C-INST-GYROS-0028 – axis and degrees of freedom


Viewing 5 posts - 1 through 5 (of 5 total)
  • Author
  • #30219

    Is a gyro with two degrees of freedom the same thing as a two axis gyro?


    What is the difference between degrees of freedom and number of axis?


    I don’t think they can be classified as the same thing because a gyro’s degrees of freedom is the measure of the amount of axes  in which gyro  displacement can take place and it does not take into consideration the gyro’s own rotational axis, so a gyro with two axis i think would be a single degree freedom gyro and one with 3 axis would be a 2 degrees of freedom

    Anthony Foxcroft

    Hi Yaseen,

    Jonathan is on the right track there.

    A gyro can be assessed by looking at its freedom to spin on its axis (the plane of rotation) and whether they have freedom in the 2 other axes which are 90 degrees to the plane of rotation and to each other.

    The planes of freedom includes the plane of rotation.

    The degrees of freedom does not include the plane of rotation.

    Exam questions can use either of these terms so be sure to read the question carefully to decide whether or not to include the plane of rotation in your answer.


    Thank you, I understand your explanation.

    However, there is a question I got wrong in the quiz that I used the principles you explained and got it wrong. Or I’m misunderstanding the question itself.


    Anthony Foxcroft

    I see what you mean, that question is not nicely worded but that is believed to be exactly how the CAA asks it.

    When they ask about a “2 axis gyro” we should interpret that as 2 degrees of freedom with a third spin axis. This should lead you to the right answer – in this question they’re asking about the AH.

Viewing 5 posts - 1 through 5 (of 5 total)
  • You must be logged in to reply to this topic.
Log in below to access your courses.
Forgot Password
Enter your email address or username and we’ll send you instructions to reset your password.