 {| |} the martin jrm mars is a large, four-engined cargo transport seaplane originally designed and built in limited numbers for the u.s. navy during the world war ii era. it was the largest allied flying boat to enter production, although only seven were built. the united states navy contracted the development of the xpb2m-1 mars in 1938 as a long range ocean patrol flying boat, which later entered production as the jrm mars long range transport. the surviving aircraft were later converted for civilian use to firefighting water bombers. one example of the aircraft still remains in active service.  ==design and development== the glenn l. martin company scaled up their pbm mariner patrol bomber design to produce the prototype xpb2m-1 mars.goebel, greg. "the martin mariner, mars, & marlin flying boats." air vectors, 6 may 2006. retrieved: 13 november 2010. the xpb2m-1 was launched on 8 november 1941. after a delay caused by an engine fire during ground runs, the aircraft first flew on 23 june 1942. after flight tests with the xpb2m between 1942 and 1943, she was passed on to the navy. the original patrol bomber concept was considered obsolete by this time, and the mars was converted into a transport aircraft designated the xpb2m-1r. the navy was satisfied with the performance, and ordered 20 of the modified jrm-1 mars. the first, named hawaii mars, was delivered in june 1945, but with the end of world war ii the navy scaled back their order, buying only the five aircraft which were then on the production line.bridgeman 1946, pp. 244â245. though the original hawaii mars was lost in an accident on chesapeake bay a few weeks after it first flew, the other five mars were completed, and the last delivered in 1947. ==operational history== ===u.s. navy service=== thumb|left|the prototype xpb2m-1 mars named the marianas mars, philippine mars, marshall mars, caroline mars, and a second hawaii mars, the five production mars aircraft entered service ferrying cargo to hawaii and the pacific islands. the last production airplan
Aerial_firefighting Flying_boats Four-engined_tractor_aircraft High-wing_aircraft Martin_aircraft United_States_military_transport_aircraft_1940a1949