What is the purpose of reaching the best glide speed?

Reaching the best glide speed is critical for ensuring a safe landing in the event of an engine failure or other emergency requiring a glide. This speed is the optimal airspeed at which the aircraft can achieve the greatest distance per altitude lost, allowing the pilot to glide as far as possible to a suitable landing area. By maintaining this speed, pilots can better manage their descent and improve their chances of successfully reaching a safe landing spot.

In contrast, maximum fuel efficiency focuses on sustained flight rather than emergency descent, maintaining altitude does not apply when the engine is not producing thrust, and increasing airspeed is not desirable in a glide scenario since it may reduce lift and result in a steeper descent. Therefore, reaching the best glide speed aligns directly with the goal of ensuring a safe landing.