During the 1950s and 60s the Lockheed Neptunes were employed by RAAF ... evolutionary step between the Lincoln bombers and the P-3B Orions that eventually succeeded the Neptunes in the late ...

In 1957, the U.S. Navy solicited bids to replace the piston-engined Lockheed P-2 Neptune and the Martin P-5 Marlin, two outdated maritime patrol and antisubmarine warfare airframes. In the spirit ...