given any further information about who; how or what may have contributed to the Input rod becoming disconnected after he and the Inspector signed-off their work on the Task Cards.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.