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Rear seat moved back

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pbrannan

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So, I'm slowly getting in gear on my Marquart project. One of the issues that I need to deal with is that the prior project owner moved the pilot seat back approximately 2 inches. I'm not wild about this and am leaning toward undoing his changes. Attached are two photos, the first detailing the modification to the upper seat cross member and the second showing the modification to the lower seat cross member.

My options are:

1) Cut out the mods and change everything back to plan.

2) Make new rear cockpit sheet metal and leave things the way they are. The welds aren't pretty, but are probably sound.

As far as I can tell, the CG would still be workable with the seat back 2.5 inches.

So here are the factors I'm considering.

1. Aircraft CG. I'm not a fan of screwing around with the CG but believe in this case it's probably going to be OK. If W&B turns out like other examples that I have data for you could still get a 250lb guy in the back. CG would be aft, but not out of limits.

2. Small pilots. I have a couple of teenage kids who are glider pilots who might want to fly this someday. I'm 6' & 185 but neither of them will hit that number. This might be a deal breaker. My daughter is small enough that an additional 2.5 inches back might make it unworkable.

3. Wind the cockpit. Bigger opening = more wind.

4. Structural integrity. If I change back I'll end up making yet another set of alterations to the upper longeron in a 4-inch length. Might need to reinforce.

Left side rear seat upper mod: https://photos.app.goo.gl/BnEWTRW0PpEVmYiw1
Left side rear seat lower mod: https://photos.app.goo.gl/0LYcu6k4ERpj7Xy33

Any thoughts or advice would be appreciated.

Pat
 

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