Texas Summer and the RV-7

Hello folks, I'm seriously considering an RV-7 and am currently assimiliating as much information as possible. One of the details I'm trying to track down is how comfortable an RV-7 would be in the Houston, Texas area. We have months of 95+ degree heat and 90% humidity out here. You sweat so much in the cockpit (typically a 172) that I have to bring a towel to stay dry during the flight.

The canopy of the RV-7 sure looks like it would turn the cockpit into a greenhouse. Do you find that there is enough ventilation (moving air) when airborne? How is the heat when you are taxing out?

I believe that there are two styles of canopies? One tilts up, and the other slides back. From the pieces of information I've stumbled across, it appears that this in an option for the RV-7? If this is correct, is one configuration better from a *comfort* point of view?

I would appreciate any feedback you can toss my direction
thanks,

Lee Jordan

If you go with the Slider Canopy vs. the Tip Up you can taxi with the canopy fully open and close it as you turn on the runway and open it after you touchdown. Much better than the C-172. In addition, once you are airborne the airflow through the vents is moving at a much higher speed than a C-172. Summer climbouts are usually done at 120 mph and 1000-1500 fpm. Since you also get higher quicker you get some cool air just minutes after takeoff.

I installed a Kroger Sun Shield on my RV-6A and even though it was a tip up canopy it was to unbearable for West Texas.

Best thing to do is find somebody that has a slider RV-6 or RV-7 and get a ride. Just be prepared to buy if it is your first ride in and RV.

Best regards,

Russ Daves
N65RV (RV-6A Sold)
N710RV (RV-10 Fuselage Stage)

My Take

I live in Houston also and am not building yet so this is my unexperienced opinion. I do drive in cars though and I know they get dang hot during the summer. There ain't no getting around it! Houston is hot and muggy about 4 ot 5 months out of the year. There have been times when I was putting up Christmas decorations in shorts while drinking ice-tea but for the most part I think about 7-8 months out of the year are bearable. This has been a hot summer so far. Just walking down the driveway to take out the trash at 7AM has been pretty uncomfortable. I try to walk twice a day and have had to do it before sunrise and after sunset lately. Even then I am still dripping when I get home. When it hits 98-99 with 90%+ humidity and cools down to a balmy 92 at night with equal humidity, it is going to be hot hot hot no matter what we do. Yes the canopy will act as a greenhouse and the temp inside the cockpit will climb quickly when the canopy is sealed. How about those guys flying fighters in Iraq with 120+ temps and full flight suits! Now that has got to be hot. Of course they can get to 20K in about 3 or 4 seconds but it is still hot on the ground.

Altitude is an answer, but with the class B veil covering a good deal of the Houston area, you will have to get out a ways to climb to an altitude that will actually make it "cool". Yes any gain in altitude will technically be "cooler" but dropping the inside temp from 120 to 110 still leaves you hot and dripping.

I don't have any data to justify this statement but I would guess the hi-wing Cessna does a better job of keeping the cockpit cool through shading than the extra speed of the RV does through ventilation. I could be wrong. No matter how you size it up, they are both going to be hot. I see many a 172's taxing around with both doors propped open.

The heat gain through the RVs plexiglass has got to be pretty significant. In this regard, I would consider a sunshade and a ballcap required safety equipment. Especially for those who are foliclely impaired. Can you say second-degree burns!

Slider verses tip-up. No doubt the slider gives you more airflow while taxiing. Enough said. But it is still going to be hot sitting out there on the concrete with 99 degree sun beaming down and 140 degree heat radiating off the concrete and 100+ degree air hitting you in the face. Airflow can only work if you are sweating so dehydration can be an issue that could create additional safety issues in flight. Take plenty of water with you and drink it before you start feeling dry.

I am really surprised that we don't see more activity around putting AC in these planes. I realize the weight and power consumption are big issues but it wouldn't take a lot to cool the small volume of a cockpit. I would go on a diet and lose 20 lbs if it meant I could be cool in the cockpit. Or I would pay the extra cost for a 200hp engine over the 180hp if I could turn that extra 20HP into cool air. Even a small Yugo or Geo system could provide some significant relief with not too much weight, I would think.

