Wednesday,
August 22, 1956, marked the end of an era for one of the most awe-inspiring aircraft ever operated by the U.S. Navy, as the JRM flying boat
Marianas Mars completed its last scheduled passenger run from Honolulu, Hawaii. While some planes were remembered for the speed with which they traveled through the sky, the flying boat that splashed into the waters off Naval Air Station (NAS) Alameda, California, on that summer day drew attention with its sheer size. Its tail reached a height of 44 ft. off the ground when the plane sat on beaching gear ashore, the wingspan of the behemoth stretching 200 ft. [from the home team’s goal line to the opposing team’s 34 yard line on a football field]. Such was the size of Mars flying boats that when the first one was built, its construction milestones mirrored that of a ship, complete with a keel laying ceremony and launching with a ceremonial bottle of champagne smashed against its bow. That was in 1940, amidst a global war that spawned the era of the Cold War in which the passengers disembarking at Alameda sixteen years later lived and worked.
Ordered by the Navy on August 23, 1938, the XPB2M-1 [the JRM was the designation of a later transport version] was built on the heels of the Glenn L. Martin Company’s successful PBM Mariner, which first flew in 1939 and developed into a mainstay of Navy patrol and patrol bombing squadrons during World War II. Yet, the Mars took the flying boat to an entirely new level, and in the heady days of World War II the public seized upon what one newspaper called “this huge, two-decked flying battleship. Appropriately named, it is one of the grimmest looking monsters of destruction in Uncle Sam’s rapidly –expanding arsenal.” While this may have made good copy, the Mars was not destined to ever serve as a combat aircraft, instead receiving modifications for service as a transport . Designated the XPB2M-1R in this configuration, the airplane established an international seaplane endurance record on October 4-5, 1942, remaining aloft for 32 hours and 17 minutes. Placed in operational service in November 1943, the plane proved itself immediately, that month completing a non-stop flight between Maryland and Brazil carrying a payload of 13,000 lb. Shifted to the Pacific, the plane affectionately called the “Old Lady” proved a lifeblood for the war effort in that theater, transporting everything from people to plasma as part of the three million pounds of cargo it carried between January 1944 and March 1945.
Such was the favorable performance of the XPB2M-1R that the Navy decided to procure improved versions of the plane for transport duties. Eventually, four JRM-1 and one JRM-2, outwardly different from their predecessor with their single tail configuration, entered service. All received nicknames reflecting island chains in the Pacific—
Marshall Mars,
Marianas Mars,
Philippine Mars,
Hawaii Mars, and
Caroline Mars—with flights commencing from NAS Alameda in 1946 as part of the Naval Air Transport Service.
For the ensuing decade, the Mars flying boats graced the skies carrying tens of thousands of passengers, including a record-setting 301 by the
Marshall Mars in May 1949. Yet, the war that had spawned the birth of the Mars flying boats had a hand in their ultimate demise, the occupation of island bases throughout the Pacific creating a network of airfields that increasingly facilitated the use of landplanes in transoceanic flight. Thus, the Mars served as one of the final chapters of a golden era of commercial aviation that began with the Pan Am Clippers traversing the Pacific to distant and exotic locales.
Retired from active service the four remaining Mars flying boats—
Marshall Mars caught fire during a test flight in April 1950 and sank after making a forced landing—received a new lease on life in 1959 when they were purchased by Forest Industries Flying Tankers Limited in Canada. Operating from the numerous lakes and bays in that country, they were put to work as “water bombers,” fighting forest fires. Two of the venerable aircraft,
Philippine Mars and
Hawaii Mars, continue to serve in that role to this day, tangible links to a bygone era.
Pictured above, Glenn Martin Company employees stand on and around the XPB2M-1, giving a perspective on its mammoth size, an ambulance delivers patients for loading on a Mars flying boat, and
Philippine Mars makes a Jet Assisted Take-Off (JATO).
Other Significant August Events in Naval Aviation History
August 1964- Tonkin Gulf Incident
August 24, 1968- Adoption of NFO wings
August 19. 1981- Gulf of Sidra incident