Is AD 2004-06-51 a recurring Airworthiness Directive?

Yes — AD 2004-06-51 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2004-06-51 apply to?

AD 2004-06-51 applies to Boeing Vertol — models 234. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2004-06-51

recurring

Official AD 2004-06-51 · FR doc 04-12442 · 2004-06-03 · airframe

Airworthiness Directives; Boeing Defense and Space Group Model 234 Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2004-06-51, which was sent previously to all known U.S. owners and operators of Boeing Defense and Space Group (Boeing) Model 234 helicopters by individual letters. This AD requires, before further flight, inspecting the upper shaft extension for a crack and modifying the aft vertical shaft assembly (assembly). Thereafter, this AD requires, before the first flight of each day, inspecting the upper shaft extension for any crack. If any crack is found during any of the inspections, replacing the assembly with an airworthy assembly is required before further flight. This amendment is prompted by the discovery of a crack in the upper shaft extension of an assembly. The actions specified by this AD are intended to detect a crack in the upper shaft extension, which could result in catastrophic failure of the assembly 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 2004-06-51 applies to

MakesBoeing Vertol

Models234

Serial-conditional — narrows to serials ?–181.

Part-conditional — 234D3300.

Applies only if aft vertical shaft assembly P/N 234D3300, S/N A-181 or lower, is installed.

Whether AD 2004-06-51 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 2004-06-51 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.