Weight and balance

[Waynes56]

Does anybody have the cg weight and balance sheet for a yarrow arrow 2 ?

[Jim Heffelfinger]

I am going to make a few assumptions here as the request is not very detailed. If my assumptions are not correct ignore what might be known information
Each aircraft has it's own W&B sheet that actually should change each time a piece of equipment is changed, or moved. The W&B sheet is a product of actual measurements and calculations on each aircraft. These calculations are checked against designed limits by the designer/kitter. A blank work sheet might look like this http://members.eaa.org/home/homebuilders/building/weight/4Weight%20and%20Balance%20Form.html
and FAA Doc H-8083-1 documents the creation of this form and graphing load limits. http://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/media/FAA-H-8083-1A.pdf

Since the Arrow 2 is a homebuilt there are usually no standard sheets like found on a certified aircraft.

[Waynes56]

Yes I believe in what your saying but every kit built aircraft I have built has a specific location for the forward and aft cg limitations given by the company ,and this is what I am looking for or am I making it harder then it is.

[Jim Heffelfinger]

Actually Wayne not harder... you want the CG limits of the Arrow. Now that is "calculations are checked against designed limits by the designer/kitter"
These limits vary with the airfoil and to a degree with the airframe moments ( correct me if I forgot something here gang) .
Now we can go out and research your inquiry.

[Jim Heffelfinger]

this from a EAA365 forum thread.

Hi John - I have a Yarrow Arrow II that I have flown since 2000. I have done a complete restoration and flown it for 370 hours. Contact me at dennisr5@telus .net and I will send you any information I can.Dennis Richardson

[Waynes56]

Thanks guys appreciate it.Dennis I tried to email you but my mail program would not work email me @stinky@mtintouch.net

[1600vw]

I am going through this right now finishing up my condition inspection. Here is the formula that is used on this Fisher Avenger tail Dragger:


R x L=____ / w = _____ + D = CG

R= Wieght of Tail wheel
L= Distance to tail wheel from main wheel
W= Wieght of aircraft
D= Datum ....Mine is the leading edge of my wing from the main wheel center. This is my Datum.


Not sure if this is of any help.

Fly Smart

[1600vw]

I am going through this right now finishing up my condition inspection. Here is the formula that is used on this Fisher Avenger tail Dragger:


R x L=____ / w = _____ + D = CG

R= Wieght of Tail wheel
L= Distance to tail wheel from main wheel
W= Wieght of aircraft
D= Datum ....Mine is the leading edge of my wing from the main wheel center. This is my Datum.


Not sure if this is of any help.

Fly Smart


39 x 139 = 5421 / 563 = 9.628 + 4 = 13.628 cg range 12.5 - 17.5

Me in the airplane no fuel...As you see I fall within my CG..

[1600vw]

39 x 139 = 5421 / 563 = 9.628 + 4 = 13.628 cg range 12.5 - 17.5

Me in the airplane no fuel...As you see I fall within my CG..

But now fill the tanks:

33 x 139 = 4587 / 609 = 7.532 + 4 = 11.532

Now I am outside my CG or forward of my cg range by 1 inch.... Also note gross wieght of my airplane is 600. I am over by 9 lbs. This is with a full load of fuel, I could leave a gallon and half in the gas can and still have over 4 hrs fuel on board burning 1.5 gallons and hr. So I am not quite done yet. Still more work to do.

Fly Smart..Do not fly an out of CG airplane.

[Waynes56]

The datum line is what I am not sure about where it actually is on this bird.The rest of it I can do but?

[Jim Heffelfinger]

Wayne,
1600vw missed the redirect of your question . You already have the needed information to measure your CG and create a W&B report.
The datum ( the reference point where all measurements originate) can be anywhere. It could be on the hangar wall. It could be behind the airplane - just making the math a bit odd. .
You need the CG limits as defined by the designer.
I passed on this thread to the email address for Dennis. I hope he comes through. the 365 forum was so slow and unwieldy that HQ shifted to this one. Not all members shifted over.

[Waynes56]

Thanks Jim appreciate it.

[Waynes56]

Just talked to a very nice fella in Canada who a few years ago rebuilt a yarrow 2 and he said when he did his weight and balance he used 25% of the cord to use as his cg and he said it came out very close so I'll go with that and see how it calculates.