Boeing 747 FFRATS Documentation

[chris341]

Hi all,

I am attempting to replicate a high fidelity simulation of the Boeing 747 classic in flight simulator. I have the autopilot and general flight model completed thanks to documentation from NASA/Boeing, the autopilot functions on all of the gains and formulas perfectly.

However, I have not been able to track down documentation on how the FFRATS autothrottle computers worked, including such information as the logic and gains used in computing a throttle setting from airspeed errors, damping values, etc. Does anyone happen to know where such documentation could be found?

Thanks!
Chris

[Luc Lion]

I don't have this information.
but, out of curiosity, have you coded yourself the aerodynamic and kinetic computation (matrices, tensors, matrices for referential changes) or have you plugged your code onto an existing engine?

[chris341]

I don't have this information.
but, out of curiosity, have you coded yourself the aerodynamic and kinetic computation (matrices, tensors, matrices for referential changes) or have you plugged your code onto an existing engine?

It's all working in an existing engine, Microsoft Flight Simulator 2004.

[Luc Lion]

I see.
15 years ago, from 2008 to 2010 I helped à team of enthusiasts who were developing an Open Source flight simulator. The name was Fly!Legacy. I think that it survived 5 years from 2010 to 2015.
Mostly I was involved with matrix computation and correcting or tuning aerodynamic calculations.
If I remember well the most difficult part the team was entangled with was transposition and composition of matrices in the context of referential changes.