Is AD 2023-12-20 a recurring Airworthiness Directive?

No — AD 2023-12-20 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2023-12-20 apply to?

AD 2023-12-20 applies to Bombardier, Inc. — models CL-600-2B16, CL-600. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2023-12-20

one-time

Official AD 2023-12-20 · FR doc 2023-15177 · 2023-07-19 · airframe

Airworthiness Directives; Bombardier, Inc., Airplanes

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2B16 (604 Variant) airplanes. This AD was prompted by reports of oxygen leaks caused by cracked, brittle, or broken oxygen hoses that were found during scheduled maintenance tests of the airplane oxygen system. This AD requires replacing oxygen system hoses having any part number in the O2C20T1 and O2C20T14 series. This AD also prohibits installation of affected oxygen hoses. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2023-12-20 applies to

MakesBombardier, Inc.

ModelsCL-600-2B16, CL-600

Serial-conditional — narrows to serials 5701–5990, 6050–6162.

Applies to the 604 Variant only when the interior has been modified in accordance with Supplemental Type Certificate (STC) ST02355NY.

Whether AD 2023-12-20 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 2023-12-20 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.