喷气式飞机
Jet aircraft do not have "VNO" and "VNE" like piston-engined aircraft, but instead have a maximum operating speed expressed in knots, "VMO" and Mach number, "MMO". Thus, a pilot of a jet airplane needs both an airspeed indicator and a Machmeter, with appropriate red lines. An ASI will include a red-and-white striped pointer, or "barber's pole", that automatically moves to indicate the applicable speed limit at any given time.