Tip Up Canopies - a comparison

[dicel87]

As I was doing my usual weekend lurking here on VAF and dreaming of RVs, something about the tip up canopies of the RV-12 and RV-6/7/9 series occurred to me.

The approach Vans took to each is quite different and, although I've not built either, it seems as if the RV-12 approach is simpler. Granted you don't have the immediate wide open access to the back of the panel but it seems more of a KISS approach.



Wonder why they changed it...structure of the 12 forward fuse would not support the other way? Or maybe it's a more evolved approach learned from the challenges (my perception) folks have in building the 6/7/9 type?

OK...back to the garage sale (aka another step with Dave Ramsey )

[mcencula]

Definitely an evolution IMO. I can see several advantages of the new design over the old:

1. Covered avionics area keeps rain from leaking on your electronic goodies
2. Easier access to pivot points for canopy removal
3. More rigid mounting point (right at the longerons rather than at top of fwd skin)
4. More direct loadpath from pneumatic struts to canopy to pivot point, thus decreasing the deformation and poor fit caused by the struts.
5. No gap between canopy skin and forward skin to allow the canopy skin to lift past the forward skin. Instead, the canopy just sits atop the forward skin.
6. Keeping the pivot point close to the longeron should improve the clearance between the aft edge of the canopy and the forward edge of the back window for the first couple inches of opening travel.
7. Probably more stuff I haven't thought of...

I actually considered modifying my -7 to use this style, but decided that was too much change for me to take on.

[wil]

Why did Van's change the design? Weight and simplicity.

[dwrichey]

Looks like to me, one reason for the design change is for easier entry and exit. Notice how moving the pivot point further forward causes the canopy to swing further forward, out of the way.

[danielhv]

Not sure it would change anything or not... but the RV-12 isn't going 200+ mph either... looks like you would have some air conditioning at that speed unless there is some special seal between the front of the canopy and the panel.

I like the old look better tho, everything internal, clean, sleek, glassed, etc.

[dicel87]

Originally Posted by danielhv

... looks like you would have some air conditioning at that speed unless there is some special seal between the front of the canopy and the panel.

Good point!

Mod the canopy and skip the fresh air vents!

[rvbuilder2002]

Originally Posted by danielhv

Not sure it would change anything or not... but the RV-12 isn't going 200+ mph either... looks like you would have some air conditioning at that speed unless there is some special seal between the front of the canopy and the panel.

I like the old look better tho, everything internal, clean, sleek, glassed, etc.

Actually it seals up quite well if constructed properly.

Originally Posted by dwrichey

Looks like to me, one reason for the design change is for easier entry and exit. Notice how moving the pivot point further forward causes the canopy to swing further forward, out of the way.

This is the primary reason for the difference.
For those unaware, You enter the RV-12 from in front of the wing. The canopy needs to open far enough to allow stepping inside when a foot is positioned near the wing leading edge.