Aircraft Recyclers Strive To Maintain Composites, Metal Qualities

While efforts to recycle more components and materials from end-of-life aircraft continue, another trend is emerging: keeping them in the aerospace industry.

That circularity requires retaining the material’s properties, and therefore their value, which in turn makes recycling more profitable, helps established players grow and attracts new companies to the business. Although strides are being made in metal recycling, composites have struggled to achieve that circularity.

Research is underway to find ways to separate fibers of carbon-fiber-­reinforced plastics (CFRP) from resin in order to recycle them. The fibers have valuable mechanical qualities for airframe construction. Tarmac Aerosave, a specialist in aircraft storage, maintenance, modification and dismantling, has kept a close eye on those studies and trials. “Some companies and research centers have demonstrated the effectiveness of their processes,” says Sébastien Medan, Tarmac’s facility, environment health and safety director. “However, they focus on production offcuts.”

Large quantities of offcuts can be found at factories, and new material is a more straightforward starting point than composites at the end of a life cycle. Used composites may also be mixed with other materials such as metallic inserts.

“The solution exists, but the business case is too challenging,” Medan says. In other words, the long-sought goal of recycling CFRP while maintaining the fiber’s grade remains out of reach. Even worse, the carbon fiber recovered from offcuts has yet to find buyers because of its higher price. Airframes also use fiberglass, but the quantity Tarmac handles—one metric ton per year—is too small to make its recovery worthwhile.

As a result, most of the composites Tarmac handles go to a landfill. The partner companies in charge of collecting waste at Tarmac’s sites in Tarbes, France, and Teruel, Spain, may send some composites to the incinerator, Medan says. While those composites then become a source of energy, that proportion remains relatively low and is contingent on the proximity of incinerators and whether they accept industrial waste.

Composites from airframes are mixed with various plastics—from seats, window blinds, water ducts and other cabin interior equipment—and textiles, such as carpets and curtains. The mix totals 300-400 metric tons per year, but only 15-20% of that are composites because most dismantled aircraft are older-generation. This year, as Tarmac works to complete the dismantling of five Airbus A380s and starts on another four, the composites-plastics-textiles mix will be close to 50%.

CFRP recycling startup Fairmat has found a process that does not rely on massive energy consumption or industrial chemical processes and instead uses mechanical precision and advanced software, founder and CEO Benjamin Saada says. Fairmat plans to recycle 150 metric tons of material this year at its factory near Nantes, France, and increase that quantity to an annual 3,000 metric tons in the coming years. Aerospace accounts for 50% by weight of what Fairmat processes, Saada says.

The output’s applications have yet to include aerospace, however, and focus instead on industries such as sports equipment and car interiors.

Composites might become easier to recycle if thermoplastic resins replace thermoset resins. While both thermosets and thermoplastics enable lightweight designs, thermoplastics have an edge in sustainability. The difference lies in the resin (the matrix) rather than the fibers (the reinforcement). When heated, a thermoplastic resin softens and melts; when cooled, it can resolidify without losing any of its properties. Thermoplastics thus can be reshaped multiple times and can be produced from offcuts and scrapped parts.

Greene Tweed, a composite materials specialist in Lansdale, Pennsylvania, has signed a contract to supply an unnamed engine manufacturer with thermoplastic components. These include brackets and aerodynamic fairings in the fan area and close behind, the company says.

That contract represents only minor progress for thermoplastics, however. Widespread use in aircraft construction is a remote prospect. Aura Aero, a startup in Toulouse that manufactures two-seaters for aerobatics and is developing a hybrid-electric, 19-seat regional aircraft, has chosen thermosets. “Thermoplastics are expensive, and amortizing the tooling is an issue,” explains Wilfried Dufaud, co-founder, executive director and head of airworthiness at Aura Aero. “And civil aviation authorities are cautious about certification for primary structures.”

