The trio hopes that E-Fan X will quickly "mature" hybrid aircraft and lead to an honest-to-goodness commercial single-aisle aircraft. It could be a long while before you're flying aboard a hybrid jumbo jet, then, but this could lead to short-hop aircraft that consume much less fuel. And that's bound to be helpful in reducing not just emissions, but running costs. Carriers may have a vested interest in adopting these vehicles simply because they could improve the bottom line -- helping the environment would be a nice (if important) bonus.