# AD 68-21-06: Deactivate AFCS

- Type: Airworthiness directive
- Status: Current
- Products: Sikorsky S-61A, S-61L and S-61N
- Effective: October 24, 1968
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-671
- Registered aircraft: 52 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4D4ED9249294729786256A55006DACB6.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/68-21-06

## The airworthiness directive

68-21-06 SIKORSKY: Amendment 39-671. Applies to S-61A, S-61L, S-61N Type Helicopters.

  (a) Within the next ten hours time in service after the effective date of this Airworthiness Directive unless already accomplished, deactivate the automatic flight control system (AFCS) by disconnecting the power sources to the AFCS system and the channel monitor panel as follows:

  (1) Pull circuit breakers for electric power to the channel monitor panel and the AFCS system and safety the circuitbreaker buttons in the tripped position.

  (2) Disconnect electrical connectors at the aux. servos and secure to wire bundle. Electrically ground all three pins on each plug on the aux. servos.

  (b) For Models S-61L and S-61N, the AFCS may be reactivated when Sikorsky Service Bulletin No. 61B55-10A, dated October 4, 1968, or later FAA approved revision, or equivalent alteration approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

  (c) For Model S-61A, the AFCS maybe reactivated when an alteration approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region is incorporated.

This amendment is effective October 24, 1968, and supersedes the telegram dated September 17, 1968 on this subject.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1H15](https://openairdocs.org/tcds/1H15): Sikorsky Aircraft; names 2 of 4 models: S-61N, S-61L
- [TCDS H2EA](https://openairdocs.org/tcds/H2EA): Sikorsky Aircraft Corporation; names 1 of 4 models: S-61A

## 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: 52 (52 by airframe model, 0 by engine model)
- Makers: Sikorsky 51, Carson Helicopters / Sikorsky 1

Models with the most aircraft:

- [Sikorsky S-61N](https://openairdocs.org/model/sikorsky-s-61n): 45 aircraft (airframe model)
- [Sikorsky S-61A](https://openairdocs.org/model/sikorsky-s-61a): 5 aircraft (airframe model)
- [Sikorsky S-61L](https://openairdocs.org/model/sikorsky-s-61l): 1 aircraft (airframe model)
- [Carson Helicopters / Sikorsky S61A](https://openairdocs.org/model/carson-helicopters-sikorsky-s61a): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/68-21-06/models.md
Every aircraft: https://openairdocs.org/ad/68-21-06/aircraft.md

Its text cites no advisory circulars or STCs.

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