Private Pilot Private Exam

What does the red line on an airspeed indicator represent?

1. Stall speed

2. Never-exceed speed

3. Maximum structural cruising speed

4. Landing gear operating speed

The correct answer is: Never-exceed speed

The red line on an airspeed indicator indicates the never-exceed speed, also known as Vne. This is the maximum speed that an aircraft should not exceed in flight under any circumstances, as going beyond this speed can lead to structural damage or failure. The significance of Vne is that it represents the upper limit of the aircraft's airspeed envelope, above which the stresses experienced by the airframe can exceed safe levels. Understanding Vne is crucial for pilots as it helps them maintain safe operational limits and avoid conditions that could compromise the aircraft's integrity. In many aircraft, the red radial line marks this critical threshold, serving as a clear visual reminder during flight to avoid exceeding this maximum airspeed for safety reasons.