Bob Myers wrote:
> No, they don't; that's complete and utter nonsense. While aircraft very
> often do have gyro-based instruments, they're not always required, nor do
> such instruments have anything to do with holding a "plane of rotation
> [relative] to the surrounding stars."
Yup, if they did have such gyros, then after 12 hours they's be flying
upside down. Also, on very long-distance flights, ignoring the
earth's rotation, they'd end up upside down because the ground is now
on the "wrong side". High-end inertial measuring systems compensate for
this by calculating both the earth's rotation and the change in longitude
latitude, so they compute where the center of the earth now is relative
to the position of the plane.
Simpler attitude gyro systems are allowed to drift, and have a pendulum that
keeps them right-side-up.
Jon