# AD 79-23-07: Soloy Conversion per STC SH657NW - Type: Airworthiness directive - Status: Current - Products: Allison 250-C18A, -C18C, -C20, -C20B engine (Siam Hiller Holdings STC SH657NW) - Effective: November 26, 1979 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-3613 - Registered aircraft: 412 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/73412500A63B462286256A340055DF26.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/79-23-07 ## The airworthiness directive 79-23-07 BELL HELICOPTER TEXTRON: Amendment 39-3613. Applies to Bell 47G series helicopters certificated in all categories that have been converted to turbine power Soloy Conversions, Ltd., Supplemental Type Certificate SH657NW. A. Within the next 25 hours time-in-service, after the effective date of this AD, inspect the turbine engine mount rod ends with a magnet to determine if the NMB Inc. P/N AH FTL5, or Soloy P/N 100-2205-2B rod ends are installed. These suspect stainless steel rod ends are identified by the fact that they are non-magnetic. B. If the non-magnetic stainless steel rod ends are found to be installed, replace the rod ends with Heim P/N HFL-5M or Soloy P/N 100-2205-1B in accordance with Soloy Conversions, Ltd., Service Bulletin 03-660 dated July 16, 1979, within 25 hours time-in-service after the effective date of this AD. C. Return the suspect stainless steel rod ends to Soloy Conversions, Ltd., for disposal within 30 days after removal. D. Alternate replacements which provide an equivalent level of safety may be used when approved by the Chief, Engineering and Manufacturing Branch, FAA Northwest Region. The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer, may obtain copies upon request to Soloy Conversions, Ltd., P.O. Box 60, Chehalis, Washington, 98532. These documents may also be examined at FAA Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108. This amendment is effective November 26, 1979 and was effective earlier, for all recipients of the airmail letter dated August 21, 1979, which contained this Amendment. ## Affected data sheets (2) (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 2 of 9 models: 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: 412 (412 by airframe model, 0 by engine model) - Makers: Bell 400, Bell-K-Copter 3, Bell-Carson 1, Bell-Huddleston And Wilson 1, Bell-Intermountain 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-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 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-K-Copter 47G](https://openairdocs.org/model/bell-k-copter-47g): 2 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-Intermountain 47G-3B-1](https://openairdocs.org/model/bell-intermountain-47g-3b-1): 1 aircraft (airframe model) - [Bell-Huddleston And Wilson 47G-3B1](https://openairdocs.org/model/bell-huddleston-and-wilson-47g-3b1): 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) All 25 models: https://openairdocs.org/ad/79-23-07/models.md Every aircraft: https://openairdocs.org/ad/79-23-07/aircraft.md ## Related documents - [STC SH657NW](https://openairdocs.org/stc/SH657NW): Installation of Allison 250-C18A, -C18C, -C20, -C20B engine and related changes.. Siam Hiller Holdings Inc, Named in the applicability --- 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.