Canopy hinge question

[paszekj]

Long story why but I ended up having to remove my canopy during the condition inspection. When looking to put it back on, I see that one of the hinges seems to have a pin that I don’t see on the other side. I can’t find anything in the plans mentioning an extra pin on the hinge and it doesn’t seem necessary for the canopy to be placed back on but thought I should check before I go ahead. Anyone in the process of building that would be able to take a look?
The first photo is the left hinge, the second is the right, then the third is the right with me placing a dental pick in the hole.

 

[mc607]

The pin on the right is missing and has broken and fallen out. I believe it acts as a stop so when you put your canopy on you can’t over open it which could cause damage to the canopy and or fwd skin. First, I would try to find the pin that broke off so it doesn’t become FOD. Second, I would order replacement parts. If that pin broke, I would be worried about the lower, much more critical pin.
You can see the welds for those 2 pins in the attached picture from the Vans store.

Canopy Cradle

store.vansaircraft.com

 

[avatty]

The pin on the right is missing and has broken and fallen out. I believe it acts as a stop so when you put your canopy on you can’t over open it which could cause damage to the canopy and or fwd skin. First, I would try to find the pin that broke off so it doesn’t become FOD. Second, I would order replacement parts. If that pin broke, I would be worried about the lower, much more critical pin.
You can see the welds for those 2 pins in the attached picture from the Vans store.

Canopy Cradle

store.vansaircraft.com

View attachment 85566

 

[avatty]

I meant to write that mc607 is "correct as usual," I'm working with these parts right now. If these airplanes weren't Experimental, repair/replacement would be mandatory.

 

[JDA_BTR]

OP: why do you think it broke? Did it take a hard drop, or was the handle pulled to remove when you weren't ready for it and it took a bounce? Or was it just routine service?

 

[paszekj]

This is very helpful. Thank you all. Now I realize that even though the lower pin is where the canopy bracket sits on, the side of the bracket still must rest on the missing pin based on the wearing of the powder coating on the left side where the pin is intact.

As far as why it’s missing, I have no idea. No hard drops (except once when I was building 5 years ago).
The fuselage was a quickbuild, received in 2019, so the canopy hinge brackets and gas springs were already in place.
I learned late while building that the initial gas springs used by Van’s were found to be inadequate to hold up the larger canopy of the 14 and recommended to replace them with a higher-tension spring. I was able to replace the left one but the right was impossible to get to because of avionics in the way. The canopy seemed to stay open fine so I ended up just replacing the left one at the time.
I’ve noticed recently that the canopy doesn’t stay up as well as it used to and had the potential to blow down in a moderate wind so I decided it was time to replace the original one on the right. It was after removing the canopy that I noticed the missing pin. I think this is the first time I’ve removed the canopy since finishing building in 2021 so I’m not sure how long it’s been missing.
Interestingly, the gas spring on the right had completely failed to where I could compress it by hand. If I had expected a pin to break it would have actually been on the left side where the one spring was doing all the work.

Now I realize I definitely need to remove the right bracket and either replace it or see if I can have a pain welded in there. Since the brackets are >$120 I’d like to see if I can get it welded first. Thanks all!

 

[czechsix]

OP: why do you think it broke?

Follow-up to the below: I checked with Van's and they confirmed that the upper pin is only welded on one side by design.

A while back when I was painting the canopy cradles, I noticed that the upper pin (the one closer to the hinge point) is only welded on one end. The lower pin is welded on both ends, but the upper pin is only welded on the right side and it just floats in the hole on the left side of the cradle. At least that's how mine are...see area circled in red in the picture...no weld there. Does everyone else have the same? At first I thought maybe the welder made a mistake, but since the two cradles were both that way, it is more likely intentional to allow the hinge point to be compressed slightly when it gets sandwiched between the two canopy hinge brackets without putting too much stress on the upper pin since it can move laterally. However...it may be more susceptible to breaking without being welded on both ends.

 

[PeteT]

When I began to prep the canopy cradles, I noticed a difference in the pins. I figured that one end was free to “ride” in the hole opposite of the welded end. However, one pin resided in the hole and was flush, but the other cradle’s pin wasn’t long enough to rest in the hole at all. In other words, the pin was only secured at one end where the weld is. I obtained a new cradle from Van’s. I’m not sure if anything is wrong- I just felt better having the pin supported at each end.

Pete

 

[sloengineer]

I just found this post. We also received a QB and we had a pin missing in that bracket from the factory. I had to get a replacement and install it. It was a challenge to get out. Is it possible it wasn't in from the beginning? When I called for a replacement, it sounds like I wasn't the first.

 

[paszekj]

I just found this post. We also received a QB and we had a pin missing in that bracket from the factory. I had to get a replacement and install it. It was a challenge to get out. Is it possible it wasn't in from the beginning? When I called for a replacement, it sounds like I wasn't the first.

I did end up replacing my canopy bracket. I didn’t want to take any chances. It could have been missing for years for all I know. I also replaced a faulty strut on that side. It was quite a project but replacing the strut was much easier with the canopy removed so that there was no tension on the strut. Sure hoping I never have to do that again.

 

[sloengineer]

Completely agree about replacing it. Just curious if it might have been missing all along instead of falling out. A battery powered 1/4" ratchet and a wobble extension were a blessing for my replacement of those parts. And at 6'4", the contortion to get under there was quite the sight to behold.

 

[paszekj]

Completely agree about replacing it. Just curious if it might have been missing all along instead of falling out. A battery powered 1/4" ratchet and a wobble extension were a blessing for my replacement of those parts. And at 6'4", the contortion to get under there was quite the sight to behold.

I’ve wondered that myself. It was a QB fuse so I certainly wouldn’t have noticed if it was. I had to replace the struts as the original ones already installed on the QB fuse were inadequate. I had discovered that when I was still building, but nearing completion. I replaced the left one while building but left the right one because it was so difficult to get to (would have had to remove the VPX and some other wiring. I finally decided to replace it as the canopy wasn’t reliably staying open even in the slightest wind and felt it was a safety hazard. When I replaced that one, I discovered the strut was completely shot. I could literally compress it with my hands. I don’t know if that was related, but I suppose possibly if that missing pin was putting more stress of that strut. Or I suppose it’s possible the failed strut could have put undue pressure on the pin and broke it off? I looked everywhere and never did find it. But all is good now.