Service Bulletin No. 573

DATE: February 23, 2007

MODELS AFFECTED

Lycoming new, rebuilt, overhauled or repaired TIO-540-A2C, -J2B, -U2A, -AE2A, -AG1A, -AH1A, -AJ1A, -AK1A, -F2BD, -J2BD with serial numbers listed in Table 3.

TIME OF COMPLIANCE

At the next maintenance event or within 50 hours of engine operation; whichever occurs first.

A relief valve and system check can be performed with either the model 11-10090 Air Flow Tester with the setup shown in Figure 2, or with the alternate setup as shown in Figure 3. See Table 1 for applicability. The parts needed for the setup in Figure 2 are one pressurized regulator and two regulated pressure gauges which will read from one (1) to ten (10) psi. The two gauges must be able to be read in ¼ psi increments. The part needed for the setup in Figure 3 is one regulated pressure gauge which will read from one (1) to ten (10) psi. The gauge must be able to be read in ¼ psi increments.