Aluminum recycling uses only 5% of the energy required for primary production. In June, Tarmac and aluminum supplier Constellium announced joint success in recycling and remelting aluminum from end-of-life aircraft into new, high-performance material suitable for aerospace applications. Airbus supported the project.

The demonstration was a world first. “In theory, the recyclability of a given aluminum alloy was acknowledged, as the atomic structure of aluminum does not evolve over time,” Medan says. “What was missing was a production process.”

The Tarmac-Constellium project demonstrated the use of aluminum from end-of-life aircraft as an ingredient in new ingots. One kilogram (2.2 lb.) of end-of-life aluminum was converted into 1 kg of aircraft-production-ready 2024 aluminum alloy.

“The aluminum came from fuselage components as we sorted them,” Medan says. “The project’s team developed intermediate processes to keep the metal compatible with Constellium’s casting standards and create new ingots.” These processes involved removing the last contaminants, including other alloys and traces of paint and mastic.

Constellium determined the resulting material was sufficiently characterized and could be sold to OEMs such as Airbus and Safran. The demonstration, however, only involved 20 kg of metal, and the industry has yet to create a new sector. More tests are ongoing, such as studying the cooling rate to make the recycled metal suitable for rolling and hot-die forging.

Scaling up would be the next step. “Those processes can ramp up—at issue is mainly finding customers,” Medan says. “They may see convincing arguments such as the captive resource, sovereignty in aluminum supply and a smaller carbon footprint.”

While Airbus was involved in the demonstration, other airframers have only followed the progress and not yet invested time or money in aerospace-grade aluminum recycling. Safran might be interested in the material for its nacelles, landing gears and seats. Airbus and Safran co-founded Tarmac with waste treatment specialist Suez and are shareholders.

The material’s competitiveness is difficult to predict at this stage and hinges on production volume. As the process eliminates ore extraction and transport, recycled aerospace-grade aluminum could become cheaper than primary aluminum.

Tarmac’s dismantling activities in Tarbes and Teruel generate 2,000-3,000 metric tons of aluminum per year, a total the company predicts will increase. “Five levels of quality can be found in the total, and two of them cannot join the circular process, as they are mixed with other materials, such as titanium and other metal,” Medan says. “We intend to circularize the other 60% in the coming years.”

Tarmac salvages up to 92% of an aircraft’s materials by weight and intends to integrate recycling as high as possible in the value chain. “In automotive, you do not see as much high-end material,” Medan says. “Aerospace is one of the most demanding industries in terms of material quality. We want to keep materials in aerospace, and what we generate is clean, and we control quality.”

Aluminum is the most advanced material in the industry’s circularity project. Nickel- and cobalt-based superalloys could be recycled, but such projects have yet to start, Medan notes.

Recycled titanium from aircraft does not stay in aerospace either. So far, it has been used as an ingredient in alloys in other industries. “We are working to demonstrate that titanium can maintain an aerospace grade and be reused in the aeronautics industry,” Medan says. After engines, landing gear and airframes account for most titanium use in aircraft.

France-based EcoTitanium, the shareholders of which include metal supplier Aubert & Duval, recently achieved a key first step. Since 2024, the company has been recycling titanium scraps recovered from engine pylon production at an Airbus factory in Toulouse. In June, EcoTitanium produced the first ingot containing end-of-life titanium from an Airbus pylon, working with Airbus and IMET Alloys. Aubert & Duval will use this ingot to manufacture new forged airframe parts.

EcoTitanium estimates the potential recycled content in titanium ingots could reach up to 75%. The company’s manufacturing process uses four times less energy than the traditional method with titanium sponge.

Avionics also use metal, including precious metals. Ametek MRO Muirhead Avionics generates about 100 kg of electronics waste per month at its facility near London. Meanwhile, the UK’s Royal Mint has set up a precious metal recovery process for electronics components. Under an agreement, the Royal Mint now extracts silver, platinum and gold from the circuit boards Ametek provides. The MRO notes that the geographical proximity between the two facilities leads to lower CO₂ emissions than the former method, in which waste was processed outside the country.