Re: [Jsbsim-devel] Prop aircraft yaws to the right on take-off.

[Alan T. <ajt...@v-...>]

On 03/09/2019 23:57, Ron Jensen wrote:
>
> On Monday 02 September 2019 02:34:13 pm Alan Teeder wrote:
>
>> It would have been better to work with stand-alone JSBSim, but this
>> particular FDM has many hooks to Flightgear systems which would all need
>> sorting out.
>>
>> Alan
> Do you have a link to this particular aircraft's FDM? I haven't used FG in
> quite awhile now.
>
> Ron

Ron

The latest version is at https://github.com/FGMEMBERS/J3Cub.

Following Bertrand´s reply I seem to be getting somewhere. I now use 
JSBSim Output to make a .csv file which seems to give me  all the 
parameters that I need to see what is going on.  .csv data goes nicely 
into a spreadsheet which is ideal for this purpose.

It is making some sense, but the numbers add up to nose right instead of 
nose left. A large contribution was a fixed rudder trim ( on the Cub the 
owner would do this by bending the rudder). Making this zero helped but 
was not sufficient. However the presence of this fixed trim makes me 
think that it was needed in the past to counteract a nose left swing.

I have plenty  of parameters remaining to look at.

Alan