Question

what is the speed of aeroplane measured in

Answer 1

knots

In aviation speed is most often expressed in knots (kt). One knot is one nautical mile per hour. In an aircraft the speed is "measured" with a pitot tube. Together with the static pressure one can determine not the speed of the aircraft, but the speed of the air flowing around the aircraft, the airspeed.

Answer 2

In aviation speed is most often expressed in knots (kt). One knot is one nautical mile per hour.