# AD 85-15-06: Tail Rotor Drive Shaft Bearings

- Type: Airworthiness directive
- Status: Current
- Products: Sikorsky S-76A
- Effective: November 25, 1985
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-5164
- Registered aircraft: 19 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E80F4FCC3404EF1D86256A4D0073FA95.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/85-15-06

## The airworthiness directive

85-15-06 SIKORSKY AIRCRAFT: Amendment 39-5164. Applies to Sikorsky Model S-76A helicopters certificated in all categories.

Compliance is required prior to further flight, unless already accomplished.

To prevent failure of certain tail rotor drive shaft bearings which may have been installed without lubricant, accomplish the following in accordance with Sikorsky Aircraft Alert Service Bulletin (ASB) 76-66-20, paragraph E.1, dated July 25, 1985.

  (a) Remove all Part Number (P/N) SB1138-101 bearings manufactured by MRC not identified with either a white dot on the grease fitting or a serial number and with under 100 hours operating time.

  (b) Replace removed bearings with MRC P/N SB1138-101 bearings identified with either a white dot on the grease fitting or a serial number or both, or with the alternate bearing manufactured by Fafnir and approved for this installation.

  (c) Aircraft may be ferried in accordance with the provisions of FAR Section 21.197 and 21.199 to a base where the AD can be accomplished.

  (d) Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Boston Aircraft Certification Office, ANE150, 12 New England Executive Park, Burlington, Massachusetts 01803. Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Manager, Boston Aircraft Certification Office, ANE-150, may adjust the compliance time specified in this AD.

Sikorsky Aircraft ASB 76-66-20 is 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 Mr. R. E. Warren, Sikorsky Aircraft Division, United Technologies Corporation, North Main Street, Stratford, Connecticut 06601. These documents also may be examined at the Rules Docket, Office of the Regional Counsel, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76106.

This amendment becomes effective November 25, 1985, as to all persons except those persons to whom it was made immediately effective by priority letter AD No. 85-15-06, issued July 30, 1985, which contained this amendment.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H1NE](https://openairdocs.org/tcds/H1NE): Sikorsky Aircraft Corporation; names 1 of 4 models: S-76A

## 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: 19 (19 by airframe model, 0 by engine model)
- Makers: Sikorsky 19

Models with the most aircraft:

- [Sikorsky S-76A](https://openairdocs.org/model/sikorsky-s-76a): 19 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/85-15-06/models.md
Every aircraft: https://openairdocs.org/ad/85-15-06/aircraft.md

Its text cites no advisory circulars or STCs.

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