Is AD 2001-18-51 a recurring Airworthiness Directive?

No — AD 2001-18-51 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2001-18-51 apply to?

AD 2001-18-51 applies to Eurocopter — models SA.315B, SA.316C, SA.316B, SA 318B, SA 318C, SA.319B, SA.315, SA.316. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2001-18-51

one-time

Official AD 2001-18-51 · FR doc 01-25694 · 2001-10-16 · airframe

Airworthiness Directives; Eurocopter France Model SA.315B, SA.316C, SA 3180, SA 318B, SA 318C, SA.319B, SE.3160, and SA.316B Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-18-51, which was sent previously to all known U.S. owners and operators of Eurocopter France (ECF) Model SA.315B, SA.316C, SA 3180, SA 318B, SA 318C, SA.319B, SE.3160, and SA.316B helicopters by individual letters. This AD requires, within 10 hours time-in-service (TIS), inspecting the magnetic drain plug and the main gear box (MGB) filter for a rust- colored deposit, inspecting the MGB to determine the angular displacement on the MGB output flange, and periodically examining oil samples. If a rust-colored deposit is found on the drain plug or filter, if the oil is rust-colored, or if the angular displacement is 1 millimeter (0.039 inch) or more, this AD requires replacing the MGB with an airworthy MGB before further flight. Repairing or overhauling the gearbox, or re-identifying certain gearboxes that have already been appropriately overhauled, is terminating action for the requirements of this AD. This AD is prompted by an accident of an ECF Model SA.315B helicopter that lost power to the tail rotor. The loss of power to the tail rotor was due to wear of the splines of the output bevel drive pinion in the MGB. The actions specified by this AD are intended to prevent a loose splined coupling, spline wear, loss of power to the tail rotor, and subsequent loss of control of the helicopter.

Which aircraft AD 2001-18-51 applies to

MakesEurocopter

ModelsSA.315B, SA.316C, SA.316B, SA 318B, SA 318C, SA.319B, SA.315, SA.316, SA 318, SA.319, SE.3160, SA 3180

Part-conditional — 319A62-00-000-1, 319A62-00-000-2, 319A62-00-000-3, 319A62-00-000-4.

Applies only when one of a discrete list of ~190 specific serial-numbered main gearbox assemblies (MGB), P/N 319A62-00-000-1/-2/-3/-4 (serials with no prefix, 'M-' prefix, or 'NT-' prefix), is installed; not a continuous serial range — see original AD 2001-18-51 text for the full list.

Whether AD 2001-18-51 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 2001-18-51 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.