High Quality Content by WIKIPEDIA articles! The Lockheed P-7 was a four turboprop-engined patrol aircraft ordered by the U.S. Navy as a replacement for the P-3 Orion. The external configuration of the aircraft was to be very similar to that of the P-3. Development had not progressed very much before the development was cancelled in early 1990s as a cost cutting measure following the end of the Cold War.