The Murphy Builders Site

Here an example file on 1800 amphibs. You may have to format it a bit.
You won't need the line that says header tank.
If I run it out of gas while solo with nothing but safety equipment on
board I'm forward of the recommended limit but within the allowable
limits. I never get near the aft limit and I prefer flying with an aft
loading. My empty weight has gone up a bit since these examples. I
think
I also measured my fuel as being farther aft than some examples. The
amphibs definitely move my empty c of g forward.
Ken
subaru with firewall moved back 3 inches


Sample loading of Amphib configuration 1730 lb. gross
Datum is center of door post.

Recommended C. of G. Limits 10.85 to 18.10 inches
Permissible C. of G. as per Murphy Aircraft MFG. are: Maximum
Forward C
of G = 7.7 inches Aft Of Datum (AOD).
Maximum Rearward C of G = 19.7 inches A.O.D.


Forward Limit
item weight arm moment C. of G.
aircraft empty 1253 8.04 10074.12
pilot 175 18 3150
pax
main fuel 30 24 720 min. reserve
header tank fuel 13 65 845
anchor/ropes 0 100 0
baggage 0 43 0
1471 14789.12 10.05 A.O.D.


Aft Limit
item weight arm moment C. of G.
aircraft empty 1253 8.04 10074.12
pilot 175 18 3150
pax 0 18 0
main fuel 89 24 2136
header tank fuel 13 65 845 full
baggage 200 43 8600
1730 24805.12 14.34 A.O.D.


Typical Gross Weight
item weight arm moment C. of G.
aircraft empty 1253 8.04 10074.12
pilot 175 18 3150
pax 175 18 3150
main fuel 114 24 2736 half tanks
header tank fuel 13 65 845 full
baggage 0 43 0
1730 19955.12 11.53 A.O.D.


On 2/13/2011 10:46 PM, Rebecca Brownell wrote:

Awesome!That should help getting that paperwork filled out.And
please,
very helpful to have examples when figuring all this out.Thanks to
you
both Wayne,Ken greatly appreciated.More questions to come I'm sure.
Thanks
Jason
"Muskrat"817R
On 13-Feb-11, at 10:37 PM, Ken wrote:

Yup
34.5 * 933 for mains = 32188 in-lbs
-72 * 291 for front = -20952 in-lbs
add those together to get 11236 in-lbs
divide 11236 by 1224 lb empty weight to get 9.18 inches aft

I'd probably leave the battery where it is or if it is not bolted
down
yet perhaps move it forward a little to the first convenient place
to
mount it.

I have examples of forward limits and rearward limits at 1730 lb
gross
if you need them.

Ken

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