FCS Hawker Fury

[djs1]

The only thing that spoils this wonderful aircraft is the violent shaking which seems to occur after 170mph or so, given that its maximum speed should be around the 200mph mark. Has anyone else experienced this and if someone out there, with more expertise than I have, can suggest a suitable tweak of the config file it would be most welcome.

David

[OBIO]

In what manner does the plane shake? Up and down or side to side? The answer to that will dictate what tweaks need to be made to the config file.

OBIO

[djs1]

HI OBIO
It is a very definate side-to-side, with a slight twitch in the nose, if that makes sense. Thanks for the reply and here's hoping

David

[OBIO]

Okay.....sounds like MOI settings need some adjustment. I copied a set of MOI data from a plane to show you what is what and how to adjust them.

empty_weight_pitch_MOI = 278670 <<lower this number to fix up/down shakes
empty_weight_roll_MOI = 109624 <<lower this number to fix rolling
empty_weight_yaw_MOI = 279527 <<lower this number to fix side to side shakes

The stronger the shake, the larger the reduction needs to be to correct the problem. For severe shaking, reduce the number by 50%. For medium shakes, reduce by 30%. For minor shakes, reduce by 20%. If the shakes continue, reduce by an additional 5 to 10% of the original value until the go away.

Be aware, that changing these number to correct flight behavior can cause new issues with ground handling. I would trade taxi stability for flight stability any day of the week.


DSICLAIMER: I am not a flight dynamics guru. I know just enough about flight dynamics to be dangerous and/or really annoying. Use the information above at your own risk.

Always make a back up of the stock config file before you start following my advice...that way if what I suggest blows your plane up, you will have a working config file to put back into place and use until someone who actually knows something comes along.

OBIO

[djs1]

Hi OBIO
First of all here are the original MOI settings -

;Moments of Inertia
empty_weight_pitch_MOI = 1850.000
empty_weight_roll_MOI = 1750.000
empty_weight_yaw_MOI = 1400.000
empty_weight_coupled_MOI = 0.000

The more I reduced them, the worse the shakes got, even stationary with the engine off. Next I looked at the MOI in Ted Cooks Osprey and these are -

;Moments of Inertia
empty_weight_pitch_MOI = 3656.0
empty_weight_roll_MOI = 2175.0
empty_weight_yaw_MOI = 4897.0
empty_weight_coupled_MOI = 0.0

I increased the Fury as follows and guess what, perfect

;Moments of Inertia
empty_weight_pitch_MOI = 4000.000
empty_weight_roll_MOI = 2200.000
empty_weight_yaw_MOI = 4000.000
empty_weight_coupled_MOI = 0.000

I don't pretend to understand the numbers, but I am very grateful being pointed in the right direction.

Kind regards
David

[djs1]

OBIO, Thanks again and if "living" proof were needed, here it is !!

David