Carbon fiber seat in aluminum plane

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12notes

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I've had an idea to make a composite seat, although I know making it out of fiberglass would be easier and a lot cheaper, because of planned future projects, I'd like to make it out of carbon fiber so I can renew my decade-old experiences with it. I'd like some opinions from those with experience it this.

My plan is to put a plastic bag in the single seat cockpit, partially fill it with construction foam, and sit on the bag until it hardens. I would then remove the bag from the plane and use that as a mold for the seat. This will give me a seat molded exactly to me, which should be comfortable and not need padding. After curing, I would remove the foam filled bag from the seat, and add a thin foam and extra layers of CF to the back of the seat for strength, then a layer of Kevlar or Innegra on everywhere that would touch aluminum to prevent galvanic corrosion.

The sides of the cockpit would have 1/8" plastic spacers during the foam bag step to leave room for the side of the seat to fold back to meet the bulkhead. The floppiness of the seat would be limited by the seat having nowhere to deform to, as it would be trapped top and bottom by the cockpit bottom and turtledeck bow (basically an oval) , front to back by the rear bulkhead and spar cover, and on the sides by the cockpit sides and siderail, so it can be fairly thin and should be light.

Is this a reasonable plan? Has anyone else done anything similar?
 

sming

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Beware of exothermic reaction? I remember reading somewhere (here?) a guy who tried something like your plan, but he sat on the curing fiberglass. Was some pretty painful experience apparently...
 

crusty old aviator

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I guess the real trick will be calculating how much foam you'll need to mix and put in the bag: too little, you'll have to try it again; too much and what a mess!
 

meglin1

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We did almost the same thing once. We chose the biggest ass so that the rest of us would have more space in our clothes. We also fly in winter, at minus 30 Celsius.
Here's what we got :).
But carbon when destroyed gives sharp cutting edges. That's why we only use fiberglass for the seats.
 

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wsimpso1

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The seat really should stay put and in one piece through as severe a crash as the rest of your structure, and maybe a little more. Nominal Part 23 is a darned good idea. There is a longitudenal pulse and an up and back pulse in the refs. When the plane holds together and the seat belts stay put, so should the seat. If the seat breaks up, you will get a pile of injuries. Design the seat to carry you through this and the surrounding structure to take it to, you will have a fighting chance in a forced landing. Perhaps a ply of Kevlar between carbon fiber and you would be a good idea too.
 

Victor Bravo

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If I'm remembering the story right, the German Akafliegs did a LOT of research on small aircraft seating and cabin design in the 1980's, and it resulted in tremendous crash safety improvements. The AS-W24 s was the first sailplane by a major manufacturer to incorporate these findings and guidelines into the design of a production glider. Definitely worth some research for anyone looking at composite seats. Combinations of carbon and Kevlar, where the properties of each are used to advantage, are worthwhile. The newer types of carbon laminate materials apparently hold together better, and differently, than the original "brittle" versions.
 

Hot Wings

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My plan is to put a plastic bag in the single seat cockpit, partially fill it with construction foam,
You can get kits for this from the auto world.

 

User27

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Be a little careful with completely carbon seats - in a crash the carbon has a tendency to splinter into sharp jagged pieces that can cause a lot of injury. A carbon/kevlar or carbon/twaron seat will be much kinder to you.
 

12notes

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The seat really should stay put and in one piece through as severe a crash as the rest of your structure, and maybe a little more. Nominal Part 23 is a darned good idea. There is a longitudenal pulse and an up and back pulse in the refs. When the plane holds together and the seat belts stay put, so should the seat. If the seat breaks up, you will get a pile of injuries. Design the seat to carry you through this and the surrounding structure to take it to, you will have a fighting chance in a forced landing. Perhaps a ply of Kevlar between carbon fiber and you would be a good idea too.
I tried to say that I was going to put a layer of Kevlar in the middle and also Kevlar or Innegra everywhere that touches aluminum, but I didn't English gooder enough in my original post.

The seatback perimeter would be attached to a bulkhead and the fuselage skin on the bottom and turtledeck bow on top would encircle the edge in an oval shape, as long as it can't move forward, it shouldn't be able to deform, as compression in one direction would require expansion in another, and there isn't room for it to expand.
 

12notes

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You can get kits for this from the auto world.

I saw these (well, a similar one), I'm going to make an attempt to do it cheaply first, if my homebrew solution doesn't work for the mold, I'll probably get one like this.
 

TFF

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Not for the seat but F1 race cars have the first layer in the leg tunnel, Kevlar. The seat is Carbon but there has to be a bunch of sub structures that have Kevlar in them for the ballistic protection. Any bolt hole I would have Kevlar area not just for separation but for hardware pull through in a crash. I think I would want it the outside layer next to me to be Kevlar.
 
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