Why Do Some Pilots Retract the Flaps After Landing?

Community pilots and flight crews frequently notice that, upon landing, the flaps are often retracted. This practice is not just a matter of routine but is rooted in several practical reasons that enhance safety and efficiency. Let's explore why pilots typically retract the flaps after landing and the importance of the post-landing checklist.

Understanding Flaps

Flaps, which are devices that extend along the trailing edge of an aircraft's wing, serve multiple purposes, most notably during takeoff and landing. When extended, flaps increase the wing's surface area and alter the airfoil shape, creating extra lift and decreasing the stall speed. This is crucial for takeoff, enabling aircraft to become airborne more quickly, and for landing, providing a controlled descent and a shorter stopping distance.

Why Retract Flaps After Landing?

Despite their valuable role during takeoff and landing, flaps are also susceptible to damage if not properly managed after the landing phase. Here are several key reasons why pilots retract flaps once the aircraft has touched down:

To Reduce the Risk of Wind Gusts Causing Sudden Lift-off

A sudden wind gust can temporarily lift the aircraft, which could result in a dangerous situation. By retracting the flaps, pilots significantly reduce the lift capacity of the wings, eliminating this risk. This practice ensures that the aircraft remains firmly on the ground after landing.

To Improve the Field of View and Maximize Ground Clearance

With flaps retracted, the pilot can enjoy a clearer view through the cockpit, improving their awareness of the immediate surroundings. Additionally, having a clear space under the wings minimizes the risk of objects being blown into or colliding with the flaps, which could cause damage or malfunctions.

To Prevent Damage from Loose Objects or Jet Wash

After landing, the ground can be littered with debris such as stones, loose parts, or even objects caught in the jet wash from other aircraft. Retracting the flaps reduces their exposure to such hazards, further protecting the aircraft's delicate components from potential damage.

To Mitigate the Risk of Foreign Objects Lodging in the Flap Tracks

Flap tracks can trap small objects, which can lead to jams or damage to critical components. Retracting the flaps during the rollout minimizes the chances of foreign objects becoming lodged in these tracks, thus reducing the risk of in-flight malfunctions or the need for maintenance.

To Protect Against Cold/Wet Weather Conditions

In cold or wet weather, the interior of the wing structure can be exposed to water. This water might freeze, potentially compromising the structural integrity of the wings. Retracting the flaps during landing can help minimize exposure to such conditions, thereby reducing the risk of ice accumulations or moisture damage.

The Importance of the Post-Landing Checklist

The post-landing checklist is a critical part of maintaining safety and efficiency. Pilots must follow a series of steps to ensure that the aircraft is in peak condition before commencing taxi operations on the airport. One such step is to retract the flaps, among other important tasks:

Taxiing Safely

Taxiing with the flaps extended is not recommended because obstacles can strike the flaps and debris can be thrown into them, posing a risk to the aircraft's components. Moreover, the pilot's “flaps up” call ensures that the flaps are in a safe position, allowing for an unobstructed view and a smoother taxi movement.

Controlling the Aircraft in Windy Conditions

In a light plane, flaps play a crucial role in controlling the aircraft. Once the landing gear is firmly on the runway, retracting the flaps helps to reduce lift on the wings and increase the weight on the landing gear. This is particularly important in windy conditions, where it can affect the aircraft's control and maneuverability when transitioning from the runway to a taxiway.

Conclusion

In conclusion, the practice of retracting flaps after landing is a well-founded safety measure that benefits aircraft and their pilots. It minimizes the risk of unexpected lift-offs, reduces exposure to external hazards, and ensures the aircraft is in optimal condition for taxi operations. Understanding these reasons can help enhance the safety and reliability of flight operations.