Is AD 2008-21-02 a recurring Airworthiness Directive?

Yes — AD 2008-21-02 requires a repetitive inspection every 60 months. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2008-21-02 apply to?

AD 2008-21-02 applies to Boeing — models 737-600, 737-700, 737-700C, 737-800, 737-900, 737. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2008-21-02

recurring

Official AD 2008-21-02 · FR doc E8-23573 · 2008-10-09 · airframe

Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes Equipped With CFM56-7 Engines

What this AD requires

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 737-600, -700, and -800 series airplanes. That AD currently requires repetitive inspections to detect damage of the aft strut insulation blanket, and eventual replacement of the insulation blankets with new, improved blankets. This new AD adds airplanes to the applicability and requires installation of a new heat insulation blanket and new cover plate on the left and right side engine struts. This new AD does not retain the requirements of the existing AD but does terminate the requirements of the existing AD. This AD results from reports of damaged heat insulation blankets on the engine struts. We are issuing this AD to prevent exposure of the lower surface of the strut to extreme high temperatures, consequent creation of a source of fuel ignition, and increased risk of an uncontrollable fire and possible fuel tank explosion.

Repetitive inspection. Re-inspect every 60 months. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2008-21-02 applies to

MakesBoeing

Models737-600, 737-700, 737-700C, 737-800, 737-900, 737

Applies to airplanes as identified in Boeing Special Attention Service Bulletin 737-54-1045, dated July 25, 2007 (damaged heat insulation blankets on the engine struts).

Whether AD 2008-21-02 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 2008-21-02 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.