Shown here is a U.S. Marine Corps Lockheed PV-1 Ventura night fighter of Marine Night Fighter Squadron Five Three One (VMF(N)-531) in the Southwest Pacific in 1943. A few PV-1 patrol planes had been modified with AI Mk IV air-search radar for interim use as night fighters. Photo Maj. William Henson, USMC. Scan from the official U.S. Marine Corps publication: Charles J. Quilter II and John C. Chapin: A History of Marine Fighter Attack Squadron 531. History and Museums Division Headquarters, U.S. Marine Corps, Washington, D.C. 2001, p. 16