6 April 1939

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The Bell XP-39 prototype in the original turbosupercharged configuration. The intercooler and waste gates created significant aerodynamic drag. (Bell Aircraft Corporation)
The Bell XP-39 prototype, 38-326, in the original turbosupercharged configuration. The intercooler and waste gates created significant aerodynamic drag. (U.S. Air Force)

6 April 1939: ¹ After being shipped by truck from the Bell Aircraft Company factory at Buffalo, New York, the XP-39 prototype, 38-326, (Bell Model 4) made its first flight at Wright Field, Dayton, Ohio, with test pilot James Taylor ² in the cockpit. During the test flight, Taylor flew the XP-39 to 390 miles per hour (628 kilometers per hour) at 20,000 feet (6,096 meters). The service ceiling was 32,000 feet (9,754 meters).

The XP-39 was designed by Bell’s chief engineer, Robert J. Woods, to meet a U.S. Army Air Corps requirement, X-609, issued in March 1937, for a high altitude interceptor. A contract for the prototype was issued 7 October 1937. On 15 April 1939, Assistant Secretary of War Louis Johnson announced that the U.S. Army had purchased the experimental Bell XP-39 and the Seversky XP-41. The War Department announced a $1,073,445 contract to purchase 12 YP-39s and one YP-39A on 27 April 1939.

The Bell XP-39 Airacobra was a single-place, single-engine prototype fighter with a low wing and retractable tricycle landing gear. The airplane was primarily built of aluminum, though control surfaces were fabric covered.

Bell XP-39 Airacobra 38-326. (U.S. Air Force)

As originally built, the XP-39 was 28 feet, 8 inches (8.738 meters) long with a wingspan of 35 feet, 10 inches (10.922 meters). The prototype had an empty weight of 3,995 pounds (1,812 kilograms) and gross weight of 5,550 pounds (2,517 kilograms).

The Bell XP-39 Aircobra in original configuration. (Allison Engine Historical Society)
The Bell XP-39 Aircobra in original configuration. (U. S. Air Force)

The XP-39 was unarmed, but it had been designed around the American Armament Corporation T9 37 mm autocannon, later designated Gun, Automatic, 37 mm, M4 (Aircraft).³ The cannon and ammunition were in the forward fuselage, above the engine driveshaft. The gun fired through the reduction gear box and propeller hub.

The XP-39 was originally powered by a liquid-cooled, turbosupercharged and supercharged 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-E2 (V-1710-17), a single overhead cam (SOHC) 60° V-12 engine with a compression ratio of 6.65:1. The V-1710-17 had a Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m. at 25,000 feet (7,620 meters), and Takeoff/Military Power rating of 1,150 horsepower at 3,000 r.p.m. at 25,000 feet, burning 91 octane gasoline.

Bell P-39 Airacobra center fuselage detail with maintenance panels open. (U.S. Air Force photo)

The engine was installed in an unusual configuration behind the cockpit, with a two-piece drive shaft passing under the cockpit and turning the three-bladed Curtiss Electric constant-speed propeller through a remotely-mounted 1.8:1 gear reduction gear box. The V-1710-17 was 16 feet, 1.79 inches (4.922 meters) long, including the drive shaft and remote gear box. It was 2 feet, 11.45 inches (0.900 meters) high, 2 feet, 5.28 inches (0.744 meters) wide and weighed 1,350 pounds (612 kilograms).

Allison V-1710 E19 (V-1710-85) with extension drive shaft and remote propeller drive gear unit. (Allison Division of General Motors)

On 6 June 1939 the XP-39 was flown to the National Advisory Committee for Aeronautics (NACA) Langley Memorial Aeronautical Laboratory at Hampton, Virginia, by Lieutenant Mark E. Bradley, Jr. The prototype was tested in the Full-Scale Wind Tunnel. Improvements in aerodynamics were recommended and Bell rebuilt the airplane as the XP-39B with an Allison V-1710-E5 (V-1710-37) engine.