Short of an AC solution, you better plan on taking an extra towel and plenty of deoderant with you. Or as some would say, "Suck it up and enjoy the flight." I guess I am getting old and am a whimp because I am looking at putting AC in my garage before I start building. Working out in the yard in the heat for 4 or 5 hours really drains my energy these days. An 8-12 hour session in relative coolness seems a lot more productive then a 4 hour session in blazing heat. Much more enjoyable also.

I guess the other option is to move north where the guys complain they can't fly 6 months out of the year because of snow and cold. It is always something.

So I would say don't let the heat stop you from building, it doesn't stop you from driving your car. Come to the Houston area monthly meetings and ask some of the guys and gals in person. I have learned a lot in a short period of time from a bunch of nice guys and gals by attending. Besides, the excitement is contagious and will help you get over the decision. I plan to order my tail-kit and get some tools at Oskosh. I can't wait!

Houston

I live in Houston and just finished my tail. I can relate to the heat issues...the very first thing I do after starting the 172 is stick my head out the window in a (futile) attempt to cool off!

But flying in winter sure is nice.. beats -20 F up north... If you can't take the heat move to California

I'm also in Houston and am building a slider specifically so that I can taxi with it open.

Once airborne, though, remember that you'll get a temperature drop of around 3 degrees per 1000 feet so if you lift off on a 100 degree day and then climb to, say 8000 feet, you should feel quite comfortable at around 76 degrees.

I've been flying my Grumman AA1 out of Houston for over twenty years, and it has as big a bubble as the -7's. I am really hoping that the vents on my -8 are really effective at moving air, becasue the only time I close the Grumman's canopy is if I'm in the rain - it's just too much of a bloody solar collector around these parts! The fact that you can't fly the -8 with the canopy open has been one of the little worries in the back of my head...but I have to be honest and say that it is just about the only one!

Bottom line - I plan to taxi the -8 with it open, and climb out from under the class B as quick as I can....


Paul Dye
AA1B-160 (flying!)
RV-8 (finish kit)

Lee, I've been flying a "tip-up" RV-6 in Texas for over 12 years. There's plenty of airflow. Look for my -6 at the fly-ins. Mine is the one with the top of the canopy painted. From a distance the canopy resembles a Glasair. If I built another one today, I wouldn't do anything different.
Mel...DAR

-8A in Houston

Hi Lee,
We've got an -8A flying now in Houston and yes, it's hot and bumpy until you can get to altitude. We preflight the plane in the hangar and don't pull it out until it's ready to crank, and even then your really sweating until the engine is running. In the afternoons when I go flying it's usually 100 degF during taxi and the last thing on the checklist is "Canopy - LATCHED", which you don't want to do until you're ready to roll. From West Houston I can climb to 2500' right away, 3500' within a minute or two, and as high as I want shortly after that (outside Bravo then). I was up at 10,000' Wednesday afternoon (just because I could ) and it was only 62 degF... very nice.
A while back I took some pictures of what it looks like before and after you get out of the hazy, humid air around Houston and as soon as you're above it the turbulance goes away, you stop sweating, and can really enjoy the ride.

Below 4,500 (no, it's not IFR just hazy)


Above 4,500



Shade would help with the big bubble canopies. I don't want anything permenant because I really enjoy looking out with an unrestricted view (roll bar does that well enough, so we're going to get some stick-up shades.

Paul, regarding the air flow in the -8... I split the air from the forward NACA inlet to two eyeball vents on the panel and I don't get enough air out of them down low to be comfortable. On the next one I'll stick with one of Van's big vents for me. The rear vent on the other hand puts out LOTS of air. During Phase 1 I pointed it forward to get some air up inside the bottom of my shirt, but now that Diana rides in back I lost my air. I'm soaked, but it's worth

Sorry for the long post, but I'm just having too much fun with our new toy not to share everything.

Hello Jeff,

That haze looks familiar!

