Engines in tomorrow's fighter planes and bombers will be arranged to give the craft the best possible defensive firs power, according to designs studied by military aviation experts. Although details are closely guarded sécrets, the outward appearances of some have been made known. One, called the “Canard,” would fly tail first-with-the-propeller at the extreme rear, thus eliminating rough air over the plane. One four-engined bomber would have two propellers of the pusher type and two of the tractor type mounted in thie wings, Both designs offer advantages in the placement of guns.