The Economist looks at a back-of-the-envelope proposal from engineers at Airbus that adapts aircraft carrier technology to civil use:
Mindful that many passengers are already nervous about the whole process of getting a plane airborne, the engineers prefer to call their proposal “Eco-climb”. But the idea is straight out of “Fireball”. The aircraft to be launched would sit on a platform that ran along a track where the runway would otherwise be. The platform would accelerate to take-off speed, at which point the plane would lift into the air powered by its own engines.
[. . .]
Altogether, according to Airbus’s back-of-the-envelope calculations, Eco-climb would reduce fuel consumption by 3% on a typical 900km (560-mile) flight, even with existing aircraft designs. But it would also allow for the design of lighter aircraft, with smaller engines, which would cut fuel consumption, noise and emissions further.
Nor is the idea complete fantasy. General Atomics, an American military contractor, has already built and tested a linear-induction-motor-based system of this sort at an airbase at Lakehurst, New Jersey. The General Atomics system is now being scaled up to be fitted on a new generation of aircraft carriers for the American navy.