How Does an Airplane Stop so Quickly?
Q: When a plane lands, how does it come to a stop so quickly? It sounds like the engines rev up immediately after touchdown. I can’t imagine how, but are the engines somehow reversing?
On most jets the engines indeed reverse, and that is exactly why you hear the “rev” just after meeting the pavement. The thrust is re-directed by the deployment of deflectors It’s not a true reverse, but more of an acutely angled, semi-forward vector like the effect of blowing into your cupped hand. If you’re seated with a view of the engines, you can usually see this deployment quite clearly. Once in this condition, engine power is increased.
Turboprop engines can reverse as well. Most people aren’t aware of it, but propeller blades are able to change angle, and will twist to a setting that forces air forward rather than backward. Thus you’ll hear a turboprop increasing power after touchdown as well. (No, neither jets nor turboprops will reverse during flight.)
It’s the brakes, however, that do most of the stopping. They are helped by the reverse thrust, drag from the flaps, and the deployment of spoilers. Spoilers are multi-purpose panels that rise above the wing, in this case killing the wing’s lift and effectively pressing the airplane onto its landing gear, whereby the brakes can take on the work.
This Q&A is part of a collection that originally appeared on Salon.com. Patrick Smith, 38, is an erstwhile airline pilot, retired punk rocker and air travel columnist. His book, Ask the Pilot (Riverhead) was voted “Best Travel Book of 2004” by Amazon.com. Patrick has traveled to more than 55 countries and always asks for a window seat. He lives near Boston.