Built for a 1935 UN Navy requirement for a patrol bomber flying boat, the Consolidated PB2Y Coronado was relatively successful although saw itself overshadowed by the preference given by naval authorities to the famous Catalina. Despite this, it had superb performance characteristics including a considerably greater maximum speed than either the Catalina or the Mariner, the other two major US flying boats of the war, thanks to two-stage supercharged engines. It also featured self-sealing fuel tanks, heavy defensive armaments and sometimes ASV radar in a radome behind the cockpit. Coronados served with the US Navy throught the full extent of the conflict and was also supplied to Britain via Lend-Lease where it was used by RAF Transport Command as freight and passenger transports in the North and South Atlantic. Many converted US aircraft also served in this role and as aerial ambulances.

Maiden flight of the Consolidated Model 29 took place on 17 December 1937 as the XB2Y-1. The first production versions were designated PB2Y-2 which was eventually replaced by the PB2Y-3, the most widely produced variant of this aircraft and the last to be built from scratch. The PB2Y-3B was sent to Britain where it was redesignated Coronoado Mk. I while the P2BY-3R was a transport conversion which could carry up to 44 passengers. Lastly, the P2BY-5 and -5R included more powerful engines and increased fuel capacity. Finally, the P2BY-5H was an aerial ambulance capable of carrying 25 stretchers.