A Consolidated PB2Y-5 Coronado showing the mixture of darker non-specular sea blue merging into pale grey-blue lower down.

Plans for the development of a maritime patrol-bomber larger than the PBY Catalina were drawn up by the US Navy very soon after the first flight of the Catalina's XPBY-1 prototype. The aim was to procure a patrol flying-boat with increased performance and better weapon load capability. on 29 June 1935 Sikorsky received a contract for a single prototype and on 27 July 196 Consolidated received a contract for a competing prototype. Sikorsky's XPBS-1 flew for the first time on 13 August 1937, but despite introducing a number of new features it was the Consolidated Model 29 which, when evaluated as the XPB2Y-1 following a first flight on 17 December 1937, was regarded as the more suitable for production. As at that time the US Navy had no funds for immediate procurement of any of these aircraft, Consolidated had almost 15 months in which to rectify the short-comings revealed by initial flight tests.

Most serious of the problems was lateral instability, which the company attempted to rectify by the addition of two oval-shaped fins, mounted one each side of the tailplane. This was a move in the right direction, but stability was still far from satisfactory and was resolved finally by the design of a new tail unit with "Zulu Shield" endplate fins and rudders similar to those of the B-24 Liberator which was first introduced on the PB2Y-3. The other problem concerned hydrodynamic performance of the flying-boat's hull, fortunately, the delayed procurement allowed time for redesign, the new hull being deeper than that of the prototype, with a much changed nose profile.

Eventually, on 31 March 1939, the US Navy was able to order six of these aircraft under the designation PB2Y-2 and the name Coronado, and delivery of these to US Navy Squadron VP-13 began on 31 December 1940. They were impressive aircraft, powered by four radial engines mounted on the high-set cantilever wing. Construction was all-metal, and interesting features included stabilising floats which retracted to form wingtips in flight, and bomb bays formed in the deep-section wing. Accommodation was provided for a crew of ten.

These PB2Y-2s were used for service trials (lacking any armour or self-sealing fuel tanks), leading to the procurement of the PB2Y-3 Coronado, following the conversion of one of the PB2Y-2s as a prototype XPB2Y-3. They differed by having increased armament and the provision of self-sealing tanks and 2,000 lbs (907 kg) of protective armour, A total of 210 of this version was built, late production aircraft being equipped with ASV Air to Surface Vessel) radar. Ten of the aircraft, designated PB2Y-3B, were supplied to the RAF and based initially at Beaumaris, Anglesey, intended for service with Coastal Command. Their stay there was only brief, for they were transferred to No. 231 Squadron of Transport Command and Used from June 1944 to operate freight services.

Variants in US service, converted from PB2Y-3s, included 31 PB2Y-3R transports, fitted with single-stage supercharged R-1830-88 engines and capable of carrying 45 passengers or up to 16,000 lbs (7258 kg) of freight. One XPB2Y-4 converted by the experimental installation of Wright R-2600 Cyclone engines, the PB2Y-5 modified from PB2Y-3s with increased fuel capacity and 1,200 hp (895 kW) Pratt & Whitney R-1830-92 Twin Wasp 14-cylinder radial engines which gave better performance under 10,000 ft (3050 m). A number of PB2Y-5H casualty-evacuation aircraft which saw service in the Pacific theatre accommodating 25 stretchers.

The PB2Y Coronado was never widely used in the maritime reconnaissance role as preference grew for used of land based aircraft such as the Consolidated PB4Y-1 Liberator which required no specialist training in water operations while the Consolidated PBY Catalina remained unequalled for long distance ocean reconnaissance. All PB2Y Coronado's were withdrawn from service at the end of the war.

Variants

XPB2Y-1 Prototype - The XPB2Y-1 prototype first flew on 17 December 1937. It was considered more suitable for production and won out over Sikorsky's XPBS-1 entry. At the time, the US Navy had no funds for immediate procurement, and it would be 15 months more before orders were forthcoming. This was a mixed blessing for Consolidated as it did allow them to fix problems encountered with the test flights.

