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weighing a taildragger advice

danny

Well Known Member
I'm at the point where my RV9 is needing w/b but I'm kinda concerned about nosing over when it gets leveled without fuel. What did you other taildragger guys do?
I don't see too many options. Maybe fill the tanks and subtract fuel weight? Will it tip over? Am I just over thinking? I have jacked up the tail with a tail-mate but not up to level.
Thanks for any help ahead of time...this really makes me nervous!
danny
owner/builder of an expensive paper weight, soon to transform into real airplane.
 
Unless you have a really heavy nose for some reason, this is non-issue. The -9 will balance nicely at level longerons.

If you are concerned, practice off the scales and use a tie down strap around the aft fuselage and/or put something under the engine mount or fwd fuselage just for piece of mind.

Good luck. Sounds like you are getting close.
 
Wheel chocks on the main gear is the main thing. As long as it doesn't roll it won't tip over when level.
 
I'm at the point where my RV9 is needing w/b but I'm kinda concerned about nosing over when it gets leveled without fuel. What did you other taildragger guys do?

It will not nose over. You would need to raise the tail far more than just longeron level, like tailwheel high as your head or more.
 
You guys are awesome. You won't believe how much I need others to "weigh" in.
Thanks, Gents.
 
It won't nose over, but the weight on the TW is not too high empty .. I measured 64 lbs in level condition -- this seems to pretty typical based on other poster's W&B numbers.
 
You guys are awesome. You won't believe how much I need others to "weigh" in.
Thanks, Gents.

Good pun!

Actually your question serves as a nice illustration of how important it is to get the airplane really, truly longeron-level when weighed. The tailwheel weight varies a fair bit from tail low to tail high, and its recorded weight is a big factor in establishing empty CG.
 
Wow! 37 lbs. That’s the lowest I’ve heard of. Mine was 50.4 and I have a slightly heavier engine than normal - O-360 - which should make the tail slightly lighter, relatively. Like Dan said, make sure your longerons are level, and the canopy is closed. It will affect your CG calc.
 
Wow! 37 lbs. That’s the lowest I’ve heard of. Mine was 50.4 and I have a slightly heavier engine than normal - O-360 - which should make the tail slightly lighter, relatively. Like Dan said, make sure your longerons are level, and the canopy is closed. It will affect your CG calc.

O-360 with a hartzell C/S prop and the standard battery in the standard location. it is a bit nose heavy. it needs 212 pounds in the pilot seat to put it on the forward limit. I really wish i could get to the point that I need to add weight in the baggage to get in in CG :) good part is i can put a pretty good size person in the back seat and stay in cg. also makes it real easy to get it back in the hangar, grab the tail spring and lift it up and pull it in.


bob burns
RV-4 N82RB
 
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I am told the desired weight on the tail is 5% of the total weight. 1100 lb aircraft 55 lbs would be perfect.
 
Slightly off topic - more on weight than on balance.

It's not necessary to weigh the tail wheel in a horizontal position!

1 Weigh all three wheels on the ground to get the total aircraft weight.
2. Weigh the main gear only with the tail lifted to horizontal attitude.
3. Subtract #2 weights from total aircraft weight to get the tail wheel weight in horizontal position.

I found this much less cumbersome that trying to put the tail wheel on a scale while elevated.

PS: I didn't trust to theory, and placed a loose rope and concrete blocks over the tail to engage if nose over ever started to occur. Dolly and I previously flew a Globe Swift and they had to have tail weighted to prevent nose over when doing annual gear up tests.
 
Slightly off topic - more on weight than on balance.

It's not necessary to weigh the tail wheel in a horizontal position!

1 Weigh all three wheels on the ground to get the total aircraft weight.
2. Weigh the main gear only with the tail lifted to horizontal attitude.
3. Subtract #2 weights from total aircraft weight to get the tail wheel weight in horizontal position.

Drat, beat me by an hour. I was going to say the same thing. I'll offer one further simplification if you have only two scales: Use the two scales on the main wheels and a block of wood under the tailwheel that's the same thickness as one of the scales.

1. Weigh the mains in three-point attitude.
2. Weigh the mains with tail raised to horizontal.
3. Roll plane off scales.
4. Take one of the scales and weigh just the tailwheel in three-point attitude (yes, the angle changes slightly but not enough to make a significant change on the tail weight).

1 + 4 is your empty weight.
1 + 4 - 2 is your tail weight when horizontal.

And you have all the numbers you need for your W&B.
 
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