Stall Speed Equation?

Question

What percent increase in stall speed would you get in a 45* bank, and is there a good rule of thumb or equation to figure out this kind of problem?

Answer 1

Bank in itself does not increase stall speed. Stall speed is increased by the square root of the load factor.

Answer 2

Michel's answer is right on.  Read his answer, and if you need it simplified, here it is:

This all assumes the airplane is maintaining level flight in the turn (not descending).

Load factor = 1/(cos bank angle)

Stall speed (banked) = (Stall Speed [level])/sqrt(cos bank angle)

Answer 3

That is an interesting question because there isn't such a thing as stall speed; it is stall angle of incidence of the wing. But, with a given gross weight and level flight, a stall speed can be calculated.

As you probably know, when you are in a coordinated turn (the ball in the center) the gravitational force increases by the inverted cosine of the angle. For example, turning at 60 degrees (cos 60 = 0.5) gives you 2 Gs.

Once you know your level stall speed, you can calculate it for a turn by doing the inverse: Multiplying it by the square root of the gravity you must endure. Hence at 60 degrees bank, your stall speed increase by your level stall spee times the square root of 2, or 1.41 Say your stall speed at level is 40 knots. At 60 degrees banking, it would then be 56 knots.

If you turn in a coordinated bank of 45 degrees, you will feel an increase of Gs of 1 / cos(45) or 1,43 Gs and your stall speed will be 40 x Square Root (1,43) or 48 knots.

Answer 4

Google "accelerated stall" and see what you get.  Yes, there is an increase in stall speed and it is constant, so you should find it.