Cessna configured the cabin air control in the early 180's for push open, pull off. IMHO it's counter-intuitive, and also weird to have one knob pulled out when everything's off, but that's how they did it. The original placards on my panel are all long gone, I've placarded everything but I'm not sure if I should label the cabin air knob "pull closed" or "push open" or just what. I checked the owners manual & the IPC but I couldn't find anything on how the placard read in either one. Does anyone have the original placard wording?

Mine's just labeled 'Cabin Air'. Lots of other switches have 'Pull On', but the cabin air knob does not.

Personally, I like the logic because 95% of the time I fly all the knobs are in. Of course, that's in SoCal. I might think differently if I was in Alaska.

Chris

The TCDS doesn't specify, either.

The cabin heat scat is connected upstream of the cabin air damper, so you must have the cabin air on for cabin heat. Cabin heat is configured for pull on- so for heat you must have cabin air pushed in and cabin heat pulled out. The cabin air was mislabeled "pull on" when I bought the airplane, luckily a buddy of mine with a 54 180 told me that his was push on so I checked under the hood. Yep, he was right.

I believe the cabin air on my 170 is labeled "pull closed".

hotrod180 wrote:Cessna configured the cabin air control in the early 180's for push open, pull off. IMHO it's counter-intuitive, and also weird to have one knob pulled out when everything's off, but that's how they did it. The original placards on my panel are all long gone, I've placarded everything but I'm not sure if I should label the cabin air knob "pull closed" or "push open" or just what. I checked the owners manual & the IPC but I couldn't find anything on how the placard read in either one. Does anyone have the original placard wording?

Too hard to remember which is which???

MTV

Nope, just trying to get it right, hopefully legal, and make it easier for the next guy. The cabin air was actually labelled "pull on" when I bought the airplane which wasn't correct- the seller had it for 17 years and I'm sure he knew how it worked, but apparently he never bothered to properly placard it.
So Rob, does the cabin heat in your late-model 170 work the same way-- gotta have cabin air open to get cabin heat? My old ragwing 170 didn't have cabin air, other than the wing root vents- just a "pull on" cabin heat knob.

hotrod180 wrote: So Rob, does the cabin heat in your late-model 170 work the same way-- gotta have cabin air open to get cabin heat? My old ragwing 170 didn't have cabin air, other than the wing root vents- just a "pull on" cabin heat knob.

Yeah, that's how it works, I didn't realize this when I first bought the plane. My wife and I were flying the plane home to Cheyenne at about 11,500ft over Idaho. We were wondering why it was so damn cold even with the cabin heater on. I finally figured out you have to keep the cabin air on along with the cabin heat for it to work.

My 180 owner's manual cautions against pulling cabin heat without first pushing cabin air-- says damage to the muffler/ heat muff may result, although I don't see how. I tried cabin heat with the cabin air (improperly) pulled on-- like you, I found it didn't produce any heat. Properly pushed on, heat is pretty satisfactory- at least for the usual moderate temps here in the Puget Sound country.