fuselage length

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Tbopper
Posts: 11
Joined: Sun Dec 09, 2018 7:15 pm

fuselage length

Post by Tbopper »

When I bought our Pietenpol project, I was told the fuselage was a long one. I was not aware that a shorter version of the fuselage was available. What is the difference in the length. I am flying at the rear of the Center of gravity and I am wondering if the shorter fuselage would help. Is there a set of plans available for the shorter version?

PoconoJohn
Posts: 45
Joined: Tue Jan 14, 2020 9:07 pm

Re: fuselage length

Post by PoconoJohn »

My original plans are for the shorter fuselage with a page added to show changes for the longer fuselage. Difference is 10" if my memory is correct (about 173" and 163"). You can purchase plans here: https://www.pietenpolaircraftcompany.co ... nstruction

Earl Brown
Posts: 29
Joined: Mon Nov 04, 2019 12:24 pm

Re: fuselage length

Post by Earl Brown »

Tbopper;

The shorter fuselage might be a bit lighter, but it won't solve the rear CG issue.
Both the long and short fuselage are prone to CG issues. While it's a bit of a project to fix after the plane is finished, it can be done.
You mentioned that you bought the project, was it flying when you bought it?
Are you and the original builder about the same weight?
What engine is in the plane? Are the cabane struts vertical or slanted back any?

Tbopper
Posts: 11
Joined: Sun Dec 09, 2018 7:15 pm

Re: fuselage length

Post by Tbopper »

The plane was not finished. It was picked up in pieces. After assembly, a weight and balance was done and that is when I found the CG was out. The wing was moved back 4 inches. That helped a little bit. The engine is a continental 65. It had a wooden Edward Sterba
propeller that I changed for a 19 lb. metal prop. I 'm now 3 inches past the rear CG. I weigh 225 and stand 6' 2". My desire is to loose weight BUT that is not going well. If the difference in the length of the fuselages is 10 inches I don't think I would attempt to shorten it. Other that hanging dead weight on the nose; which I don't want to do, I'm pretty much out of ideas. It will fly hands off. If both the long and short fuselage are prone to CG issues, what as been done to correct the problem or do I just suck it up and fly it, which by the way is a blast.

Earl Brown
Posts: 29
Joined: Mon Nov 04, 2019 12:24 pm

Re: fuselage length

Post by Earl Brown »

So you are at 23" aft CG?
What are the min. and max. pilot weights shown on the W&B?
The wing is back 4"- does your W&B show how far back the wing LE is from the firewall?

at7000ft
Posts: 33
Joined: Mon Mar 06, 2017 3:06 pm

Re: fuselage length

Post by at7000ft »

Tbopper wrote:
Mon Apr 27, 2020 1:32 am
The plane was not finished. It was picked up in pieces. After assembly, a weight and balance was done and that is when I found the CG was out. The wing was moved back 4 inches. That helped a little bit. The engine is a continental 65. It had a wooden Edward Sterba
propeller that I changed for a 19 lb. metal prop. I 'm now 3 inches past the rear CG. I weigh 225 and stand 6' 2". My desire is to loose weight BUT that is not going well. If the difference in the length of the fuselages is 10 inches I don't think I would attempt to shorten it. Other that hanging dead weight on the nose; which I don't want to do, I'm pretty much out of ideas. It will fly hands off. If both the long and short fuselage are prone to CG issues, what as been done to correct the problem or do I just suck it up and fly it, which by the way is a blast.
The best solution is to make a new longer engine mount, moves cg forward and adds minimal weight.

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Terry Hand
Posts: 62
Joined: Thu May 18, 2017 2:37 pm

Re: fuselage length

Post by Terry Hand »

I would submit to you that your best option is to contact William Wynne or Ryan Mueller, let them look at your numbers and let them propose your best solution. They know the Pietenpol W&B as well as anyone.
Semper Fi,

Terry Hand
Athens GA

tom kreiner
Posts: 49
Joined: Sat Feb 25, 2017 9:49 am

Re: fuselage length

Post by tom kreiner »

Take a close look at your tailwheel, as it adds the largest moment of any component due to arm length. Reducing weight at the tail is the best bet for changing cg. Below are a few suggestions.

I had a 7 lb. Matco tailwheel given to me, and rather than using it, I am fabbing the twin tubing open frame per plans along with a lightly modified RV-6 tailwheel mechanism. One change drops weight by over 3 lbs. Don’t use the triple springs for your tailwheel; they’re solid steel!

Dropping 3.5 lbs at that arm will put my plane close to forward cg.

Also, if you have 1/8 tailplane wires, consider using 1/16 in wires. Plenty of Piets have HUGE t’buckles, fittings, and wire at the tail that really affects cg.

Drill 1” holes in the turtle deck stringers, several Piets have done this and while in the uncovered state they look like Swiss cheese, you’ll drop another lb. or so.

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