Consolidated PB2Y Coronado The PB2Y Coronado was a large flying boat patrol bomber designed by Consolidated Aircraft . As of 2005 , one Coronado remains at the Pensacola , Florida National Museum of Naval Aviation . Design and development . After deliveries of the PBY Catalina , also a Consolidated aircraft , began in 1935 , the United States Navy began planning for the next generation of patrol bombers . Orders for two prototypes , the XPB2Y - 1 and the Sikorsky XPBS - 1 , were placed in 1936 ; the prototype Coronado first flew in December 1937 . After trials with the XPB2Y - 1 prototype revealed some stability issues , the design was finalized as the PB2Y - 2 , with a large cantilever wing , twin tail , and four Pratt & Whitney R - 1830 radial engines . The two inner engines were fitted with four - bladed reversible pitch propellers ; the outer engines had standard three - bladed feathering props . Like the PBY Catalina before it , the PB2Y ' s wingtip float s retracted to reduce drag and increase range , with the floats ' buoyant hulls acting as the wingtips when retracted . Development continued throughout the war . The PB2Y - 3 , featuring self - sealing fuel tank s and additional armor , entered service just after the attack on Pearl Harbor and formed most of the early - war Coronado fleet . The prototype XPB2Y - 4 was powered by four Wright R - 2600 radials and offered improved performance , but the increases were not enough to justify a full fleet update . However , most PB2Y - 3 models were converted to the PB2Y - 5 standard , with the R - 1830 engines replaced with single - stage R - 1830 - 92 models . As most existing PB2Y - 3s were used as transports , flying low to avoid combat , removing the excess weight of unneeded superchargers allowed an increased payload without harming low - altitude performance . Operational history . Coronados served in combat in the Pacific , in both bombing and anti - submarine roles , but transport and hospital aircraft were the most common . The British Royal Air Force Coastal Command had hoped to use the Coronado as a maritime patrol bomber , as it already used the PBY Catalina . However , the range of the Coronado ( 1 , 070 miles ) compared poorly with the Catalina ( 2 , 520 mi ) , and the Short Sunderland ( 1 , 780 mi ) . Consequently , the Coronados supplied to the RAF under Lend - Lease were outfitted purely as transports , serving with RAF Transport Command . The 10 aircraft were used for trans - Atlantic flights , staging through the RAF base at Darrell ' s Island , Bermuda , and Puerto Rico , though the aircraft were used to deliver vital cargo and equipment in a transportation network that stretched down both sides of the Atlantic , from Newfoundland , to Brazil , and to Nigeria , and other parts of Africa . After the war ended 5 of the RAF aircraft were scrapped , one was already lost in collision with a Martin Mariner and the last four were scuttled off the coast of Bermuda in 1946 . Coronados served as a major component in the Naval Air Transport Service ( NATS ) during World War II in the Pacific theater . Most had originally been acquired as combat patrol aircraft , but the limitations noted above quickly relegated them to transport service in the American naval air fleet also . By the end of World War II the Coronado was outmoded as both a bomber and a transport , and virtually all of them were quickly scrapped , being melted down to aluminum ingots and sold as metal scrap . XR - 1830 - 72 Twin Wasp < / a > s , engines , one built .