Adding to the many decisions to be made in designing a commercial aircraft, the choice of material is becoming more complicated as more choices become available. Yet the issue is as decisive as almost any other, since overly costly construction will burden an aircraft with a competitive disadvantage throughout its life, while an airliner that is cheap but heavy will burn too much fuel for decades ahead—decades in which fuel prices could rise far beyond expectations.

A facial expression hints at the Chinese aerospace executive's concern. “Yes, it is indeed a big challenge,” he says, sounding serious. As he stops to sip his coffee, he begins to look a shade more serious. Maybe the challenge is just too big.

About 70% of air routes from Wuhan of fewer than 600 km (380 mi.) have been closed since the arrival of fast train services to the central Chinese city. The latest service to be closed is that to Nanchang, hard on the heels of the abandonment of Nanjing flights that China Southern and Henan airlines had tried to keep going after high-speed rail competition began in 2009. They eventually decided that the prospect of higher train frequencies was too much for them.