# Martin JRM Mars

The Martin JRM Mars is a large, four-engined cargo transport flying boat designed and built by the Martin Company for the United States Navy during World War II. 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.
Four of the surviving aircraft were later converted for civilian use to firefighting water bombers. Two of the aircraft remained based at Sproat Lake just outside of Port Alberni, British Columbia, with one, the "Hawaii Mars", remaining in operation until 2016. The British Columbia Aviation Museum acquired the "Hawaii Mars" and it was flown there in 2024. The same year it was announced that the "Philippine Mars" would be acquired by the Pima Air & Space Museum in Tucson, Arizona, to be put on permanent display there.

## Design and development

The Glenn L. Martin Company scaled up their PBM Mariner patrol bomber design to produce the prototype XPB2M-1 Mars. The XPB2M-1 was announced on 8 November 1941. Delayed 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. Though the original Hawaii Mars was lost in an accident on the 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

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 on 23 January 1944. The last production airplane (the Caroline Mars) was designated JRM-2, powered by 3,000 hp (2,200 kW) Pratt & Whitney R-4360 engines, and featured a higher maximum weight and other improvements. On 4 March 1949, the Caroline Mars set a new world passenger load record by carrying 269 people from San Diego to San Francisco, CA. On 5 April 1950, the Marshall Mars was lost near Hawaii when an engine fire consumed the airplane after her crew had evacuated. The remaining "Big Four" flew record amounts of Naval cargo on the San Francisco-Honolulu route efficiently until 1956, when they were beached at NAS Alameda.

### Civilian use

In 1959, the remaining Mars aircraft were to be sold for scrap, but a Canadian company, Forest Industries Flying Tankers (FIFT), was formed and bid for the four aircraft and a large spares inventory. The company represented a consortium of British Columbia forest companies, and the bid was accepted and the sale completed in December 1959. The four aircraft were flown to Fairey Aviation at Victoria, British Columbia, for conversion into water bombers. The conversion involved the installation of a 27,000 L; 7,200 US gal (6,000 imp gal) plywood tank in the cargo bay with retractable pick-up scoops to allow uploading of water while the aircraft was taxiing. The scoops allowed 27 tonnes (27 long tons; 30 short tons) of water to be taken on board in 22 seconds. Later some of the hull fuel tanks were replaced with water tanks.
The Marianas Mars crashed near Northwest Bay, British Columbia, on 23 June 1961 during firefighting operations; all four crew members were lost. Just over a year later, on 12 October 1962 while parked onshore at the Victoria airport, the Caroline Mars was damaged beyond repair by Typhoon Freda when she was blown 200 metres/yards, breaking her back. The Hawaii Mars and Philippine Mars had their conversion into water bombers advanced and entered service in 1963. They appeared at local airshows, demonstrating their water-dropping ability. Flying Tankers Inc. flew the water bombers to hot spots around the province when a need developed, such as in August 2003, when a large forest fire threatened the outskirts of Kelowna, British Columbia.
On 10 November 2006, TimberWest Forest Ltd. announced they were looking for buyers of the Mars. A condition of sale was that the purchaser would have to donate one plane back to Port Alberni when they were retired, as a historic attraction. The Glenn L. Martin Maryland Aviation Museum and British Columbia Aviation Council initiated a joint effort to preserve the aircraft, one for display in Maryland and the other at the current location in Canada. On 13 April 2007, TimberWest announced the sale of both aircraft to Coulson Forest Products, a local forestry company in Port Alberni, British Columbia. The two surviving tankers were operated by Coulson Flying Tankers from their base at Sproat Lake near Port Alberni until their retirement in 2024. On 25 October 2007, the Hawaii Mars ("Redtail") arrived at Lake Elsinore in southern California, on a private contract, to assist with firefighting efforts at the California wildfires of October 2007. Meanwhile, the Philippine Mars had been undergoing "extensive maintenance and renovation" and was expected to be ready to fly again by 2010. As of 13 August 2009, the Hawaii Mars was in service fighting the La Brea Fire east of Santa Maria in Southern California.
The aircraft can carry 7,200 US gal (27,000 L; 6,000 imp gal) of water and each deployment can cover an area of up to 4 acres (1.6 hectares). The aircraft can also carry up to 600 US gal (2,300 L; 500 imp gal) of foam concentrate for gelling the load drop. They are mainly used to fight fires along the coast of British Columbia and sometimes in the interior. As of 29 July 29 2010, the Martin Mars was being used to fight the Mason Lake/Bonaparte Lake fire north of Kamloops.
On 23 August 2012, the Coulson Group announced that the Philippine Mars, due to its lack of use for five years, would be retired and flown to the National Naval Aviation Museum at Naval Air Station Pensacola, Florida, to become a static exhibit. The aircraft was repainted to its original U.S. Navy colors and was to have been delivered to the museum in November 2012. After many delays, the trade deal of transferring the aircraft to the museum was put on hold by the Navy in June 2016, pending the outcome of the 2016 US Presidential election.
On 10 May 2013, the B.C. provincial government announced that the Hawaii Mars would no longer be placed on contract after the 2013 season, due to not having been used to fight any B.C. fires for two years and the operation of newer and more versatile aircraft by the Coulson group including a Lockheed C-130 Hercules converted to firefighting use. Although Coulson has stated that the Hawaii Mars has been under numerous recent upgrades to make it safer and more reliable, no buyers have come forward to purchase the aircraft. Coulson also cautioned against any plans to open the aircraft as a tourist attraction, citing the 2013 closure of the Flying Tankers Bomber Base Museum from poor attendance.
In May 2015, the Hawaii Mars received a small contract to be used briefly for training Chinese pilots. This was done using the Martin Mars to evaluate against civil certification regulations by the International Test Pilots School on how to handle such a large amphibious aircraft. The pilots would be involved with the Chinese state-owned Aviation Industry Corporation of China as they got ready to launch their forthcoming AVIC AG600 airplane. In July, the training program of 22-hour was completed over six days. In July 2015, the airplane was put back in service, being awarded a 30-day contract from the BC Government to help with a particularly bad fire season.
In 2016, the Hawaii Mars made its first appearance at EAA AirVenture Oshkosh in hopes of being sold or leased to a new home or business. One of the pilots on the way to Oshkosh was well-known Kermit Weeks.
In January 2022, the Hawaii Mars was the subject of multiple news articles when it was placed on sale by the company Platinum Fighter Sales for over $5 million. In June 2023, plans were being finalized for the transfer of the Hawaii Mars to the British Columbia Aviation Museum.

