The P-7 was designed as an enlarged version of the original P-3C. The fuselage, of similar cross-section to that of the P-3, was lengthened by 2.40 m (8 ft), and the wingspan by 2.10 m (7 ft). The wing center section was increased in length, which moved the engines farther away from the fuselage to reduce noise levels in the cabin. The tailplane was increased by about 25% in area, but shortened in height compared to that of the P-3. The P-7A was to be powered by four General Electric T407-GE-400 turboprops with 5-blade propellers.