Flying boats are an important piece of aviation history. A century ago, when land-based runways were few and far between, flying boats transported travelers to far-flung destinations faster than cars or boats using floatplanes. These historic machines are still around more than a century later, and the largest working flying boat is returning to the skies for its final flight. The 79-year-old Martin JRM3 Mars “Hawaii Mars” has been resurrected and will take off on its final flight before becoming part of the museum.
The Hawaii Mars is the only operational flying boat of its kind, and they didn’t build very many of them to begin with. The Martin JRM Mars is said to be the largest operational flying boat built in the United States. The distinction is a bit odd, though, and excludes the giant Hughes H-4 Hercules. But the JRM Mars is not what anyone would call small. It’s a few inches longer than a Boeing 737 MAX 7 and has a wingspan wider than a Boeing 747SP. For those of you who are numbers-obsessed, it’s 117 feet long and has a wingspan of 200 feet.
Only seven of these flying boats were built during and after WWII, and most no longer exist. Four of them were scrapped or destroyed early in their construction, but survived to become water bombers. Of those four, only two survived, and they ended up in the hands of aerial firefighting company the Coulson Group. The only remaining flying boats are the Philippine Mars, which hasn’t flown since 2006, and the Hawaiian Mars (actually the Hawaiian Mars II), which hasn’t flown since 2016.
While both flying boats are heading to their new homes, Hawaii Mars is leaving in style: the flying boat was mostly run while parked, and will be restored to life for one final flight before being placed on permanent display at the BC Aviation Museum.
A forgotten piece of history
Unfortunately, you probably don’t hear much about these flying boats — if you even hear about them at all. The last time these flying boats were in the news was in 2022 when the Coulson Group was looking to sell Hawaii Mars for $5 million. I was one of the people who wrote about it back then.
It’s a shame, as these flying boats are an important part of aviation history.
According to the Glenn L. Martin Maryland Aviation Museum, the story of these aircraft begins with aviation pioneer Glenn Luther Martin. Martin’s aviation achievements date back more than a century. In 1912, Martin held the record for America’s longest overwater flight, flying 66 miles from Newport Bay, California, to Avalon, Catalina Island in 80 minutes. A year later, he flew an airplane to an altitude of 9,000 feet. Martin is also known for his successful aircraft designs, including World War I-era bombers.
He also founded the Glenn L. Martin Company in 1912. In the mid-1930s, Glenn L. Martin built Martin M-130 “China Clipper” flying boats for wealthy passengers aboard Pan American World Airways liners. Although these flying boats were already among the largest fixed-wing aircraft of their time, Glenn L. Martin dreamed of a larger, more capable flying boat.
In 1938, the US Navy became interested in a large seaplane, a kind of flying battleship, that would have a range of 5,000 miles, four hydraulic machine gun turrets, a bomb delivery system, and would be built like a ship with living quarters for the sailors, a galley, and even showers.
The first example was the prototype XPB2M-1, a flying boat that was essentially a scaled-up version of the PBM Mariner patrol bomber. The aircraft was introduced in 1941, but flight testing was delayed until 1942 due to a glitch caused by an engine fire. Unfortunately, when the Navy finally got their hands on the XPB2M-1 (designated Mars), they decided that the boat was too slow and not agile enough for its intended purpose as a flying battleship. Luckily, the military was in desperate need of transport aircraft, and they were able to put the Mars to good use.
The Navy originally wanted 20, but due to all the shortages and production delays during World War II, the order was scaled back to just 5. We’ll leave it to the National Museum of the U.S. Navy to tell you more from here.
Developed in 1938 by the Glenn L. Martin Company as a long-range maritime patrol flying boat. The prototype, XPB2M-1, was launched on November 8, 1941. After testing in 1942-1943, the Navy approved the aircraft as a transport. The aircraft accommodated a crew of four and one relief personnel, and was approximately 117 feet long. Seven aircraft were built, including the prototype, which was assigned to the Second Fleet Tactical Support Squadron (VR-2) at Alameda, California, before being scrapped in 1945. The aircraft was primarily used for flights between California and Hawaii. All aircraft except the Hawaii Mars I were upgraded to the JRM-3.