Bell XP-39 Airacobra 38-326 in the NACA Langley Memorial Aeronautical Laboratory Full-Scale Wind Tunnel, Langley Field, Virginia. (NASA)
Bell XP-39 Airacobra 38-326 in the NACA Langley Memorial Aeronautical Laboratory Full-Scale Wind Tunnel, Langley Field, Hampton, Virginia, 9 August 1939. The fuselage has had all protrusions removed. (NASA)
Bell XP-39 Airacobra 38-326 in the NACA Langley Memorial Aeronautical Laboratory Full-Scale Wind Tunnel, Langley Field, Hampton, Virginia. (NASA)

The turbosupercharger had been removed, which reduced the airplane’s power at altitudes above 15,000 feet (4,572 meters). The V-1710-37 had a maximum power of 1,090 horsepower at 3,000 r.p.m. at 13,300 feet (4,054 meters). This resulted in the P-39 being used primarily as a ground-attack weapon.

The XP-39B, with test pilot George Price in the cockpit, was damaged when when its landing gear did not fully extend, 6 January 1940. It was repaired and test flights resumed. On 6 August 1940, Captain Ernest K. Warburton stalled the prototype on landing. The impact resulted in significant structural damage, beyond economic repair. The airplane was later scrapped.

Bell Model 12 (XP-39) prototype 38-326, at Bell Aircraft Co., Buffalo, New York
Bell XP-39B Airacobra prototype, 38-326, at the Bell Aircraft Corporation airfield, Buffalo, New York, 1940. (Bell Aircraft Corporation)

On 27 April 1939, the U.S. Army announced that a contract to Bell Aircraft had been issued in the amount of $1,073,445 for delivery of thirteen YP-39s. 9,584 Bell P-39 Airacobras were built during World War II. More than half were sent to the Soviet Union.

Bell XP-39 prototype, serial number 38-326. (Bell Aircraft Corporation)
Bell XP-39B prototype, serial number 38-326. (Bell Aircraft Corporation)

¹ Reliable sources indicate the date of the first flight as both 6 April 1938 and 6 April 1939. The Bell Helicopter Company web site, “The History of Bell Helicopter: 1935–1949” states 1938. However, contemporary newspaper articles strongly suggest that the date was 1939. The first newspaper references to the XP-39 located by TDiA are dated 16 April 1939. On 18 April 1939, the Dayton Daily News reported:

     The radically-designed XP-39 is at the field now undergoing further testing. Its purchase was announced Saturday in Washington. It had been at the materiel division for about two months before its initial flight on Army Day, April 6.

—Dayton Daily News, Dayton, Ohio, Vol. LXII, No. 240, Tuesday, 18 April 1939, Page 8, Column 7

LCDR James B. Taylor, Jr., USNR, 1942.

² James Taylor may have been James Blackstone (“Jimmie”) Taylor, Jr. (23 September 1897–25 May 1942). Taylor (Lieutenant Commander, United States Naval Reserve) was a well-known test pilot of the time. He was famous for his high-speed power dive from 20,000 feet (6,096 meters) over Farmingdale, New York, in the Seversky NF-1, 25 June 1937.

³ The 37-mm Aircraft Gun Matériel M4 is a recoil-operated aircraft weapon designed by John M. Browning. It has an overall length of 7 feet, 5 inches (2.26 meters). The barrel, or “tube,” is 5 feet, 5 inches (1.65 meters) long with a caliber of 1.457 inches (37.0 millimeters) and weighs 55 pounds (25 kilograms). The barrel is part of the recoiling section of the gun and moves rearward 9-5/8 inches (245 millimeters). The weight of the gun with a loaded 30-round magazine is 306.4 pounds (138.98 kilograms). The M4 fires a high-explosive tracer round with a muzzle velocity of 2,000 feet per second (607 meters per second). Each M54 shell is 9.75 inches (248 millimeters) long and weighs 1.93 pounds, of which the projectile makes up 1.34 pounds (0.608 kilograms). The cannon has a cyclic rate of fire of 125–150 rounds per minute.

© 2023, Bryan R. Swopes

6 April 1927

Aviation, ,
William MacCracken’s Pilot Identification Card
United States of America Pilot License No. 1

6 April 1927: William Patterson MacCracken, Jr., Assistant Secretary of Commerce for Aeronautics, became the first person to be issued a pilot’s license by the government of the United States. License Number 1 was a private license, signed by then Secretary of Commerce Herbert Hoover, who would later become the 31st President of the United States of America.

Assistant Secretary MacCracken had offered the first pilot certificate to aviation pioneer Orville Wright, but Wright declined, as “he no longer flew and did not think he needed a Federal license to show that he had been the first man to fly.”

