Upper fwd skin avionics access

I searched but could not find any previous threads. I think I know the Vans answer but has anyone built an access panel from the upper skin to the avionics bay on the left side?

I have an access door in the bulkhead on the right side from the baggage compartment but would like some way to reach the back side of the -650 and pitot/static lines without having to due super human moves under the panel.

Thanks
- Strike

Sort of...

I added an access panel opposite the baggage door. This was to give me better access to the boost pump / filter. But it also gives better access to the left side of the panel. Not flying yet so use at your own risk.

But what about water intrusion from rain, snow, etc.? I love the idea but would be cautious about this issue.

Pretty work Chris.

Where did you find those clamps...the ones on the scat hose?

Mark, can't comment on the structural aspects, but water entry can't be any worse than the baggage door, which is generally not a problem with a canopy cover.

Strike, be aware that late model big screen avionics often pull out of the panel face with a few screws, leaving a huge hole to work through while sitting in the seat. Just put a generous tail on the wiring harness. I have a totally removable glareshield (Showplanes canopy mod) and it's been off exactly once in 315 hours, early on to replace a dead-from-birth component.

Cris,
I like the way you tied the cold air intake in with the heated air. Do you have a way to shut off the cold air when you just want heat?
JimS

DanH said:

Pretty work Chris.

Mark, can't comment on the structural aspects,

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I would be careful when considering cutting access holes in skin panels. I know just enough to know that cutting a large hole in a stressed skin may not be the smartest thing to do, I personally would not do it without an engineering blessing. The forward part of the fuselage (like the wings) is a highly stressed area. The skin on these aircraft are structural members not aerodynamic fairings.

When I was a kid I cut the roof off my Cadillac thinking it would make a nice convertable, only trouble was the doors would close after that!

Your caddy reminds me of some high school buds that put a V8 in a pinto. One holeshot and their doors wouldn't open either.

DanH said:

Pretty work Chris.

Where did you find those clamps...the ones on the scat hose?

......

Click to expand...

Would they be these?

http://www.summitracing.com/search/...yle/t-bolt?SortBy=Default&SortOrder=Ascending

I wouldn?t be too worried about the loads in this area. The loads from the engine mounts go into the welded brackets on the firewall and pass into the longerons and the skins. He has a good doubler and loads will go through the doubler into his door skin by way of the countersunk fasteners. A good rule of thumb to follow when adding a cutout in a skin is your doubler should have the same amount of material as the amount of material you remove (cutout); if you are removing a 4?X4? section your doubler should have at least 16sqin of material. This is if you want the doubler to carry all of the loads and have the removable panel unloaded. In this case the removable panel will carry loads. I can?t see this being an asymmetric design where the load path all goes on the left side because of the hole from the baggage door on the right.

Dan, the clamps I found at Aircraft Spruce but since I bought them, I haven't been able to find them again. They are similar to the ones Gil pointed out but I think specifically for scat hose. I'll look at one tonight and see if I can find who makes them and what the part number is.

Jim, I have a valve on the cold air side that is RC servo driven. The heat valve is also RC servo driven and I have a controller that I built to control mixing like on a car. We'll see how this works? Experimental...





Walt, as far as the structural strength of this mod is concerned, I believe that this area of the fuse skin is not really a stressed skin member based on the fact that the baggage door is on the other side and I don't believe there is assymetrical loading in this area. The doubler ties in to the firewall and the next bulkhead by replacing the spacers that are used in this area. I think the engine mount loads are transfered directly into the longerons. This is my own engineering basis and in now way should be treated as gospel. Modify at your own risk.