FSX/FSX acceleration Martin Mars waterbomber On 23 August 1938 the US Navy ordered from Martin a single prototype of the Martin 170 design for a patrol bomber of flying-boat configuration. Designated XPB2M-1, it was the world's largest flying-boat when flown for the first time on 3 July 1942.Only six more of the type were ordered at the end of WWII. These served as transports until 1956, when they were retired. In 1959, the remaining four were purchased for conversion to firebombers. Two remain flying to this day, the Philippine Mars and the second Hawaii Mars. Alphasim freeware AI mdl made flyable in FSX/FSX acceleration. Complete 2D panel and outward look but no VC. Water dropping effect added. Conversion by A.F.Scrub.