What does the red line on an airspeed indicator represent?

• A. Never exceed speed
• B. Stall speed
• C. Best glide speed
• D. Cruise speed

Answer: (A)

The red line represents the never-exceed speed, the maximum indicated airspeed you should not fly faster than. It marks Vne, the upper limit of the aircraft’s structural capability in normal flight. Exceeding this speed increases air loads dramatically and can lead to structural damage or loss of control, especially in gusts or with improper configuration. In practice you’ll stay well below it, using the other colored ranges (green for normal operations, white for flap operating range, yellow for caution) to guide safe speeds. The stall speed is a lower limit, not shown by this red line, and governs the minimum speeds you must maintain to avoid stalling.