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  • Q811338

    The logic behind this one eludes me.

    If the LF is proportional to the square of Vs, than the change should be proportional to the change in speeds, shouldn't it?
    Reversing the question, according to the explanation in the question - if a gust at Vs x 1.25 gave a LF of 1.56, What would the same gust give at Vs x 2?
    The answer to this, according to the explanation would be 2^2=4, which is obviously wrong.
    Can someone clarify this for me please?
    Thank you.

  • #2
    The first sentence of the question states that we are flying at a steady speed (2Vs) when we get a vertical gust. The increased load factor is the result of an increase in alpha, not speed.
    The question then asks what would have happened if we'd been flying at a lower IAS. At lower speed, our alpha would be higher and the upgust would have less effect.
    The method of getting to the answer is simply explained in the explanation to QID 810941.
    The strange thing about Q811338 is that the new speed is so slow that the upgust will cause that aircraft to stall, as shown in the first part of the explanation.
    I'm not convinced that the question writer realised this. Although it's quite a new question, we've had no reports of it re-appearing in recent exams.


    • #3
      Thank you