Stall warning activation point

I don’t see any information in the SDK about how the stall warning activation
point is determined. I assume it is based on AOA, but how is this triggering
AOA determined? Can this AOA be specified, or adjusted? I did notice that the
stall warning activation point is affected by whether or not the airplane has
a stall protection system enabled, but I could not find any information on why
or how the new stall warning activation point is determined.

Hello @donstim By default, it’s computed as 70% of
the stall angle of attack. The stall AOA is itself being computed from the
lift_coef_aoa_table , as the AoA that gives the most lift in the
[10°;20.5°] range. If the stall protection is enabled, the stall warning
will be triggered if your AoA is above the value provided with the
on_limit parameter. Does that answer the question? Regards, Sylvain

Ahh, so that confirms the results I got from my own testing. For example,
where the stall AOA is 15 degrees, the stall warning initiated at an AOA of
10.5 degrees. With stall protection enabled, it was much higher, but did not
realize it was associated with the on limit parameter. Can this be made
configurable in some way? I don’t know about GA airplanes, but a stall warning
at 70% of the AOA for CLmax is inappropriate for transport category airplanes.
For transport category airplanes, the regulatory requirement is that stall
warning occur at a speed at least 3 knots or 3%, whichever, is higher, above
the speed for Clmax. Since MSFS AOA is directly proportional to CL, and CL is
proportional to speed squared, the stall warning should be at about a 6% lower
AOA than CLmax, not 30% lower. As it is now, the stall warning activates at
AOAs well within the normal flight envelope and well away from a potential
stall. The transport category airplane regulations also require the stall
warning to occur 5 knots or 5%, whichever is greater, before the actual onset
of stall (which occurs after CLmax). This has implications for airplanes with
stick pusher systems. The activation of the stick pusher is considered an
indication of stall, so the stall warning must occur 5 knots or 5% before the
stick pusher activation point. Regards, Don

Hello. Thanks for your feedback :slight_smile: I’ll forward your suggestions. Regards,
Sylvain

Hi! Was there a solution for this? I need the stall horn to be activated 5-10
knots prior to where it is activated now. How can i adjust this? Regards,
Andreas

seems the likely answer is write your own formula using INCIDENCE ALPHA.