What are the Parts of an Airplane Wing?


To most passengers, the wings are just part of the airplane however, they are one of the most technologically advanced parts of an aircraft. They carry not only the load of the passengers and fuel but also of the aircraft itself.

They are fundamental in the creation of lift that makes airplanes fly in the first place but they are also the preferred place for mounting engines, storing the fuel, and controlling how the aircraft flies. In addition to this, they have to do it efficiently over a whole spectrum of flight regimes.

Airplane wings are made up of spars, ribs, and stringers and contain items to control how the aircraft flies. Ailerons, spoilers, slats, flaps, engine pylons, winglets/sharklets, lights, and vortex generators are all found on modern wings as well as storing fuel within them.

We all know that wings are what produced the lift to make the airplane fly but what are all the added extra parts that a keen eye may see moving during various parts of a flight?

If you want to know what makes up a modern airplane’s wing please read on…

Common Terms Used on Airplane Wings:

Before we jump into what components are found on an airplane’s wings, we need to have a look at some common terms regarding airplane wings:

1. Leading Edge:

The leading edge is the front of the wing as seen while standing in front of the airplane. It provides the attachment for the pylon where the engine is attached. It also contains a number of other components such as slats and Krueger flaps.

2. Trailing Edge:

The trailing edge is the back of the wing as seen from the rear of the aircraft. It has a number of components attached such as ailerons, flaperons, trailing edge flaps etc. 

3. Wing Root:

The point where the wing attaches to the body of the aircraft is known as the wing root. Usually, the wing is the thickest at the wing root.

4. Wing Tip:

The point of the wing furthest from the body of the aircraft is known the wing tip. 

Common Components on an Airplane Wing

Pretty much all airplane wings are primarily composed of spars and ribs. Think of spars as parallel support structures that start from the wing root all the way to the wing tip. They create the spine of the wing and take most of the load.

Wing Spars

Ribs are perpendicular support structures that run from the leading edge of the wing to the trailing edge. Spars and ribs provide the basic structure for the wing. Just like the ribs in out own bodies, they create the profile shape of the wing and create the cavity within the wing.

Wing Ribs

Modern wings are made from light, yet strong materials such as carbon fiber, reinforced carbon carbon(RCC), and other composite materials. In addition, advanced manufacturing techniques such as 3-D printing, honeycomb structure design, and computer modeling are used to make wings lighter yet capable of carrying heavier loads than before, with even less drag and more lift created.

Components on a Wings Leading Edge:

The leading edge of a wing features the following components:

1. Krueger Flaps / Slats:

Krueger Flaps are lift augmentation devices positioned between the wing root and the inboard side of the engine. Their main purpose is to allow the inboard section of the wing to create a larger amount of lift at slower speeds. The amount of lift created by a wing is based on airspeed, among a few other factors.

They are mainly used at takeoff and landing to allow more lift to be generated during these low-speed portions of flight. More lift generated, allows for shorter runway distance to be used on takeoff and slower landing speeds during approach.

Slats however are positioned from the outboard side of the engine to the wing tip. The primary purpose of a slat is to increase the surface area of the upper portion of the wing and alter the shape of the wing to be more efficient at slower speeds.

Just like how airspeed affects how much lift is produced, so does surface area. By increasing the surface area of the wing this allows more lift to be produced at slower speeds.

Without the Kruger Flaps and Slats, airplanes would need a higher speed to land and take off to create the required amount of lift meaning more runway used leaving a smaller margin for aborted takeoffs and landings.

Slats / Krueger flaps can be operated either hydraulically or electrically on most aircraft by the pilots. The flaps and slats can be deployed to set positions depending on the current performance of the aircraft for the given runway length and atmospheric conditions.

2. Engine Pylon

The engine pylon connects the engine with the wing. Pylons are designed to be highly aerodynamic and reduce air resistance as much as possible while providing an extremely strong, yet flexible mounting point for the engine.

Typically each engine is pinned to the pylon with 4 bolts known as ‘Fuse Pins’.

A Pylon with Engine Cowls Removed – Source: Mgw89

In addition to the mechanical connection, they also hide the electrical, pneumatic, hydraulic, fuel, and oil connections from the engine to the rest of the aircraft and vice versa. Because the fixing points need to be strong they are constructed out of Titanium to keep the weight down. Using steel would dramatically increase the pylon weight by several hundred pounds each.

Learn More
Try These Articles:
* Vertical Tail Fins – Why Do Aircraft Have Them?
* Do Airplanes Use Hydraulics?

Components on a Wings Trailing Edge:

The trailing edge of a wing includes the following components:

1. Trailing Edge Flaps:

Trailing edge flaps are located at the rear of the aircraft wing. Their main purpose is twofold; first, they provide the same amount of lift at slower speed, second, they reduce takeoff, approach, and landing speeds to within acceptable limits.

