A320
Maintenance Powerplant; Maintenance Airframe
Situational Awareness; Confusion; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Equipment / Tooling; Human Factors; Incorrect / Not Installed / Unavailable Part; Manuals; Chart Or Publication; Aircraft
Nose Landing Gear (NLG) AFT Door. AFT Hinge Repair Bushings Part Number (P/N) XXX-1. These flanged bushings are part of a repair for worn hinges (Oversized). The problem is this P/N XXX-1; I believe; are not Manufactured (MFG'd) correctly; compared to the others we have had in the past. These bushings are approximately half the length of the others. If you look at Page 4 of 4; of the Airbus Supplement to the Aircraft Maintenance Manual (AMM) 52-003; it does not show what the length should be for the Flanged bushing; but the non-flanged bushing shows a typical length of .155' to .160' of an inch. In my opinion the flanged bushing should be .155' to .160' of an inch; plus the flanged dimension of .078' to .080' of an inch. Most of the bushings are found in [Stores] Kit XXX [Parts Bin] for the Maintenance Base; since this is a common repair at every [C-Check] visit.
Reporter stated the Flanged/Hat bushings were driven by a Service Bulletin from Airbus and made in their Air Carrier's Machine Shop. But the Airbus Maintenance Supplement to their Aircraft Maintenance Manual (AMM) never gave any dimension length. So the drawings from company Engineering to the Machine Shop never included the Flange/Hat thickness dimension as an additional length to the original Aft Door hinge fitting bushings. The Machine Shop had assumed the 'Hat' thickness was inclusive of the total bushing length; due to the Engineering drawing did not specify otherwise. There are two bushings involved; one bushing floats and one is the 'Flange/Hat' bushing.Reporter stated the Airbus Service Bulletin was issued in response to pilot reports about high noise vibration in the aircraft's nose section during Takeoff rotation. The Flange/Hat bushings were designed to protect the Aft Door rod assemblies from being crushed during re-assembly. The bushings were only part of the Service Bulletin to address the nose vibrations.
A Technician reports the Nose Landing Gear (NLG) Aft Door; Aft Hinge Repair Bushings found in their Stores Kits are approximately half the length of the replacement bushings they have been using in the past on their A320 aircraft during Maintenance Visits. The bushings were part of an Airbus Service Bulletin to address nose vibrations on takeoff rotations.