Canopy icing
 

Hi all

A friend and I each have RV4?s without cockpit heaters and we are looking for advice. We both fly helicopters too and have had the bubble windows fog up badly, from the inside, with abrupt temperature changes and we have a concern that the inside of the RV canopy could also fog up when flying in the MidWest where it gets rather chilly. I realize I could just wipe it off if it?s not too bad and it does not freeze, but I would appreciate hearing from anyone who has experienced this, or whether we are being needlessly paranoid.

Thanks, Gary

The only time my canopy fogged up was in Florida, in the flare. I could only see the edges of the runway in my peripheral vision. Thanks to 50 hours in a Pitts S2C, it was an easy landing.

I am also curious about this.

Can't say about a 4, however The F1 Rocket flown for several years down to -20C
zero issues in flight. While taxing with canopy closed it can be an issue. especially if you shovelled snow or pulled the AC out of hangar and worked up any sweat. Easy solution is to leave the canopy unlatched and let the COLD outside air and the big fan on the front of the Lycoming keep it clear. A few times I let it fog and freeze while backtracking and letting the oil warm up. Just open the canopy about 30 seconds before take off and defect some propwash cold air across the inside and it quickly sublimates clear.

Same deal with a side by side for 1700 hours through many winters previously with a Falco canopy.

No cracks and no icing issues (inside in flight) with either. I suspect leaks and/or adequate air flow across the inside is the key to keeping clear.

Now I know why I live in Australia, you guys are welcome to those sorts of temps!:D

I wouldn't worry about fogging in midwest winters. The only fogging I get is on the ground and easily cleared by opening the canopy for 10 seconds. Flying them without heat is another matter. I can barely stay warm enough with 2 heat muffs.

Larry

No guarantees !
 

Cracking the canopy works as stated. I have an RV10 side vent to open for taxi and takeoff when canopy is shut. I have had the canopy fog on takeoff roll but clear quickly airborne with heat on and vent open.

It is scary and the only improvement I can invision is a canopy ?cracked? mechanism that can be safely controlled and closed in flight. I asked Jim Winings if I needed to build in a defogger option on the canopy while building my 3B. He said ?never had a problem? so go figure ?

Thanks for all the responses, that?s pretty much what we figured, especially if you have been exerting yourself before climbing into the cockpit. Anybody have this happen in flight, other than Michael where it happened just above the ground 😮

Not in 600 hours here.

I had it happen after takeoff in my RV-8 maybe 50 feet up or so. Was actually in the fall an hour before sunrise with dew point just below the outside temp. Cleared up in 30 seconds or so by itself. Instruments did come in handy at that moment... .

Never happened when it's really cold ... .

Oliver