Clean Aviation's regional aircraft technology testbed #2 demonstrates advances with composites

The Airbus C295 Flight Test Bed 2 (FTB#2) successfully performed its flight campaign, testing a new semi-morphing wing, as well as on-ground structural tests of a novel composite outer wing box. Source | Clean Aviation, Airbus Defence and Space

As reported by the Clean Aviation program, the Green Regional Aircraft (GRA) program’s Flight Test Bed 2 (FTB#2) — a modified version of the Airbus C295 — has successfully completed its flight test campaign. Marking a significant milestone in progressing next-gen technologies for sustainable aviation, the aircraft integrates advanced aerodynamics, innovative flight controls and new composite technologies to enhance efficiency and reduce emissions including:

• Up to 43% CO2 and 70% NOx emissions reductions in regional aircraft multi-mission scenarios, alongside a 45% noise reduction during takeoff.
• A semi-morphing wing, dynamic winglets and an advanced flight control system were successfully tested to optimize aerodynamic performance.
• Innovative manufacturing processes — including additive manufacturing and one-shot composite assembly — to improve production efficiency.

These combined achievements are timely in the context of mounting global pressure to curb aviation’s environmental impacts. Stricter regulations on carbon emissions, coupled with society’s increasing demand for sustainability, are driving the need for greener air travel. The FTB#2 demonstrator’s successful flight highlights Europe’s leadership in sustainable aviation and reinforces the importance of the Clean Sky 2, now Clean Aviation, initiative in pioneering these essential advancements.
 

The success of the flight test activities was made possible through a combination of these design/fabrication elements in conjunction with other aerodynamic enhancements to the C295 flight demonstrator aircraft, such as lightweight composite materials and a more efficient propulsion system. Altogether these modifications optimize fuel consumption while maintaining the aircraft’s reliability and versatility. Data collected during the flight provides valuable insights into real-world performance, confirming the effectiveness of these innovations.

FTB#2 multi-mission platform testing

As explained by Clean Aviation project officer, Costin-Ciprian Miglan, FTB#2 is a multi-mission platform that can support multiple configurations for a range of roles. “For example, it can be used to carry passengers, transport supplies or humanitarian aid, or the aircraft can also be equipped with fire-retardant substances and used to combat wildfires,” says Miglan.

The flight test campaign involved 12 successful flights conducted over 17 flight hours, with all planned test points fully achieved. The results were highly satisfactory, confirming the maturity of key technologies tested on board. These included innovations in a composite external outer wing box and morphing control surfaces.

Advances composites use

This flight campaign was complemented by a ground-based demonstrations of an out-of-autoclave (OOA) cured carbon fiber-reinforced plastic (CFRP) outer wing box based on a highly integrated design that minimizes components using two different materials and manufacturing processes. The first is liquid resin infusion (LRI), which was used for the lower skin to integrate the spars, stringers and main structure into a one-shot infused part. The second was in situ consolidation (ISC) using automated fiber placement (AFP) to produce a thermoplastic composite (TPC) upper skin with integrated stringers. Together, this resulted in a weight reduction of 5.6% compared with equivalent conventional components.

A highly integrated composite winglet based on a one-shot multi-spar torsion box (which saves 20% weight compared to conventional architecture) was also put through a comprehensive structural test campaign from detail to full-scale. This improved winglet also reduces cost due to reduced riveting during manufacture.

Commenting on the stepped processes of flight and ground testing, Clean Aviation’s Miglan explains that “Step one was the flight test; step two involved further maturing other technologies, but only on the ground — such as the outer wing box and actuation systems for the movable surfaces. The flight test was a major milestone for Clean Sky 2. During this campaign, the entire outer wing, from the engine to the wingtip, was completely replaced. This achievement was the result of multiple ‘Core Partner’ and ‘Call for Proposals’ projects under the airframe and regional platforms, all integrated by Airbus Defence and Space.” 

See Clean Aviation Regional Aircraft for more details on FTB#1 and #2 as well as the flight and ground test programs.

Overcoming challenges in development

Developing the C295 demonstrator was no easy feat. The project faced several challenges that had to be addressed to achieve success.

“Merging multiple advanced systems into an existing aircraft while ensuring compliance with safety regulations required precise integration strategies,” emphasizes. Miglan. “Engineering challenges associated with new aerodynamic designs, composite materials and propulsion technologies had to be overcome through rigorous testing and iteration. Aligning efforts among various European partners — each contributing specialized expertise — demanded strong coordination and communication. Meeting stringent aviation certification standards was another crucial factor in ensuring that all new technologies were safe and viable for future applications.”

Despite these challenges, the project’s success underscores the strength of collaborative innovation in advancing sustainable aviation. Looking forward, Airbus Defence and Space will continue to contribute to Clean Aviation’s next phases. The experience gained from the C295 demonstrator will inform future projects, ensuring continued progress in aviation sustainability. The project has generated valuable insights that could lead to further technological innovations and commercial applications.

Environmental benefits

The FTB#2 demonstrator sets a new standard for environmentally responsible regional aircraft operations. The incorporation of advanced materials, innovative technologies and aerodynamic improvements aimed at reducing noise, CO2 and NOx emissions has surpassed initial expectations.

“During a typical search and rescue mission, we estimate that these innovations could achieve up to a 43% reduction in CO2 emissions and a 70% decrease in NOx emissions during a typical 400-nautical-mile search and rescue mission, along with a 45% reduction in noise during takeoff,” says Luis Benítez Montañés, formerly the chief engineer in the Clean Sky 2 program for Airbus Defence and Space, who led the Airbus side of the FTB#2 project. “These improvements not only support Airbus’s sustainability goals but also pave the way for more eco-friendly air travel options worldwide.”