Photo by Peter Krok
That's why! I've flown in a slider-equipped RV, and I'm the first to admit that it really doesn't matter when it comes right down to it in terms of functionally interfering with your view. It's not that it's any less enjoyable for sure. 99% of the time, you don't even realize it's there. But it's there! And I'll tell you, having a canopy-equipped plane, whether it has a slider or tip-up, one of the biggest advantages is the wonderful visibility for photos and video. So why impinge on that at all?
Here's a great in-flight comparison of a slider versus a tip-up. These are pretty much otherwise very similar RV-6s. The one on the left has a slider, and the one on the right has a tip-up. Can't see the guy's face on the left, huh? Sure, he can see "just fine," but c'mon...there are steel tubes right in his view! The guy with the tip-up doesn't even think on that level since he doesn't have to. No head craning required. It's just a wide-open panoramic view...
It's not that the ugly steel tubes actually ruin the photos, but wouldn't it be nicer if they weren't there?
So what's the downside to the tip-up? There are several, and I'm the first to admit that...but they're only relevant on the ground! It comes down to temperature control. When you're sitting in the plane on the ground, the slider can be wide open, and you can hang your arm out the side. Plenty of breeze, it's a thing of beauty. With a tip-up, the best you can do is leave the canopy cracked open slightly as you taxi (the propwash pushes it down), and it can heat up really quickly in there. It's a greenhouse after all. Thing is, I'm willing to sweat a bit on the ground for that excellent visibility in the air. I mean seriously...how much time do you spend in the plane on the ground as opposed to the time you spend flying? I'm configuring this plane for my ultimate experience in the AIR, after all.
One other downside to the tip-up, which also only manifests itself on the ground, is the ability to leave the canopy open. With the slider, you just leave it slid back...no problem. With the tip-up, it tilts up and forward and becomes vulnerable to the wind. Some have said it's like a big sail. That's about right. In calm conditions, you can leave the thing open no problem. But if it's blowing, you'll want to keep it closed, or at least closed to the ajar position. What's the big deal? Well, at airshows and gatherings we all like to open our planes up to display our proud creations, and a plane is a little friendlier to onlookers if it's open. So I'll sacrifice that advantage, again, so that I can have a better experience in the air.
One more thing, and this is fairly minor, is that with the tip-up you have access to behind the panel from above, which makes maintenance a whole heck of a lot easier than having to lay down on your back and reach up for all that. Just a minor point, but it will be nice if and when it comes time to tweak avionics or instruments.
Also...and this is only slightly related...here's why I'm going with a panel-mounted compass. There's no reason to put that big ugly box up there in your line of sight!
UPDATE: October 30, 2003
I wrote this little diatribe about the decision over canopy style a while back, and I have to say that I'm still very happy with my decision. When I originally wrote the comments above, I was considering mostly aesthetic and functional differences. Well, let's look at another area where the tip-up just freakin' shines, and that's the maintenance aspect of this whole game. If you ever intend on doing anything to your instruments or avionics, I'll tell you, the tip-up is the way to go. I took the following photo when removing and replacing the Dynon EFIS-D10 one day back in August 2003. Granted, the plane still wasn't finished, but this is a pretty accurate representation of how easy it's going to be in the future to do behind-the-panel maintenance.
The tip up leaves the area between the panel and sub-panel wide open for access from above and from the sides. This is going to be a real treat if and when anything needs to be done. So think about that in your decision making process...that with a slider, you're gonna be on your back, lying upside down in the fuselage just to muck with this stuff. Check this out...here's where I located my altitude encoder. It's on the right side of the panel rib, between the panel and sub-panel. Need to do an IFR check? Open the canopy...simple as that.
So that's my latest update from the practical side. Tip-ups rock the house. Better visibility, easier to work on your panel components, less steel (lighter weight), easier to build than the slider, etc.