An Introduction to Leading Edge Extensions in Airplanes

Not all airplanes have plain, smooth leading edges. Whether it’s a commercial jet or a small private airliner, many of them feature leading edge extensions. What are leading edge extensions exactly, and how do they work in airplanes?

What Are Leading Edge Extensions?

Leading edge extensions are appendages found on the leading edges of an airplane. The term “leading edges” refers to the front of an airplane’s wings. Most airplanes have two leading edges: one at the front of each wing. These leading edges may feature appendages or extensions.

Common Types of Leading Edge Extensions

There are many different types of leading edge extensions. They all consist of appendages — either fixed or adjustable — on the front of an airplane’s wings. Some of them, however, feature a different design than others.

Dogtooth is a common type of leading edge extension. Dogtooth extensions are fixed appendages in a zig-zag pattern. With this pattern, they are able to create a vortex. You can find dogtooth extensions on both straight wings and swept wings.

Another common type of leading edge extension is cuff. Also known simply as wing cuffs, leading edge cuffs are adjustable appendages that pilots can lower or raise.

Finally, there are leading edge root extensions. Leading edge root extensions are distinguished from other types of leading edge extensions by their shape. They feature a triangular shape. Like dogtooth extensions, leading edge root extensions are able to create a vortex.

Why Airplanes Have Leading Edge Extensions

Leading edge extensions are used for airflow purposes. Depending on the particular type, they can improve the aerodynamic properties of airplanes while subsequently reducing drag during high-speed flights. Dogtooth extensions fall under this category. Many airplanes use dogtooth extensions to reduce drag at high speeds.

In addition to improving airflow, leading edge extensions are often used to improve handling. They can help pilots control the airplanes on which they are installed. And some leading edge extensions can even lower stall speeds. The stall speed of an airplane is the minimum speed at which it must travel to maintain lift. If an airplane’s speed drops below its stall speed, it will fail to produce a sufficient amount of lift.

In Conclusion

While all airplanes have leading edges, some of them have appendages on these wing surfaces. Common types of leading edge extensions include dogtooth, cuff and leading edge root extensions.

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