What is the consequence of having flaps set outside the takeoff range?

Setting the flaps outside the takeoff range can lead to a large drag penalty that negatively affects the aircraft's acceleration during takeoff. Flaps are designed to increase lift at lower speeds, allowing the aircraft to take off at a lower speed, and they also contribute to increased drag when improperly configured.

When flaps are set in a position that is not optimal for takeoff, they can cause excess drag, which can hinder the aircraft’s ability to accelerate effectively down the runway. This can result in longer takeoff distances and may even compromise safety margins if the aircraft is unable to reach the necessary speed for takeoff within the available runway length. Therefore, proper flap configuration is crucial for optimal aircraft performance during takeoff, ensuring that lift is maximized while drag is minimized.