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.


Views: 468

Reply to This

Replies to This Discussion

Patrick gave an excellent report on the Vans vents. Just wanted to say that I’m in DFW and had them in my Sonex. You will not believe how much air comes thru those vents!!! It’s almost inconvenient to have anything like paper or pieces of fabric with you because it’ll just be blown around. Again, no ducting involved. Just the little flap that was by my knee. Easy open/close. I often flew with only one side open, even here in Texas. 

Hello Eugene,

Another thing to consider is hot air from the cowling being sucked into the cockpit.  While flying there is actually a negative pressure created within the cockpit if not well vented from the outside with positive pressure. Be sure to review the firewall sealing for potential entry points of hot air. Just an alternate possibility to consider. Many times problems can be caused by an assortment of issues with cumulative effect. 

If its 100 degrees in the cockpit with the outside air temp at 40 degrees, you may need to look at the airflow thru your cowling. You must have a very high temp in your engine compartment to generate that kind of cockpit temperature. 

You have 40 degree air going into your engine compartment and 40 degree air coming on thru your vents - and its still 100 degrees in the cockpit. That just doesnt seem right.

I fly my 601 xl in 100 deg. takeoff temps but by the time i get up to 5500 feet or so, it's cool in the cockpit. My engine is an O-235 and I have the larger Vans SV eyeball vents connected to the standard NACA inlets.

I do have the Rosen sunshade.

Check your cabin heat valve for either the arm slipping on the shaft, cable slipped, or valve plate lose on the shaft. All 3 have happened to me in one ac or another ( 2 of them zeniths).


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...


Weather Maps

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Apparel from EAA:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Golden Eagle Aviation

Pianosa Flying Farm

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2020   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service