Plain English Meaning

A simple metal sleeve wrapped around the exhaust pipe. Air passes through the sleeve, picks up heat from the hot pipe, and that warm air is then sent to the cabin heater or to the carburetor to keep ice from forming.

Full Definition

Metal shrouds fitted around portions of the engine exhaust system that capture heat from the hot exhaust pipes. Outside air is routed through these shrouds, warmed by contact with the exhaust surface, and then ducted into the cabin for heating and into the carburetor intake to prevent or remove carburetor ice.

Context Anchor

You may encounter heat muffs during preflight inspection, cabin heat checks, checks, and discussions of the exhaust system.