Why Are Aircraft Wings Swept Backwards?

Whenever we picture an aircraft in our mind we may think of an Airbus A380 or a Boeing 737 or if you're a little old school the McDonnell Douglas DC-6. But all of them have something in common.

An Airbus A380

Obviously, all of them are planes but what makes them similar is the shape of the wings. The wings are tapered and sometimes I keep thinking why. After learning more about this topic, I thought of writing a blog on this topic.

Before we get started we should first learn the different aircraft wing designs.

I’m only going to cover only some of them or this video will take forever to finish. If you want me to cover all the other wings, you can comment below.

Rectangular Wings

First and foremost is the Rectangular Wing. This wing has, obviously, rectangular-shaped wings. This design is used in small airplanes like the Piper PA 38.

A Piper PA 38 with Rectangular Wings.

This design is also very easy to manufacture and design. It can also hold more fuel than its other counterparts and can be evenly thick throughout the wing.

But this design of the wings are not used in bigger airplanes as they are aerodynamically inefficient as they induce a lot of drag on the structure.

Elliptical Wings

This particular design is one of the most iconic as, you guessed it, the Supermarine Spitfire had used this design for its wings.

A Spitfire with Elliptical Wings.

This design is very aerodynamically efficient as it induces one of the least drag on the wings than any other design. But manufacturing this design was tedious due to its smooth and incredibly thin design.

But the biggest problem of the design was due to its uniform or almost-uniform distribution of lift, caused the aircraft to stall in mid-flight, potentially causing loss of control. And this is a problem, especially in passenger flights.

Delta Wings

Next up are the Delta Wings. These wings are used in combat aircrafts as they are designed to reduce drag at lower speeds.

A Delta Winged Fighter.

Also these wings are incredibly stable in pitch and don’t need a separate tail surface. As an added bonus, these wings can store more fuel even at a low relative thickness.

But due to their low aspect ratio, the wings induce a lot of drag. And as big as a bummer, these wings have a high angle of attack which can potentially lead a stall, and as we know, it's not a good thing.

Swept Back Wings

Finally, the wings you’re here for. These are one of the most if not the most common wing design flying. Almost all modern passenger airplanes use this design.

A Boeing 747 with Swept Back Wings.

The main use of these wings is because they reduce drag at transonic speeds which are the speeds airplanes fly at. It also gives more lateral stability to the aircraft. And, as icing on the cake, these wings also cause less turbulence when speed abruptly changes.

But nothing is perfect and nor are these. The bending moments in the wing will become torsion moments when you change the sweep angle. And this could possibly compromise the structural integrity of the aircraft, if not maintained well.

This design iteration was investigated by the Germans all the way back in 1935,

just before the end of the Second World war. And this came to become a boon for the then growing “travel by air” era, as more and more people took to the sky as mere passengers as this gave the pilot more visibility than ever on a plane before and also was more efficient than other wings at this scale.

Thanks for watching and meet you guys on the next one.