56-23-03: Horizontal Hinge Pin Assembly

FAA order 56-23-03 is an airworthiness directive. The FAA's subject line: Horizontal Hinge Pin Assembly. It names Sikorsky S-55: about 15 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: other and general.

What it applies to as the FAA lists it

Kind of product: Aircraft
Makes: Orlando Helicopter Airways, Inc.; Sikorsky Aircraft Corporation
Models: HRS-1/CH-19, HRS-3/H-19B, S-55, S-55B, S-55C
On this site: Sikorsky S-55 15 registered

Dates and paperwork

Docket: Unknown
Status: Current
The FAA's document: Read the order on the FAA's site

The order itself the regulatory text, as published

Show the full text (619 characters)

56-23-03   SIKORSKY:   Applies to All Model S-55 Helicopters. 

	Compliance required as indicated. 

	Due to additional failures, it has been found necessary to lower the retirement time specified in AD 56-10-02. Accordingly, the horizontal hinge pin assembly, P/N S10-10-3331 and S10-10-3331-1 with 750 hours service must be replaced by December 1, 1956, or prior to the accumulation of 850 hours, whichever occurs first.  Parts with 850 hours or more must be replaced prior to further service. Thereafter, P/N S10-10-3331 and S10-10-3331-1 are to be retired at not more than 750 hours. 

	This supersedes AD 56-10-02.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/56-23-03.json · aircraft systems.