 When finally flown briefly in 1947, its wingspan made it the largest plane ever to fly, and it has never been equalled.It required 8 Pratt & Whitney R-4360 Wasp Major radial engines to get it into the air.By then, the landplane had taken over long-distance flight and the H-4 - having made no more than a single mile-long flight less than 100 ft off the water - never flew again.