© 2018, Bryan R. Swopes

6 April 1924

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One of the four Douglas World Cruisers taxis on Lake Washington prior to departure, 6 April 1924. (National Archives)

6 April 1924: Four United States Army Air Service Douglas DWC single-engine biplanes departed Sand Point, near Seattle, Washington, on the first aerial circumnavigation of the world. The airplanes were named Boston, Chicago, New Orleans and Seattle.

Pilots for the operation had been personally selected by Chief of the Air Service, General Mason Patrick. Pilot of Seattle, (A.S. 23-1229) and in command of the flight, was Major Frederick Leroy Martin. His mechanic was Staff Sergeant Alva L. Harvey. The second airplane, Chicago, (A.S. 23-1230) was piloted by 1st Lieutenant Lowell Herbert Smith, with 1st Lieutenant Leslie P. Arnold. 1st Lieutenant Leigh Wade flew Boston (A.S. 23-1231) with Staff Sergeant Henry Herbert Ogden. The final DWC, New Orleans, (A.S. 23-1232) was flown by 1st Lieutenant Erik Hemming Nelson, with 2nd Lieutenant John Harding, Jr.

Two of the pilots, Martin and Wade, would rise to the rank of major general, and a third, Nelson, to brigadier general. One of the mechanics, Hank Ogden, would become a colonel. Another mechanic, Harding, became a vice president of the Lockheed Aircraft Corporation.

The prototype Douglas World Cruiser, A.S. 23-1210, McCook Field project number P318. (Library of Congress)

The five Douglas World Cruisers, a prototype and four production airplanes, were modified from current production U.S. Navy  DT-2 torpedo bombers. The DWC was a single-engine, two-place, single-bay biplane. The landing gear could be switched from wheels to pontoons for water landings. Fuel capacity was increased to 644 gallons (2,438 liters).

The DWC was 35 feet, 9 inches (10.90 meters) long with a wingspan of 50 feet, 6 inches (15.39 meters) and height of 13 feet, 9 inches (4.19 meters). With pontoons installed, the length increased to 39 feet (11.89 meters), and height to 15 feet, 1 inch (15.08 meters). The airplane had an empty weight of 4,380 pounds (1,987 kilograms) with wheels, and 5,180 pounds (2,350 kilograms) with pontoons.

The DWC was powered by a water-cooled, normally-aspirated, 1,649.336-cubic-inch-displacement (27.028 liter) Liberty L-12 single overhead cam (SOHC) 45° V-12 engine with a compression ratio of 5.4:1. The Liberty produced 408 horsepower at 1,800 r.p.m. The L-12 as a right-hand tractor, direct-drive engine and it turned turned a two-bladed fixed-pitch wooden propeller. The Liberty 12 was 5 feet, 7.375 inches (1.711 meters) long, 2 feet, 3.0 inches (0.686 meters) wide, and 3 feet, 5.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms).

The Douglas World Cruiser had a maximum speed of 103 miles per hour (166 kilometers per hour) and ceiling of 10,000 feet (3,048 meters). Its range was 2,000 miles (3,219 kilometers).

Seattle was delayed at Sand Point after being damaged during takeoff. Once repaired, Martin and Harvey followed the others, but on 30 April, they crashed in Alaska. The two men were lost in the wilderness for ten days, but only slightly injured. On 2 May, Lieutenant Smith was ordered to assume command of the flight.

The planned route of the first aerial circumnavigation of the world. (National Archives)

175 days later, after flying 27,553 miles (44,342.3 kilometers) in 371 hours, 11 minutes, two of the World Cruisers, Chicago and New Orleans, complete the flight and return to Seattle.

Chicago is on display at the Smithsonian National Air and Space Museum and New Orleans is in the collection of the Los Angeles County Natural History Museum.

Douglas DWC A.S. 23-1230, Chicago, at the Smithsonian Institution National Air and Space Museum. (NASM)

© 2017, Bryan R. Swopes

5 April 1968

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Flt-Lt. Pollock flies his Hawker Hunter through the Tower Bridge, 5 April 1968. Illustration by Flight Artworks.

