Which item describes the flight standard for airspeed tolerance?

• A. Maintain airspeed, ±10 knots indicated airspeed (KCAS)
• B. Maintain airspeed, ±5 knots
• C. Maintain airspeed, ±20 knots
• D. Maintain airspeed, ±15 knots

Answer: (A)

Maintaining a consistent airspeed within a small tolerance is essential for predictable handling and staying within safe performance limits. The typical flight standard described for airspeed tolerance is to hold indicated airspeed within plus or minus 10 knots, written as KCAS. This uses the airspeed indicator reading (KCAS), which reflects what the pilot actually sees in the cockpit, and accounts for minor instrument and system errors while keeping the aircraft’s performance within its designed margins. The other tolerances would be either too tight or too loose for the general standard, unless a specific maneuver or procedure calls for them. Therefore, the description of maintaining airspeed within ±10 knots KCAS best matches the common standard.