Jim
Thank you for confirming my intuition and stating it more elegantly.
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Jim
Thank you for confirming my intuition and stating it more elegantly.
Doug
FAA-H-8083-1A, the weight & balance handbook, is available on the FAA web site in PDF format for reference.
I have a spreadsheet for calculating w&b for a type III, which I imagine is close. If you'll send me some data, I'll be happy to calculate it for you.Quote:
Originally Posted by dalords
You will need:
Empty weight
Gross Wt
Location of main gear axle centerline from the leading edge of the wing
Location of nose gear axle centerline from the leading edge of the wing
Max allowable forward CG
Max allowable aft CG
When you measure the location fo the axle centerlines, the aircraft has to be level (it may already be sitting on a tricycle gear).
Cheers,
As I posted above, I strongly recommend using the above spreadsheets on the Kitfox website; they are very easy to use once you have the data from going thru the procedure posted by KFfan. It doesn't matter which spreadsheet you use (model 4, 5, 6 or 7) as long as you use the fore & aft CG limits for your particular airplane. The spreadsheet doesn't calculate the limits, it only calculates the actual CG for a particular loading. You then take this actual CG number and compare it to the fore & aft limit range to see if you fall within it.Quote:
Originally Posted by jiott
One more thing: make sure you plug in the "arm" distances for pilot/passenger, fuel, baggage for your actual airplane (given in the last page of KFfan's post) in the appropriate places in the spreadsheet. Then with that spreadsheet you can quickly explore what happens to the CG with various combinations of fuel, baggage, and pilot/passenger weights. The calculation formulas are built into the spreadsheet so you don't have to do any math.
Doug
Here are the original W&B pages for S/N359. Happy calculating!
Thanks everyone for the replies. Jim and Lou here is where I run into the problem, its not figuring out the weight and balance, its the wording in the manual that Lou sent. For the most aft CG it tell you to add a gal of fuel to the fuselage tank and then add bodies or weight in the seat basically till you reach your gross weight, then for the most Fwd CG it tells you to fill the fuselage tank all the way and add a single roughly 120lbs person. My problem, I don't have a fuselage tank, just wing tanks, so then do I omit that part of the procedure? for aft max CG add weight to my gross weight and take a scale reading, same for the Fwd CG, just add 120lbs in the seat and take the scale reading?
The old kitfox manual weight and balance instructions had you weigh the plane with couple different fuel loads and a couple big boys to sit in it to determine where the CG would be located with those weights. You then knew if those loads produced a CG that was outside the limits. That is a very confusing way of doing it.
The conventional method is to include only the things in the plane that would be in it for every flight except fuel and pilot. The only fuel in the plane should be the "Unusable" fuel. That will give you the Empty CG. All other loading possibilities can then be easily calculated.
Hope that doesn't confuse you more.
Doug
Your last post caused my brain to flash back to, I think, seeing some pages that describe the process step by step. I have gone through quite a few pages of the documents I have. Tomorrow I'll see if I can rediscover them. When I do, I'll scan and post them.
Tom
You were posting as I was. What you relate vaguely strikes a bell.
That's kind of what I was thinking Tom. So with the basic empty weight add total fuel plus max passenger weight to get to total gross weight and then do the math to find max aft CG? Same with max fwd, except with only one small guy? I noticed on the spread sheet for weight and balance for model 4 on the kitfox website it already list max fwd CG at 10.2 and max aft at 16. shouldn't I fall somewhere close to that?