C680A Flight Crew reported continuous banging when attempting to retract landing gear after take off. The Nose Landing Gear would not retract. The flight crew performed an air turn back and a precautionary landing with the nose gear strut not extended.
Synopsis
C680A Flight Crew reported continuous banging when attempting to retract landing gear after take off. The Nose Landing Gear would not retract. The flight crew performed an air turn back and a precautionary landing with the nose gear strut not extended.
Narrative
I was made aware that there has been an investigation on Aircraft X in which I may have inspected items on while it was here for a base inspection on or around date. Aircraft Hours at the time 3583.4/cycles 2381. It may be determined; that during disassembly/reassembly of the nose gear upper barrel; hi-locks were blocking fully seating the barrel properly; thus not allowing constant engagement of the nose gear up lock switch. During the work order I inspected 3 pulley attach bolts on top of steering unit; 2 attach bolts for steering unit and 2 bolts through the tow buckets require sealant; nose gear WOW (Weight on Wheels) switch rigging; and nose strut requires full servicing. During the inspection of these items; there was no defects noted; the procedures went without incident or abnormal issues. I do remember the team of individuals working on these task did not swing the gear; which would normally be checked afterwards; but it was determined that the gear would be swung at a later date (which it was) on date1 due to a wiring mod being done landing gear up lock switches; and no gear swing was required at that present time; even though the maintenance manual did not require a gear swing for the task we performed afterwards. The maintenance manual really needs a required measurement check of the upper barrel to see if it's been fully seated after disassembly and reassembly; and could also use a required gear swing; when it's all been done.
Second reporter narrative
Flight Crew writes - 'During flight climbing through 41600 ft.; we started hearing and feeling a very loud and continuous banging underneath our feet'. Several attempts to extend the NLG failed; priority handling was requested; and the aircraft landed with NLG still retracted. On Date; we were assigned to perform the task 32-20-00-XXX-XXX (Nose Landing Gear Shock Strut Special Detailed Inspection) - UPPER BARREL ASSY-NOSE GEAR. This involves removal of the upper barrel assembly from the trunnion. We completed this task without incident and did not experience any issues of note. Removal and installation of the upper barrel went without incident. The tear down of the nose gear revealed that during the previous assembly of the nose landing gear; the upper barrel assembly was not fully engaged through the upper bearing creating a gap of at least a 1/8'. Additionally; the 5 Hi-Loc heads securing the nose steering spline had been improperly installed; the countersink required to fully seat the heads of the Hi-Locs was insufficient. Therefore; the protruding heads interfered with the full seating of the barrel assembly through the upper bearing. There is no frame of reference or measurement to observe when installing the upper barrel into the trunnion. The upper barrel 'seated' for us and we installed the locking nut correctly as per the CE680A CMM 32-20-01. There is no check for distance of full seating of the upper barrel into the trunnion. A good fail safe would be to have a measurement or note to verify full seating of the upper barrel into the trunnion.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.