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Cabin Top/Windows/Motor Does the Order Matter

Lynnb

Well Known Member
I was just curious if the engine could be hung and worked on before the Cabin top was installed?

If the cabin top is installed, does the front windshield need to be installed before the engine is hung?

I'm still working on my cabin top, doing some fiberglass, planning some painting etc and was thinking I could start some of the baffling and cowling work in my down time while stuff is curing/drying.

Thanks,
Lynn
 
From an engineering perspective, there's nothing to stop you from doing what you propose. I would install the vertical hinges along the sides of the firewall before you hang the engine. That will firm up the front structure for the 400 lb+ engine.

Also, remember that once you put the airplane on its gear, you absolutely will need a ladder to work on the cabin top - at least the upper portion. That would be a show stopper for me. I don't need/want that inconvenience.

Sez the guy who just "finished" the cabin top, doors, and windows, and put the airplane on its gear a week ago today...
 
Don?t underestimate the time needed for cabin top, doors and glass. Consider the downside of taking the nice pickled engine out of the crate for such an extended period.

The other consideration is all the glass dust you will generate from sanding. No need to trash the engine with that.

Carl
 
Perfect segue opportunity here:

I'm tired of working on wingtip mounting hinges (got all 4 hinge pins in place and I'm declaring victory for now).

Have firewall insulation and SS foil ready to mount and seal with FireBarrier 2000 or whatever it's called. Before covering the firewall with fibrefrax and foil, I need to first rivet the forward top ribs to the firewall with 1/8" flush rivets, and the plans say to attach the top skin to them (in a very specific riveting pattern) before attaching the subassembly to the firewall.

I was going to rivet the ribs to the upper part of the firewall and put the top skin on later, after all necessary holes cut for avionics/wiring. May not have that luxury if the sequence detailed in the plans is critical for some as yet unappreciated reason.

I'm probably going Quik-Panel AFS or Dynon. Hopefully there wont be a lot of cabling to do upside down underneath the panel in "the position." :p Yeah, right. Any advise on what sequence to do this work in? I'm trying to keep the skins forward and aft of the cabin top off as long as possible, but there comes a time you run out of other things to do. I don't own an engine or avionics yet, so the airframe is all I have to expend my energies on.

I'm intermittently sanding and filling the cabin top and leveling/blending same with doors and side skins. Can't finish that work until the skins are all on. Transparencies from Cee Bailey soon, I hope.
 
Lynn,
It will be much easier working on the cabin top, doors and windows when the fuselage is down low. Get all that done prior to putting the plane on its gear. It will save a ,it of work on a step stool or ladder.
 
Thanks for the info. I've actually already fitted the doors and done all the trimming to fit the top, door seals, rivet backing strips etc. I'm just still deciding on interior paint, working on a fiberglass overhead and some of that sort of stuff. I have a bit vertically challenged, that's why I've kept it off the gear for so long.

As always I appreciate the feedback.

Lynn
 
Same thoughts....

Bill. I was thinking the same with riveting the forward fuse structure on and adding the skin later after wiring and sub panel avionics boxes are mounted.

The other models have us do this. I guess it's a trade-off of lying on your back bucking rivets or trying to do the other tasks inverted... Either way we have to pay the Piper

I'm tired of working on wingtip mounting hinges (got all 4 hinge pins in place and I'm declaring victory for now).

Have firewall insulation and SS foil ready to mount and seal with FireBarrier 2000 or whatever it's called. Before covering the firewall with fibrefrax and foil, I need to first rivet the forward top ribs to the firewall with 1/8" flush rivets, and the plans say to attach the top skin to them (in a very specific riveting pattern) before attaching the subassembly to the firewall.

I was going to rivet the ribs to the upper part of the firewall and put the top skin on later, after all necessary holes cut for avionics/wiring. May not have that luxury if the sequence detailed in the plans is critical for some as yet unappreciated reason.

I'm probably going Quik-Panel AFS or Dynon. Hopefully there wont be a lot of cabling to do upside down underneath the panel in "the position." :p Yeah, right. Any advise on what sequence to do this work in? I'm trying to keep the skins forward and aft of the cabin top off as long as possible, but there comes a time you run out of other things to do. I don't own an engine or avionics yet, so the airframe is all I have to expend my energies on.

I'm intermittently sanding and filling the cabin top and leveling/blending same with doors and side skins. Can't finish that work until the skins are all on. Transparencies from Cee Bailey soon, I hope.
 
