Air intake around exhaust pipe.

I got to looking at the Vultee BT-13's a little closer while at Oshkosh and noticed they all had a small air intake on a shroud that enclosed the exhaust pipe. What does this do? I'm guessing it's suppplying hot air to something.

[Michel Lemieux]

To the pilot......

On British AC like the Blenheim & Lysander, using the Mercury engine, it was used to heat up the cockpit

[Ollie]

Don't forget the Harvard with its very long heating sleeve!

On some Kittyhawks it's carby heat.

hi its called a heat muff which uses exhast heat to warm the cabin or for carb deicing it is an inclosed chamber that takes in fresh air that is heated from the exhast pipe and delivers warmed fresh air to the pilot only the heat is transfered not the exhast fumes thanks Mike

[Don Martin]

Just like a#@$&^%*& V.W. Beetle heater!

Something wrong with Volkswagen's?

[Don Martin]

Other than the heater, no. Did you ever drive one in the north , sub-zero winter days and try to get ANY HEAT at all out of it? There is none to be had. Other then that, a fun little car!