# AD 78-21-02: External Load Link Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Bell Helicopter Textron 204B, 205A, 205A-1 and 212 with STC SH149WE or SH17NW
- Effective: October 12, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-3317
- Registered aircraft: 125 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7C0A3E7F4F3C785686256A3400554138.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-21-02

## The airworthiness directive

78-21-02 BELL: Amendment 39-3317. Applies to all Bell Helicopter Models 204B, 205A, 205A-1, and 212 modified by Chadwick, Inc., STC's SH149WE or SH17NW.

Prior to further flight involving external-load operations over congested or densely populated areas, replace Chadwick, Inc., load cell link assembly P/N 47-40200-19 with parts approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Northwest Region.

This amendment is effective October 12, 1978, and was effective earlier for all recipients of the airmail letter dated September 18, 1978, which contained this amendment.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H1SW](https://openairdocs.org/tcds/H1SW): Bell Textron Inc.; names 3 of 5 models: 205A, 204B, 205A-1
- [TCDS H4SW](https://openairdocs.org/tcds/H4SW): Bell Textron Inc.; names 1 of 4 models: 212

## 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: 125 (125 by airframe model, 0 by engine model)
- Makers: Bell 117, Bell Helicopter Textron 6, Bell/Southwest Florida Aviatio 2

Models with the most aircraft:

- [Bell 205A-1](https://openairdocs.org/model/bell-205a-1): 56 aircraft (airframe model)
- [Bell 212](https://openairdocs.org/model/bell-212): 54 aircraft (airframe model)
- [Bell 204-B](https://openairdocs.org/model/bell-204-b): 7 aircraft (airframe model)
- [Bell Helicopter Textron 212](https://openairdocs.org/model/bell-helicopter-textron-212): 5 aircraft (airframe model)
- [Bell/Southwest Florida Aviatio 205 A1](https://openairdocs.org/model/bell-southwest-florida-aviatio-205-a1): 2 aircraft (airframe model)
- [Bell Helicopter Textron 205A-1](https://openairdocs.org/model/bell-helicopter-textron-205a-1): 1 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/78-21-02/models.md
Every aircraft: https://openairdocs.org/ad/78-21-02/aircraft.md

## Related documents

- [STC SH149WE](https://openairdocs.org/stc/SH149WE): Installation of Chadwick electronic weighing system C47.. Onboard Systems, Named in the applicability
- [STC SH17NW](https://openairdocs.org/stc/SH17NW): Installation of Chadwick Electronic weighing system C-47.. Onboard Systems International, Named in the applicability

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