Tag Archives: Browning Machine Gun Caliber .50 AN-M2

21 September 1942

Boeing XB-29 takes off from Boeing Field, Seattle, Washington. (Boeing)
A Boeing XB-29 takes off from Boeing Field, Seattle, Washington. (Boeing)
Edmund T. ("Eddie") Allen
Edmund T. (“Eddie”) Allen

21 September 1942: At Boeing Field, Seattle, Washington, the Boeing Model 345, the first of three XB-29 prototypes, Air Corps serial number 41-002, took off on its first flight.

Edmund T. “Eddie” Allen, Director of Aerodynamics and Flight Research, was in command, with Al Reed, Chief of Flight Test and Chief Test Pilot, as co-pilot. They climbed to 6,000 feet (1,829 meters) and began testing the XB-29’s stability and control, control power and response, and stall characteristics.

The flight was uneventful. Landing after 1 hour, 15 minutes, Allen is supposed to have said, “She flew!”

The XB-29 was 98 feet, 2 inches (29.921 meters) long with a wing span of 141 feet, 3 inches (43.053 meters), and 27 feet, 9 inches (8.458 meters) high to the top of its vertical fin. The prototype bomber had a gross weight of 105,000 pounds (47,627 kilograms).

Boeing XB-29-BO, 41-002, the first XB-29 built. (U.S. Air Force)
Boeing XB-29-BO, 41-002, the first of three prototypes. (U.S. Air Force)

The prototype bomber was powered by four air-cooled, supercharged and fuel-injected 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division Duplex-Cyclone 670C18H1 (R-3350-13) twin-row 18-cylinder radial engines with a compression ratio of 6.85:1. The R-3350-13 was rated at 2,000 horsepower at 2,400 r.p.m., and 2,200 horsepower at 2,800 r.p.m. for takeoff, burning 100-octane gasoline. These engines drove 17-foot-diameter (5.182 meters) three-bladed Hamilton Standard constant-speed propellers through a gear reduction of 0.35:1. The R-3350-13 was 76.26 inches (1.937 meters) long, 55.78 inches (1.417 meters) in diameter, and weighed 2,668 pounds (1,210 kilograms). Wright built 50 of these engines.

Boeing XB-29 Superfortress 41-18335. This is the third prototype. (Boeing)

The XB-29 had a maximum speed of 368 miles per hour (592 kilometers per hour) and cruised at 255 miles per hour (410 kilometers per hour). Its service ceiling was 32,100 feet (9,784 meters).

The airplane was designed to carry 20,000 pounds (9,072 kilograms) of bombs. Though the prototypes were unarmed, the production B-29s were defended by 10 Browning AN-M2 .50-caliber machine guns in four remotely-operated power turrets, with 2 more .50-caliber machine guns and a single AN-M2 20mm autocannon in the tail.

Boeing B-29A-30-BN Superfortress 42-94106, circa 1945. (U.S. Air Force)
Boeing B-29A-30-BN Superfortress 42-94106, circa 1945. (U.S. Air Force)

The B-29 Superfortress was the most technologically advanced—and complex—aircraft of the War. It required the manufacturing capabilities of the entire nation to produce. Over 1,400,000 engineering man-hours had been required to design the prototypes. It was manufactured by Boeing at Seattle and Renton, Washington, and at Wichita, Kansas; by the Glenn L. Martin Company at Omaha, Nebraska; and by Bell Aircraft Corporation, Marietta, Georgia. There were three XB-29 prototypes, 14 YB-29 pre-production test aircraft, 2,513 B-29, 1,119 B-29A, and 311 B-29B Superfortress aircraft. The bomber served during World War II and the Korean War and continued in active U.S. service until 1960.

The first prototype, 41-002, was scrapped in 1948.

© 2017, Bryan R. Swopes

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2 September 1944

Lt. (j.g.) George H.W. Bush, USNR, VT-51, in cockpit of TBM-1C Avenger Bu.No. 46214, USS San Jacinto (CVL-30), 1944. (U.S.Navy)

2 September 1944: Lieutenant (Junior Grade) George Herbert Walker Bush, United States Naval Reserve, led a flight of four TBF/TBM Avenger torpedo bombers of Torpedo Squadron 51 (VT-51), from the Independence-class light aircraft carrier USS San Jacinto (CVL-30), against a radio transmission station on the island of Chichi-Jima.

The Avenger had a crew of three. Along with Lt (j.g.) Bush were Lt. (j.g.) William G. White, USNR, gunner, and radio operator ARM 2/c John Lawson Delaney, USNR.

