Suspended between discrete skeletal jigs, it wouldn't attract a second glance on an aircraft assembly line. Yet inside an anonymous hangar in northern Germany, a matt-black fuselage section — or barrel, in the jargon — could be the super-efficient shape of things to come. Novel techniques and materials are accelerating a rethink of aero-structure production.
Clean Sky 2 is an ambitious, EU-backed public-private partnership whose overarching goal is to help reduce aircraft CO2, nitrous oxides and noise emissions by up to 30% in line with the European Green Deal. Launched in 2014, the Multifunctional Fuselage Demonstrator (MFFD) is eight metres long and four metres wide, made largely from thermoplastic composites.
Lighter, faster fuselages
Thermoplastics can enable significant improvements, largely since the weighty fasteners that join conventional metallic fuselage sections together are either no longer needed or the number needed is far lower. Also known as CFRTP composites, thermoplastics are moldable at high temperatures and solidify on cooling. Their introduction could lead to a structural weight saving of over 10% per aircraft. CFRTP composites also offer a more immediate advantage: they are simpler to reuse and recycle than metallic or carbon fibre components.
Pre-equipped modules
The MFFD consists of two half-cylinder shells, or modules. The lower module is pre-equipped with systems and cabling; the upper with some cabin monuments. Thermoplastics enable these modules to be assembled using novel methods — shells are joined by automated ultrasonic or laser spot-welding, rather than riveted together.
By the project's conclusion in late 2024, the MFFD had overachieved its weight-saving target, at neutral cost compared to a metallic fuselage barrel. Over 40 technology 'bricks' had been tested to a high level of readiness. MFFD's disruptive methods could enable a CFRTP composite fuselage build rate of up to 100 units per month.
York Roth, Airbus leader of the Clean Sky 2 Large Passenger Aircraft platform: "The MFFD is a fantastic example of what can be achieved if academia, research centres and industry players align around a common objective."
Source: Airbus
