I fly a Zodiac CH601XL. Recently, I flew it from KFFZ (Mesa, AZ) to KBRG (Belen, NM). In spite of the fact that I typically flew at 10,500 or 11,500 MSL the air temperature in the cockpit was about 100 degrees. That was true even when the OAT was about 40 degrees.

The plane has two eyeball vents. However, they do almost no good in bringing cool air into the cockpit.

Does anyone have recommendations for reducing the air temperature in the cockpit? Thanks!


In response to my previous posting (see above) I received several very helpful suggestions, including:

1. Drill a 3" hole in the aft bulkhead of the baggage compartment to promote adequate airflow through the cockpit.

2. Install larger eyeball vents.

3. Install Vans vents on the sides of the cockpit.

4. Install a Koger ventshade. 

I will try these and provide a report at a later date on how they worked!

Thanks to everyone who offered useful recommendations.


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Hi Eugene
Wow! That’s hot!
I’m in Florida and I manage the cockpit temps by utilizing a koger
Sun shade, honestly I don’t see how you can fly in a bubble canopy without one, I also have two air vents in my canopy in addition to the two naca vents in the fuselage.
When I get up to 4000 feet it’s nice and cool.

Dear David,

Thanks for your reply. What are the other two vents? Where are they installed? Can you send a photo of the pilot side?

I live southwest of Fort Worth, Texas.  I closed off the NACA inlets and installed the vents that VANS sells. Also put in some sun shades from Walmart which have been on for a couple years now, and are $1000 cheaper than the shades that Koger was selling (650 canopy).

Much improved.  No performance degredation with the vents.

Passenger Side

Pilot Side

Walmart Sun Shades

Patrick Hoyt


Dear Patrick:

Thanks for your reply. My plane has NACA inlets on both sides going to eyeball vents on the lower left and lower right of instrument panel. They are next to useless. 

The vents you installed look great. Appears that they let in quite a bit of outside air. How far back from the leading edge of the wings are they installed? Where do the vents lead to on the inside of the cockpit?

Thanks again!



The vent on the Pilot's side of my plane is about 3 inches ahead of the leading edge of the wing, just aft of where the existing NACA vent was. 

The vent on the Passenger's side is about 21 inches aft of the leading edge of the wing.  This location was chosen simply so I could reach it in flight if no passenger is seated there.

The vents don't lead anywhere.  They simply open to the interior of the cockpit.  I don't have any tubes or eyeball devices or anything like that.

If I were to do it again, I think I'd cover the pre-existing NACA vent cut-out with a piece of .025 aluminum, and place the vents (on both sides) approximately even with the front of the leading edge of the wing, and roughly even with the top of the thickest part of the wing at the root. 

The reason I'd try it in that location is due to flow separation that happens further aft, as shown in this video of some tuft testing of my vents. It's counter-intuitive, but it is possible to reduce drag by introducing turbulence ahead of areas where flow separation is ocurring.  That video shows "closed" and "open" footage of my vents in flight, and looking at the area at the wing root (just above the flap) it's clear that flow separation is reduced when the vent is open.

Patrick Hoyt


Dear Patrick:

Thanks for the link to the video. It gives me a good idea on the placement of the vents.


Is this the type of vent kit to order from Vans?


Yes, those are the ones that I used.

- Pat

I can’t get a shot of the vents in the canopy, but they are the standard plastic vents that aircraft spruce sells, they are pop in that rotate for air flow.

next time at the airport I’ll take a pic for you.

 but they are on the forward sides of the canopy.

as far as a Walmart sun shield, the Kroger shield covers almost the entire canopy, is adjustable to any length in a second.

the Walmart shield wouldn’t cut it here in Florida.

$1000 less, must be a typo as the Kroger is less than $200 and is the best improvement I have ever made to my airplane.


No typo.  I personally walked the guy from Koger over to see my airplane at Oshkosh 2013 when I was shopping for a sunshade (he originally wanted to sell me a one-piece sunshade for a 601, and he'd never seen the two-piece split canopy of the 650). 

He measured the canopy sections on my airplane, and then gave me a quote of well over $1,000.  He said it was double the price of a custom sunshade because it was really two separate custom pieces.

If he's now selling them for anywhere near $200, then either something has changed (maybe he can make them cheaper now), or maybe he's selling a one-piece one-size-fits-all sunshade that they mass produce, instead of something for the two-piece canopy.

If it works, it works.  And if it works for $200, then that's even better.  Perhaps it would be more accurate to say that the Walmart shades are only $190 cheaper, but I imagine the Koger ones do look a lot nicer.

I was stationed in Florida.  Don't recall it being any hotter there than it is here in Texas, but I was a lot younger then.  It's right at 100 degrees here right now, as I type this...   ;-)

- Pat

Eugene, do you have any sort of vent behind the cockpit to pull out the hot air?

Hi Eugene. Thanks for this post about the 601 being hot, despite the outside air temperature being 40 degrees. I live in Socorro NM. 41 miles south of Belen. I fly a 701. But I am building a 650B. I wondered about temperatures in the glass canopy. I saw a picture with snap vents in the canopy. For a total of 4 vents.Does a person need to provide an escape route for all the incoming air. I assume you have a sun shade. I also thought about a tinted canopy.


Take a look around your fuse and I think you'll find plenty outlets for the escape air.This subject was addressed before after I went out and purchased grills for escape vents and of course, they could not be returned.



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