## Retirement Timeline
### Hawaii Mars

On 1 April 2024, Coulson Aviation announced that Hawaii Mars would be donated to the British Columbia Aviation Museum, located at the Victoria International Airport in North Saanich, BC. On 28 March, the province of British Columbia provided a $250,000 grant to "protect and preserve" the plane.
On 25 April 2024, Coulson Aviation announced that Philippine Mars would be donated to the Pima Air & Space Museum in Tucson, Arizona.
On 4 June 2024, Coulson Aviation announced that they would offer two tiers of "VIP Experience Packages" to paying customers wishing "to get up close and personal with their Martin Mars water bombers." These packages were described in $5,000 and $15,000 USD tiers, with a $1,000 CAD "Alberni Residents" tier added later, which required proof of address to purchase. The VIP packages included a base "Water Taxi" package. "This experience will consist of a detailed walk around the airplane and participation in the daily inspection with the maintenance team." The top tier was the "Pilot Recurrency" Package. "This is for our hardcore aviation enthusiasts who dream of getting behind the controls of a 100,000 lb (45 t), 10,000 hp (7,500 kW) behemoth." The VIP Experience Program sold out in 3 days.
On 1 August 2024, Hawaii Mars took flight for the first time since 2016, undertaking a short test flight before a technical issue required the in-flight shutdown and feathering of the number-four engine. After overnight repairs, the aircraft performed multiple other test flights coinciding with its "VIP Experience" program rides.
On 10 August 2024, Hawaii Mars was flown around the Beaufort Range and Comox Glacier accompanied by a Short Skyvan photo ship. On board the latter were photographers tasked with capturing Hawaii Mars for media outlets including Skies Magazine.
On 11 August 2024, Hawaii Mars left Sproat Lake on its final flight. It made celebratory low-passes of the Sproat Lake Bomber Base, Port Alberni Harbour Quay, and the city, before embarking on its journey around multiple communities "with a flight path from Port Alberni to Campbell River, Powell River, then back to Comox and down the coast to Victoria." Its arrival at Patricia Bay, accompanied by the Canadian Forces Snowbirds, was live streamed on YouTube.
On 14 August 2024, Hawaii Mars was carefully manoeuvred past breakwaters at the Patricia Bay Coast Guard station. In the following days, the aircraft was carefully jacked onto a custom-built 360-degree swivelling trailer, and on 21 August was transported from the coast guard station to a parking spot at British Columbia Aviation Museum.
On September 20, 2024, The BC Aviation Museum hosted a private ribbon cutting ceremony honouring Hawaii Mars and the "monumental efforts by all involved to bring the aircraft to its forever home". Many former Mars crewmembers and VIPs including the Coulson family were present.
On September 28, 2024, Hawaii Mars was officially opened to the public with much fanfare. The BC Aviation Museum is actively modifying the aircraft for public viewing while best preserving the aircraft.