Undated photo of future United States President George H.W. Bush as a United States Navy pilot seated in the cockpit of an Avenger. (U.S. Navy)

Each airplane was armed with four 500-pound¹ general purpose bombs. The flight was joined by eight Curtiss-Wright SB2C Helldiver dive bombers of VB-20, escorted by twelve Grumman F6F-5 Hellcat fighters of VF-20, from USS Enterprise (CV-6).

Chichi-Jima is the largest island in the Ogasawara Archipelago of the Bonin Islands, approximately 150 miles (240 kilometers) north of Iwo Jima and 620 miles (1,000 kilometers) south of Tokyo, Japan. The United States Hydrographic Survey described the island in 1920 as “very irregular in shape,” approximately 4¼ miles (7.2 kilometers) long and 2 miles (3.2 kilometers) wide. The area of the island is presently given as 23.45 square kilometers (9.05 square miles). Its highest point is 326 meters (1,070 feet) above Sea level. The island has a small sea port where midget submarines were based beginning in August 1944. Chichi-Jima was heavily garrisoned with 20,656 Imperial Japanese Army and Navy personnel, and 2,285 civilian workers.²

A Curtiss-Wright SB2C Helldiver over Chichi Jima. (U.S. Navy)

Lieutenant Bush’s flight was scheduled for a time over target of 0825–0830. They encountered heavy antiaircraft fire and Bush’s Avenger was hit. With the torpedo bomber on fire, Bush continued the attack and later reported good results. Unable to return to the aircraft carrier, he flew away from the island to limit the risk of capture of the crew by the enemy when they bailed out.

Bush and one other crewman (which one is not known) bailed out. While Bush parachuted safely, the second crewman’s parachute never opened. The third crewman went down with the airplane. Both Lieutenant White and Radioman Delaney were killed.

The Gato-class fleet submarine USS Finback (SS-230) was stationed near the island on lifeguard duty during the attack. At 0933, Finback was notified of an aircraft down nine miles northeast of Minami-Jima.  Escorted by two F6F fighters, the submarine headed for the location. At 1156, Finback picked up Lt. Bush, floating in his life raft. A search for White and Delaney was unsuccessful. Their bodies were not recovered.

Lt. (j.g.) George H. W. Bush, USNR, in inflatable raft, is rescued by the crew of USS Finback (SS-230), 2 September 1944. (U.S. Navy)

(Later that same day, Finback, while submerged, towed a second pilot and his life raft away from Magane-Iwa, as he held on to the sub’s periscope.)

Lieutenant Bush and the other rescued pilots remained aboard for the remainder of Finback‘s war patrol (her tenth), and were then returned to Pearl Harbor. In November he rejoined San Jacinto for operations in the Philippines.

Gato-class fleet submarine USS Finback (SS-230) off New London, Connecticut, 7 March 1949. (U.S. Navy)

George Herbert Walker Bush was born at Milton, Massachusetts, 12 June 1924, the son of Prescott Sheldon Bush and Dorothy Walker Bush. He attended high school at the Phillips Academy in Andover, Massachusetts.

One day after his 18th birthday, 13 June 1942, Bush enlisted as a seaman, 2nd class, in the United States Naval Reserve. He was appointed an aviation cadet and underwent preflight training at the University of North Carolina, Chapel Hill. He was honorably discharged 8 June, and commissioned as an ensign, United States Naval Reserve, 9 June 1943. At the age of 19 years, 2 days, he became the youngest Naval Aviator in history. (His age record was broken the following month by Ensign Charles Stanley Downey, who was commissioned 16 July 1943 at the age of 18 years, 11 months, 14 days.)

Aviation Cadet George H. W. Bush, USNR, 1942. (U.S. Navy)

Ensign Bush continued flight training at NAS Pensacola, Florida, and then the Carrier Qualification Training Unit, NAS Glenville, Illinois. After training with the Atlantic Fleet, Ensign Bush was assigned to Torpedo Squadron Fifty-One (VT-51), in September 1943. He was promoted to lieutenant (junior grade), 1 August 1944.

After leaving San Jacinto, Bush was assigned to NAS Norfolk, Virginia, from December 1944 to February 1945. He then joined Torpedo Squadron Ninety-Seven (VT-97) and then VT-153.

Lieutenant (j.g.) Bush was released from active duty on 18 September 1945, retaining his commission. He was promoted to lieutenant 16 November 1948. On 24 October 1955, Lieutenant Bush resigned from the U.S. Navy.

