Stall Speed vs Altitude
Stall Speed vs Altitude
(OP)
Can anyone help me understand these graphs?
I thought the Stall/CLmax would occur at a roughly constant KCAS. What could explain the kinks in the curves? The graphs are for a Gulfstream IV (blue) and a G450 (green). The have a virtually identical wing, except for fewer vortex generators on the G450.
Thanks!
I wasn't sure how to attach two files, so hopefully these links work:
http://files.engineering.com/getfile.aspx?folder=9...
http://files.engineering.com/getfile.aspx?folder=0...
I thought the Stall/CLmax would occur at a roughly constant KCAS. What could explain the kinks in the curves? The graphs are for a Gulfstream IV (blue) and a G450 (green). The have a virtually identical wing, except for fewer vortex generators on the G450.
Thanks!
I wasn't sure how to attach two files, so hopefully these links work:
http://files.engineering.com/getfile.aspx?folder=9...
http://files.engineering.com/getfile.aspx?folder=0...





RE: Stall Speed vs Altitude
The pilot flies always KCAS (calibrated air speed, knots) information that gives the Airspeed indicator. From a certain pressure altitude, KCAS is practically constant. Obviously the TAS (true air speed) increases with the pressure altitude.
The shape of KCAS curves may result from low speed buffet boundaries at high pressure altitude.
RE: Stall Speed vs Altitude
CAS is indeed what the pilot sees on the instrument, is close to EAS, whereas TAS has the density ratio factoring.
Quando Omni Flunkus Moritati
RE: Stall Speed vs Altitude
If the middle segment was a constant Mach number, I believe the CAS would decrease with altitude.
Since we are dealing with low speeds, I wouldn't think compressibility needs to be considered.
Any other ideas?
RE: Stall Speed vs Altitude
http://en.wikipedia.org/wiki/Coffin_corner_(aviati...)
B.E.
RE: Stall Speed vs Altitude
I will try below.
B.E.
RE: Stall Speed vs Altitude
Please explain.
Thx.
RE: Stall Speed vs Altitude