Yes. You’d use it in the case of something like a fire where you need to get the smoke out NOW Here’s what it looks like on a 737: http://www.b737.org.uk/image

Yes. You’d use it in the case of something like a fire where you need to get the smoke out NOW Here’s what it looks like on a 737: http://www.b737.org.uk/images/cpcspanel.jpg http://www.b737.org.uk/images/cpcspanel.jpg The switch is the guarded toggle a bit left of center on the bottom, next to the two round gauges.