Is AD 98-24-13 a recurring Airworthiness Directive?

Yes — AD 98-24-13 requires a repetitive inspection every 100 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 98-24-13 apply to?

AD 98-24-13 applies to Eurocopter, Mbb — models BK117. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-24-13

recurring

Official AD 98-24-13 · FR doc 98-30788 · 1998-11-19 · airframe

Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) (Eurocopter) Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1 Helicopters

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to Eurocopter Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters, that currently requires initial and repetitive inspections of both surfaces of the tail boom vertical fin (vertical fin) spar, the skin, and the left-hand and right-hand frame sheets for cracks or loose rivets. That AD also requires repairing certain cracks, if found, and repairing and reporting those loose rivets and certain other cracks, if found. This amendment requires the same inspections, repairs, and reporting as the existing AD, but changes the reference to the service bulletin and prohibits the use of blind rivets for the vertical fin spar repair. This amendment is prompted by an accident that occurred on April 15, 1997, resulting in one fatality. The actions specified by this AD are intended to prevent failure of the vertical fin and subsequent loss of control of the helicopter.

Repetitive inspection. Re-inspect every 100 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 98-24-13 applies to

MakesEurocopter Mbb

ModelsBK117

Part-conditional — 105-304061.03, 1120-30406.03, 117-30423-03, 105-304011.18, 1120-30402.08.

Tail boom vertical fin spar (P/N 105-304061.03, 1120-30406.03, or 117-30423-03) and skin (P/N 105-304011.18 or 1120-30402.08); inspect for cracks/loose rivets, repair per Eurocopter/MBB ASB-MBB-BK117-30-106 Rev 3/4, with repeat-inspection intervals varying by whether repair has been made.

Whether AD 98-24-13 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 98-24-13 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.