Friday, 5 April 1968: Flight Lieutenant Alan Richard Pollock, No. 1 Squadron, Royal Air Force, based at RAF West Raynham, southwest of Fakenham, Norfolk, was leading a flight of four Hawker Hunter FGA.9 close air support fighters. Pollock described the weather:

“Over London the weather was still one of those rare perfect 8/8 Gordon’s crystal, gin clear days when all the colours shout out brightly.”

Pollock broke away from the formation and flew toward London.

FLIGHT International reported:

Hunter to Tower—Under

     An RAF Hunter few through the Tower Bridge, London, in a down-river direction just after noon last Friday, April 5. The Hunter, carrying underwing tanks, was glimpsed momentarily from Flight‘s offices in a descending, mushing turn until lost to sight behind United Africa House. Previous flights through Tower Bridge—never in a jet, and never so fast—have invariably been made in an up-river direction.

     The MoD was investigating as we closed for press; the supposition was that the aircraft was an FGA.9 of 1 or 54 Squadrons, which comprise the close-support wing at RAF West Raynham. The station refused comment, but flying was taking place that day. Visibility was excellent. Some authorities attributed the incident to widespread resentment that the RAF had been deprived of a ceremonial fly-past on the 50th anniversary day, April 1. The Red Arrows were expecting to make this fly-past last month, but permission was presumably denied. A Ministry of Defence spokesman to whom we were referred at press time by the duty officer at RAF West Raynham, was not then able to reveal the name of the pilot.

—FLIGHT International, Vol. 93, Number 3083, 11 April 1968, at Page 500, Column 3

Diagram of Tower Bridge, with dimensions. (Wikipedia)

. . . and the following week:

The Man Who Shot the Bridge

     The RAF pilot who flew a Hunter FGA.9 through Tower Bridge, London, on April 5 was no youthful prankster but a senior flight commander of 1 Sqn, RAF West Raynham, an Old Cranwellian, and the father of four children.

     He was Flt Lt Alan Richard Pollock, aged 32. He was named on Sunday, April 7, by MoD (Air) too late, owing to Easter press schedules, for mention in our last week’s story. Flt Lt Pollock was placed under close arrest on April 5 and released into open arrest on April 7. A board of inquiry was convened at West Raynham on April 8. An all-party motion signed by six MPs [Members of Parliament] was tabled in the Commons in his support but was ruled unacceptable.

     Whatever their views on the responsibility and possible consequences of flying a jet fighter through the 200ft-wide, 110ft-deep aperture framed by the towers, the bascules and the upper span of Tower Bridge, there is unanimity among pilots that it was a handsome piece of flying.

     Flt Lt Pollock was the first pilot to fly through the bridge in a downstream direction, following the gentle sinuousities of King’s Reach from the Waterloo Bend—and passing over Blackfriars’ two bridges (road and rail), Southwark Bridge, Cannon Street rail bridge, and London Bridge. After clearing the last he probably had little more than five seconds to align himself with the eye of the needle presented by Tower Bridge, retaining until the last fraction of a second the option of pulling up had he found the opening partly obstructed by abnormally high vehicles, by hanging cradles or by the bascules opening.

     It has been reported that Flt Lt Pollock peeled off from a formation returning from RAF Tangmere, where he had led four Hunters on display duties. This might have accounted for his choice of direction. The absence of pre-placed photographers, who always seem to have been around on previous Tower Bridge buzzings, seems to rule out premeditation. Another explanation of why he preferred the crane-lined Upper Pool downstream of Tower Bridge for his climb-out when all previous pilots have used it for the run in may have been to avoid climbing through the flight levels occupied by airliners on the approach to Heathrow had he made a westerly climb-out. He turned to port over the City.

     The RAF and civil authorities were tussling last week about whether Flt Lt Pollock should be court-martialled or tried in a civil court. His one-man fly-past was construed in and outside the RAF as an expression of resentment felt by many in the Service—including those now responsible for deciding his punishment—of the way the Royal Air Force is being treated by the Government. It may be that the last straw was the cancellation of the 50th anniversary fly-past over the capital on April 1. A fly-past planned in conjunction with the Lancaster House dinner with the Queen was cancelled at the last moment as “inappropriate.” A mid-day fly-past, seen by the maximum number of Londoners and visitors, would have been most “appropriate” on this occasion.

