FAA figures/8080-5H/Figure 18

Figure 18: Stall speed vs. load factor

FAA-CT-8080-5H · Flight & Ground Instructor supplement · asked on the Flight Instructor test

FAA Figure 18Stall speed vs. load factorFAA-CT-8080-5H · Flight & Ground Instructor supplement
How to read it: Enter the bank angle on the right scale, cross to the red curve, read the percent increase in stall speed on the bottom axis (30° ≈ 7 %, 60° = 41 %).

2 FAA questions that refer to this figure

  1. Question 1 · Flight Instructor

    (Refer to FAA-CT-8080-5H, Figure 18.) What is the stall speed of an airplane in a 30 degree bank turn if the level stall speed is 100 knots?

    • A.100 knots.
    • B.102 knots.
    • C.108 knots.
    Show answer and explanation

    Correct: C. 108 knots.

    A 30-degree level bank produces a load factor of 1.154, and stall speed increases with the square root of the load factor: 100 x square root of 1.154 = 100 x 1.074 = about 107, or 108 knots from the chart. 102 knots understates the increase.

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  2. Question 2 · Flight Instructor

    (Refer to FAA-CT-8080-5H, Figure 18.) What is the stall speed of an airplane under a load factor of 2 if the unaccelerated stall speed is 100 knots?

    • A.115 knots.
    • B.129 knots.
    • C.140 knots.
    Show answer and explanation

    Correct: C. 140 knots.

    Stall speed increases in proportion to the square root of the load factor. At 2 G, the stall speed is 100 x square root of 2 = 100 x 1.414 = about 141 knots, which matches 140 knots. The other values would correspond to lower load factors (about 1.3 and 1.7 G).

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Practice this figure under exam conditions

In the Rotate Pilot study session and timed practice exams the figure sits right under the question, with the same pinch-to-zoom viewer, and your misses come back in your personalized study guide.

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