Amphibious aircraft XPBM-5A
Despite the improvements made in the PBM-3D version, the PBM was still considered underpowered when carrying heavy loads under certain conditions. The Navy had recognized the need for more power as early as mid-1941, when they ordered 180 PBM-4s powered by R-3350 engines. Unfortunately, this plan had to be abandoned due to all R-3350 engines being allocated to B-29 production. As an alternative, two PBM-3 airframes were retrofitted with Pratt & Whitney R-2800-34 engines rated at 2,100 hp in early 1944 and tested as the XPBM-5. Flight trials showed improved takeoff and climb performance, as well as a top speed increase of 12 mph (19 km/h), although range was slightly reduced. Production was switched entirely to the PBM-5 in mid-1944, with 592 aircraft completed by the end of the war and a further 137 delivered by June 1947. From late 1944 through 1945, the Coast Guard received 41 examples lacking armament, designated as the PBM-5G. Thirty-four amphibious variants, the PBM-5A, were manufactured postwar from April 1948 to March 1949, which marked the end of all PBM production.