Do Planes Have Flaps on the Top and Bottom of Their Wings? Unveiling the Airfoil's Tricks

The humble aircraft wing, with its subtle yet crucial features, is a marvel of aerodynamic design. A common query among aviation enthusiasts is whether planes really have flaps on the top or bottom of their wings. The answer, as we'll explore, is that they don't do so in the conventional sense, but the wing's design maximizes lift through a complex system of mechanisms called 'flaps.'

The Science Behind Lift

The flow of air over an aircraft's wing creates a unique phenomenon known as camber. This curved shape causes higher pressure under the wing and lower pressure above, resulting in what we call lift. The term 'push up' is not accurate because it's the lower pressure above the wing that pulls the aircraft upward, resulting in the airplane's ability to fly.

While this primary lift is achieved through the cambered wing, additional mechanisms can enhance lift even further. One fascinating effect is the ground effect, which is the interaction between an aircraft and the ground. Close to the ground, within one wingspan, the aircraft benefits from the reflection of airflow from the ground, significantly increasing lift. Although this effect is rarely practical for long-distance travel during takeoff and landing, the Soviets built a large transport aircraft that exploited it effectively.

Laminar Flow and Wing Design

The wing's design must maintain a smooth and steady flow of air, known as laminar flow. Any protrusions, such as flaps on the top or bottom, would disrupt this delicate flow, thereby reducing lift efficiency. This is why the majority of modern aircraft feature flaps on the back of the wing, sometimes referred to as trailing edge flaps, and occasionally on the leading edge as 'leading edge flaps.'

Leading and Trailing Edge Flaps

Leading edge flaps are typically found on the inboard side of the engines, like on a Boeing 737, where they improve lift by altering the camber of the wing during takeoff and landing. On the other hand, trailing edge flaps are located on the back of the wing and can be deployed to increase lift and decrease stall speeds.

Furthermore, some larger aircraft include spoilers on the top of the wing. These spoilers disrupt airflow and help in reducing lift and increasing drag, which is particularly useful during landing or descent. In fact, spoilers can also be used to provide a more accurate angle of attack during takeoff and landing, contributing to better control and a smoother ride.

Special Flaps: Dive Breaks

Some aircraft, particularly older designs, utilize specialized flaps called dive breaks. These are designed to assist dive bombers, allowing them to slow down during steep or vertical dives. By deploying these flaps, the aircraft can maintain stability and prevent the wings from shearing off at high speeds, ensuring the safety of the pilot and the aircraft.

To sum up, while planes don't have flaps on the top and bottom of their wings in the traditional sense, the complex system of leading and trailing edge flaps, spoilers, and other aerodynamic features ensure the aircraft's lift and control are optimized for takeoff, landing, and various maneuvers in the air.

Photo Credit: PMFlight