Airworthiness Directive · Amendment 39-18234 · Tail rotor
Airbus Helicopters (Previously Eurocopter France) (Airbus Helicopters) Helicopters
This AD applies to Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with tail rotor hub pitch horn (pitch horn) assembly, part number (P/N) 350A121368.01, 350A121368.02, 350A121368.03, or 350A121368.04, with a pitch horn, P/N 350A121368.XX, where XX stands for a two-digit dash number, installed, certificated in any category. The pitch horn may be marked with either the pitch horn assembly P/N or pitch horn P/N.
We are superseding Airworthiness Directive (AD) 2013-21-01 for Eurocopter France Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. AD 2013-21-01 required certain inspections of each tail rotor pitch horn assembly (pitch horn) for a crack, replacing a cracked pitch horn before further flight, and a one-time visual inspection of pitch horns above certain hours time-in-service (TIS). This new AD retains the requirements of AD 2013-21-01 but requires a repetitive visual inspection for all pitch horns regardless of hours TIS. This AD was prompted by a report of a crack in the yoke of a pitch horn and is intended to detect a crack in the pitch horn to prevent failure of the pitch horn, loss of the anti-torque function, and subsequent loss of control of the helicopter.
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.
(1) For parts with 155 or less hours time-in-service (TIS), before exceeding 165 hours TIS, or for parts with more than 155 hours TIS, within 10 hours TIS, and thereafter at intervals not to exceed 165 hours TIS, visually inspect each pitch horn for a crack in the areas shown in Figure 1 of Eurocopter Emergency Alert Service Bulletin (EASB) No. 05.00.74 or No. 05.00.65, both Revision 1 and both dated June 25, 2013, as appropriate for your model helicopter.
(2) If there is a crack, before further flight, replace the pitch horn with an airworthy pitch horn.
(3) Do not install a pitch horn, P/N 350A121368 (any dash number), with more than 0 hours TIS on any helicopter unless it has passed a dye penetrant inspection for a crack in the areas shown in Figure 1 of Eurocopter EASB No. 05.00.74 or No. 05.00.65, both Revision 1 and both dated June 25, 2013, as appropriate for your model helicopter.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
