Martin P3M
The Martin P3M was a twin-engined parasol-monoplane patrol flying boat built by the Glenn L. Martin Company for the U.S. Navy. It was the production version of Consolidated's XPY-1, the Navy's first monoplane flying boat: Consolidated built and flew the prototype, but Martin won the contract to build it in quantity by underbidding its creator. Only nine were built, three P3M-1s and six P3M-2s, and after a short front-line life the improved Consolidated P2Y displaced the type into training and utility duties.
Why It Mattered
The Martin P3M was the production form of Consolidated's XPY-1, the U.S. Navy's first monoplane flying boat. Consolidated had built and flown that prototype, yet the contract to manufacture it went to the Glenn L. Martin Company, which had underbid the aircraft's own creator. Wikipedia attributes the split to standard Navy practice of the day: production contracts were opened to rival bidders rather than awarded to the firm that had designed and proved the aircraft. Only nine P3Ms were built, and the type was soon eclipsed by Consolidated's own improved successor, the P2Y. Its place in a longer line is the larger part of its significance: History of War's account of the Catalina's development starts the Consolidated flying-boat sequence with the XPY-1 and describes the P2Y as an obvious ancestor of the Catalina.
Design Notes
The underlying design was a Navy-side product: Wikipedia credits Isaac M. "Mac" Laddon with designing the XPY-1 to specifications laid down by Captain Holden C. "Dick" Richardson. The P3M kept that layout, a parasol monoplane with its two engines mounted in the space between the fuselage and the wing above it. Martin's own XP2M prototype had instead put its engines in nacelles at the wing's leading edge, and in its XP2M-1 form it had three Wright Cyclones, the third being removed to make the XP2M-2. Production aircraft split by powerplant: the three P3M-1s used two 450 hp Pratt & Whitney R-1340-39s, while the six P3M-2s used 525 hp R-1690-32 Hornets. The crew numbered four or five, and the armament was two .30-inch machine guns on flexible mounts. In size and outline the P3M stayed close to both the XPY-1 and the P2Y that followed.
Operational History
The programme began with a U.S. Navy contract dated 28 February 1928, and Consolidated's Model 9 prototype, the XPY-1, first flew on 10 January 1929 from Anacostia NAS, Washington, D.C. The Martin aircraft itself first flew in 1931, the year Wikipedia's listing of Glenn L. Martin Company products gives for the P3M, and nine were built in total. History of War counts those nine as three P3M-1s and six P3M-2s, distinguished by their Pratt & Whitney engines. Consolidated recovered the initiative on 26 May 1931, when the Navy contracted with it for the improved Model 22, the future P2Y. The P3M's front-line career was correspondingly short: once the P2Y appeared, the Martin boats were withdrawn to training and utility work. The P2Y went on to become the Navy's standard patrol aircraft for most of the 1930s.
Afterlife
After the patrol role passed to the P2Y, the nine P3Ms spent the rest of their service on the training and utility work History of War records for them. The sources used for this record give the type no second act: no export operator, civil career or preserved example appears in them. What survived instead was the design line: the XPY-1 stood at the head of Consolidated's three Navy flying boats, and the line ran on through the P2Y toward the Catalina. The procurement episode also outlasted the aircraft, leaving the P3M as the standing example of a prototype's builder losing production to a lower bid.