Your seat back is in its full upright position and your hand luggage is stowed neatly under the seat. But as the engines roar and propel the aircraft down the runway, you can't help wondering: how is a 200,000-pound metal tube possibly going to get airborne? Are those rumbles you hear and bumps you feel normal? For those who want to know more about how an airliner flies, airline Captain Julien Evans, an experienced Boeing 757 pilot who has comforted...