Seaplane doors: bottom door frame buildup

[Zzz]

I've always really liked the gullwing-style seaplane doors on aircraft like the Highlander, and plan to build them for my Bearhawk. One problem that is inherent to all 4-place Bearhawks is the steep angle of the struts up to the wing, causing an impingement for the door swing. I'm not a fan of the mouse door, so I see two options, both involved adjusting the height of the door.

1. Build up the door frame so that the entire door is shorter (red line in photo.)
2. Build up only a short section of the door frame, building a complementary cutout in the door itself that meshes when the door is closed (blue line in photo.)

Without the luxury of have wings bolted on, my question is: How much does the lower door frame need to be raised to accommodate a door that will clear in the upswing?

If anyone has done this, it would be great to see some in-process photos. Thanks!

[Battson]

You only need to raise the lower sill in the forward area, I think (from memory)... But I think it was about 3". I have some photos from someone who did it, I'll see if I can find them...

Scratch that - I already posted them on this forum, they were from Heath. He used a mouse door. It must have been someone else I remembered seeing with a raised door sill.

[whee]

I'm following this with interest. Glad your going down this road before me Z.

alaskabearhawk has some good pics on his kitlog site. He said he had to raise the door frame 2". I think I'm going to raise the sill like alaskabearhawk did but I'm not going to add the extra tube.

[Zzz]

I think I'm going to raise the sill like alaskabearhawk did but I'm not going to add the extra tube.

My original plan was to just build a little box section out of 16 or 20 gauge steel, the minimum size for the door cutout, and weld it to the existing door sill. I was going to do a thin stainless flash over the door sill anyway, and it would all be covered up. I really don't want to build the entire thing up since on the AviPro quickbuild, the sill is all done and nice.

[jaredyates]

To me raising the sill seems like one of those jobs that could end up being far more involved than it first seems. Could you do a mouse door on the seaplane door, with some sort of spring action to keep it out of the way on the down swing? In another week or two I could try and get a measurement of the closest distance from the window hinge line to the strut. Would you be planning to use the OEM window hinge parts as door hinge parts, or would you be beefing those up?

[Battson]

See the door questions thread:

http://bearhawkforums.com/forum/bearhawk-general-discussion-news/2257-door-questions

[Gavin Chester]

I had to raise the door sill 3", have a door frame clearance of 1/4" to door sill and a door skin overlap of door frame of 1/2" to give about 3/8" clearance to the wing strut when opened.

[alaskabearhawk]

I must have had a brain fart or something as I only raised mine two inches, not three like Gavin. I know Rob Taylor raised his two inches and it works fine. After all the work I put into mine I'm not going to do the extra inch and make it work as is. Dang it!

[mswain]

There is also the mod Colin did, yet another way to avoid the mouse door.

http://bearhawkforums.com/forum/bearhawk-4-place-plans-build/3813-flip-up-cabin-doors

[Battson]

I must have had a brain fart or something as I only raised mine two inches, not three like Gavin. I know Rob Taylor raised his two inches and it works fine. After all the work I put into mine I'm not going to do the extra inch and make it work as is. Dang it!

I think it will depend on how much overlap you like between the door and the fuselage. Less door overlap will mean more strut clearance.

There is also the mod Colin did, yet another way to avoid the mouse door.
http://bearhawkforums.com/forum/bear...up-cabin-doors

I think this is great! The more content we can share and compile into one place, the stronger and more useful / helpful and inspiring the Bearhawk forum becomes.

[Aero_tango]

I raised mine by 2" . I attached few photos after i was done with the wing installation and tried the door to assess clearance with the strut. The maximum radius from the hinge line to the strut is 32". I have about 1.5 " clearance between the strut and door frame. More than enough for a good door skin overlap.
Mike.

[Zzz]

I raised mine by 2" . I attached few photos after i was done with the wing installation and tried the door to assess clearance with the strut. The maximum radius from the hinge line to the strut is 32". I have about 1.5 " clearance between the strut and door frame. More than enough for a good door skin overlap.
Mike.

Nice, tango. What did you use for hinges?

[Aero_tango]

Nice, tango. What did you use for hinges?

I'm using the existing window's hinge, made of 3/8 tubing.

Mike

[Zzz]

I'm using the existing window's hinge, made of 3/8 tubing.

Mike

That was my plan as well, but I'm considering welding on at least another, possible 2. I enjoy flying with the doors open (at slow speeds.)

[Mark Moyle]

Here's the seaplane door hinges for the pacer. These are adjustable in and out. I should have used plastic washers between the door hinge plate and the door jamb hinge.