Is AD 2018-09-12 a recurring Airworthiness Directive?

No — AD 2018-09-12 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2018-09-12 apply to?

AD 2018-09-12 applies to Boeing — models 747-200B, 747-300, 747-400, 747. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2018-09-12

one-time

Official AD 2018-09-12 · FR doc 2018-09865 · 2018-05-15 · airframe

Airworthiness Directives; The Boeing Company Airplanes

What this AD requires

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-200B, 747-300, and 747-400 series airplanes. This AD requires replacing certain low-pressure oxygen flex- hoses with new non-conductive low-pressure oxygen flex-hoses in the gaseous passenger oxygen system in airplanes equipped with therapeutic oxygen. This AD also requires a general visual inspection of the low- pressure passenger oxygen system to ensure there is minimum clearance of the oxygen system components from adjacent structure and systems. This AD was prompted by reports of low-pressure flex-hoses of the flightcrew oxygen system that burned through due to inadvertent electrical current from a short circuit. We are issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2018-09-12 applies to

MakesBoeing

Models747-200B, 747-300, 747-400, 747

Applies to airplanes identified in Boeing Special Attention Service Bulletin 747-35-2134, dated November 22, 2017.

Whether AD 2018-09-12 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 2018-09-12 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.