Martin P4M Mercator

The Martin P4M Mercator was a maritime reconnaissance aircraft built by the Glenn L. Martin Company for a United States Navy requirement for a long-range maritime patrol bomber, with work on the Model 219 beginning in 1944 as a replacement for the PB4Y Privateer and optimisation for long-range minelaying. Its most unusual feature was a mix of piston and jet power: two Pratt and Whitney R4360 Wasp Major 28-cylinder radial engines, with two Allison J33 turbojets in the rear of the enlarged nacelles for takeoff and combat boost, burning gasoline rather than jet fuel. It first flew on 20 October 1946, lost the production contest to the Lockheed P2V Neptune, and had a limited life as an electronic reconnaissance aircraft until final withdrawal in 1960, after which the remaining aircraft were scrapped.