Hi All,
can you please help me with the following theoretical problem?
I am trying to write a material about AOA indicators and stuck with a contradiction. It is about what will display an AOA indicator which is calibrated with clean config and the plane stalls at landing config? Or vice versa, what will display the instrument at a clean stall, but calibrated to dirty stall.
If we know that the aircraft with flaps will stall at a lower AOA and also at a lower pitch, then I should think the instrument calibrated to clean stall, will show lower AOA than the critical AOA when executing a dirty stall.
In spite of it, the manuals of the manufacturers write the opposite:
"The system is calibrated with the aircraft in the clean configuration which means that when the flaps are lowered the display may indicate a higher angle of attack (deeper into the red) before stalling."
Or in an other way:
"When the optimum alpha angle (OAA) is calibrated in landing configuration as above, the indication in the clean configuration with no flaps will be slightly different. In the PA46 it will typically indicate one LED segment lower on the display."
By the way the display of the AOA indicator of Aspen Evolution EFD corresponds to the two above mentioned statement also, see the pic:
https://www.aopa.org/-/media/images/...nd-mfd_web.jpg
So I know the mistake is on my side, but please explain me, why?
Thank you in advance.