Biofuel aviation future

Shoreham Airport, originally uploaded by seadipper.

A Virgin aircraft has made a flight, powered partly by biofuel. Is this part of a sustainable future for aviation?

No. It takes a huge amount of energy to just get an aircraft off the ground. Even the light aircraft in the picture are greedy little fuel gobblers, though things are not quite so bad if you go on a long flight in a straight line.

As a means of mass transport, the days of aviation with heavier-than-air machines are numbered. In fact, I would go further and suggest that the era of cheap travel over distances of thousands of miles is just a short-lived historical aberration.