# AD 66-04-03: Main Rotor Blades

- Type: Airworthiness directive
- Status: Current
- Products: Orlando Helicopter Airways HRS-1/CH-19, HRS-3/H-19B, S-55, S-55B, S-55C and S62A
- Effective: April 27, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-2577
- Registered aircraft: 17 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E3D7D24F030A2EFD86256A4D00504BB0.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/66-04-03

## The airworthiness directive

66-04-03 SIKORSKY: Amdt. 39-194 Part 39 Federal Register February 12, 1966, as amended by Amendment 39-1563 is further amended by Amendment 39-2577. Applies to Models S-55 Series and S-62A Helicopters.

Compliance required as indicated.

To prevent operation with fatigue cracks in the spar of a main rotor blade, accomplish the following:

  (a) Except as provided in (e), remove from service S14-10-2100 series main rotor blades with 2,225 or more hours' time in service on the effective date of this AD within the next 25 hours' time in service.

  (b) Except as provided in (e), remove from service S14-10-2100 series main rotor blades with less than 2,225 hours' time in service on the effective date of this AD before the accumulation of 2,250 hours' time in service.

  (c) Except as provided in (e), remove from service S14-10-2201 series main rotor blades with 2,100 or more hours' time in service on the effective date of this AD within the next 150 hours' time in service.

  (d) Except as provided in (e), remove from service S14-10-2201 series main rotor blades with less than 2,100 hours' time in service on the effective date of this AD before the accumulation of 2,250 hours' time in service.

  (e) The service life limits specified in (a), (b), (c), and (d) may be extended to 6,000 hours' total time in service for S14-10-2201-9 main rotor blades and S14-10-2100 series and S14- 10-2201 series blades modified to S14-10-2201-9 blades, provided the blades are inspected at the times and in the manner set forth in Sikorsky Service Bulletin No. 55B10-7E dated March 26, 1976 or No. 62B10-6E dated March 26, 1976 or later FAA approved revisions, as applicable, and, if low pressure is indicated, the cause is determined and corrected before further flight in accordance with the applicable service bulletin.

Amendment 39-194 became effective February 12, 1966.

Amendment 39-1563 became effective November 30, 1972.

This Amendment 39-2577 becomeseffective April 27, 1976.

## Affected data sheets (3) (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
- [TCDS 1H13](https://openairdocs.org/tcds/1H13): Centerpointe Aerospace Inc.; names 1 of 1 models: S62A

## 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/66-04-03/models.md
Every aircraft: https://openairdocs.org/ad/66-04-03/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.