Is AD 98-13-21 a recurring Airworthiness Directive?

Yes — AD 98-13-21 requires a repetitive inspection every 800 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 98-13-21 apply to?

AD 98-13-21 applies to Rolls-Royce, Snecma — models Olympus 593 Mk. 610-14-28, Olympus 593. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-13-21

recurring

Official AD 98-13-21 · FR doc 98-16467 · 1998-06-25 · turbine engine

Airworthiness Directives; Rolls-Royce Limited, Aero Division- Bristol, S.N.E.C.M.A Olympus 593 Series Turbojet Engines

What this AD requires

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce Limited, Aero Division-Bristol, S.N.E.C.M.A Olympus 593 series turbojet engines. This action requires initial and repetitive visual inspections of the low pressure (LP) shaft signal system for cable wear and refurbishment of the LP shaft signal system at when the cable is found frayed, or at every engine shop visit, whichever occurs first. This amendment is prompted by reports of frayed rear cables in the LP shaft signal system. The actions specified in this AD are intended to prevent LP shaft signal system failure, which could result in an LP turbine overspeed, burst, uncontained engine failure, and damage to the aircraft in the event of a LP shaft failure.

Repetitive inspection. Re-inspect every 800 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 98-13-21 applies to

MakesRolls-RoyceSnecma

ModelsOlympus 593 Mk. 610-14-28, Olympus 593

Installed on but not limited to British Aerospace/Aerospatiale Concorde series aircraft; applies to each identified engine regardless of modification, alteration, or repair status.

Whether AD 98-13-21 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 98-13-21 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.