51-23-04: Rotor Link Assemblies
FAA order 51-23-04 is an airworthiness directive. The FAA's subject line: Rotor Link Assemblies. System: other and general.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sikorsky Aircraft Corporation
- Models
- S-51
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 (1,051 characters)
51-23-04\tSIKORSKY: Applies to All Model S-51 Helicopters. \n\nCompliance required as indicated. \n\n1.\tCompliance required prior to next flight. \n\nInspect all main rotor link assemblies (P/N S510348) received from the manufacturer between June 1 and September 6, inclusive for location of the identification stamp "F". Links with the "F" metal-stamped in the critical area on the inner faces of the ears should be retired from service. Those with the "F" stamped on the outer faces or on noncritical areas of the inner faces of the ears should be polished locally with emery and crocus cloth to remove the "F" and the links may be returned to service. (See Figure 6.) \n\n\n\nAD 51-23-04 \n\n(Sikorsky Information Circular No. 175, dated September 7, 1951, covers this same subject.) \n\n2.\tMain rotor link assemblies (P/N S510348) shall be retired from service when a total flight time of 960 hours on the links has been accumulated. \n\n(Sikorsky Information Circular No. 122, Revision B, dated September 10, 1951, covers this same subject.)
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/51-23-04.json · aircraft systems.