Ever since I put the big engine (160) on my AA1B years ago, I have never messed around with the heat and humidity if I could avoid it, just like you and your -8A. When you can climb fast...why not?!

I'm based at Clover (Excuse me..."Pearland Intergalactic", or whatever they like to call it these days...), and have do do a few level-off's to avoid getting into the class B in the Grumman, which climbs about 1600 fpm at gross on a hot day. At least the the -8 will have better forward speed to get out quicker.

I did the "two eyeball vent thing" becasue I liked the way it looked, even though I heard that it doesn't cool as well... Oh well, in a few more years I can retire, become a consultant, and live someplace cooler!

Paul Dye
Nassau Bay, TX

Thank you all for the advice and information. It seems that the slider is the way to go, there's one less decision to fret about.

I've been stuck in Cessnas my whole life and being able to shoot up to 8K just for the cooler ride hasn't been a practical option. Ninety percent of my flying is done in the area and half of that is spent dodging restricted airspace.

Having a hotrod (can you call a RV-7 a hotrod?) to jockey around would certainly make for some interesting options.

Just to recap on how to beat the Texas heat...

1. Slider Canopy
2. Pre-Flight in the hanger (I like this one)
3. Suction cup shades on the canopy
4. Install air vents (factory option?)
5. Lastly, climb to cooler air.

Until some one makes a practical a/c this appears to be as good as it gets. Thanks again for the advice and grats on getting the -8A flying.

Lee

I have seen a thread of a portable self-contained A/C unit. It consisted of a cooler full of ice and a battery operated fan blowing air over the ice. It will fit in the baggage area of a 6 or 7 easily.

Derrell
7A Finish

hot & fighters

How about those guys flying fighters in Iraq with 120+ temps and full flight suits! Now that has got to be hot. Of course they can get to 20K in about 3 or 4 seconds but it is still hot on the ground.

Click to expand...

i don't know for sure, but i'd bet that the fighters are air-conditioned. reason: they gotta be pressurized, and bleed air is so hot as to require air-conditioning. at least the only pressurized plane i ever owned (p210) had a/c.

mho,

john

Howdy Lee (and all),

I have a tip up RV-6 w/Koger shade and taxi with the canopy in the 'semi' open position (lets call it position 1):
http://www.vansairforce.net/RazorsEdge/finished2.jpg. I get almost as much cooling air as the slider in this config. A couple splashes of cold water on the face helps <g>.

If I need a really big, quick cool off I open it fully while taxiing to what I call 'position 2'. I do this holding short often - it evacuates all hot air from the cockpit instantly and provides a huge visual reminder to lock the canopy.

Then, as Paul D. said, I get out from under class B and start climbing as quickly as I can . Yesterday, when flying back from Idaho, we stopped in Dalhart, TX for fuel/lunch (KDHT). Can't get any hotter than that in TX!!! After climbing up to 11,500 it was 65F in the cockpit.

If I were doing another 6/7/9 I'd do tip-up again - for ME the improved visibility is more important than the temp while taxiing (I do a lot of formation and picture taking).

My .02 and hope it helps.

Best (and still tired from 8.4 hrs in the cockpit yesterday),

Fighters and air conditioning (getting a bit off topic)

>i don't know for sure, but i'd bet that the fighters are air-conditioned. >reason: they gotta be pressurized, and bleed air is so hot as to require air->conditioning. at least the only pressurized plane i ever owned (p210) had >a/c.

>mho,

>john

John,
I don't know for sure either but I do know that some pressurized aircraft get their A/C (cold air) from bleed air. If I remember correctly it's about 500 psi and 500F degrees. It's passed through an "intercooler" with outside air as the cooling air. So then it's 500 psi and a lot cooler, but not cool enough yet.
But then the air is released into a chamber "evaporator of sorts" and when it goes from 500psi to cabin pressure it gets cold due to expansion.

I know a little bit about a lot of things but not a lot about anything...

Mel

Can you send me a pic of your canopy. Thanks

DeltaRomeo said:

If I need a really big, quick cool off I open it fully while taxiing to what I call 'position 2'. I do this holding short often - it evacuates all hot air from the cockpit instantly and provides a huge visual reminder to lock the canopy.

