Building a Nieuport 11...

[Floatsflyer]

...I'm ten pounds too light at the tail.

Well, that's better than the other way around! But I've got to figure out how to put some weight back there without doing major surgery. I've a few ideas, some of which aren't Wile E. Coyote in complexity.

You've opened up some delicious satirical replies. How about a tail hook? You could then do banner towing and practice carrier landings. :>;

[Dana]

I forget what you had for an engine and too lazy to search back... if you're hand propping a glider tow hook is useful weight...

[Frank Giger]

1915cc VW (85hp) direct drive.

Oh, and I have a starter....hand propping is "of the Devil" IMHO.

Pics tomorrow on my solution for the weight issue.

[edit]

On snarky comments, I've always been considered heavy in the head and light in the ass. Sort of the definition of a nerd!

[Frank Giger]

Sooo....ten pounds to the tail. Well, let's plan some surgery:



I already had an inspection hole there for getting to the nuts that hold the vertical stab to the fuselage.

So I built a box that rests on the lower longerons and has brackets going across front and back.

It was getting cold, dipping below 50 degrees, so I was going fast to keep warm...and didn't take photos of them.



With the box in place (what a PITA) and the rivets taped over, I put the 12 weight sleeves into the box:



Where did I get lead shot sealed into thick plastic bags of a convenient size that allow me to easily remove weight if I need to?

It's a secret.



Box sealed up and a couple "drop tests" from knee high to see if it shifts (it didn't).



Ready for fabric repair.



A few notes:

The box is well clear of both the elevator control rod and the rudder cables.

I re-weighed the tail and she's put me in the CG limits, though at the forward end of them, which I'll take all day long.

[jdanneel]

Hi Frank,

in your CG calculation the position of the mains wheels is at 7.125in, this looks far back to me ?
if the front "leg" is vertical, then from what I make out of the plans this could be max 4 to 4.5in aft of firewall; which results in a CG calculation shift 2 inch more fwd ?

greetings

Johan

[bookmaker]

I can answer that. Since most of the AA planes are using VW engines, that are lighter than the original engines, the wings are swept back farther than original to move the center of lift, and therefore the C/G, back. Otherwise, a lot of nose weight would be required. Prior to the AA kits, the builders of the Graham Lee Nieuports found that moving the C/G back generated a little problem with ground handling, so many of the early builders of the Graham Lee planes moved the main wheels back closer to the C/G. Sweeping the front landing gear legs back. This helped with ground control. Robert's Nieuport plans (at least mine) show the forward leg being vertical, but the dimensions he gives for the legs result in sweeping the forward legs back to do the same thing.

Therefore, Frank's front landing gear legs are swept back, not vertical as was on the originals.

Now, in my case, I am building the full size AA N17 and since I am using the heavier Rotec R2800 radial, I have removed much of the added sweep in the wings and therefore repositioned the forward landing gear legs back to vertical. I have discussed this with Robert and others who have built Nieuports.

Dale

[Frank Giger]

Dale is exactly right; when I was at the HOP,* Robert suggested we deviate from the plans and bring the gear rearward in order to improve ground handling. It's a mod the KC Dawn Patrol guys all made on their planes with great improvement.

I naturally agreed whole heartedly that we do this; I want a plane that looks like a Nieuport 11 more than I want a Nieuport 11.

* HOP = "House of Pain," a euphemism for the builder's assist program Mr. Baslee puts on, immortalized by Dick Stark in his second book. Robert's shop is climate controlled in the most fundamental way - it's mostly controlled by the climate outdoors. In my case, it was a very warm summer where even the cat was walking around with its tongue out due to the heat. A couple of swamp fans helped, but one rarely found himself in front of them.

Work at the HOP is dictated by the builder - if one is slow not much gets done. Robert and Jim are there to assist and teach, not build one's plane for them. However, Robert doesn't dally about - this is a man that built the four Nieuport 17's for Flyboys from phone call and a blank sheet to airworthy in 60 days. He tends to get one moving quickly from task to task and encourages hustle.

I had the fuselage done and on gear as well as that tailfeathers mounted in four days at the HOP. If I had the means and the cash there is no doubt in my mind that I could have had a flying plane in less than a month with his oversight and help (assuming he would be available for that).

But even for an old soldier like me it was a test. Loads of bending over, repetitive motions, and having to use one's brain while doing repetitive motions. Every skill needed for the build is taught, from basic design to basic tool use to annealing and swagging cables. Worth every dime!

[Frank Giger]

Sigh and a big whew.

When I did the measurements, I didn't really do the upper wing offset, as Robert hadn't made it clear to me. So I came up with it using math to determine sides of a right triangle.

The problem is that the wing doesn't start at the firewall, but is well forward in the center. Instead of an eight inch offset for the upper wing, it's two inches! Recalculate and not only is no weight required to be added, doing so would put me out of the right range.

So pull all the weights out, patch the fabric, and frown at the seams that didn't need to be there in the first place.

The good news is that I did everything over for W&B from scratch and that was the only thing I had wrong. My weights were even the same, which I thought might be different for some reason. They shouldn't be, as I had the same level on the longeron at the cockpit.

[Dana]

I thought ten pounds in the tail seemed like an awful lot, but you sounded so sure...

[Frank Giger]

LOL, I always sound sure.

But that doesn't mean I won't always rely on empirical data over mathematical data whenever possible. So all the math is done and I figured I'd make it easy on myself and make the chart for the POH:



The odd thing that might stick out is how much five pounds in pilot weight matter between 180 and 185. This is because the gas tank and the pilot dance around the CG; that's the tipping point where the pilot wins and offsets the weight of the fuel. I may make the one gallon cell on the 180 line yellow, as it's close.

But at the FAA approved 170 pounds (with clothes on), I'm okay to run out of fuel. Sure the engine will go into whisper mode, but hey, the CG will still be okay for my unscheduled landing!