On my quest to determine how efficiency in planes can be increased, one major issue must be understood. The weight of a plane restricts a plane from expressing its true potential and requires engineers to develop solutions where benefits can be made to a plane, without increasing the mass. All airplane designers must construct parts that meet all functional requirements of a plane, while reducing the weight of the plane as much as possible. Less weight permits less thrust to be used, thus decreasing fuel consumption. One way to reduce the mass of an aircraft is to reduce the mass of its material composite, while still having it serve as a sturdy exterior.

Originally, commercial transport aircrafts were made with an aluminum skin over an aluminum frame. Aluminum proved to be a decent material composite for planes, due to being light and being strong when alloyed, until several side effects were encountered. These side effects were corrosion and metal fatigue. Recently, a carbon fiber reinforced plastic, introduced in the Boeing 787, proved to be a lighter weight, corrosion proof, and sturdier replacement for Aluminum. Steel is also a material composite used in planes due to being four times stronger and three times stiffer than aluminum, but is also three times heavier. Steel is commonly found in the landing gear of planes where strength is required and it has also been used in some high speed airplanes due to holding its strength at higher temperatures. Different metals are being alloyed in order to improve the power to weight ratio in aircrafts for the performance of aircrafts to improve while experiencing fewer costs.

The use of material composites allows planes to have an exterior with a lighter mass and to be even stronger when facing harsh weather conditions. Graphite-epoxy consists of strong fibers fixed in a resin and thin sheets of the fiber can be stacked in multiple ways to achieve a certain strength or stiffness. Graphite-epoxy is as strong as aluminum, but weighs have as much, promoting a greater power to weight ratio. 

Another composite found in the structure of planes is titanium. Titanium is about as strong as steel and weighs less and is able to maintain its strength at high temperatures, as well as resist corrosion more than steel or aluminum. The Lockheed SR-71 Blackbird, the world’s fastest jet propelled aircraft, possesses an airframe that is composed mostly of titanium and alloys which enabled it to travel at greater speeds and at higher altitudes, without its exterior corroding or weakening.