Airworthiness Directive · Amendment 39-21986 · Flight 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, with a bellcrank assembly part number (P/N) 429-001-523-101, 429-001-523-103, 429-001-532-101, or 429-001-532-103 installed.
The FAA is superseding Airworthiness Directive (AD) 2020-20- 06, which applied to certain Bell Helicopter Textron Canada Limited (now Bell Textron Canada Limited) Model 429 helicopters. AD 2020-20-06 required repetitive inspections of certain cyclic and collective assembly bearings. This AD was prompted by new bellcrank assemblies, which have been upgraded with corrosion resistant steel bearings. This AD retains certain requirements of AD 2020-20-06, and depending on the inspection results, requires removing certain parts from service and installing the upgraded cyclic and collective bellcrank assemblies. This AD also requires installing the upgraded collective and cyclic bellcrank assemblies on certain helicopters if not already installed, and prohibits installing certain bellcrank assemblies. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For Model 429 helicopters serial number (S/N) 57001 through 57296 inclusive, within 12 months after the helicopter was manufactured or 30 days after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 6 months:
(i) Disconnect the forward ends of the collective control tube, longitudinal stability and control augmentation system (SCAS) actuator, and lateral SCAS actuator. Stow the collective control tube and each SCAS actuator to prevent binding.
(ii) Move the cyclic stick fore, aft, and laterally, and the collective stick up and down from stop to stop to determine if there is any roughness. If there is any roughness in the flight control system, before further flight, remove each pivot bearing P/N MS27646-41, each arm assembly bearing P/N MS27643-4, and each sleeve P/N 120-13-4A from service and install bellcrank assemblies P/N 429-001-523-101FM and 429-001-532-101FM; or 429-001-523-107FM and 429-001-532-107FM; or 429-001-523-107 and 429-001-532-107.
(iii) Inspect the collective arm assembly P/N 429-001-525-101, the lateral arm assembly P/N 429-001-527-101, and the longitudinal arm assembly P/N 429-001-530-101, by rotating each bearing and determining whether each bearing rotates freely. If there is any binding in any arm end bearing or on the longitudinal bellcrank assembly, before further flight, remove each pivot bearing P/N MS27646-41, each arm assembly bearing P/N MS27643-4, and each sleeve P/N 120-13-4A from service and install bellcrank assemblies P/N 429-001-523-101FM and 429-001-532-101FM; or 429-001-523-107FM and 429-001-532-107FM; or 429-001-523-107 and 429-001-532-107.
(2) For Model 429 helicopters S/N 57001 through 57296 inclusive, unless already accomplished by following paragraphs (g)(1)(ii) or (iii) of this AD, within 24 months after the effective date of this AD, install bellcrank assemblies P/N 429-001-523-101FM and 429-001-532-101FM; or 429-001-523-107FM and 429-001-532-107FM; or 429-001-523-107 and 429-001-532-107.
(3) As of the effective date of this AD, installing bellcrank assemblies P/N 429-001-523-101FM and 429-001-532-101FM; or 429-001-523-107FM and 429-001-532-107FM; or 429-001-523-107 and 429-001- 532-107, constitutes a terminating action for the recurring inspections required by paragraph (g)(1) of this AD.
(4) As of the effective date of this AD, do not install any bellcrank assembly P/N 429-001-523-101, 429-001-523-103, 429-001-532-101, or 429-001-532-103 on any 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.
