What would the indicated stall speed be in a 60° banked turn with the gear and flaps up?

What would the indicated stall speed be in a 60° banked turn with the gear and flaps up?

• A. 100 KIAS
• B. 117 KIAS
• C. 120 KIAS
• D. 130 KIAS

Answer: (B)

In a banked turn, the stall speed of an aircraft increases due to the additional load factor introduced by the bank angle. The load factor increases with the bank angle, affecting the stall speed, which is the speed at which the aircraft can no longer maintain lift.

When the aircraft is in a level turn, the load factor can be calculated using the formula:

Load Factor = 1 / cos(θ),

where θ is the bank angle. For a 60° bank, the load factor becomes 2, meaning the aircraft experiences twice the gravitational force acting on it.

The stall speed increases in proportion to the square root of the load factor. Thus:

New Stall Speed = Original Stall Speed × √(Load Factor).

If we consider that the original stall speed of the aircraft in straight and level flight is known, we can then double this speed in a 60° bank. The stall speed increases significantly, and in this scenario, the indicated stall speed ends up being 117 KIAS, reflecting the increased demand for lift due to the higher load factor in the turn.

This understanding indicates that the indicated stall speed correlates directly with the bank angle and load factor, which is crucial for pilots flying in such conditions.