The arrangement where the fuel is behind the center of gravity is one of
the reasons I chose the Europa. If the dynamic C of G range is properly
set up then any fuel burn will result in a more forward C of G. You
shouldn't ever get into a situation where you are going to takeoff with
an in ballance airplane but at landing have a tail heavy plane to contend
with. From the description of the dynamic C of G range for your plane it
looks like something needs to be moved from the back to the front or the
engine moved forward. Now lets see, the extra weight of a 914 would
place the C of G where? ;-)
I am really interrested in using carbon fiber and vacuum bagging the tail
plane. It is good to know that the margin is such that it is to our
advantage to get weight out of the tail.
Steve Eberhart
newtech@newtech.com
Europa wannabe - hope to order wing and tail kits at Sun 'n Fun
On Sat, 15 Mar 1997 Gramin@aol.com wrote:
> In the Europa the passengers are forward of the c.of g, (cog) while the
> fuel and the baggage are well aft, the numbers being -4, 16 and 28
> respectively (from a nominal 60"). While any particular set of conditions is
> easy to calculate it is more instructive to run a program which will explore
> the limits. The first thing that turns up is that it is virtually impossible
> to get out of limits in the forward direction (-2) with passenger load.
> Indeed the reverse is true, i.e. it is easy to have too low a passenger
> weight, and the fuel pushes you out of the aft limit (2.5). So you may have
> to collect a passengers or bags of cement to put full fuel aboard. The same
> goes for baggage only more so, as it is further aft. You need more
> passenger/ballast in the right hand seat to get maximum fuel and baggage.
> This is eased somewhat if you have a heavy fit of instruments for they can
> substitute for passenge/ballast, being even further forward. You will know
> this as soon as you complete the weighing, as your cog will probably then be
> found to be less than 60 from datum.
>
> As I have yet to fit anything heavy on the instrument side, my cog is already
> nearing the 61 specified as the aft limit for first flight. Which means I can
> load very little fuel for it, even if there is a crew of two !. Sandbags on
> the feet ?
>
> Grinding out tables of numbers also shows that max. a.u.w. weight only limits
> loading in rare cases, as fuel or baggage usually sends the cog too far aft
> first.
>
> Perhaps all this is obvious to those flying but I would recommend wriiting a
> suitable progam, as there are some constants specific to each aircraft to be
> fed in, before the correct conclusions can be drawn. Anyone is welcome to
> mine if they are too busy building.
>
> Graham C.
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