When on approach to landing, within how many knots should you maintain the recommended approach speed?

Maintaining the recommended approach speed within a range of plus 10 or minus 5 knots is crucial for ensuring a safe and stable landing. This range allows for adequate control of the aircraft, helping to maintain optimal performance parameters during the final approach phase. Approaching too fast can lead to a longer landing distance and reduced control, while being too slow increases the risk of stalling, especially in a configuration during approach where the aircraft may be more susceptible to stall conditions.

This standard is widely accepted within aviation protocols, as it ensures that pilots can manage both the handling characteristics of the aircraft and the effects of changing wind conditions or unexpected variations in airspeed. Adhering to this speed management strategy aids in achieving a safe touchdown and landing on the intended runway.

In contrast, narrower or broader ranges, such as those suggested in the other options, could compromise flight safety, as they may not provide the necessary buffer for managing varied approach circumstances effectively. Maintaining a recommended approach speed is vital for a smooth landing experience, managing descent rates, and ensuring the aircraft remains within safe operational limits.