During World War II, George H. W. Bush flew 58 combat missions. He flew a total of 1,221 hours and made 126 carrier landings. He was awarded the Distinguished Flying Cross, the Air Medal with two gold stars (three awards), and the Presidential Unit Citation.

He would later become the forty-first President of the United States of America.

Grumman TBF or General Motors TBM Avengers over Wake Island, 1943. (U.S. Navy)

The airplane flown by Lt. (j.g.) Bush on 2 September 1944 was a General Motors TBM-1C Avenger torpedo bomber, Bu. No. 46214. This was a licensed variant of the Grumman TBF-1C Avenger, built by the General Motors Corporation Eastern Aircraft Division at Linden, New Jersey.

The Avenger was designed by Robert Leicester Hall, Chief Engineer and Test Pilot for the Grumman Aircraft Engineering Corporation, Bethpage, New York. The prototype XTBF-1 made its first flight 1 August 1941. It was a large single-engine aircraft, operated by a crew of three (pilot, radio operator and ball turret gunner). It was equipped with folding wings for storage on aircraft carriers. Production of the torpedo bomber began with the opening of a new manufacturing plant, Sunday, 7 December 1941. The first production Avenger was delivered to the U.S. Navy in January 1942.

The TBF-1 and TBM-1 were 40 feet, 11 inches (12.471 meters) long, with a wingspan of 54 feet, 2 inches (16.510 meters) and overall height of 16 feet, 5 inches (5.004 meters). The airplane had an empty weight of 10,545 pounds (478 kilograms), and its maximum gross eight was 17,895 pounds (8,117 kilograms). The Avenger was the largest single-engine aircraft of World War II.

LCDR Albert B. Cahn, USN, gives the take-of signal to a General Motors TBM-1C Avenger of Torpedo Squadron 51 (VT-51) aboard the light aircraft carrier USS San Jacinto (CVL-30), during exercises on 16 May 1944. (U.S. Navy)

The Avenger was powered by one of several variants of the Wright Aeronautical Division Cyclone 14 (R-2600): GR2600B698 (R-2600-8 and -8A); GR2600B676 (R-2600-10); and 776C14B31. The R-2600 was series of air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.688 liter), two-row 14-cylinder radial engines. The engines used in the Avengers all had a compression ratio of 6.9:1, supercharger ratios of 7.06:1 and 10.06:1, and propeller gear reduction ratio of 0.5625:1.

The R-2600-8, -8A and -10 had Normal Power ratings of 1,500 horsepower at 2,400 r.p.m. at Sea Level, and 1,700 horsepower at 2,600 r.p.m. for takeoff. The R-2600-20 was rated at 1,600 horsepower at 2,400 r.p.m., and 1,900 horsepower at 2,800 horsepower, respectively.

Dimensions and weights varied. The R-2600-8 and -8A were 64.91 inches (1.649 meters) long. The -10 was 74.91 inches (1.903 meters) long, and the length of the -20 was 66.08 inches (1.678 meter). The R-2600-8 and 8A and -10 were 54.26 inches (1.378 meters) in diameter. The -20 was 54.08 inches (1.374 meters). The -8 and -8A both weighed 1,995 pounds (905 kilograms). The -10 weighed 2,115 pounds (959 kilograms) and the -20 weighed 2,045 pounds (928 kilograms).

The engines drove a three-bladed Hamilton Standard Hydromatic constant-speed propeller.

The TBF/TBM had a cruise speed of 147 miles per hour (237 kilometers per hour) and maximum speed of 276 miles per hour (444 kilometers per hour) at 16,500 feet (5,029 meters). The service ceiling was 30,100 feet (9,174 meters). Its maximum range was 1,010 miles (1,625 kilometers).

The Avenger was armed with one air-cooled Browning AN-M2 .50-caliber machine gun mounted in each wing, firing forward. Another .50-caliber machine gun was installed in an electrically-operated dorsal ball turret. In the ventral position was a Browning M2 .30-caliber aircraft machine gun in a flexible mounting.

The primary weapon of the Avenger was carried in an enclosed weapons bay. It could be armed with one Mk. 13 aerial torpedo, ³ or up to 2,000 pounds (907 kilograms) of bombs.

