# AD 62-23-02: Main Rotor Mast Thrust Bearing - 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47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B and 12 more - Effective: October 29, 1962 - Published: October 23, 1962 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Registered aircraft: 490 may be affected, by airframe or engine model (OpenAirDocs) - FAA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/4FF5E4E3E18F6EBF86256CE5006E7869.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/62-23-02 ## The airworthiness directive 62-23-02 BELL: Amdt. 498 Part 507 Federal Register October 23, 1962. Applies to Model 47 Series Helicopters Equipped with Main Rotor Mast Thrust Bearing, P/N 47-130-110-1. Compliance required as indicated. Excessive wear and evidence of impending failure of the main rotor mast thrust bearing have occurred. To preclude progression of bearing deterioration to a hazardous degree, accomplish the following: (a) Within the next 25 hours' time in service following the effective date of this AD and thereafter at periods not to exceed 25 hours, conduct a close visual inspection of the engine oil filter. (b) If metal particles are found during any inspection of the engine oil filter, the following shall be accomplished prior to further flight: (1) The source of the contaminant shall be located and eliminated and other components of the engine and transmission which may be jeopardized by metal particles shall be inspected and overhauled as prescribed by the appropriate Bell maintenance manual; and (2) The main rotor mast thrust bearing, P/N 47-130-110-1, shall be thoroughly inspected and replaced with a like component if found not to be in a serviceable condition. (c) Clean engine oil filter carefully before reinstalling. NOTE: For the purpose of this AD, the operations outlined under (a) and (c) are considered to be preventive maintenance and may, therefore, be accomplished by persons specified in Section 18.10(c) of the Civil Air Regulations. This directive effective October 29, 1962. Revised September 16, 1966. ## 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/62-23-02/models.md Every aircraft: https://openairdocs.org/ad/62-23-02/aircraft.md Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (2) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB CHI03FA277](https://openairdocs.org/ntsb/CHI03FA277), Aug 21, 2003: Bell TH-13T (N38CD), Light, AR, substantial damage. Probable cause: The total failure and seizure of the main rotor transmission while in cruise flight leading to the helicopter’s impact with terrain. - [NTSB MIA87LA155](https://openairdocs.org/ntsb/MIA87LA155), May 3, 1987: Bell 47G-3B1 (N43CD), Panama City Bch, FL, substantial damage --- 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.