Can Recycled Materials be used in Commercial Aircraft?

A single modern commercial aircraft today contains anywhere between 30,000 and 66,000 kilograms of aluminum. Every time an airplane reaches the end of its life, it could become the raw material for the next generation of aircraft. This is possible because nearly 75% of all aluminum ever produced is still in use today, and recycling aluminum requires 95% less energy than producing it from scratch. But if aircraft contain so much recyclable metal, why aren't airplanes made entirely from recycled materials?

Currently, balancing sustainability in aerospace materials with high performance and efficiency remains a major issue. An important factor is aircraft fatigue. In the early 1900s, approximately 80% of flight accidents were attributed to mechanical or structural failures. The aviation industry has come a long way with safety, and that includes using the right materials for each aircraft. Aircraft experience enormous stress through every flight, so it remains imperative to calculate the Limit of Validity (LOV). The LOV is expressed in flight hours or flight cycles and measures how long an aircraft structure can safely operate before structural failure becomes a concern.

As of 2011, the Federal Aviation Administration (FAA) required all aviation manufacturers and operators to report the LOV of their active aircraft and not fly beyond the LOV unless the FAA approves it. As a result, airplanes that have exceeded their LOV are sent to “aircraft graveyards,” where they are carefully dismantled.

Regulations and guidelines make using recycled materials very challenging. Engineers must know the chemical compositions and fatigue life of every structural component used in an aircraft. However, many components, such as end-of-life (EOL) aluminum, can contain a mix of alloys and contaminants, such as plastics and textiles from the interiors of the airplane. Moreover, dismantling structures from airplanes, cleaning the materials, and finding new uses for the recycled materials are very expensive.

On the other hand, recycled materials can be very useful in some parts of aircraft. Many high-value components, such as the engine, auxiliary power unit (APU), avionics components, and the hydraulic systems, are being used in some operational aircraft around the world or sold to some automobile companies. The aluminum recovered from dismantling components in “aircraft graveyards” is cleaned and separated to be sold to aluminum casting foundries. Some of the recycled aluminum is also utilized to make lightweight aircraft seats, with seat cushions and the flooring of planes being made from other sustainable recycled materials. Furthermore, the specialized plastics used in aircraft are currently being researched to be integrated into the manufacturing process of aircraft. Additionally, the U.S. FAA and the European Aviation Safety Agency (EASA) have overseen the use of approximately 40%-50% of EOL aircraft in parts distribution pipelines. Excess carbon fibers found in airline manufacturing are also used in automobile manufacturing to reduce manufacturing waste.

Over the next decade, approximately 12,000 aircraft are expected to reach the end of their service lives, creating a growing need for efficient recycling and material recovery. By 2035, if recycling is not implemented in the aviation industry, about 24,000 tons of EOL carbon fibers will accumulate in “aircraft graveyards.” These statistics highlight the urgency of developing more effective aircraft recycling technologies. If aircraft manufacturing companies continue to work on fixing this major issue, fleet lifespans could be extended, operation expenses could plummet, and manufacturing times could become reduced. By transforming retired aircraft from waste into valuable resources, the aviation industry could make future flights not only safer and more efficient, but also significantly more sustainable.