### Philippine Mars

On 3 December 2024, Philippine Mars flew for the first time since 2007 as part of a series of test flights. Due to a cracked crank case on #2 engine (left inboard), the #2 engine from Hawaii Mars was installed on Philippine Mars. Subsequent test flights were successful and the aircraft was deemed ready for its final flights.
On 11 December 2024, Philippine Mars departed Sproat Lake for supposedly the final time, en route to San Francisco. However, as it passed North Nanaimo, an indication of low oil pressure in the #2 engine necessitated its shutdown prior to landing. The aircraft returned to the lake shortly afterward and landed without further incident.
On 15 December 2024, Philippine Mars made its second attempt at flying south. Due to fog on Sproat Lake it landed, taxied back up Taylor Arm and again departed, hours behind schedule. The flight followed the same initial route as the first attempt, then followed the east coast of Vancouver Island. The aircraft made low passes of Nanaimo Harbour, Nanaimo Airport (CYCD) and Ladysmith Harbour before climbing to 2,500ft and proceeding toward Victoria International Airport, where it overflew Hawaii Mars. It then proceeded southeast toward the Puget Sound. As the aircraft neared Port Townsend, Washington, a sudden loss of oil pressure in the #4 (right outboard) engine necessitated an immediate in-flight shutdown. The crew made an immediate course reversal. Philippine Mars was seen flying over San Juan Island with its #4 engine shut down and propeller feathered as it returned to Patricia Bay. Philippine circled for nearly two hours before landing in the bay.
On 22 December 2024, after engine maintenance at Patricia Bay, the aircraft was untied from its mooring for taxi-tests. Shortly after startup, the #4 engine errupted in smoke, having suffered a contained complete failure and fire. The aircraft was towed back to its mooring. The aircraft was effectively grounded pending replacement of the #4 engine.
On 6 January 2025, Phillippine Mars was towed from Patricia Bay to Cowichan Bay by a Coulson tender. Repairs would be completed there, as Cowichan Bay provided sheltered waters, with the aircraft much closer to shore.
On 7 January 2025, the serviceable #4 engine was removed from Hawaii Mars, and installed onto Philippine Mars.
On 10 January, Philippine Mars departed Cowichan Bay, following successful run-ups and taxi checks. The aircraft landed at the Sproat lake Bomber Base without incident.
On 9 February 2025, Philippine Mars left Sproat Lake for the final time, lifting off at 11:03am PST. The aircraft made a fast pass of the bomber base, Harbour Quay and Port Alberni paper mill, before departing the area via the Alberni Inlet. Multiple general aviation aircraft were present in the area prior to, and during the departure. The aircraft was visible on several coastal webcams along its route of flight, up to and including its approach into San Francisco Bay. About midway through the journey, Philippine Mars was joined by two vintage aircraft, a privately registered Howard DG15 (N858H) and a PBY Vultee 28 Catalina (N9767, owned by Soaring by the Sea Foundation of Eugene, Oregon). Both aircraft followed Philippine for several miles between Lincoln City and Florence, Oregon, with Philippine adjusting her speed to accommodate them. Following a successful landing in San Fransisco Bay, the aircraft was towed to a mooring buoy at the Alameda Seaplane Base, to await its final planned flight to an undisclosed lake, where it is due to be disassembled at its factory assembly joints and transported the remaining distance to Pima Air & Space Museum by road.
On February 10, 2025, Philippine Mars departed San Francisco Bay, lifting off at 11:57am PST. The aircraft flew outbound over the Golden Gate Bridge and followed the coast past Santa Cruz and Monterey before flying inland toward its final destination of Lake Pleasant, Arizona. As the aircraft neared Palm Springs, California, it was joined by an array of historic aircraft, including the world's only remaining airworthy Consolidated PB4Y-2 Privateer (N2871G), as well as a P-51D Mustang (N44727), which escorted the aircraft the remaining distance to Lake Pleasant, Arizona. Philippine Mars landed without incident, and officially marked the end of an era by successfully completing the last flight of a Martin Mars aircraft. Philippine Mars will be de-watered in the coming days, while a timeline for when preparations will begin for dismantling of the aircraft has yet to be released.

