What happens when flaps are extended during flight?

When flaps are extended during flight, one of the primary effects is that it lowers the stalling speed of the aircraft. This occurs because the flaps change the airflow over the wings, increasing the wing's camber and allowing it to generate lift at lower airspeeds. By providing additional lift at these reduced speeds, pilots can operate the aircraft safely at slower velocities, which is particularly important during takeoff and landing phases of flight.

With flaps deployed, the aircraft can maintain controlled flight at lower speeds near the stall margin, enhancing safety during critical phases. This is crucial for landing approaches where maintaining control at lower speeds is necessary for a safe touchdown.

The other options do not accurately describe the effects of extending flaps during flight. For instance, extending flaps typically increases drag, which can contribute to higher fuel consumption, making it less efficient. Additionally, the climb rate may decrease due to the increased drag, contrary to what would be suggested. The focus on lowering stalling speed emphasizes the safety and operational benefits of using flaps correctly during flight.