The canopy debate is a lively one among RV enthusiasts, and there seem to be
many pilots and builders on each side of the discussion.
If you are not sure what the difference is, we've got some pictures here that
should clear that up:
What we'll do
is attempt to
outline the pros and cons of each type in what should be a
moderately objective way. This
will be followed by an explaination of why I picked the one that I did.
Advantages of the tip-up canopy:
- Better visibility - with the tip up canopy, there is not the
obstructions to forward visibility
that are in the way when you've got the slider. The exception to
this seems to be if you're trying to look directly behind you, in
which case the slider will actually have less of an obstruction
to visibility than the tip-up.
Looking behind you isn't outrageously important as you're faster than many of the
Cessnas with whom you share an airport. To quote Gumball Rally: "Whassa
behind me is notta important." It's possible that backwards visibility is useful
if you're flying formation - having never flown formation, I wouldn't know.
It's important to remember, however, that an
RV with a either type
of canopy still has better visibility than virtually any production
aircraft that you can buy. However, as far as overall visibility, the tip-up
canopy is a bit better.
- Instrument panel access - with the tip-up canopy, it's easier to
pull the entire thing off and get to the instrument panel, as the entire
canopy can pop off. With the slider, the front part of it won't come off.
I have Dan to thank for
of getting behind the panel
on a tipper. Whether or not
this makes any difference to you depends greatly on how much you're going to
keep changing stuff around after you've got the airplane completed, but it seems
nice to have the option of doing that easily.
- Easier to building - I can't vouch for this as I haven't built it
yet, but from what buiders have told me, the tip-up canopy is easier when one
is trying to persuade the canopy to seal correctly. Also, it seems to involve
less (but not necessarily easier) work to build it in the first place.
- Less weight - there's just not as much metal in the tip-up canopy
design, and any place you can save weight is nice.
Advantages of the slider canopy:
- Improved taxi ventiliation - although the tip-up canopy can be
opened when you're taxing, it cannot be opened as wide as the slider, which can
be opened pretty much all the way. The advantage, when taxing or when waiting on
the ramp, especially in the summertime, is obvious. With the bubble canopy,
RVs just get hot on sunny days when they're on the ground.
- It's just plain cooler - sliders just look cooler when
you are inside them taxing around. I think the
appeal of being able to taxi somewhere with the window open and wave at all the
people that wish they were flying an RV is part of the appeal of this design.
- Easier in manage on the ground in the wind -
I didn't realize until I read it in one of the Tony Bingeles books:
all tip-up canopies, and particularly those that
have to cover two people side-by-side, are
subject to general weirdness when there is any
appreciable amount of wind and you've got the canopy open
on the ground. With the slider, you don't have a big hunk of plastic
sticking way above the airplane when the canopy is open. If your RV gets
caught by a hefty gust of wind from an awkward angle when your canopy is open,
the slider has much less of a chance of being damaged.
- Exiting the aircraft in an emergency -
seems like if something went seriously wrong with your RV and you had to part
company with the aircraft when it was still in the air, you'd have a better chance
of doing this with the slider. There are canopy-release handles that you can put
in a tipper, but there seems to be some question as to whether or not they really
work (to my knowledge,
nobody's volunteered to try it while in flight) and in any case it's fairly
common to not put them on at all. Last I heard, no one has successfully bailed
out of an RV. Although it's possible to think up situations where you would
need to bail out
(the engine and alternator quit when you're in a VFR on top of IFR situation,
or the tail falls off of
they are all pretty unlikely.
There's a weird disadvantage to
tipper RVs that should go in here somewhere but
as it's a combination of several things, I'm not entirely sure into which
category it falls.
The RV-7 (and the 6, too, I suppose), if built with both
a taildragger configuration
with a tip-up canopy, have a weird characteristic that if you open the canopy
while it is covered with water, a large percentage of the water will find it
necessary to dump itself behind your instrument panel. (With the tricycle-gear
RVs with tip-up canopies, all of the water
should dump on the cowling and you'll
be okay.) This is obviously bad, but it's really not a situation that you would
be likely to encouter - most of the time when it's raining, you won't be flying,
and hopefully you'll be keeping your RV in a hanger anyway. Nonetheless, it's
something to consider.
I am building a tip-up canopy. To me, the advantages of the tipper
make it an obvious choice, but hey - that's just me.
I suppose this depends on just where your
priorities are. I like the greater visibility in the tipper.
I'm not entirely sure that this can be
understood until you get a ride in both of them. I'm
less concerned about the way it looks on the ground and cabin ventilation,
and I figure the amount of time that you spend taxing the airplane is so
much smaller than the amount of time you spend flying it that the greater
visability is a better trade off.
In this area of the country (South; i.e., hot) I can understand that
cabin ventilation when you taxi
could be important to someone, and it seems the
slider is a bit better for that.
Also, I'm concerned about weight. I'm thinking about cramming
a bunch of IFR-like instruments in this airplane, so I'm looking to save
weight any other place I can.
Also as I'm building a noseroller (that's a topic for a different rant,
so nothing more about that here), so the weird
water-behind-the-canopy issue hopefully won't effect me at all.
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