Canopy Gap

[bmckinney10]

Working through some small items on the VariEze.  The prior owner repainted the plane and replaced all of the canopy seals.  The seal was too thick which prevented full closure and latching of the canopy.  I believe the plane sat in a hanger or garage most of this year in the spring/summer heat in a closed, but not latched position.  The canopy would have had some stress on the hinge side with the "too-thick" rubber seal.

I have removed all the seals and took the attached picture.  You can see that the hinge side of the canopy is sitting higher than the latch side by about 1/8" or slightly more.  When full latched, there is a sizable gap when viewing from the inside.  Maybe close to a 1/4".

I have new, more compressible, seals that will work well with a small gap as found on the remainder of the canopy when closed.

I am looking for feedback regarding:

(a) Can the VE be flown with the canopy lip sticking that that high above the fuselage?
(b) Is there a know procedure to warm up the canopy in that area and lay weights on it to relax it back into position?  I've read this being done for other warped parts of the plane.

I appreciate the help!

 

 

[Marc Zeitlin]

31 minutes ago, bmckinney10 said:

(a) Can the VE be flown with the canopy lip sticking that that high above the fuselage?
(b) Is there a know procedure to warm up the canopy in that area and lay weights on it to relax it back into position?  I've read this being done for other warped parts of the plane.

a) Yes. Flies fine with WAY worse - just might leak a little air. As long as the hinges are intact and not loose, there's no issue.

b) Not going to work. And these canopies changes shape substantially with temperature changes - when it's cold, they "banana" up, due to the differential CTE's of the fiberglass and acrylic.

[bmckinney10]

Thanks Marc, great point on the temps.  It's cold here in MN right now and I try to keep my hanger heated in the 40's.  Will be interesting to see what it is like next summer.

Thanks,
Brian

[Kent Ashton]

If the gap is 1/4” on the hinge side, It might be preferable to inset the hinges deeper into the longeron.   There are probably some layers of BID and UNI over the longeron  you would have to hog out and replace to deepen the recess.   The hinge part on the longeron could be removed and the canopy fit checked.   Maybe the problem is not the hinge 

[bmckinney10]

40 minutes ago, Kent Ashton said:

If the gap is 1/4” on the hinge side, It might be preferable to inset the hinges deeper into the longeron.   There are probably some layers of BID and UNI over the longeron  you would have to hog out and replace to deepen the recess.   The hinge part on the longeron could be removed and the canopy fit checked.   Maybe the problem is not the hinge 

I attached another picture and you can see that the gap shrinks down to a minimal height ahead of the hinge.  In this pic, it is not latched so the entire canopy is riding slightly high, but you can see the pronounced corner.  It appears that there was some warping on the front corner at some point.  I don't see that In looking at the old pictures from 1980 when it was first built.

[Kent Ashton]

Ah yes, your fit is pretty good at the hinges.  My idea probably wouldn't work.

A number of EZs have an additional canopy lock in the right forward corner to pull the canopy down.  What happens is that at altitude in cold weather the acrylic shrinks and lifts the forward edge of the canopy.  In fact, your problem might go away in the summer.  :-)  You might just live with it for a while and see.