Why are bubbles used on an airplane

Plastic planes: Small planes can already do without aluminum, while the plastic era is just beginning for large planes

At first glance, nothing has changed. The dimensions of an Aerospaciale aircraft from the 50s are almost exactly the same as the Airbus of the 90s. But instead of around 90 passengers, there is now space for almost 150 people. This is made possible, among other things, by a large part of plastic inside but also in the outer skin of the aircraft. This saves weight, which is then available for luggage and passengers.

Just a few years ago, plastic was an outsider in the coat of airplanes. Today, however, large and small aircraft manufacturers rely on the new material. "Not two and a half, but five to ten tons of plastic should be used in the next Airbus aircraft", corrects Peter Radden from the plastics manufacturer Ticona in Kelsterbach, Germany. 500 to 850 travelers should be able to be transported in the new machine.

Boeing also announced that it intends to manufacture the basic structure of the wings and fuselage of the next aircraft mainly from plastic. In 2008 this machine should be ready to go.

The Austrian company Diamond Air Technologies in Wiener Neustadt is already building small flying machines without any metal in the outer shell. "All of our aircraft are made from 100 percent plastic combined with glass or carbon fibers," reports the technical director, Christian Trieb. The fibers give the plastic the necessary strength.

Diamond Air Technologies expects to receive the certificate for a new four-seater made from the plastic-fiber mix in May. The aircraft has already completed its maiden flight for test purposes. At around a ton, the model weighs less than some cars.

With the small machines, however, it is not just the weight that determines the choice of material. Trieb mentions other advantages: “We can build the aircraft from a single cast and thus give them any shape. This gives us a completely smooth surface. That lowers fuel consumption ”.

However, plastics cannot replace aluminum in one fell swoop in large passenger planes. There the change is more likely to take place step by step. The plastic era for large aircraft began a few years ago rather by accident: the rudder of a DASA aircraft was too small and should be enlarged later. The premiere for the new material came out of necessity. For the first time, plastic combined with glass or carbon fibers formed the nose ribs for the rudder on a large passenger plane.

Various plastic composite materials are now available for aircraft. The Ticona company also produces such a material. The company's plastic mixture is a fifth lighter than aluminum and also stronger and more robust. The plastic mix is ​​not attacked by ice in the air, while metal rusts. And where aluminum gets dents when it collides with a bird, the fiber-reinforced plastic remains intact.

The properties speak for the plastic-fiber mix. "But the necessary tests are tedious because safety comes first," says Peter Radden to ddp. Nevertheless, huge components made of fiber-reinforced plastic for aircraft construction are already being supplied and welded together on site. With conventional aluminum plates, on the other hand, the parts have to be riveted in a laborious manner.

Boeing announces that it intends to have large components delivered from Europe for the new type of aircraft and to design its own aircraft shuttle. One of the companies with which the aircraft manufacturer is in contact is Ticona.

In the upcoming Airbus model, 20 percent composite material from Ticona will be processed. The weight saved corresponds to that of 150 passengers with luggage. “However, there is still room for improvement. Our goal is 40 percent, ”announced Peter Radden from Ticona. However, load-bearing parts such as the wings of large airplanes could not be built entirely from plastic compounds for the foreseeable future.

March 29, 2004

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