The Cessna 120-140 Association Forum

AD 62-24-03, effective Nov 21, 1962 addresses modifications for attaching the heat muffs to the exhaust stacks of Cessna 120/140/140A/Luscombe 8E/8F aircraft by following McKenzie Aircraft Repair Service Bulletin number 1 dated Sept 6, 1962. The Flight Standards District Office is unable to locate the McKenzie service bulletin. The AD addresses cutting off the heat muff attaching straps and attaching the muffs per the McKenzie service bulletin. If anyone knows how to obtain the service bulletin or the modifications involved, I would appreciate your feedback. Thank you

Found this if its what your looking for?

Do you have a Lycoming engine installed under one of the McKenzie approvals? If not, it doesn't apply.

The Cessna McKenzie STCs were acquired by Gus Warren, I think. Maybe he has the service bulletin, too.