Is AD 2004-08-10 a recurring Airworthiness Directive?

No — AD 2004-08-10 is a one-time directive. Verify it was complied with in the aircraft's records.

Airworthiness Directive 2004-08-10

Q: Which aircraft does AD 2004-08-10 apply to?

AD 2004-08-10 applies to Teledyne Continental Motors — models TSIO-520-NB, TSIO-520-VB, TSIO-520-WB, TSIO-520, 520, 550. Serial/part conditions may narrow it to specific aircraft.

one-time

Official AD 2004-08-10 · FR doc 04-8877 · 2004-04-20 · reciprocating engine

Airworthiness Directives; Engine Components Incorporated (ECi) Reciprocating Engine Cylinders

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for Teledyne Continental Motors (TCM) models 520 and 550 series engines with certain ECi cylinders installed. This AD requires replacing certain serial-numbered (SN) cylinders supplied by ECi before further flight. This AD results from reports of 34 failures of cylinder heads marketed by ECi. We are issuing this AD to prevent loss of engine power due to cracks in the cylinder head and possible engine failure caused by separation of a cylinder head.

Which aircraft AD 2004-08-10 applies to

MakesTeledyne Continental Motors

ModelsTSIO-520-NB, TSIO-520-VB, TSIO-520-WB, TSIO-520, 520, 550

Part-conditional — AEC631397.

Applies to (1) TCM TSIO-520-NB, -VB, and -WB engines modified by STC SE4327SW, SE09104SC, or SE09261SC for operation at 325 HP or greater (so-called RAM TSIO-520-NB, -VB, or -WB Series III, IV, and VII engines), and (2) TCM model 520 and 550 series reciprocating engines with ECi cylinders P/N AEC631397 installed.

Whether AD 2004-08-10 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 2004-08-10 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.