What does the barber pole on the airspeed indicator represent?

The barber pole on the airspeed indicator signifies the velocity or Mach limiting pointer. This important feature serves as a visual cue, indicating the maximum safe operating speed for the aircraft at various altitudes and conditions. Pilots use this reference to avoid exceeding speeds that could lead to structural damage or aerodynamic issues, ensuring safe flight operations. Understanding this marker is crucial for maintaining control and compliance with the aircraft's operational limits, particularly during critical phases of flight such as climb, cruise, or descent where airspeed naturally varies due to changes in altitude and atmospheric conditions.