Paris Air Show: The chief technology officer for Airbus parent EADS is skeptical of composites for the A320 class of airplane while Boeing considers the material to be the “baseline preference” for what officials call the New Small Airplane (NSA).
The emerging new metal alloys seem to attract more favor at EADS while Boeing officials are intrigued but still leaning toward the bet they made with the composite 787, which structurally is 52% composite with the fuselage and wings made of the substance.
Airbus’ new A350 is also comprised of 52% composites, but the studies over the NSA class illustrate the differing approaches the Big Two OEMs seem to be leaning at this stage.
Jean Botti, chief technical officer for EADS, told us in an interview during the EADS media day that he is not yet convinced that the cost and economics of making a composite airplane for the fuselage and wings, as on the 787 and A350, for an NSA are present yet. While he hasn’t ruled out the idea, it’s clear he seems more receptive to the emerging new metal alloys, such as aluminum lithium, for the NSA.
In contrast, Boeing officials consider a composite airplane the “baseline” that the new metals have to overcome.
Botti says “The main issue here that we’re talking about is…grounding for lightning strike. How do we do that today? We’re meshing the structure with copper or you’re putting a cable around the entire airplane for return” conductivity in the 787. “In the A350, we have structure for conductivity but we still need meshing (for the wings) and this adds a lot of weight.” Meshing and the cable adds about one or two tons in a plane the size of the 787.
“You add cost and complexity and you add weight,” Botti says. “When you have a long trip and you look at the delta for the aircraft, [it works]. For a short haul of two hours, it is not obvious to me anymore the economical equation makes sense.”
Botti acknowledges that there is still the potential for less maintenance costs. “However, when you look at the product qualifications, you need to control extremely well the process for composites.
“I’m not saying no [to composites] (compared with today’s metals) but tomorrow the new generations of alloys are trying to answer all these questions. This is a new field.”
Botti says that some research and development remains for the new alloys, but it’s entirely possible these could be substituted for today’s metals in “running changes” for A320neo to reduce weight. Alcoa, one of the makers of Al-Li, says the new material can cut 10% from the weight of an airplane in the A320 class. Working with Al-Li, once a difficult process, is easier than composites, Botti says.
Although Boeing considers composites as its baseline materials choice, it is studying the new alloys as part of its research on the NSA.
“The decision point is range, size and cost,” Botti says. “For me this boils down to an economic equation. What would drive me to make a switch? Fuel economy and cost. Fuel economy is how much? For a short range, it’s much more impacted by what we are doing now with the engine” on the A320neo.