# AD 70-14-02: Tail Rotor Hub Assembly Bolt - Type: Airworthiness directive - Status: Current - Products: Scotts-Bell 47 47D, 47D1, 47G, 47G-2 and 47H-1 - Effective: August 10, 1970 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-1023 - Registered aircraft: 211 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F53A9BFC6E67468686256A340052CA18.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/70-14-02 ## The airworthiness directive 70-14-02 BELL: Amendment 39-1023. Applies to all Bell Model 47D, 47D-1, 47G, 47G-2 and 47H-1 helicopters certificated in all categories, and to any other helicopters equipped with tail rotor hub assembly bolt (also called a blade grip retaining bolt or a bearing retaining bolt), P/N 47-641-052-3. Compliance required as indicated. To detect and prevent possible failure of the tail rotor hub assembly bolt due to a fatigue crack and to correct any improper installation of the hub bolt, accomplish the following: (a) Within the next 50 hours time in service, remove and replace bolts with 550 hours or more total time in service on the effective date of this AD. (b) Within the next 50 hours time in service, inspect, one time, bolts with less than 550 hours total time in service on the effective date of this AD as follows: (1) Remove and disassemble the tail rotor assembly and remove the hub assembly bolts. (2) Inspect the bolt head to shank radius for cracks using a magnetic particle or equivalent inspection method. (3) Replace cracked bolts before further flight as specified in paragraph (e). (c) Remove and replace bolts with less than 550 hours total time in service on the effective date of this AD at or prior to accumulating 600 hours total time in service. (d) Remove and replace all replacement bolts at or prior to accumulating 600 hours total time in service. (e) Install bolts in accordance with paragraph 6-16.e., Section VI, Model 47D-1, 47G and 47G-2 Maintenance and Overhaul Instruction Manual, as revised August 15, 1961, or in accordance with equivalent FAA approved procedures. This amendment becomes effective August 10, 1970. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H-1](https://openairdocs.org/tcds/H-1): Scott's-Bell 47 Inc; names 5 of 9 models: 47H-1, 47D1, 47D, 47G-2, 47G ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 211 (211 by airframe model, 0 by engine model) - Makers: Bell 199, Bell-K-Copter 3, Bell Kitz Kopters 1, Bell-Allied Helicopter 1, Bell-Carson 1, Bell-Olympic Helicopters 1, Bell-Shippey 1, Bell-Tellijohn 1, Bell-Transworld Helicopter Cor 1, Bell-Yehnert 1 Models with the most aircraft: - [Bell 47G-2](https://openairdocs.org/model/bell-47g-2): 87 aircraft (airframe model) - [Bell 47G](https://openairdocs.org/model/bell-47g): 55 aircraft (airframe model) - [Bell 47D1](https://openairdocs.org/model/bell-47d1): 47 aircraft (airframe model) - [Bell 47H-1](https://openairdocs.org/model/bell-47h-1): 6 aircraft (airframe model) - [Bell 47D](https://openairdocs.org/model/bell-47d): 4 aircraft (airframe model) - [Bell-K-Copter 47G](https://openairdocs.org/model/bell-k-copter-47g): 2 aircraft (airframe model) - [Bell Kitz Kopters 47D1](https://openairdocs.org/model/bell-kitz-kopters-47d1): 1 aircraft (airframe model) - [Bell-Allied Helicopter 47D1](https://openairdocs.org/model/bell-allied-helicopter-47d1): 1 aircraft (airframe model) - [Bell-Shippey BELL 47G](https://openairdocs.org/model/bell-shippey-bell-47g): 1 aircraft (airframe model) - [Bell-Carson 47G](https://openairdocs.org/model/bell-carson-47g): 1 aircraft (airframe model) - [Bell-Tellijohn 47G-2](https://openairdocs.org/model/bell-tellijohn-47g-2): 1 aircraft (airframe model) - [Bell-K-Copter 47G-2](https://openairdocs.org/model/bell-k-copter-47g-2): 1 aircraft (airframe model) - [Bell-Transworld Helicopter Cor 47G-2](https://openairdocs.org/model/bell-transworld-helicopter-cor-47g-2): 1 aircraft (airframe model) - [Bell-Olympic Helicopters 47G2](https://openairdocs.org/model/bell-olympic-helicopters-47g2): 1 aircraft (airframe model) - [Bell-Yehnert 47G-2](https://openairdocs.org/model/bell-yehnert-47g-2): 1 aircraft (airframe model) - [Continental Copters 47G](https://openairdocs.org/model/continental-copters-47g): 1 aircraft (airframe model) All 16 models: https://openairdocs.org/ad/70-14-02/models.md Every aircraft: https://openairdocs.org/ad/70-14-02/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.