A friend has bought a used Precedent Fly Bi 25 and we need the CG to
make sure this plane has more than just one flight.
I've trolled the net but Precedent (UK) stopped production a few
years ago and it's impossible to find any reference to their products
If anybody has the CG to this plane and maybe the throws I'd
appreciate the help.
Is this a biplane? If it is, use 25 % from the leading edge of both of the
wings, then take the point halfway between the two, or more rightly, shade
towards the larger wing, from halfway, a little.
Throws, if the moveable area is 25% of the horizontal, or slightly more, go
30 degrees up, and 25 down.
I've got one of these, but I'm not going to be able to check where the CofG
should be for 24 hours or so - if you can wait that long! ;-)
Just a couple of notes about the handling for you, take 'em or leave 'em ...
Having built it with exactly what was in the box, mine came out at the top
end of the weight range. If it was built true to the plan/instructions I
would expect yours to be the same - mine is somewhere around 4½ lbs IIRC and
it likes to be flown relatively fast. A floater it ain't! Mine is actually
the second one I built (this one is about 5 years old built from a kit I
bought years ago) but the weight of the first one (built 20 years or so ago)
was almost identical to this one. The big difference was that I put a .28
ballraced engine in the second one whereas the first only had a .25 plain
bearing on the front and that change transformed the handling of #2 compared
to #1. Although it's a Bi-Fly 25 I felt that the .25 was a little lacking
in grunt. The .28 has quite a bit more available and has made #2 a much
nicer (exciting!) aircraft to fly. That said, you DO have to fly it all the
time - and don't take your eyes off it as it will get small very quickly.
Keep the speed up on approach to land - not lifting the paint off the
leading edges, but a bit faster than you think necessary. If you get too
slow you will find out that it gets out of shape very quickly. Better to
roll sedately off the end of the patch because you've come in a tad too fast
than to watch it flick into a sickening crunch before you've even reached
the mown bit.
I'll also check on what throws I've used. I'm pretty sure they're the
recommended ones but they've got plenty of bite. The rudder is quite
powerful so be careful on takeoff but the rudder authority in the air makes
it a seriously good spinner and the flick-rolls are amazing. Inverted spins
are no problem either, uphill or downhill.
Let me know how you get on with it.
I have the plans for this plane, sent to me by a guy from this group a
few years ago. I haven't ever gotten around to building it yet....
The CG is 8.5 centimeters from the leading edge of the top wing.
I spent a few minutes looking at the plans again. It's amazing how
small the wings of this plane are. I hope your model was built light.
It looks like the kind of plane that drops like a rock when you cut the
engine, if you build it too heavy.
Did you get the impression that this plane is essentially a miniature