Martin JRM Mars

Transport Flying Boat / Waterbomber

Martin JRM-3 Mars © Douglas Noblet
Photo ©: Douglas Noblet (Photos at
The Martin JRM Mars is a four-engine transport flying boat produced by the US-American manufacturer Glenn L. Martin Company.
The total production of the JRM Mars includes one prototype aircraft, five JRM-1 (later converted to JRM-3) and one JRM-2. The JRM Mars was initially operated by the US Navy. After retirement of US Navy service, four JRM Mars were converted to civil water-bombers for aeral firefighting, operated by Flying Tankers Inc., later by Coulson Flying Tankers. The payload for water is 27.216 kg (60.000 lbs).
Propulsion4 Radial Engines
Engine ModelWright R-3350-24WA Duplex Cyclone
Engine Power (each)1864 kW2500 hp
Speed356 km/h192 kts
  221 mph
Service Ceiling4.450 m14.600 ft
Range8.001 km4.320 NM
4.971 mi.
Empty Weight34.279 kg75.572 lbs
max. Takeoff Weight74.800 kg164.906 lbs
Wing Span60,96 m200 ft 0 in
Wing Area342,4 m3686 ft
Length35,74 m117 ft 3 in
Height11,71 m38 ft 5 in
First Flight1941
Production Statusout of production
Production Range1945-1947
Total Production6
Data for (Version)Martin JRM-3 Mars
VariantsJRM-1, JRM-2, JRM-3