AD 2021-03-15 Airworthiness Directives; Leonardo S.p.a. Helicopters

This AD replaces AD 2020-13-02, Amendment 39-21147 (85 FR 37551, June 23, 2020) (AD 2020-13-02).

(1) Within 10 hours time-in-service (TIS), remove the lockwire that secures the T/R plug P/N 129-0160-45-103 (T/R plug) to the bearing liner assembly P/N 109-0135-16-101 (bearing liner assembly). Without loosening the T/R plug first, inspect the tightening torque of the T/R plug by increasing the torque up to 30.5 Nm and inspect for any movement the moment torque is applied. (i) If there is no movement and the tightening torque is at least 30.5 Nm, before further flight, install lockwire by following the Accomplishment Instructions, part I, paragraph 4, of Leonardo Helicopters Emergency Alert Service Bulletin (EASB) No. 119-105, Revision A, dated June 3, 2020 (EASB 119-105 Rev A). (ii) If there is any movement or the tightening torque is less than 30.5 Nm, before further flight, comply with paragraph (f)(2) of this AD. (2) Within 50 hours TIS, unless required before further flight by paragraph (f)(1)(ii) of this AD, and thereafter at intervals not to exceed 200 hours TIS, inspect to determine whether the P/N and serial number (S/N) are visible on the outboard and inboard faces of the T/R duplex bearing by following the Accomplishment Instructions, part II, paragraphs 4 through 13 (except paragraphs 9.1, 13.1, and 13.2), of EASB 119-105 Rev A. Instead of the excluded steps, do the following: Note 1 to paragraph (f)(2): You are not required to discard parts and you may use equivalent tooling to that identified in EASB 119-105 Rev A. (i) If the P/N and S/N markings are visible on the outboard or inboard face of the T/R duplex bearing, before further flight, remove from service the T/R duplex bearing, internal spacer P/N 129-0160-43-101 (internal spacer), external spacer P/N 129-0160-44-101 (external spacer), bearing liner assembly, and T/R control rod P/N 109-0135-02-101 (T/R control rod). (ii) If the P/N and S/N markings are not visible on the inboard face of the T/R duplex bearing, before further flight, inspect the T/R duplex bearing, T/R plug, and nut by following the Accomplishment Instructions, part II, paragraphs 14 and 15 (but not paragraphs 15.1 through 15.2), of EASB 119-105 Rev A. For purposes of this inspection, damage to the races may be indicated by non-movement of the inner race, movement of the outer race, deformation, roughness, or incorrect installation; and damage to the threads of the T/R plug and nut may be indicated by uneven threads, missing threads, or cross-threading. (A) If the T/R duplex bearing has any rough rotation, brinelling, spalling, chipping, flaking, evidence of overheated bearing balls, or damage to the races, before further flight, remove from service the T/R duplex bearing, the internal spacer, the external spacer, the bearing liner assembly, and the T/R control rod. (B) If the T/R plug or nut has any damaged threads, before further flight, remove from service the affected part. (C) Reassemble the T/R duplex bearing assembly by following the Accomplishment Instructions, part II, paragraphs 16 through 31, of EASB 119-105 Rev A. (3) As of the effective date of this AD, do not install a T/R duplex bearing P/N 129-0160-11-103 on any helicopter unless you have complied with the requirements in paragraph (f)(2) of this AD.

(1) Accomplishment of AD 2020-13-02 before the effective date of this AD is considered acceptable for compliance with paragraph (f)(1) and the initial inspection required by paragraph (f)(2) of this AD. (2) Actions accomplished before the effective date of this AD in accordance with the procedures specified in Leonardo Helicopters EASB No. 119-100, dated August 7, 2019, or Leonardo Helicopters EASB No. 119-105, dated May 18, 2020, are considered acceptable for compliance with the corresponding actions specified in paragraph (f)(1) and the initial inspection required by paragraph (f)(2) of this AD.

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.

This AD defines the unsafe condition as structural failure of the T/R assembly, possibly due to an incorrect installation. This condition could result in loss of T/R pitch change control and subsequent loss of control of the helicopter.