AD 73-11-06

73-11-06 MAULE: Amdt. 39-1646. Applies to Models M-4-180 and M-4-220 certificated in all categories as indicated below.

Compliance required within the next 50 hours' time in service after the effective date of this airworthiness directive.

To prevent possible engine overheat during climb and to obtain a correct cylinder head temperature reading accomplish the following or an equivalent approved by Chief, Engineering and Manufacturing Branch, Southern Region:

1. For Model M-4-220C serial numbers 2135C through 2175C and 2177C: Install Maule slug P/N 6002B-3 in the No. 4 cylinder head thermocouple hole in accordance with Maule Service Letter No. 25. The slug is to be installed prior to relocation of cylinder head sender unit.

2. For Model M-4-180C serial numbers 3001C through 3006C; Model M-4-220S, Serial Number 2001S; Model M-4-220C; Serial Numbers 2001C through 2126C, 2129C through 2175C, and 2177C: Relocate the cylinder head temperature sender to the No. 4 cylinder head in accordance with Maule Service Letter No. 24.

3. For Model M-4-180C, Serial Numbers 3002C through 3006C, and Model M-4-220C Serial Numbers 2053C through 2126C, 2129C through 2175C and 2177C: Install engine top baffle, Maule P/N 5031X-3, in accordance with Maule Service Letter No. 26.

This amendment becomes effective May 29, 1973.