Airworthiness Directive 2015-25976

recurring
AD 2015-25976 · 2015-10-20 · airframe

Airworthiness Directives; Various Sikorsky-Manufactured Transport and Restricted Category Helicopters

What this AD requires

We are superseding Airworthiness Directive (AD) 98-26-02 for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-61A, D, E, L, N, NM, R, and V helicopters. AD 98-26-02 required determining whether the main rotor shaft (MRS) was used in repetitive external lift (REL) operations, performing a nondestructive inspection (NDI) for cracks, replacing any unairworthy MRS, and establishing retirement lives for each REL MRS. This new AD retains some of the requirements of AD 98-26- 02 but determines a new retirement life for each MRS, expands the applicability to include additional helicopters, and requires removing from service any MRS with oversized dowel pin bores. This AD was prompted by the manufacturer's reevaluation of the retirement life for the MRS based on torque, ground-air-ground (GAG) cycle, and fatigue testing. We are issuing this AD to prevent MRS structural failure, loss of power to the main rotor, and subsequent loss of control of the helicopter.

Repetitive inspection. Re-inspect. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2015-25976 applies to

Applicability depends on the aircraft’s type certificate — check it against the specific tail.

Whether AD 2015-25976 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

Supersession

Supersedes AD 98-26-02.

How AD compliance is recorded

A valid compliance record (14 CFR 43.9) states:

Method of complianceThe specific action taken (inspected, replaced, modified) and to what revision.
DateWhen the work was done.
Aircraft timeTotal time in service / tach at compliance — how recurring next-due is computed.
Signature & certificateThe A&P/IA who returned it to service, with certificate number.
Is AD 2015-25976 complied with on your aircraft?

Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.

Look up a tail number →Read the full directive (Federal Register)

Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.