# AD 57-07-02: Rotor Hub Equalizer Link - Type: Airworthiness directive - Status: Current - Products: Scotts-Bell 47 47, 47B, 47B3, 47D, 47D1, 47E, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B and 12 more - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Registered aircraft: 490 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/157184BF5358BA4B86256A34004F9A09.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/57-07-02 ## The airworthiness directive 57-07-02 BELL: Applies to Model 47 Helicopters Except the Following: Model 47G 1529, 1689 and Up; 47G2 1506, 1957 and Up; Model 47H1 1361, 1534 and Up; Model 47J 1420, 1421, 1423, 1424, 1428 and Up; Model 47K. Compliance required as indicated. 1. In order to insure that rotor hub equalizer link assembly, P/N 47-120-025-1, is assembled with sufficient threads engaged to meet safety requirements, the following inspection must be conducted and part reworked as necessary by April 15, 1957, unless item 2 has been accomplished. (a) Inspect rod end, P/N 47-120-025-7, for adequate distance between end of shank to safety inspection hole, 0.230 to 0.270 inch required. (b) Inspect for adequate distance between shank end of P/N 47-120-025-5 rod end shank end of P/N 47-120-025-7 rod end. Maximum of 15/32 (0.468) inch is allowed. NOTE: If dimension between rod ends exceeds 15/32 (0.468) inch, hub assembly must be rerigged and link assemblies must be adjusted until this dimension is below this valve. 2. Rework on, or before, next overhaul of main rotor hub assembly. Rework link assemblies, P/N 47-120-025-1, which do not meet conditions described in above inspection, item 1(a) as follows: (a) Remove link assembly, P/N 47-120-025-1 from main rotor hub assembly and remove rod end, P/N 47-120-025-7 from link assembly. (b) Drill a No. 50 (0.070) inch diameter hole through shank at a point 0.230- 0.270 inch from shank end and 90 degrees from existing inspection hole. (c) Reassemble link assembly, install on hub assembly, and rerig hub assembly. Use new safety inspection hole to determine that rod end has sufficient threads engaged. (Bell Service Bulletin No. 118SB dated February 1, 1957, covers this same subject.) ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 2H3](https://openairdocs.org/tcds/2H3): Scott's-Bell 47 Inc; names 11 of 11 models: 47G-2A, 47G-3B, 47G-3, 47G-4A, 47G-5A, 47G-5, 47G-3B-2A, 47G-3B-2… - [TCDS H-1](https://openairdocs.org/tcds/H-1): Scott's-Bell 47 Inc; names 9 of 9 models: 47H-1, 47B, 47B3, 47D1, 47D, 47G-2, 47G, 47… - [TCDS 2H1](https://openairdocs.org/tcds/2H1): Scott's-Bell 47 Inc; names 4 of 4 models: 47K, 47J-2, 47J-2A, 47J ## 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: 490 (490 by airframe model, 0 by engine model) - Makers: Bell 476, Bell-K-Copter 3, Bell Kitz Kopters 1, Bell-Allied Helicopter 1, Bell-Carson 1, Bell-Huddleston And Wilson 1, Bell-Intermountain 1, Bell-Olympic Helicopters 1, Bell-Shippey 1, Bell-Tellijohn 1 Models with the most aircraft: - [Bell 47G-2](https://openairdocs.org/model/bell-47g-2): 87 aircraft (airframe model) - [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1): 86 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 47G-5](https://openairdocs.org/model/bell-47g-5): 40 aircraft (airframe model) - [Bell 47G-3B-2](https://openairdocs.org/model/bell-47g-3b-2): 26 aircraft (airframe model) - [Bell 47G-4A](https://openairdocs.org/model/bell-47g-4a): 20 aircraft (airframe model) - [Bell 47G-2A](https://openairdocs.org/model/bell-47g-2a): 19 aircraft (airframe model) - [Bell 47G-5A](https://openairdocs.org/model/bell-47g-5a): 19 aircraft (airframe model) - [Bell 47G-3B](https://openairdocs.org/model/bell-47g-3b): 15 aircraft (airframe model) - [Bell 47G-2A-1](https://openairdocs.org/model/bell-47g-2a-1): 13 aircraft (airframe model) - [Bell 47G-4](https://openairdocs.org/model/bell-47g-4): 13 aircraft (airframe model) - [Bell 47G3B2A](https://openairdocs.org/model/bell-47g3b2a): 7 aircraft (airframe model) - [Bell 47H-1](https://openairdocs.org/model/bell-47h-1): 6 aircraft (airframe model) - [Bell 47J](https://openairdocs.org/model/bell-47j): 6 aircraft (airframe model) - [Bell 47J-2](https://openairdocs.org/model/bell-47j-2): 6 aircraft (airframe model) - [Bell 47J-2A](https://openairdocs.org/model/bell-47j-2a): 5 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 47B](https://openairdocs.org/model/bell-47b): 1 aircraft (airframe model) All 35 models: https://openairdocs.org/ad/57-07-02/models.md Every aircraft: https://openairdocs.org/ad/57-07-02/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.