## Variants
### XPB2M-1

    Model 170 prototype long-range patrol flying boat powered by four Wright R-3350-8 piston engines, one built, converted to XPB2M-1R.

### XPB2M-1R

    Prototype converted in December 1943 as a prototype transport version, armament removed, installation of additional cargo hatches and cargo loading equipment, existing hatches were enlarged and the decking was reinforced.

### JRM-1

    Model 170A, production long range transport variant, originally 20 aircraft ordered later reduced to six. Single-tail design, and having a longer hull with fewer bulkheads and a larger maximum take-off weight. It had also been fitted with equipment for overhead cargo handling and was powered by four Wright R-3350-24WA Cyclone engines with 4-bladed propellers, five built, surviving four converted to JRM-3.

### JRM-2

    The last JRM-1 on order was completed as the JRM-2 with the engines changed to 3,000 hp (2,200 kW) Pratt & Whitney R4360-4T engines with 4-blade, 16 ft 8 in (508 cm) diameter Curtiss Electric propellers. Gross weight increased by 20,000 lb (9,100 kg).

### JRM-3

    Model 170B, conversion of the remaining four JRM-1s re-engined with 2,400 hp (1,800 kW) Wright R3350-24WA engines turning 16 ft 8 in (508 cm) Curtiss-Electric props, of which the inboard two engines were fitted with reversible-pitch devices.

### Aircraft

* The Old Lady – Bureau Number (BuNo) 1520. Ordered on 23 August 1938 and completed as the prototype long-range patrol XPB2M-1, it was first flown on 3 July 1942 and converted in December 1943 to transport variant and designated XPB2M-1R. Assigned initially to VR-8 at NAS Patuxent River, Maryland for crew training, it was later transferred to VR-2 at NAS Alameda, California and scrapped in 1945.
* Hawaii Mars I – JRM-1 BuNo 76819 first flown on 21 July 1945 and delivered to the United States Navy. It sank on 5 August 1945 in the Chesapeake Bay and was disposed as scrap.
* Philippine Mars – JRM-1 BuNo 76820, delivered to the USN on 26 June 1946 and assigned to VR-2 at NAS Alameda, California. Converted and re-designated JRM-3. Withdrawn from service on 22 August 1956 and sold in 1959, it was converted to forest fire fighting aircraft and registered CF-LYK (later C-FLYK). The aircraft continued to fly with Flying Tankers Incorporated until she and the Hawaii Mars were purchased in 2007 by the Coulson Group. The Philippine Mars has not flown on fires since the summer of 2006 and was repainted to original U.S. Navy markings in preparation for transfer to be a museum display at the National Naval Aviation Museum at NAS Pensacola, Florida. The plan to ferry her to the museum in April or May 2016 was put on hold.
* Marianas Mars – JRM-1 BuNo 76821, delivered to the USN on 26 February 1946 and assigned to VR-2 at NAS Alameda. Converted and re-designated JRM-3, it was withdrawn from service on 22 August 1956 and sold in 1959. Converted to forest fire fighting aircraft and registered CF-LYJ, the aircraft crashed into Mount Moriarty near Nanaimo, Vancouver Island, on 23 June 1961, when the water drop mechanism failed, leaving the aircraft unable to climb quickly enough to clear a mountain. In the ensuing crash, the crew of four were killed.
* Marshall Mars - JRM-1 BuNo 76822, delivered to the USN, converted and re-designated JRM-3. It was destroyed by an engine fire and sank on 5 April 1950 off Diamond Head, Oahu, Hawaii.
* Hawaii Mars II – JRM-1 BuNo 76823, delivered to the USN on 23 April 1946 and assigned to VR-2 at NAS Alameda. Converted and redesignated JRM-3, it was withdrawn from service on 22 August 1956 and sold in 1959. Converted to forest fire fighting aircraft and registered CF-LYL (later C-FLYL), it remains the only aircraft of this type in service and flew with FIFT (Forest Industries Flying Tankers), FTI (Flying Tankers Inc.) and the Coulson Group at Sproat Lake, British Columbia until 2013 and briefly in 2015. According to aircraft fleet information provided by the Coulson Aviation website, "Coulson Aviation has significantly upgraded the Hawaii, bringing it to the higher aviation and safety standards of modern-day firefighting. The next-generation Hawaii Mars has an EFIS glass cockpit and the ability to stream live data from certain key on-board indication systems. Other data available from the aircraft included real time flight tracking, load data measuring, aircraft performance statistics, atmospheric condition at drop readings, and accurate drop location reporting." The aircraft also is equipped with a satellite phone and cockpit voice recorder, Coulson Group Vice President Britt Coulson told CNN's Thom Patterson during a tour of the flight deck in 2016. It made its final flight to the BC Aviation Museum on August 11, 2024.
* Caroline Mars – JRM-2 BuNo 76824, delivered to the USN on 10 May 1948 and assigned to VR-2 at NAS Alameda. It was sold in 1959 and converted to forest fire fighting aircraft by Forest Industry Flying Tankers. Registered CF-LYM. The aircraft was damaged beyond repair during Typhoon Freda at Victoria, Canada on 12 October 1962.
* "SHIP 8" – The unfinished nose section of what would have become the 8th Martin JRM aircraft. This nose section was originally acquired by Forest Industries Flying Tankers in the 1960's, and was stored at the Sproat lake Bomber Base near Port Alberni. It lay in the bush for decades before it was recovered by Coulson Aviation, and in 2007 placed on display at the Sproat Lake Visitor Centre. Currently, "SHIP 8" resides at the Sproat lake Bomber base. The name "Ship 8" comes from several factory labels spray-painted on unrestored interior bulkheads of the unfinished section that read "SHIP8."

