Is AD 98-04-39 a recurring Airworthiness Directive?

No — AD 98-04-39 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 98-04-39 apply to?

AD 98-04-39 applies to Pratt & Whitney — models JT8D-1, JT8D-1A, JT8D-1B, JT8D-7, JT8D-7A, JT8D-7B, JT8D-9, JT8D-9A. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-04-39

one-time

Official AD 98-04-39 · FR doc 98-4408 · 1998-02-25 · turbine engine

Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

What this AD requires

This amendment adopts a new airworthiness directive (AD) that is applicable to Pratt & Whitney (PW) JT8D series turbofan engines. This action requires a one-time borescope inspection of the combustion chamber outer case (CCOC) for cracks on engines identified by serial number that were ultrasonically inspected in accordance with AD 96-23- 14 with defective probes. In addition, this AD requires an ultrasonic probe functional check at PW prior to using the probe to perform an ultrasonic inspection if the probe was overhauled, repaired, or otherwise altered since original manufacture and not subsequently functionally checked by PW. This amendment is prompted by reports of defective probes discovered in the field. The actions specified in this AD are intended to prevent uncontained engine failure, inflight engine shutdown, engine cowl release, and airframe damage.

Which aircraft AD 98-04-39 applies to

MakesPratt & Whitney

ModelsJT8D-1, JT8D-1A, JT8D-1B, JT8D-7, JT8D-7A, JT8D-7B, JT8D-9, JT8D-9A, JT8D-11, JT8D-15, JT8D-15A, JT8D-17, JT8D-17A, JT8D-17R, JT8D-17AR, JT8D

Part-conditional — 490547, 542155, 616315, 728829, 728829-001, 730413, 730413-001, 730414.

Applies only to engines with a combustion chamber outer case (CCOC) having one of the listed part numbers installed. Installed on but not limited to Boeing 737 and 727 series and McDonnell Douglas DC-9 series aircraft.

Whether AD 98-04-39 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 98-04-39 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.