Singapore Air Show

Composites or aluminum; the choice for OEMs

 - February 19, 2008, 1:32 AM

Cessna, Bombardier and Raytheon have taken fundamentally different approaches to their new business jet designs. Here at the show, the talk reflects just how stark those distinctions are.

Cessna recently announced that its Model 850 Columbus will be made entirely of aluminum, while Bombardier’s new Learjet 85 will use 100 percent composites. Raytheon has decided on a hybrid approach with its Hawker 4000, a super midsize design with an all-composite fuselage and aluminum wings. Meanwhile, Dassault–expert in composites for its military aircraft–said it will not reveal its materials decision on its new super midsize offering until the end of the year.

Bombardier insists that composites bring huge advantages to business jets. Its president, Pierre Gabriel Côté, said using the material will bring “exceptional strength-to-weight ratio, reduced maintenance and extended service life.” He added that composites help reduce parts count, and vulnerability to corrosion and fatigue damage, while their ultra-smooth surface permits “superior aerodynamics.”

But Cessna believes in simplicity, preferring to use the latest aluminum manufacturing technology to avoid the heavy investment necessary for composites. Raytheon, which gained experience through the Premier 1 entry-level business jet, prefers to use composites for the pressurized fuselage, providing improved fatigue resistance and simplifying manufacture. The U.S. company has retained its high-speed wing design, however, limiting its need to introduce expensive new wing manufacturing technology.

Industry watchers will be awaiting Dassault’s decision, the French company having pioneered the world’s first all-composite wing for a civil aircraft on a Falcon 10 in 1985. With its carbon fiber empennage, the new Falcon 7X has 20 percent composites by weight, but Dassault Aviation still says there is “no obvious solution” to the choice of materials. “We will make the best choice for our customers,” is all it will say.