Bill. I was thinking the same with riveting the forward fuse structure on and adding the skin later after wiring and sub panel avionics boxes are mounted.

You can build the entire upper forward fuselage (UFF?) structure and NOT rivet it to the fuselage until after your cabin top is attached. If you do it that way, you can set the entire UFF on the bench and do a bunch of your subpanel and panel work on the bench - subpanel cuts, mounting locations for fuseblocks, AHRS units, panel cutting, etc. Then, pull that stuff off, and you can rivet the UFF in place and reinstall all of the bits and pieces. Much easier doing all of that on the bench than trying to do it in the footwell of misery.

The one thing you can't do until the UFF is riveted in place is install the windshield.
 
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Curious...

I am curious, I have pretty much planned out my avionics and I am not seeing many instances of laying in the footwell to do the wiring. Almost everything that is required will be accessible from the cabin. I do have the Aerosport symmetrical panel, so there are three rather large holes to work through.

I am not planning on putting anything between the sub panel and the firewall. Obviously, that area is rather inaccessible at all times. I do see the value of doing a bunch of avionics work prior to riveting the forward section, however, as I do not have my avionics yet, I went ahead and riveted. So far, I have not had to get in the footwell except to rivet the forward section.

I will say that driving some of the rivets from the firewall to the forward section substructure was very challenging as the engine mount is in the way...it's doable but would have been MUCH easier without the mount installed.

So, what task is going to require time in the footwell?
 
So, what task is going to require time in the footwell?

Depends on how much stuff you put behind the panel and how/where you decide to attach it. Lots of remote avionics? Nutplates on the back of the sub-panel? You could do that stuff laying on your back in the footwell. Or you could do most of it on the bench.

I'm resigned to being under there to hook up ground wires to the forest of tabs on the firewall, to route push/pull cables, and to route engine sensor wiring.
 
Yeah...

I figured wire routing but everything I will be installing (hopefully) will be in front of the sub panel. As I have the Aerosport symmetrical panel, my full length radio will be in the center, so the plane is to make a larger than needed hole in the sub panel (reinforced per vans plans) and use that access to install any nut plates that I may need.

Pretty sure any way you look at it, you are going to spend some time in the footwell.

Wouldn't it be nice if there was a big access panel on the forward fuse assembly so you would have access to the area between the firewall and sub panel?:D
 
I figured wire routing but everything I will be installing (hopefully) will be in front of the sub panel. As I have the Aerosport symmetrical panel, my full length radio will be in the center, so the plane is to make a larger than needed hole in the sub panel (reinforced per vans plans) and use that access to install any nut plates that I may need.

Pretty sure any way you look at it, you are going to spend some time in the footwell.

Wouldn't it be nice if there was a big access panel on the forward fuse assembly so you would have access to the area between the firewall and sub panel?:D

A large access panel in the "UFF" is doable with proper engineering, but Rob Hickman recommended against it - the holes in the panel for 10 or 12 inch screens are plenty large for access from the front - except for the area between subpanel and FW. Hopefully an avionics suite can be planned without much (I didn't say any) need to work in that particular recess.

It's true you can't install the wind screen without the UFF in place. My dilemma is that I also can't cover the firewall completely in insulation and foil until the UFF is riveted to the upper firewall. I'm wanting to get that task out of the way but it's forcing a decision with how much of the UFF work to do and when. As of now, I'm inclined to "build on:" cut the radio stack center hole in the sub-panel per plans (even though I will likely go with remote mounted radios and transponder - maybe it'll help with IFR GPS navigator fitment???) and rivet that UFF sucker in.
 
Me too..

Bill,

I am also having the same dilemma. I decided to rivet my UFF on and go to town on my FiberFrax/SS sheet sandwich on the firewall. The way I see it, the only foot well items remaining would be putting control cables and wires through the firewall pass-throughs. The pass-throughs can likely be cut through the FF/SS sandwich from the engine side of the firewall. I think I will be able to do my panel work from the front, with maybe a little work in the well. I have talked with others who have done the FF/SS firewall sandwich, and they didn't seem too worried about panel work. Waiting until the last "minute" to order avionics is a good idea, I think. I guess I'll see whether or not I regret this choice.
 
Yeah, my only concern really is having to make cuts in the sub panel, sure would be easier to do with it out of the plane, but I guess till you have the panel pieces in place you really don't know where you might need more room. I do have to say there is a ton of room even with it in there to work as long at the sticks are out and the pedals aren't connected, you can push them way out of the way.
 
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