OK Thanks, By the way, dont you sleep??
Some background data. All from the same source
An aircraft on wheels weighing
Aircraft main wheels are at 12.871M
Nose wheel 4.089M
Main jack points at 12.763
Nose jack 4.426
Though I think thats irrellevant
LEMAC 11.425
MAC 2.285
(The fuselage datum lime is at 3M if thats any use)
a = Aircraft pitch attitude (+nose up attitude)
r = reaction on nose landing gear tyre
W = total wt
The H-arm M calc given is
12.908 - 0.686 sin a - (8.832 r / W)
The XG(%MAC) given is
64.9 - 30 sin a - (386.5 r/ W)
And if the aircraft has fuel then this is added into the equation as
Mfuel = Total fuel wt in Kg as indicated in #######
H-arm 12.908 - (0.686 + 0.00016 Mfuel) sin a - (8.832 r/W)
and
XG(%MAC) 64.9 - (30 + 0.007 Mfuel) sin a - (386.5 r / W)
Now obviously I can compute these equations and work from the results, but I'd love to understand what they are on about and where the numbers they use come from?
Any light you can shed would be most welcome
Cheers
Nobby