Martin P4M Mercator
An unsuccessful contender for the maritime patrol requirement won by the Lockheed Neptune, the Martin P4M-1 Mercator was first used by VP-21 for high-speed minelaying duties. In 1951 the Patrol Unit of Naval Air Facility, Port Lautey, Morroco (VQ-2) and the Special Projects Division of Naval Air Station Sangley Point, Phillipines (VQ-1), began flying thw P4M-1Q electronic reconnaissance version. In June 1955 VQ-1 was based at Iwakuni, Japan taking over US Navy SIGINT duties from the PB4Y Privateer. Twenty one Mercators were eventually built and all were powered by two P&W Wasp Major radial engines and unusually two Allison turbojets buried in the rear of the radial engine nacelles.
Between 1950 to 1960 Mercatorís were employed on Ďferretí ELINT missions along Chinese borders and far eastern Russian coasts with Fleet Air Reconnaissance Squadron One (VQ-1). The only other units to operate Mercatorís was VQ-2 who operated over the Mediterranian and Atlantic. The P4M-1Q Mercatorís generally operated with aircraft codes from regular US Navy Neptune patrol squadrons to hide their true identity. Two XP4M-1s were built but never saw active service. Of the other 19, one was shot down in 1956, another was damaged beyond economic repair in 1959 and four were lost tpo other crashes. A number of other aircraft narrowly survived attacks by Chinese MiG's
The Mercatorís were gradually replaced by the EA-3 Skywarrior, which as it operated from aircraft carriers, allowed much greater flexibility. The remaining P4M-1Q Mercator's were eventually withdrawn from service in May 1960 and only a few survived in museums.
22 Aug 56 - A P4M Mercator of VQ-1 reported being attacked by fighters 32 miles off Chinese mainland an nothing heard from aircraft again. Wreckage and the bodies of two crewmembers were eventually recovered. All 16 crew members were lost.
16 Jun 59 - A P4M Mercator of VQ-1 operating off west coast of Korea was attacked by two MiG-17s. One crewman was wounded, but the aircraft eventually forced landed safely on a Japanese airfield at Miho near Matsue.