# AD 74-25-06: Takeoff Gross Weight Limitation

- Type: Airworthiness directive
- Status: Current
- Products: Sikorsky S-61L, S-61N and S-61NM
- Effective: October 16, 1974
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-2035
- Registered aircraft: 47 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DAFD010A4115EE5086256A560045AA96.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/74-25-06

## The airworthiness directive

74-25-06 SIKORSKY: Amendment 39-2035. Applies to S-61L, S-61N, and S-61NM helicopters certified in all categories equipped with engine air inlet deflector installation (P/N S6107-21115 Series). Compliance with this airworthiness directive is required prior to next flight. Prior to each flight, reduce each takeoff gross weight limitation prescribed by the FAA approved Sikorsky Helicopter Flight Manual and applicable supplements 800 pounds until:

  (a) receipt and incorporation of Revision No. 6, dated June 13, 1974, or Revision No. 7, dated July 24, 1974, for the FAA approved S-61N helicopter Flight Manual (SA 4045-82),

  (b) receipt and incorporation of correcting revision approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region, to Supplement No. 22, dated December 6, 1973, for the FAA approved S-61L helicopter flight manual (SA 4045-30) or,

  (c) receipt and incorporation of correcting revision approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region, to Supplement No. 4, dated December 6, 1973, for the FAA approved S-61L (serial no. 61425 and subsequent) helicopter flight manual (SA 4045-100).

This amendment becomes effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated October 16, 1974.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1H15](https://openairdocs.org/tcds/1H15): Sikorsky Aircraft; names 3 of 4 models: S-61N, S-61L, S-61NM

## 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: 47 (47 by airframe model, 0 by engine model)
- Makers: Sikorsky 47

Models with the most aircraft:

- [Sikorsky S-61N](https://openairdocs.org/model/sikorsky-s-61n): 45 aircraft (airframe model)
- [Sikorsky S-61L](https://openairdocs.org/model/sikorsky-s-61l): 1 aircraft (airframe model)
- [Sikorsky S-61NM](https://openairdocs.org/model/sikorsky-s-61nm): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/74-25-06/models.md
Every aircraft: https://openairdocs.org/ad/74-25-06/aircraft.md

Its text cites no advisory circulars or STCs.

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