AD 2009-16-03

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

If the engine records don't contain the P/N of the cylinder heads, do the following:

(1) Remove the valve cover from the cylinder assembly.

(2) Look at the cylinder head for the P/N SAC 52001 I or SAC 55001 I and the word “AMCAST.”

(g) For TCM IO-520, TSIO-520, and IO-550 series reciprocating engines with SAP investment cast cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, installed, with over 750 flight hours (FH) time-in-service (TIS), do the following within 25 FH TIS after the effective date of this AD:

(1) Inspect each cylinder head around the exhaust valve side for visual cracks or any signs of black combustion leakage.

(2) Replace any cracked or leaking cylinders before further flight.

(3) Perform a standard cylinder compression test. Guidance on standard cylinder compression tests can be found in Teledyne Continental Aircraft Engine Service Bulletin SB03-3, Differential Pressure Test and Borescope Inspection Procedures for Cylinders, dated March 28, 2003.

(i) If the cylinder pressure gauge reads below 60 pounds per-square inch, determine if the unacceptable pressure is due to a cracked cylinder.

(ii) To check the cylinder, apply a 2 percent soapy water solution to the side of the leaking cylinder.

(iii) If you see air bubbles, indicating air leakage, on the side of the cylinder head, or near the head-to-cylinder interface, replace the cylinder assembly before further flight.

(h) Thereafter, repeat the cylinder visual inspections and compression tests within 50 FH time-since-last inspection (TSLI) until the cylinders reach their time-between-overhaul (TBO) limits specified in Teledyne Continental Aircraft Engine Service Information Letter SIL98-9A, Revision A, dated March 28, 2003.

(i) For TCM IO-520, TSIO-520, and IO-550 series reciprocating engines with SAP investment cast cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, replace the SAP cylinder head assembly at the first TBO after the effective date of this AD. Engines that were already overhauled may continue in service until the first TBO after the effective date of this AD.

After the effective date of this AD, do not install any SAP investment cast cylinder assembly, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, in any engine.