# AD 54-13-01: Star Assembly Bolt Replacement

- Type: Airworthiness directive
- Status: Current
- Products: Orlando Helicopter Airways HRS-1/CH-19, HRS-3/H-19B, S-55, S-55B and S-55C
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Registered aircraft: 17 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/344BEF2066E3D47486256A4D005009EC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/54-13-01

## The airworthiness directive

54-13-01 SIKORSKY: Applies to All Model S-55 Helicopters.

Compliance required as indicated.

1. The twelve (12) AN 73A bolts which clamp the S510170 retainer to the bottom of S10-10-4302 rotating star, and the eight (8) AN 73A bolts which clamp the S510156 retainer to the top of the S10-10-4302 rotating star should be replaced. The 20 new bolts should be torqued to 25-35 inch-pounds. These replacements are to be accomplished every 60 hours until the AN 74A bolts called for in item 2. are incorporated.

2. At the next major overhaul period of the star assembly S10-10-4300, replace the twenty (20) AN 73A bolts covered in 1 with 1/4-inch diameter AN 74A bolts. The AN 74A bolts should be relocated between the existing holes. When the AN 74A bolts have been incorporated, the replacements of 1 are no longer required.

3. At the next major overhaul period of the star assembly S10-10-4300, replace the twelve (12) AN 509-10R-35 screws which secure the clamp the S12-10-4015 liner and the Y96PW1-DB bearings to the S12-10-4013 stationary star. The screws should be torqued to 35- 40 inch-pounds.

(Sikorsky Service Information Circular No. 1410-222 dated March 4, 1952, through Revision D dated April 15, 1954, covers this same subject.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1H4](https://openairdocs.org/tcds/1H4): Centerpointe Aerospace Inc.; names 3 of 3 models: S-55C, S-55, S-55B
- [TCDS HR1SO](https://openairdocs.org/tcds/HR1SO): Orlando Helicopter Airways Inc.; names 2 of 10 models: HRS-3/H-19B, HRS-1/CH-19

## 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: 17 (17 by airframe model, 0 by engine model)
- Makers: Sikorsky 15, Sikorsky/Orlando 1, Sikorsky/Vertical 1

Models with the most aircraft:

- [Sikorsky S-55B](https://openairdocs.org/model/sikorsky-s-55b): 9 aircraft (airframe model)
- [Sikorsky S-55](https://openairdocs.org/model/sikorsky-s-55): 3 aircraft (airframe model)
- [Sikorsky S55B](https://openairdocs.org/model/sikorsky-s55b): 3 aircraft (airframe model)
- [Sikorsky/Orlando S-55](https://openairdocs.org/model/sikorsky-orlando-s-55): 1 aircraft (airframe model)
- [Sikorsky/Vertical S-55](https://openairdocs.org/model/sikorsky-vertical-s-55): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/54-13-01/models.md
Every aircraft: https://openairdocs.org/ad/54-13-01/aircraft.md

Its text cites no advisory circulars or STCs.

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