Just like the slats of the leading edge of the wing, they increase the surface area and alter the shape of the wing to produce more lift. By slowing the aircraft down and deploying the flaps the wing creates the same amount of lift but at lower speeds.

Flaps can also be deployed to various positions depending on the aircraft’s speed and weight during takeoff and approach. Here are typical flap settings for a Boeing 737:

Flap
Position
Up to
117,000lbs / 53,070Kg
Above
117,000lbs / 53,070Kg
Above
138,500lbs / 62,823Kg
Flaps Up210kts220kts230kts
Flaps 1190kts200kts210kts
Flaps 5180kts190kts200kts
Flaps 10170kts180kts190kts
Flaps 15150kts160kts170kts
Flaps 25140kts150kts160kts
Flaps 30Final Approach SpeedFinal Approach SpeedFinal Approach Speed
Flaps 40Final Approach SpeedFinal Approach SpeedFinal Approach Speed
For Boeing 737 – 300/400/500
Source: Andrew Fry

During approach to land, the pilots will deploy more flap as the airspeed decreases. This helps to create more lift and allows for better control as the aircraft slows and nears the ground.

During braking, the pilots deploy the spoilers which allow the airflow around the wing to escape through the flaps and tun them into a large sail.

When used in conjunction with the spoilers, reverse thrust from the engines, and the wheel brakes the aircraft can be slowed dramatically in a fairly short length of runway.

During approach to land, the pilots will deploy more flap as the airspeed decreases. This helps to create more lift and allows for better control as the aircraft slows and nears the ground.

Depending on the aircraft, trailing edge flaps are of the following types:

Source: NiD.29

On all large commercial airplanes, trailing edge flaps are deployed either electrically or hydraulically. However, on most light aircraft, trailing edge flaps are deployed using a system of rods, cables, and pulleys due to the requirement to save weight thus eliminating heavy hydraulic and electrical deployments systems.

2. Ailerons / Spoilers:

Ailerons are the primary control surfaces used to roll the aircraft along its longitudinal axis. They function by increasing or decreasing the amount of lift produced on each wing. Ailerons used in combination with flaps are called flaperons.

Low speed ailerons, positioned towards the wingtip, are locked out once the aircraft exceeds a certain speed due to the amount of rolling force they would generate at high speeds.    

Source: Jg4817

Spoilers are secondary control surfaces positioned close to the trailing edge. They have three main purposes:

  1. To slow the airplane down
  2. To provide a steeper descent
  3. To assist the ailerons

On the ground, spoilers are deployed as soon as the aircraft touches down, these increase the drag over the wing by acting like a sail or parachute and creates a downward aerodynamic force placing more weight on the aircraft wheels thus enabling the brakes to work more effectively.

Other Wing Components:

 1. Vortex Generators:

Vortex generators are small aerodynamic tabs fitted near the leading edge of the wing. Their main purpose is to create small vortices within the air flowing over them. By mixing these vortices with the sluggish airflow near the surface area of the wing they help to increase the airflow speed.

By doing so they help to decrease aerodynamic stalling on the wing and increase control surface efficiency.

2. Winglets/Sharklets

Winglets (Boeing) and Sharklets (Airbus) are designed to stop air flowing from the underside of the wing, around the wingtip and onto the topside of the wing.

When this occurs it alters the airflow over the wing area nearest the tip creating less lift to be produced. By adding these ‘Fins’ they act like a wall to the air trying to flow around the tip. Instead of the circulating air affecting the airflow on the main wing, it now interacts with the air flowing around the winglet leaving the wing to create lift along its entire length.


If you would like more specific information on Winglets and Sharklets please read this:

What are Airplane Wingtip Vortices?


3. Lights:

The wing of an aircraft contains landing lights, navigation lights, and anti-collision strobe lights.
The landing lights are powerful and are located right next to the wing root.
The navigational lights are red and green and positioned near the wingtip.

The anti-collision strobe lights are the flashing white lights on the wingtip. They are switched on when entering an active runway and switched off when vacating the runway.

4. Fuel Tanks:

Fuel tanks are created using the inside of the wing structure. A normal setup would be to have an inner tank and outer tank on each wing along with a center tank mounted inbetween the two wing roots. Fuel is transferred from one side to another using cross transfer pumps to ensure the airplanes center of gravity remains within limits   

Source: Tosaka

On most commerical airplanes fuel is transferred to the engines using engine-driven pumps located on each engine along with two electric pumps in each tank. Ideally, fuel is used up first from the center tank and then the wing tanks as this allows for optimal weight distribution.  

Learn More
Try These Articles:
* How Much Fuel Do Airplanes Carry? (With 15 Examples)
* How Long to Refuel an Airplane? – 15 Most Common Planes

Syed Anas Ali Shah

Syed has a Bachelor’s Degree in Computer Science before he enrolled in flight school in 2016 where he was awarded his Fixed-Wing CPL with Frozen ATPL. He flies as often as he writes and passing on his love for aviation is one of his greatest passions.

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