Excessive Trim required

One for the FDE Experts … I am finding the trim required for level flight is
excessive between low and high speeds for example … at Low speed … WELL
above stall… I am requiring 100 % UP TRIM and at High speed … WELL Below
VNE The required trim is 100% DOWN My weight and balance seems fine and the
COL is 25% Exactly and I am Not using Flaps… could there be a fundamental
flaw in the Cl Curve? or something else glaringly obvious I may have
overlooked … Could it be the available Trim “Range” and how would I set this
? I am No newbie when it comes to FDE … I have created MANY Famous models
over the years But this is driving me to despair ! :slight_smile:

In previous sims, this would be suggestive of CG and CL being too far apart,
there are known issues with any wing sweep affecting the relationship in MSFS
so I would suggest starting there. You don’t mention the aircraft, but not all
have the CL at precisely 25% MAC.

The CG and CL Are in approx the same location depending on Payload but never
outside the (quite narrow) Limits . The aircraft, if it matters … is the
Shorts 330

Okay, so straight wing. And if your CG and CL are on roughly the same point,
and everything else is geometrically correct, then you are down to the
guesswork which goes alongside this flight model unfortunately. There is
probably something in the flight tuning section - hstab lift perhaps? I really
am clutching at straws unfortunately - I’ve been working FDEs in FSX / P3D /
X-plane for 15 years or so, this one since release and it still does not make
any sense to me nearly two years on. Genuinely sorry not to be much help.

you were very helpful thanks … Even if it was just to confirm that I’m not
alone losing hair over MSFS FDE :slight_smile: Cheers … and good luck

PLEASE Can I re-open this and ask if Any Other FDE Expert has clue what could
be wrong ??? It is driving me to despair :frowning: