Lift_coef_mach_table

Hello,

Just to report that this parameter in the flight_model.cfg file has currently no effect at all on the flight model.

I don’t know if it’s supposed to be this way, but it’s a shame as it prevents from adjusting lift at high speeds.

Hopefully this gets fixed ASAP.

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It would be informative if the SDK documented which parameters were used uniquely or shared by the two Flight Models ( Classic & Modern).

ie It could be that “Lift_coef_mach_table” is only used by the Classic Flight Model ??

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It could be but in that case the Modern flight model wouldn’t take into account the increase in lift with increasing Mach…

Which is what your original post said is happening …

Just to report that this parameter in the flight_model.cfg file has currently no effect at all on the flight model.

Replying to myself, the table works but only accepts scalar lower than 1.

So after a bit of testing, it can be used in conjunction with cruise_lift_scalar to modulate the L/D ratio for different Mach numbers.

cruise_lift_scalar will also scale up the drag by the same amount, and the lift_coef_mach_table can be used to decrease the lift, thus allowing for lower L/D ratio.

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thanks for this useful testing. So to use it you’d get the max L/D right at whatever speed that should be, set the mach parameter to 1 for that speed, and tweak the mach parameters lower at faster and slower speeds?

it’s hard to see how that would work with ‘normal’ polar curve that the flight sim already models, i.e. above some speed the drag already increases faster than the lift so the L/D decreases anyway. Although FSX has always had a big problem for gliders (I’ve modelled a lot of them) that the L/D (hence glide ratio) always improves as you slow down, until you reach the stall (sim power pilots/developers in my experience have never noticed this, and find it hard to believe) - maybe the mach table is ideal to address this for speeds below max L/D.