When the Boeing 314 Clipper entered service in 1939, it was one of the largest of the "flying boats". Boeing employed the massive wings of its cancelled XB-15 in order to achieve the lift and range needed for trans-oceanic flights. 12 were built, of which 9 were delivered to Pan Am, with the other 3 going to BOAC. The Clipper set a standard for passenger luxury and comfort that has not been surpassed.