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Flaps are some of the most important parts of an airplane, but there are more than just one type. Learn about the types of airplane flaps in this expert guide.

Anyone that’s considering becoming a pilot likely wants to know as much as possible about airplanes and how they work. Heck, even if you’re an experienced pilot, you might not know exactly what airplane flaps are and how they operate, much less the different kinds of flaps that planes have. So what are the most common types of airplane flaps?

The most common types of airplane flaps are:

  • Plain Flaps
  • Split Flaps
  • Slotted Flaps
  • Fowler Flaps
  • Junkers Flaps
  • Zap Flaps
  • Krueger Flaps

Airplane flaps are a very important part of an airplane. They play a key role in how an airplane flies. There are several different types of flaps, and each one has its own unique purpose. In this article, we will discuss the different types of flaps and what they do. We'll start with the basics, then get into the details of each type. By the end, you'll know everything there is to know about airplane flaps!

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Table of contents


What Are Airplane Flaps?

Before we get into the different types of flaps on airplanes, it's important to take a little bit of time to make sure we explain what flaps are in the first place and what they do. Since this could be an entirely separate topic on its own, we won't go too far into the details here. Instead, I'll just give you a high-level overview so that you understand what we're talking about as we go through this article. So what exactly are airplane flaps?

Airplane flaps are a type of high-lift device located on an airplane wing that is designed to help the plane generate more lift. Flaps are usually mounted on the trailing edge of the wing and can be extended downward to increase the camber of the wing, which in turn increases lift. When not in use, flaps are usually retracted into the wing to minimize drag. There are several different types of flaps that are used on airplanes, and each one has its own unique purpose.

Different Types of Airplane Flaps

Now that you have a decent idea of what airplane flaps are, at least as decent of an idea as you can get from a single paragraph, let's get into what you're really here for. After all, at this point, you might just be thinking that airplane flaps are all the same. But there are actually all kinds of different types.

In this article, we're going to look at seven different types of airplane flaps. In fact, there are even more flaps than this, but once you get deeper than these seven, it just starts becoming combinations of the various flaps you'll see here.

Even with these seven, the first four that we'll look at are really the main four types of flaps, which are shown in the image below. The other three are then either modified versions of the main four, or new versions that were inspired by one of the four.

Four main types of flaps. Source: Flight Mechanic

But that's enough chatter, let's get into the crux of this article. These are the different types of airplane flaps.

Plain Flaps

First up are plain flaps. As the name implies, these are the most basic type of flap. They're also the oldest type of flap, dating all the way back to the early days of aviation. Plain flaps work by simply increasing the camber of the wing when they are extended. This in turn increases lift and drag.

One downside to plain flaps is that they can only be used at relatively low speeds. As speed increases, the increased drag from the extended flaps can cause problems. But without plain flaps and the downside(s) that the aviation world has learned about (and from) over the years, none of the other types of flaps would have been created. This is why plain flaps are so vital to aviation.

Split Flaps

Next are split flaps. As the name implies, these flaps are split into two parts. They work by redirecting airflow over the wing when extended. This increases lift and drag. The difference between these and plain flaps is that the increased drag from split flaps doesn't cause as many problems at high speeds. This is because the airflow over the wing is redirected, which helps to reduce drag. This makes them ideal for use on faster airplanes.

Split flaps are typically used on smaller airplanes and those that don't need as much lift. This is because they don't provide as much of an increase in lift as other types of flaps. They're also not as efficient as other types, so they cause more drag. However, they're simple and easy to use, which makes them a good choice for smaller airplanes.

Slotted Flaps

Slotted flaps are very similar to split flaps, but with one key difference. They have a slot cut into them that allows air to flow through even when the flap is extended. This helps to reduce drag and improve lift performance at high speeds. Slotted flaps are typically used on high-performance aircraft because of their ability to improve lift performance at high speeds.

The only real downside to slotted flaps is that they're more complex than other types of flaps. They have to be carefully designed and manufactured to make sure that the slot is the right size and shape. If it's not, then the flap won't work properly. Slotted flaps are also more expensive than other types of flaps because of their complexity.

Fowler Flaps

Next up in this complete guide to airplane flaps are fowler flaps. Fowler flaps are often considered as the largest and most complex type of flap, extending both backward and downward from the wing. They're named after Harlan D. Fowler, who patented them in 1915. Like other types of flaps, they increase the amount of lift generated by the wing as well as increasing drag. Fowler flaps are used on larger aircraft, such as commercial jets.

How do Fowler flaps work? When extended, the fowler flap increases the camber or curvature of the wing. This, in turn, increases the amount of lift generated by the wing. The increased drag helps to slow the airplane down during landing.

Fowler flaps are often used in conjunction with other types of flaps, such as slats and leading-edge flaps. Slats are located at the front of the wing and help to increase lift at lower speeds while leading-edge flaps are located at the rear of the wing and help to reduce stalling speed. Combined, these three types of flaps allow an airplane to take off and land safely at lower speeds.

Junkers Flaps

Junkers flaps are one of the most interesting types of flaps. They were invented by German engineer Hugo Junkers. The Junkers flap is essentially a hinged plate that is mounted on the trailing edge of the wing. When extended, it increases the wing's camber and area, which allows for better lift at lower speeds.

These flaps are typically used on gliders and small aircraft. One of the benefits of Junkers flaps is that they can be operated without affecting the airflow over the rest of the wing, which means they don't create drag like other types of flaps. However, because they only work at low speeds, they're not suitable for use on larger aircraft.

Zap Flaps

Zap flaps are a type of flap that is used on some military aircraft. They work by using a hydraulic system to move the flaps up and down. Zap flaps are designed for takeoffs and landings. They help to increase the lift of the aircraft and reduce the landing speed. Zap flaps are usually only found on military aircraft because they are very expensive to maintain.

The reason that they're so expensive is that they require a lot of maintenance. Zap flaps need to be checked regularly for leaks and wear. They also need to be lubricated often. If you're not careful, zap flaps can cause damage to the aircraft. That's why they're only found on military aircraft.

Krueger Flaps

Last up, we have Krueger flaps. Krueger flaps are used on commercial aircraft. They are different from the other types that we've looked at because they work by extending from the leading edge of the wing. When extended, they increase the wing's camber and area. This helps to increase lift at lower speeds.

Krueger flaps are usually only found on larger aircraft because they are quite heavy and require a lot of power to operate. Since they operate on the leading edge of the airfoil, they can be used in conjunction with other types of flaps. This gives the aircraft more versatility when it comes to takeoff and landing speeds.

Why Are Airplane Flaps So Important?

Now that you know all about the different types of airplane flaps, you might be wondering why they're so important. Airplane flaps are important because they help to control the aircraft. They can be used to increase or decrease the lift of the aircraft. Flaps also help to reduce the landing speed. Without flaps, aircraft would be much more difficult to control.

So there you have it! Everything you need to know about the different types of airplane flaps. Be sure to check back soon for more articles every week about all things aviation. Thanks for reading!