The P-3 Orion, originally designated P3V, is based on the same design philosophy as the Lockheed L-188 Electra. It is not the same aircraft structurally in that it has had 7 ft (2.1 m) of fuselage removed forward of the wings, as well as myriad internal, external, and airframe production technique enhancements. The prototype YP3V-1/YP-3A BuNo 148276 was in fact modified from the third Electra airframe c/n 1003. The P-3 Orion served as the replacement for the postwar era P-2 Neptune and P-5 Marlin. The Orion is powered by four Allison T56turboprops which give it a speed comparable to fast propeller powered fighters, or even slow turbofan jets such as the A-10 Thunderbolt II or the S-3 Viking. Many other countries have seen the value of this platform design and have developed similar patrol aircraft based on this model, with the Soviets adapting their own counterpart to the Orion, the Ilyushin Il-38. The P-3 also competes with the British Hawker Siddeley Nimrod adaptation of the de Havilland Comet and the French Breguet Atlantique.