Airworthiness Directive · Amendment 39-22027 · Tail rotor control system
Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
This AD applies to Bell Textron Canada Limited (type certificate previously held by Bell Helicopter Textron Canada Limited) Model 429 helicopters, certificated in any category, serial numbers 57001 through 57401 inclusive.
The FAA is superseding Airworthiness Directive (AD) 2019-11-05 for certain Bell Helicopter Textron Canada Limited (now Bell Textron Canada Limited) Model 429 helicopters. AD 2019-11-05 required inspecting the tail rotor (TR) pitch link assemblies, and replacing certain pitch link bearings. This AD was prompted by a report of a worn pitch link, and the FAA's determination that all TR pitch link assemblies are affected by the unsafe condition. This AD continues to require the actions specified in AD 2019-11-05, and revises the applicability and requires inspections of certain other TR pitch link assemblies. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For pitch link assembly part number(P/N) 429-012-112-101, 429-012-112-103, 429-012-112-101FM, and 429-012-112-103FM: Within 50 hours time-in-service (TIS) after July 12, 2019 (the effective date of AD 2019-11-05) and thereafter at intervals not to exceed 50 hours TIS:
(i) Perform a dimensional inspection of each inboard and outboard pitch link assembly for axial and radial bearing play. With a 10X or higher power magnifying glass, inspect the bearing liner for a crack, deterioration of the liner, and extrusion of the liner from the plane. If there is axial or radial play that exceeds allowable limits, or if there is a crack, deterioration of the liner, or extrusion of the liner, before further flight, replace the bearing.
(ii) Inspect the pitch link assembly sealant for pin holes and voids and to determine if the sealant thickness is 0.025 inch (0.64 mm) or less, extends over the roll staked lip by 0.030 inch (0.76 mm) or more, and is clear of the bearing ball. If there is a pin hole or void, or if the sealant exceeds 0.026 inch (0.66 mm), does not extend over the roll staked lip by 0.030 inch (0.76 mm) or more, or is not clear of the bearing ball, before further flight, replace the bearing.
(2) For pitch link assembly P/N 429-012-112-101, 429-012-112-103, 429-012-112-101FM, and 429-012-112-103FM, within 200 hours TIS following the initial inspection required by paragraph (g)(1) of this AD, or if the hours TIS of a pitch link assembly exceed 250 hours TIS or are unknown, at the next 50-hour-TIS inspection required by paragraph (g)(1) of this AD:
(i) Replace each bearing P/N 429-312-107-103 with a date of manufacture before January 13, 2015, with a bearing P/N 429-312-107-103 that was manufactured on or after January 13, 2015.
(ii) Using a white permanent fine point marker or equivalent, re-identify the pitch link assembly:
(A) Re-identify P/N 429-012-112-101 and 429-012-112-101FM as 429-012-112-111FM.
(B) Re-identify P/N 429-012-112-103 and 429-012-112-103FM as 429-012-112-113FM.
(iii) Apply a coating of DEVCON 2-TON (C-298) or equivalent over the new P/N.
For pitch link assemblies other than P/N 429-012-112-101, 429-012-112-103, 429-012-112-101FM, and 429-012-112-103FM: Within 50 hours TIS after the effective date of this AD and thereafter at intervals not to exceed 50 hours TIS:
(1) Perform a dimensional inspection of each inboard and outboard pitch link assembly for axial and radial bearing play. With a 10× or higher power magnifying glass, inspect the bearing liner for a crack, deterioration of the liner, and extrusion of the liner from the plane. If there is axial or radial play that exceeds allowable limits, or if there is a crack, deterioration of the liner, or extrusion of the liner, before further flight, replace the bearing.
(2) Inspect the pitch link assembly sealant for pin holes and voids and to determine if the sealant thickness is 0.025 inch (0.64 mm) or less, extends over the roll staked lip by 0.030 inch (0.76 mm) or more, and is clear of the bearing ball. If there is a pin hole or void, or if the sealant exceeds 0.026 inch (0.66 mm), does not extend over the roll staked lip by 0.030 inch (0.76 mm) or more, or is not clear of the bearing ball, before further flight, replace the bearing.
Accomplishing the initial inspection required by paragraph (g)(1) or (h) of this AD constitutes terminating action for the inspections required by paragraph (f)(2) of AD 2020-17-10 for that pitch link assembly only.
The repetitive inspections required by paragraph (h) of this AD are no longer required for helicopters that incorporate pitch link assemblies, P/N 429-012-212-105 or 429-012-212-107, in accordance with Part III of the Accomplishment Instructions of Bell Alert Service Bulletin No. 429-15-16, Revision C, dated October 16, 2020.
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.
