Is AD 99-20-13 a recurring Airworthiness Directive?

No — AD 99-20-13 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 99-20-13 apply to?

AD 99-20-13 applies to Eurocopter Canada Ltd. — models BO-105 LS A-3, BO-105. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 99-20-13

one-time

Official AD 99-20-13 · FR doc 99-26713 · 1999-10-18 · airframe

Airworthiness Directives; Eurocopter Canada Ltd. Model BO 105 LS A-3 Helicopters

What this AD requires

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-20-13, which was sent previously to all known U.S. owners and operators of Eurocopter Canada Ltd. Model BO 105 LS A-3 helicopters by individual letters. This AD requires, before further flight, creating a component log card or equivalent record and determining the age and number of flights on each tension-torsion (TT) strap. The AD also requires inspecting and removing, as necessary, certain unairworthy TT straps. This amendment is prompted by an accident in which a main rotor blade (blade) separated from a Eurocopter Deutschland GMBH Model MBB-BK 117 helicopter because of fatigue failure of the TT strap. The Model MBB-BK 117 and the Model BO 105 LS A-3 helicopters use the same part-numbered TT strap. The actions specified by this AD are intended to prevent failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.

Which aircraft AD 99-20-13 applies to

MakesEurocopter Canada Ltd.

ModelsBO-105 LS A-3, BO-105

Part-conditional — 2604067, J17322-1.

Applies only when rotor tension-torsion (TT) strap P/N 2604067 (Bendix) or J17322-1 (Lord) is installed.

Whether AD 99-20-13 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 99-20-13 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.