Plug in wing-root vent?

[CaptainRod]

Greetings,

My '77 P model has a plug in the right wing root air inlet, the smaller one. There is no plug in the left wing. Does anyone have any info on these plugs? The aircraft has Riley air conditioning installed.

Thanks!

[CaptainRod]

Anyone out there?

[Red Air Rambo]

I'll look at my plane tomorrow.

[CaptainRod]

Thanks! Really appreciate it.

[Red Air Rambo]

Mines a 73 and just 1 hole each side no plugs. Hope to look at a 78 tomorrow and will let you know. Talked to my A & P and he could think of no reason for the plug unless to restrict cooling. Kinda like Truckers in the winter time with their radiator shields. I'll look at the 78, then get in the manuals.

[Red Air Rambo]

Rod, do you have the parts and service manuals?

[CaptainRod]

Not yet. Being shipped. Did you find out anything? Thanks.

[Red Air Rambo]

Did not have a chance to look at the 78 model, but on page 383 of the service manual, if i'm correct (not an A & P) the air scoops on the wing go to the aft Pressurization through the ceiling of the cockpit, while the front pressurization goes thru the left inlet and heat exchanger. All P models show just one hose off the scoop for the aft pressurization. Can't find where that second hose goes yet. Any other mods to the aircraft that you know of that require air?

[Red Air Rambo]

Talked to a different A & P today that has a 210 with similar holes, He said they go to avionics or equipment for cooling. He thinks the plug is the result of removal of a piece of equipment so the cooling was no longer necessary.

[CaptainRod]

That's very helpful. Thanks very much for the info. I called Cessna yesterday and they were not much help at all. Nobody there was familiar with the 337. Sad.

[JamesC]

Took a look at the service manual - in that area of the wing the only thing there really is the plumbing for the boots - my guess is that the plug is an access port for this area but you would really have to speak to a 337 A & P to be certain. I could not find explicit mention of the plug in the service or parts sections of the manuals. My acft has two plugs (and no air conditioning). Can you feel or see anything in there ?

[CaptainRod]

Took the wing root covers off and looked around. Nothing obvious to see. The parts manual shows plugs so I'll see if I can order another and install it. Thanks for the suggestions.