Mars aircraft in US Navy service are named: Hawaii Mars I, first flew in July 1945, then sank in Chesapeake Bay in August and scrapped; Philippine Mars, delivered in 1946 and flew with VR-2; operated until 1956, later converted to a forest firefighting aircraft, awaiting display at the National Naval Aviation Museum; Mariana Mars, delivered in 1946 and assigned to VR-2 until 1956; also converted to a forest firefighting aircraft, crashed on 23 June 1961 on Mount Moriarty near Nanaimo, Vancouver Island, killing the crew;
On April 5, 1950, the Marshall Mars was destroyed by an engine fire and sank off Diamond Head, Oahu, Hawaii. The four crew members survived and the wreckage was discovered in 2004. The Hawaiian Mars II, delivered in 1946, served with the VR-2 until 1956, when it became a forest firefighter, operating in the British Columbia area. It is the only Mars still in service today. The last aircraft, the Caroline Mars, was delivered in 1948, also with the VR-2. After its naval service it was also used as a forest firefighter until it was damaged beyond repair by Typhoon Freda in Victoria, Canada in October 1962.
The Hawaii Mars II, also known as the Hawaii Mars, was completed in 1945 and delivered to the 2nd Fleet Tactical Support Squadron in Alameda, California in 1946. There, it took on a new role, carrying military cargo. This role did not last long, and it was decommissioned in 1956. The Hawaii Mars served in the Korean War, flying medical evacuations between Hawaii and California, and later as a transport between the two states.
In 1959, the Hawaii Mars was taken over by Forest Industries Flying Tankers of Canada. The aircraft was given the tail number CF-LYL and converted into a forest firefighting aircraft. Oddly enough, the Hawaii Mars stayed closer to what these flying boats were made to be, except instead of dropping bombs, it dropped 7,200 gallons of water per flight, reportedly enough to flood a four-acre fire in one flight. It was then re-registered as C-FLYL in 1983.
As the Coulson Group writes, the forest industry’s flying tankers had an effective firefighting strategy: Philippine Mars and Hawaii Mars worked as a team for 47 years, dropping as many as 14,400 gallons of water at a time on forest fires.
In 2006, Timberwest Forestry put the Philippine Mars and Hawaiian Mars up for sale, on the condition that one of the flying boats would be donated to a local museum when it reached the end of its service life. The Coulson Group took over both water bombers in 2007, with the Philippine Mars remaining on the ground and the Hawaiian Mars continuing its firefighting missions.
From 2009 to around 2016, pilot Dev Salkeld pressed the water trigger 600-700 times while flying the Hawaii Mars. That’s a lot of water on a lot of fires. Unfortunately, after the BC Wildfire Service terminated its contract, Coulson Group decided to end operations of the historic flying boat in 2016. Another factor that hindered the operation of the Hawaii Mars was that the smaller aircraft could collect water from as many as 1,700 bodies of water, while the giant Hawaii Mars could only collect water from about 113 bodies of water. After visiting EAA AirVenture Oshkosh 2016, the Hawaii Mars was put up for sale for $3 million. Its sister, the Philippine Mars, was also put up for sale for $3 million. With no buyers, Coulson Group tried to put both flying boats up for sale again in 2022 for $5 million.
Preserving History
Once again, no buyers were found, so the company decided to do something else: the Philippine Mars went to the Pima Air and Space Museum in Arizona, and the Hawaiian Mars went to the British Columbia Aviation Museum, fulfilling Timberwest’s original request: Both boats will be on permanent display, available for generations of aviation enthusiasts to see.
The donation was announced in April, and the BC Aviation Museum was scheduled to receive the flying boat this fall. Why did it take so long? Although it has been widely reported that the Hawaii Mars is airworthy (I was one of those who reported it in 2022), it has not flown in eight years. So the maintenance team at Coulson Group has been working hard to make sure the flying boat is in top condition for its final flight. It also needs to be inspected and approved before it can take to the skies again.
Apparently, this is moving ahead of schedule, as in recent weeks Coulson has been showing off videos of the Hawaii Mars gliding across the water and conducting taxi tests. And, as Vintage Aviation News writes, on August 1, the Hawaii Mars took off from Sproat Lake on Vancouver Island for the first time in eight years. Powered by the 10,000 horsepower of its four Wright R-3350 Duplex Cyclone 18-cylinder radial engines, it soared above the water and the trees in a victory for Coulson’s mechanics.
Coulson was scheduled to fly the Hawaii Mars to 6,000 feet, but a technical problem forced the pilot to shut down the plane’s fourth engine. The party ended 15 minutes after it had begun, after which the problem was fixed and the plane took off again on August 2.
Much work remains to be done before the final flight, scheduled for next week, including airworthiness inspections, crew training and additional test flights.
Eventually, the Hawaii Mars landed in the ocean outside Victoria International Airport and will be on display at the British Columbia Aviation Museum. The arrival of the two Mars flying boats at their respective museums will mark the end of over 80 years of Mars history. That’s a successful career for any aircraft, and these two are fortunate to live out their retirement in a museum instead of for scrap. While the Mars may not be as significant as other WWII aircraft, it’s still a piece of history worth remembering.
