Normally Aspirated Skymaster Cabin Heat Shutoff?

[billsheila]

Yes they leak. I have found if you safety wire the control in the full closed position from underneath (and placard the controls "inop" in the summer months) it improves the situation. I think it was a bad design and air flow opens the flap slightly in flight, leaking warm air into the cabin. Also would be real bad of course if your mufflers ever failed...ie no way to really shut off the CO from entering the cabin.

Bill