## Specifications (JRM-3 Mars)

Data from Jane's Fighting Aircraft of World War II
General characteristics
* Crew: four (with accommodations for a second relief crew)
* Capacity: JRM Mars - 133 troops, or 84 litter patients and 25 attendants or 32,000 lb (15,000 kg) payload, including up to seven Willys MB jeeps
* Water/foam load: Mars waterbomber - 60,000 lb (27,000 kg)
* Length: 117 ft 3 in (35.74 m)
* Wingspan: 200 ft 0 in (60.96 m)
* Width: 13 ft 6 in (4.11 m) Hull beam
* Height: 38 ft 5 in (11.71 m) afloat, 48 ft (15 m) beached
* Hull draught: 5 ft 6 in (1.68 m)
* Wing area: 3,686 sq ft (342.4 m$^2$)
* Empty weight: 75,573 lb (34,279 kg)
* Gross weight: 90,000 lb (40,823 kg)
* Max takeoff weight: 165,000 lb (74,843 kg)
* Fuel capacity: Hawaii Mars: 6,485 US gal (24,550 L; 5,400 imp gal) Philippine Mars: 13,200 US gal (50,000 L; 11,000 imp gal)
* Powerplant: 4 × Wright R-3350 Duplex-Cyclone 18-cylinder radial engines, 2,500 hp (1,900 kW) each
* Propellers: 4-bladed Curtiss Electric, 15 ft 2 in (4.62 m) diameter variable-pitch propellers
Performance
* Maximum speed: 221 mph (356 km/h, 192 kn)
* Cruise speed: 190 mph (310 km/h, 170 kn)
* Range: 4,900 mi (8,000 km, 4,300 nmi)
* Service ceiling: 14,600 ft (4,500 m)
* Drop speed: 138 mph (120 kn; 222 km/h)
* Landing approach speed: 115 mph (100 kn; 185 km/h)
* Touchdown speed: 92 mph (80 kn; 148 km/h)
* Fuel consumption (cruise): 420 US gal (1,600 L; 350 imp gal) per hour
* Fuel consumption (operations): 780 US gal (3,000 L; 650 imp gal) per hour
* Operations duration (normal): 5+1⁄2 hours
* Area covered, single drop: 3 to 4 acres (1.2 to 1.6 ha)
* Drop height: 150 to 200 ft (46 to 61 m)
* Full water tank load: 7,200 US gal (27,000 L; 6,000 imp gal)