Click to expand...

Ditto. I bring the engine back to idle and open the canopy fully. Hard to beat that kind of ventilation while waiting for takeoff.

And while taxiing, you can open the canopy more than the "handle resting on the roll bar" position, which would ordinarily give you 3-4" of open space. As you taxi you can push the canopy open another 6" or so. Just to the point where you can still see over the glareshield (which is elevated by doing this).

Point is...if you really like the tip-up canopy, build one. There are ways to beat the heat regardless of canopy choice.

You've already got the message. Just to add to the slider suggestion. There's not much way around the heat below several thousand feet around here (Houston). Taxi with some prop blast coming through the open canopy. Ready for takeoff, close, latch and go.

What I would do different next time - double the ventillation in the panel and add ventillation to cool the rudder pedal area.

Chilled air? Interesting, but I was born in the State 40+ yrs ago and don't mind the temps with a little air movement.

Just another tip on the slider. Add a proximity switch with light or buzzer. I did a no-no again yesterday. For the second time in 6 years, I blasted off without latching the canopy. Got to about 500' and started my little climb check and managed to notice the latch open. Had my dad with me (distration I guess). Visions of the unfortunate F1 flyer on the SW side of town went through my mind for about 2 seconds then decided to just return and land rather than fool with it in flight.

For -8 owners/flyers, the canopy seems to tend to pull closed when within a couple of inches of closed. Farther back? Who knows. I won't ever go there voluntarily.

The guy in the tower was excellent. Very helpful and calm. Asked twice if I needed assistance (equipment). Very accomodating with my 90-270 pattern and landing. Wind was calm.

Bottom line. 1. I didn't have my (canopy) backup pin in place like I usually do, 2. I now believe I will install a prox switch in my next project to warn me when I forget to latch.

canopy backup pin?

Low Pass said:

Bottom line. 1. I didn't have my (canopy) backup pin in place like I usually do, 2. I now believe I will install a prox switch in my next project to warn me when I forget to latch.

Click to expand...

What's a canopy backup pin? Glad you made it down ok with no damage!

I am going to build the RV-10 back seat vents into the airframe when I get to that part. I will probably mount the front ones where Dan put his access panels for his avionics. They will flip up like the old 49 Chevy pickups if you guys know what I mean by that. I will put a safety latch on it with some J hooks or something so that they don't open in flight. I will also add one to each side in the baggage compartment to let the air flow out. Kinda like cowl flaps. I think this will work and I am still going with the TIPUP for
visibilty.

Bruce Pauley
Emp kit #72742
Rowlett TX
http://www.mykitlog.com

rv8ch said:

What's a canopy backup pin? Glad you made it down ok with no damage!

Click to expand...

I originally drilled a 1/4 dia hole in the canopy rail about 4 inches back from the closed position. Use a t-style (?) hitch pin as a stop to keep the fwd, left roller from moving past. Figured it might keep the canopy from opening too far if ever came unlatched (or wasn't latched right in the first place!) and was a stop for taxiing with canopy open.

I've gotten lax with it since I installed the "cam" latching device that allows stopping the canopy at the 4" and mid-way location for ventillation. Course the bottom line is if I don't catch the backup pin on the checklist, I'm likely to miss the stupid latch too.

Hot is Hot

For most of the summer I live and fly in probably the hottest overall location in the country, Phx, AZ area. Hot is hot no matter what kind of canopy you have. 107 degree air is 107 degree air.

I personally have a tip up and agree with Doug, that the visibility, access to the instruments etc., far outweigh the heat incovenience. I keep the canopy open resting on the upper latch when taxiing for takeoff. After landing and off the active I open the canopy and let it rest on my arm giving a few more inches of opening. Flying in the heat isn't the issue, it is getting beat to **** going anywhere.

I will concede we don't have much humidity, about 60% today with 108. Pretty dry. "Yes it is a dry heat." So dry that when my dog craps in the yard in the morning, it is pottery by the afternoon. That's dry.