A fuel-saving flight plan

The flight patterns that today's pilots follow are broad highways, although the routes they follow can vary widely. When they are ready to land, pilots execute a "dive and drive: - a "vectored step-down" approach in which they alternately slow down and speed up as they head towards the runway. The step-down method is notoriously inefficient, burning unnecessary fuel and releasing global-warming gases - much as automobile drivers do when they repeatedly accelerate like jackrabbits and then slam on the breaks.

NEXT: The new way: Set and forget