Now this is my idea of a perfectly acceptable way to waste some time. Excerpt from the University of Westminster web site.

The exhibition LEARN TO FLY, by Mark Clews, featured a precise full-scale version of the balsa wood rubber band powered airplane of his childhood.

Fifty metres of rubber was wound up and let go at Dunsfold Aerodrome in Surrey on a runway over 6,000 feet long. Like model planes, this art work can be flat-packed and reassembled anywhere in under an hour, ready for flight.