PB2Y-2 Coronado - Eventually, on 31 March 1939, the US Navy was able to order six of these aircraft under the designation PB2Y-2 and the name Coronado, and delivery of these to US Navy Squadron VP-13 began on 31 December 1940. This was a much improved aircraft over the original prototype. The tail section was completely redesigned to overcome lateral instability problems, and the hull was also redesigned to increase hydrodynamic performance.

PB2Y-3 Coronado - Service trials of the PB2Y-2s lead to the procurement of the PB2Y-3 Coronado, following the conversion of one of the PB2Y-2s as a prototype XPB2Y-3. They differed by having increased armament and the provision of self-sealing tanks and armour, A total of 210 of this version was built, late production aircraft being equipped with ASV Air to Surface Vessel) radar.

PB2Y-3B/Consolidated Coronado Mk I - Ten of the aircraft, designated PB2Y-3B, were supplied to the RAF and based initially at Beaumaris, Anglesey, intended for service with Coastal Command. Their stay there was only brief, for they were transferred to No. 231 Squadron of Transport Command and Used from June 1944 to operate freight services.

PB2Y-3R - The military transport version capable of carrying up to 45 passengers powered by four 1,200 hp (895 kW) Pratt & Whitney single-stage supercharged R-1830-88 radial engines. 31 aircraft total. 

XPB2Y-4 - A single aircraft used to test the experimental installation of Wright R-2600 Cylone radial engines.

PB2Y-5 - The best patrol bomber version, they were all converted from exsisting PB2Y-3s with increased fuel capacity and 1,200 hp (895 kW) Pratt & Whitney R-1830-92 Twin Wasp 14-cylinder radial engines which gave better performance under 10,000 ft (3050 m).

PB2Y-5H - This was the Casualty Evacuation (Ambulance) version. Military equipment was removed to make room for the provision of 25 stretchers. This version did see limited service in the Pacific Theatre.  

Specifications (Consolidated PB2Y-3 Coronado - Model 29)

Type: Ten Seat Maritime Patrol Bomber

Design: Consolidated Aircraft Corporation Design Team

Manufacturer: Consolidated Aircraft Corporation in San Diego

Powerplant: Four 1,200 hp (895 kW) Pratt & Whitney R-1830-88 Twin Wasp 14-cylinder radial engines.

Performance: Maximum speed 223 mph (359 km/h) at 20,000 ft (6095 m); cruising speed 141 mph (227 km/h) at 1,500 ft (460 m); service ceiling 20,500 ft (6250 m); initial climb rate of 570 ft (174 m) per minute.

Range: Maximum range 2,370 miles (3814 km) with maximum fuel loadout. Range with 8,000 lbs (3629 kg) bombload 1,370 miles (2205 km). Ferry range 3,105 miles (5000 km).

Weight: Empty 40,935 lbs (18568 kg) with a maximum take-off weight of 68,000 lbs (30844 kg).

Dimensions: Span 115 ft 0 in (35.05 m); length 79 ft 3 in (24.16 m); height 27 ft 6 in (8.38 m); wing area 1,780.0 sq ft (165.36 sq m).

Armament: Two 12.7 mm (0.50 in) Browning machine-guns in the bow, dorsal and tail turrets (six total) and one 12.7 mm (0.50 in) Browning machine-gun in each of the two beam positions, plus up to 12,000 lbs (5443 kg) of bombs. Normal bomb configuration consisted of eight 1,000 lbs (454 kg) bombs carried internally and four 1,000 lbs (454 kg) bombs or two Mark XIII torpedoes carried externally. Depth charges could also be carried externally. The transport version could carry up to 45 passengers and in the freight configuration could carry up to 16,000 lbs (7258 kg) of freight. The transport and freight aircraft were unarmed.

Variants: XPB2Y-1, PB2Y-2 Coronado, PB2Y-3 Coronado, XPB2Y-3B, PB2Y-3R, XPB2Y-4, PB2Y-5, PB2Y-5H.

Avionics: (late production) ASV (Air to Surface Vessel) radar.

History: First flight (XPB2Y-1) 17 December 1937; initial deliveries (PB2Y-2) 31 December 1940.