Hello flyers, Lissette here for DNews. Flying scares the bejesus out of some people but

it’s actually one of the safest ways to travel. That’s because along with the regular

aircraft inspections, strict regulations, and thousands of hours of training pilots undergo

the aircrafts themselves are made to withstand some pretty incredible challenges.

The wings of the Boeing 787, for example, are engineered to withstand one and a half

times the most extreme forces it would ever meet in flight.

There are a lot of things that go into making the wing that strong, like its design and

construction. But the most important factor is the materials used. Materials are where

everything starts and they determine how easy a part is to machine or weld, how strong it

is, how flexible it is, how it behaves at different temperatures, how it stands up to

corrosion, and how much it weighs. These are all factors aeronautical engineers have to

consider when they’re designing different parts. And for decades,

aluminum was the go-to material.

Forty years ago, aluminum could make up as much as 70% of an aircraft. Aluminum, though

half as strong as titanium, is lighter and, more importantly, much cheaper. It gets stronger

at colder temperature but stays ductile, and has it’s own anti-corrosion mechanism. Today’s

jets are only 20% pure aluminum, but the metal is still present in abundance, it’s just

mixed with other metals to form alloys. Aluminum has so many alloys it’s hard to keep track

of all of them even though they’re numbered. The most common one used for airplanes is

7075, which uses a little zinc, magnesium, and copper as well as trace amounts of manganese,

silicon, iron, titanium, and other metals. The result is an alloy that’s as strong

as steel, but isn’t too difficult to shape, drill, or weld.

Techniques and technology for machining metals is improving - making other alloys available,

that were previously too hard to work with. New alloys like titanium aluminide are replacing

older nickel based alloys that were twice as heavy but just as heat resistant. In some

parts of the engine metals are being replaced altogether by parts that use ceramics reinforced

with silicon-carbides. The benefit of these lightweight parts is that engines can operate

at higher temperatures and run more efficiently. Reducing weight anywhere in the aircraft is

always a goal because it means the jet has to use less power to move - saving fuel. In the last decade, aircraft

makers have gotten even more clever with their materials in the pursuit of lightness.

Composite materials were first used for light structural or cabin

components, but more recently, they’ve taken over metal for some serious structural parts, too.

Composites are incredibly light and strong, and can be molded into complex shapes. This

reduces the need for heavy fasteners or joints, which are potential failure points. Boeing’s

787 dreamliner was the first commercial aircraft to use composites extensively. It has kevlar

honeycombs in the wings to make them light, flexible, and strong. The 787 also used carbon

fiber to strengthen the fuselage. This saves weight, and as a bonus, the cabin can be pressurized

more than previous aircraft, and composites can tolerate higher humidities without corroding…

making the ride more comfortable. Carbon fiber was also used in the engine housing to trap

sound and make aircraft quieter.

But engineers are never satisfied. They’re are constantly coming up with new alloys,

designs, and construction techniques to make aircrafter harder, better, faster, stronger.

HRL laboratories, in a joint venture with Boeing, recently developed the lightest metal ever.

The metal is arranged in a microlattice structure which means it’s about 99.99%

air. A light flexible material like this could be used inside the cabin and save even more

weight on future aircraft.

So that’s the technology making modern aircraft awesome. But what about future spacecraft?

What do we need to develop before we can rule the galaxy? Julian talks about that here.

Now that you know what planes are made of, does that make you more confident in flying,

or do you still get the shakes?