RV-10 builders...be careful with the door pins

I discovered that my forward pilot-side door pin was not going into the cabin structure the other day, when I was going to install www.rvbits.com stainless steel guide blocks. My guide block was 1/2" thick and Vans/rvbits guides were only 1/4" thick.

Someone had screwed up and mounted the latch assembly too far aft in the door, so my forward pin didn't penetrate the door frame structure much. The 45 degree bevel was only half way into the door frame, so someone had made a 1/2" thick door guide as a bandaid!!

I wonder how many of the RV-10's that lost doors might have had this problem.

So, today, we made a new, longer forward door pin that now penetrates the structure with a good 3/16" of straight sided material showing behind the door jamb.

Be very careful when you guys are fitting the latching assembly, that it is placed so that both pins stick well through the door/cabin structure and not only inside the guide blocks.

Best,

Good catch Pierre. I just took some photo's of mine as a point of reference for you....

When the doors are built, there is enough slop in the construction process to keep doors from being perfectly uniform. There's really no exact science, so it would be hard for me to jump on the builder about being sloppy. Mine aren't uniform either and I took quite a bit of time trying to get mine perfect. Here is a photo of the aft block on my passenger side door. Notice it's 1/2".



However, the short door pins are a sloppy craftsmanship issue. There's no excuse for not having enough travel for the pin bevel protrude fully through the door frame. If you follow Van's plans, it's possible to make them short. If you combine that with the not-so-exact science of assembling the door with short door pins, you're really in for a bad day.

Replacing the door racks is expensive. I think it's around $100/door and that's something a lot of builders won't do to get another 1/4" of travel. In my heart of hearts, I think some folks won't order replacements because it's already a miserable part of the project and they aren't wanting to redo everything. Despite the expensive cost for a simple piece of hardware and the time required, it's psychologically painful to re-do work.

Sean's advice is the best. Ignore Van's plans and split the racks right down the middle. That will give you all travel you could ever want on the pins and even if the door isn't perfect, you're still going to be safe. Between doing that and using his door pins, I have 1 3/8" travel on the long side of the bevel and 1" on the short side.

Here is a photo of the door pin extended.



Here is another photo of the same door pin going through the 1/2" block and then the door frame. You can see I have plenty of travel through the door frame. No concern about that pin at all, and it's my worst one!



I don't want to tell you what to do on your airplane, but if I were in your shoes and while the wx is cold, I'd consider rebuilding the mechanisms on both doors.

1) I'd check the blocks and make sure they are of the appropriate thickness. The doors should rest between the forward and aft blocks with minimal gap for play.

2) I'd rebuild the door racks with new racks that are split according to Sean's plans, not Vans. (Sean allows for a longer pin extension).

3) I'd cut off the taper on Van's pins and add Sean's stainless pins with Delrin blocks. They're silky smooth and as you can see, you will get plenty of extension and not require metal blocks.

4) I don't think you need to install the cam mechanism. It's nice to have, but if your doors are swinging correctly and you're getting plenty of throw on the pins, you will probably be fine. But the cam is a nice feature to have because it forces the door into a predictable position every time and the pins can't miss or the door can't close.

Just a little feedback after having been through this recently.

Good catch....

Phil

Thanks, Phil.

I did see the finishing instructions and how the gear arms should be cut. Very interesting to cut the piece in half instead. Hopefully, quite a few -10 builders will read your post and we'll prevent any more door losses, since it's so easy to avoid without any extra expense...now THAT, is a good deal

Thanks again,

Well I am glad that you have picked up this problem now and doing something about it. It is small mistakes like this that can cuase accidents down the road!