     Attitudes to the Tower Bridge exploit of past and present members of the RAF whom we have questioned vary from the very strongly censorious to the frankly admiring; but an unvarying theme was that some RAF protest was called for, without infringing flying discipline.

—FLIGHT International, Volume 93, Number 3084, 18 April 1968 at Page 567, Columns 1 and 2

The Royal Air Force did not court-martial Flight Lieutenant Pollack. A medical board discharged him from the service. The Ministry of Defence announced that Pollack had been hospitalized with pneumonia, and that, “. . . if he were brought to trial it would probably have a damaging effect on his health, both immediately and in the long term.”

An oral history recording with Alan Pollack (32 minutes, 20 seconds) is available at the Imperial War Museum:

https://www.iwm.org.uk/collections/item/object/80027439

This was not the first time an airplane had flown through Tower Bridge. On 10 August 1912, Frank McLean (later, Lieutenant Colonel Sir Francis Kennedy McLean, A.F.C.) flew his modified Short S.33 float plane, and, according to his obituary in The Times, 12 August 1955, “. . . created a record by flying up the Thames in a seaplane, passing between the upper and lower parts of Tower Bridge and under London Bridge without touching the water.”

Frank McLean flying through the Tower Bridge, 10 August 1912. (Clan Maclean)

Alan Pollock was flying a Hawker Hunter FGA.9, XF442, c/n S4/U/3318. It had been converted from a Hunter F.6 interceptor. The Hunter was a single-seat, single-engine, swept-wing jet fighter, which first entered service with the Royal Air Force in 1954. The FGA.9 ground attack variant was based on the Hunter F.6 interceptor.

Hawker Hunter FGA.9 XF511, photographed in 1974. This is the same type aircraft as that flown by Flight Lieutenant Pollack, 5 April 1968. (Mike Freer/Wikipedia)

The FGA.9 was 33 feet, 8 inches (10.262 meters) long with a wingspan of 45 feet, 10½ inches (13.983 meters) and height of 13 feet, 2 inches (4.013 meters). The wing area was 340 square feet (31.6 square meters). The wings were swept back 40° at ¼-chord, and had an angle of incidence of 1½°. There is noticeable anhedral. The FGA.9 had and empty weight of 13,010 pounds (5,901 kilograms) and maximum takeoff weight of 18,000 pounds (8,165 kilograms).

The FGA.9 was powered by a single Rolls-Royce RA.28 Avon 207 engine. This was a single-shaft axial-flow turbojet with a 15-stage compressor and 2-stage turbine. The RA.28 was 10 feet, 3.0 inches (3.124 meters) long, 3 feet, 5.5 inches (1.054 meters) in diameter, and weighed 2,869 pounds (1,301 kilograms). It was rated at 10,050 pounds of thrust (44.7 Kilonewtons).

Hawker Hunter FGA.9 XF442 at RAF Lossiemouth, 1979. This is the airplane flown through Tower Bridge, 5 April 1968. (Peter Nicholson via Airport-Data.com)

The Hunter FGA.9 had a maximum speed of 702 miles per hour at 15,000 feet (4,572 meters)—0.97 Mach—and maximum range of 1,850 miles (2,977 kilometers) with external fuel tanks.

The basic armament of the Hunter were four 30 mm ADEN autocannon installed in a removable gun pack, along with 150 rounds of ammunition per gun. The ADEN was a gas-operated revolver cannon, capable of firing 1,200–1,400 rounds per minute. The FGA.9 could also carry a 1,000 pounds (454 kilograms) bomb under each wing, twenty-four 3-inch rockets, or two rocket pods with thirty-seven 2-inch rockets, each, for ground attack.

Hawker produced 144 of the Hunter FGA.9 ground attack variant, with 12 modified from F.6 interceptors. Most of Hawker’s foreign sales were based on the FGA.9.

Hawker Hunter FGA.9 XF442 was transferred to the Fuerza Aérea de Chile, 24 April 1982, and assigned identification number J-742. It crashed near Antofagasta, in northern Chile, 20 May 1982.

