Following World War I, the Naval Aircraft Factory in Philadelphia began producing flyboats based on the British Felixstowe F.5 flying boat of the war. The American built version with two Liberty engines was designated the F.5L. The Naval Aircraft Factory built 137 Felixstowe 5.Fs, followed by Curtiss Aviation which buitl 60 (Right). Canadian Aeroplanes Limited built another 30. It produced its first flying boat in 1922. Because of the emphasis on carrier-borne aircraft, between 1922 and 1927, the design of patrol aircraft and the engines was modest. The PN-9 flying boat Commander Rogers flew from San Francisco in 1925 was simply an upgrade of the Felixstowe flying boat in overall design.

The main development at this time was the decision by the Navy to use radial engines for patrol aircraft. Engine Development 1922 and 1925, the Naval Aircraft Factory built only 3 aircraft. The PN-7 was designed with a new, short wing and airfoil, which gave it increased lift. However, the Wright T-2 radial engines proved troublesome, and the wood hull needed constant maintenance. Besides being heavier than the later metal hulls, the wooden hulls had a tendency to leak, and the hydroscopic nature of wood made for an undesireabole increase in weight. The two PN-8’s built had all-metal hulls and two Packard V-12 water-cooled engines, as did the Boeing PB-1. However, problems with the water-cooled engines forced the replacement of the Packard engines with radial engines.

The one innovation of the PN-8 was the use of metal hull, which lightened the aircraft substantially. The other innovation that was beginning to appear was the redesigned hull, which replaced the sponsons with a flat-sided broad hull (Left). This design appeared in the Boeing PB-1, which would directly influence the hull design of the Consolidated XPY-1 Admiral and the P2Y-1 Ranger patrol flying boats. The naval Aircraft Factory continued to build experimental planes, including the PN-11 which had broad sides that did away with the traditional sponsons and was fitted with twin rudders.

By 1927, development of the flying patrol boat had reached the limits of its design. The Naval Aircraft Factory designed the PN-12, which went back to the sponsons on the side of the hull and the engines still only produced approximately 575 hp. The NAF found it did not have the capacity to produce the required aircraft, and so put out the plans to three private companies: Keystone, Douglas and Martin. While the plans were provided to the companies, each made design changes which produced aircraft with different flying characteristics.

All three aircraft were slow with a top speed of 120 mph at best. Despite having a listed range of 1,300 miles, their actually operating range was closer to 400 miles. As VADM Herbert Riley, who flew all three aircraft, noted the Keystone PK-1 was the most rugged of the three but was also “a real brute” to fly (Left). The Douglas PD-1 was the most maneuverable and easily handled but had the tendency to lose its tail without warning (Right). While Riley noted this caused “major embarrassment on numerous occasions”, it could also prove fatal, as in the case of on August 9, 1933, when five of the six crew were killed on a training flight at Pearl Harbor. The Martin PM-1 proved to be the best combination of the two others. It had the structural integrity of the PK-1 but was much easier to fly (Right). Still, the range and speed to the design had reached its limit and the U.S. Navy was looking for something else.

In 1927, the USN put out a bid for patrol flying boats. The Navy’s specifications reflected its needs and concerns. The aircraft was to be a monoplane with at top speed of 135 mph, and a range sufficient to fly nonstop to Hawaii. This last specification was important. Not only did the Navy want to be able to send whole squadrons to Hawaii instead of piecemeal by boat, but partially because of rising tensions with Japan, to increase the patrol range around the Hawaiian Islands and elsewhere.

Consolidated responded with the XPY-1 Admiral. The hull was designed by hiring Issac M. (Mac) Laddon, who had designed the Boeing PB-1 hull and was a specialist in multi-engine aircraft design. On February 28, 1928, Consolidated received a contract to build a prototype of the XPY-1. The aircraft would be a parasol wing monoplane, have a dural aluminum hull, and a fabric covered wing and tail surfaces. The two Prat and Whitney Wasp 425 hp R-1340-38 radial engines would be mounted below the wing on main wing bracing struts, along with the two outboard floats. The cockpit was open, and the aircraft carried a crew of five. The prototype initially had a top speed of 118 mph, which was below the requirement. To meet the requirement, a third engine was added above the wing between the two other engines (Right - this would also be tried with the XP2Y Ranger). The aircraft reached a speed of 135 mph with the additional engine, but it was removed as being more trouble than it was worth.

The Navy at this time approved the Consolidated XPY-1 but put out the production bid to other companies. Martin underbid Consolidated since it did not have the costs of developing the prototype. Consolidated struck back by refusing to provide Martin with any engineering drawings or specifications. The result was Martin had to reverse engineer the XPY-1. It made modifications to the prototype and produced nine P3M-1s in 1931. The aircraft was underpowered and had to be immediately upgraded with Pratt and Whitney R-1690-32 Hornet radials with 390 kW (525 HP). Despite the upgrade, the P3M-2 was removed from frontline service after just a year.

Though Consolidated was stuck with development costs of the XPY-1, it had the last laugh. As the company’s Reuben H. Fleet noted, “Martin underbid us a half-million and lost a million on the job." Consolidated had hedged its bets by developing the commercial Model 16 Commodore, based on the XPY-1 Admiral. It was virtually identical to the XPY-1 except for changes made to accommodate passengers for commercial use. The cabin ceiling was changed from rounded to crown deck to give a height of 6 feet and room for sleeping bunks. Windows were added and the flight deck was enclosed (Left).

Initially six were ordered on March 1, 1929, and the first flight started on March 28, 1929 by the New York, Rio, Buenos Aires Line. Commodores flew from the United States to South America where routes extended as far south as Buenos Aires, a distance of 9000 miles from Miami. In August 1930 the airline was absorbed by Pan AM. One testimony to the Commodore in Pan Am service was made by a Pan Am pilot, Marius Lodeesen who wrote " . . . the good old Consolidated Commodore was the most reliable, trusty aircraft of the Pan American fleet during the early 1930s . . . . She was hoisted aloft by two engines. They must have been Pratt and Whitneys because they never gave any trouble. . . Waterlooping the Commodore was impossible. Making a bad landing in her was hard work. She was the loveliest boat I ever flew." By the end of 1934 the Model 16 Commodores had flown over five million miles! It would stay in service with Pan AM until 1935.

The knowledge and experience Consolidated gained in developing the Commodore would pay dividends in its development of the P2Y Ranger. [For larger and more pictures of the predecessor flying boats go to P2Y Predecessors