Martin 219 / P4M Mercator

The US Navy made several attempts to gain the benefit of high over-target performance combined with long range by introducing mixed powerplant. The Martin Model 219 patrol bomber represented one of the results of such a specification, two XP4M-1 prototypes being ordered on 6 July 1944. The first was flown on 20 September 1946 as a cantilever shoulder-wing monoplane with retractable tricycle landing gear. Its powerplant comprised two 2218kW Pratt & Whitney R-4360-4 Wasp Major radial engines, but each nacelle also incorporated a 17,350kg thrust Allison J33-A-17 turbojet. After a protracted development programme 19 P4M-1 production aircraft were built, the first being delivered to US Navy Squadron VP-21 on 28 June 1950, and all served with this unit. Most of them were converted into P4M-1Q Elint aircraft, one being shot down.

P4M-1 Mercator

P4M-1
Engines: 2 x Pratt Whitney R-4360-20A piston engines, 2424kW + 2 x Allison J33-A-10A, 2087kg
Max take-off weight: 40000 kg / 88185 lb
Wingspan: 34.75 m / 114 ft 0 in
Length: 25.50 m / 83 ft 8 in
Height: 7.95 m / 26 ft 1 in
Wing area: 121.79 sq.m / 1310.94 sq ft
Max. speed: 660 km/h / 410 mph
Ceiling: 10545 m / 34600 ft
Range: 4570 km / 2840 miles
Armament: 2 x 20mm cannons, 4 x 12.7mm machine-guns, 2700kg of bombs