Is AD 2015-33013 a recurring Airworthiness Directive?

No — AD 2015-33013 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2015-33013 apply to?

AD 2015-33013 applies to Sikorsky — models S-76A, S-76B, S-76C, S-76. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2015-33013

one-time

AD 2015-33013 · 2016-01-05 · airframe

Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

What this AD requires

We are adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C helicopters. This AD requires inspecting the main gearbox (MGB) lower housing jet bores for leaks, paint or caulk blistering, and liner protrusion. This AD was prompted by several reports of MGB low oil pressure warnings which were determined to be the result of unsecured jet bore liners that had protruded. The actions are intended to prevent failure of the MGB from loss of oil, which could result in subsequent loss of control of the helicopter.

Which aircraft AD 2015-33013 applies to

MakesSikorsky

ModelsS-76A, S-76B, S-76C, S-76

Part-conditional — 76351-09000, 76351-09500, 76351-09600.

Applies only to a main gearbox with one of the listed part number series that has been repaired in accordance with Sikorsky ORI No. 76350-065 (dated November 12, 1982) or ORI No. 76350-065, Revision A (dated September 21, 1984).

Whether AD 2015-33013 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

How AD compliance is recorded

A valid compliance record (14 CFR 43.9) states:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.

Date — When the work was done.

Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.

Signature & certificate — The A&P/IA who returned it to service, with certificate number.

Is AD 2015-33013 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.