Airworthiness Directive · Amendment 39-19873 · Main rotor gearbox
Airbus Helicopters
This AD applies to Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, certificated in any category, delivered to the first owner or customer before September 1, 2018, and with attachment screws part number (P/N) 330A22013520 installed with main gearbox (MGB) right hand (RH) side rear attachment fitting P/N 330A22270207 and left hand (LH) side rear attachment fitting P/N 330A22270206 of the MGB suspension bars.
The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters. This AD requires inspecting the attachment screws of each main gearbox (MGB) suspension bar rear attachment fitting, and depending on the outcome, applying a sealing compound, performing further inspections, and replacing affected parts. This AD was prompted by reports of an elongated attachment screw and loss of tightening torque of the nut. The actions of this AD are intended to address an unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 110 hours time-in-service, remove the sealing compound and inspect each screw on the RH and LH rear attachment fitting by identifying the number of threads “F” that extend beyond the nut as shown in Detail “B” of Figure 2 of Airbus Helicopter Alert Service Bulletin No. AS332-53.02.04, Revision 0, dated November 21, 2018 (ASB AS332-53.02.04).
(1) If there are 2 or less threads on each of the four screws; or there are 3 or more threads on any screw with a thread height “H” less than 5 mm (0.196 in), before further flight, apply a sealing compound on the nuts, and convex and concave washers.
(2) If there are 3 or more threads on any screw with a thread height “H” of 5 mm (0.196 in) or more, before further flight, do the following, and for more than one screw, do one at a time while working in a cross pattern: Remove from service the nut; and remove the screw from the helicopter and measure the length “L” of the screw as shown in Detail “D” of Figure 2 of ASB AS332-53.02.04.
(i) If any washers are bent or corroded, before further flight, remove from service the washers.
(ii) If the length “L” measurement is less than or equal to 59.3 mm (2.334 in) for each screw removed as required by paragraph (e)(2) of this AD, visually inspect the screw for corrosion and cracks.
(A) For each screw with corrosion or a crack, before further flight, replace the screw with an airworthy screw.
(B) For any screw with no corrosion or cracks, before further flight, re-install the screw and washers. Install a new nut and apply sealant.
(iii) If the length “L” measurement is greater than 59.3 mm (2.334 in) for any screw removed as required by paragraph (e)(2) of this AD, before further flight, replace the rear attachment fitting that the screw was removed from and its set of four screws, washers, and nuts, and apply sealant as shown in Figures 2 and 3 of ASB AS332-53.02.04.