Alan Pollock was recently interviewed for the Daily Mail:

http://www.dailymail.co.uk/news/article-5571423/RAF-veteran-pilot-82-relives-split-second-decision-fly-busy-Tower-Bridge.html

© 2018, Bryan R. Swopes

5 April 1950

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Martin JRM-3 Mars Bu. No. 76822, Marshall Mars, burning off Diamond Head, Oahu, Hawaiian Islands, 5 April 1950. (U.S. Navy)
Martin JRM-3 Mars Bu. No. 76822, Marshall Mars, burning off Diamond Head, Oahu, Hawaiian Islands, 5 April 1950. (U.S. Navy)

5 April 1950: While on a test flight following an engine change, a United States Navy Martin JRM-3 Mars seaplane, Marshall Mars, Bu. No. 76822, suffered an engine fire (inboard, left wing) and made an emergency landing at Ke’ehi Lagoon, off Diamond Head, Hawaii. The airplane’s crew was rescued but the airplane exploded and sank.

The wreck was discovered on the sea floor in August 2004 at a depth of approximately 1,400 feet (427 meters).

The Martin JRM Mars was a large four-engine flying boat transport built by the Glenn L. Martin Company for the U. S. Navy. originally designed as a patrol bomber, the prototype XPB2M-1 Mars made its first flight on 3 July 1942, Only five transport variants were built, four designated JRM-1, with the last one being a JRM-2. Each airplane was given an individual name derived from the names of island chains in the Pacific Ocean: Marianas Mars, Hawaii Mars, Philippine Mars, Marshall Mars and Caroline Mars. These airplanes were used to transport personnel and cargo between the West Coast of the United States and the Hawaiian Islands. All were upgraded to JRM-3.

Four Martin JRM-3 Mars flying boats in formation. (U.S. Navy)
Four Martin JRM-3 Mars flying boats in formation. (U.S. Navy)

The Martin JRM-2 Mars had a normal crew of 4, with accommodations for a relief crew. It was designed to carry 138 combat troops or 34,000 pounds (15,422 kilograms) of cargo. It was 120 feet, 3 inches (36.652 meters) long with a wingspan of 200 feet, 0 inches (60.960 meters) and height of 43 feet, 8 inches (13.310 meters), with beaching gear. The wing area was 3,686 square feet (342.4 square meters). The flying boat had an empty weight of 80,701 pounds (36,605 kilograms) and a maximum takeoff weight (MTOW) 0f 165,000 pounds (74,843 kilograms).

Martin JRM-2 Mars three-view illustration with dimensions. (U.S. Navy)

A NASA publication states, “A zero-lift drag coefficient of 0.0233 and a maximum lift-drag ratio of 16.4 made the JRM the most aerodynamically efficient of any of the flying boats. . . .”

Martin JRM-3 Mars, Bu.No. 76822, Marshall Mars. (U.S. Navy)
Martin JRM-3 Mars, Bu.No. 76822, Marshall Mars. (U.S. Navy)

The Martin Mars was powered by four air-cooled, supercharged, direct-fuel-injected, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-24WA (Cyclone 18 825C18BD1) (also known as the Duplex-Cyclone), a two-row 18-cylinder radial engines with a compression ratio of 6.70:1 and water/alcohol injection. This engine has a normal power rating of 2,000 horsepower at 2,400 r.p.m at 5,500 feet (1,676 meters) and 1,800 horsepower at 2,400 r.p.m. at 15,000 feet (4,572 meters). The engine’s takeoff power rating is 2,500 horsepower at 2,900 r.p.m. 100/130 octane aviation gasoline was required. The engines drove four-bladed 16 foot, 8 inch (5.080 meter) Curtiss Electric variable-pitch propellers through a 0.4375:1 gear reduction. (After modification to the JRM-3, the propellers on the inboard engines were reversible.) The R-3350-24WA is 6 feet, 8.58 inches (2.047 meters) long, and 4 feet, 6.13 inches (1.375 meters) in diameter. Its dry weight is 2,822 pounds (1,280 kilograms).

The JRM-3 had a cruise speed of 165 knots (190 miles per hour/306 kilometers per hour) and a maximum speed of 211 knots (243 miles per hour/391 kilometers per hour) at 15,600 feet (4,755 meters). The service ceiling was 19,700 feet (6,005 meters) and its range was 3,790 nautical miles (4,361 statute miles/7,019 kilometers).

A U.S. Navy Martin JRM Mars. (Glenn L. Martin Co.)
A U.S. Navy Martin JRM Mars. (Glenn L. Martin Co.)

© 2019, Bryan R. Swopes