A Grumman TBF-1 Avenger 4-T-2 of Torpedo Squadron Four (VT-4) drops a Mk. 13 aerial torpedo, circa 1942. Following the destruction of Torpedo Eight at the Battle of Midway, aerial torpedo attacks were rarely used by the U.S. Navy. (U.S. Navy)

The Grumman Aircraft Engineering Corporation produced TBF Avengers from Early 1942 until 1943, when production was taken over by the General Motors Corporation Eastern Aircraft Division. Grumman produced 2,290 TBFs, while Eastern built 9,836 TBMs.

Lieutenant Bush’s aircraft carrier, USS San Jacinto (CVL-30), was an Independence-class light carrier. It had been started by the New York Shipbuilding Corporation as a Cleveland-class light cruiser, USS Newark (CL-100), but was converted during construction. Construction took 11 months and the ship was launched 26 September 1943. It was commissioned 15 November 1943.

The carrier was 622.5 feet (189.7 meters) long, with a beam of 71.5 feet (21.8 meters) and draft of 26 feet (7.9 meters). It had a full load displacement of 15,100 long tons (16,912 short tons, or 15,342 metric tons). The ship was powered by steam turbines producing 100,000 horsepower and driving four shafts. San Jacinto was capable of a maximum 31.6 knots (36.4 miles per hour, or 58.5 kilometers per hour).

San Jacinto had a complement of 1,549 men, and carried 45 airplanes. For defense, it was armed with 28 Bofors 40 millimeter anti-aircraft guns and 40 Oerlikon 20 millimeter autocannon.

San Jacinto was decommissioned 1 March 1947 and was later scrapped.

USS Independence (CVL-30), late 1943. (U.S. Navy)

On 7 October 2006, the tenth and final Nimitz-class supercarrier was christened USS George H.W. Bush (CVN-77) in honor of President Bush’s service to his country.

USS George H. W. Bush (CVN-77). (U.S. Navy)

¹ The most common U.S. 500-pound general purpose bomb of World War II was the AN-M64. Nominally a 500-pound (227 kilogram) bomb, the munition actually weighed from 516.3 to 535.4 pounds (234.2 to 242.9 kilograms), depending on the explosive used. It contained 266 pounds (120.7 kilograms) of TNT, or 258.5 pounds (117.3 kilograms) of a 50/50 TNT and Amatol mixture. For easy identification, these were marked with a single 1-inch (2.54 centimeter) wide yellow band painted at the nose and tail. Composition B bombs, which were marked with two yellow identification bands, contained 272.7 pounds (123.7 kilograms) of explosive, while the heaviest was filled with 278.3 pounds (126.2 kilograms) of Tritonal. This variant was marked with three yellow bands. The bomb, without fins or fuses, was 36 inches (0.914 meters) long. The overall length was 59.16 inches (1.503 meters), including nose and tail fuses. The maximum diameter was 10.9 inches (0.277 meters).

² Personnel numbers as of 3 September 1945.

³ The U.S. Navy Torpedo, Mark 13, was a gyroscopically-steered single-speed anti-ship torpedo designed to be dropped from aircraft. It was 13 feet, 8.55 inches (4.180 meters) long, 1 foot, 10.42 inches (0.570 meters) in diameter and weighed 1,949 pounds (884 kilograms) ± 20 pounds (9 kilograms). The warhead contained a 400 pound (181 kilogram) TNT explosive charge.  The Mk. 13 was driven by a two-stage alcohol-fueled geared steam turbine, turning 10,983 r.p.m., with the coaxial counter-rotating propellers turning 1,150 r.p.m. It was capable of running at 33.5 knots (38.6 miles per hour, or 62.0 kilometers per hour), with a range of 6,300 yards (5.8 kilometers). This same type torpedo was used by the U.S. Navy’s PT boats late in the war.

Thanks to regular TDiA reader Joolz Adderly for suggesting this topic.

© 2017, Bryan R. Swopes

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1 September 1946

Alvin M. “Tex” Johnston with the Thompson Trophy and the Allegheny-Ludlum Trophy, 1946 National Air Races. (San Diego Air and Space Museum Archives)

1 September 1946: Just one year after World War II came to an end, the National Air Races returned to Cleveland, Ohio. Grandstands were set up at the site of the Fisher Body Aircraft Plant No. 2, where assemblies for B-25 and B-29 bombers had been produced.

The Thompson Trophy Race was one of the most popular events because it was in view of the crowds. Sponsored by Thompson Products Company (the predecessor of TRW), it was a ten-lap pylon race flown at low altitude around a 30-mile (48.3 kilometers) course. There were two divisions. The R Division was for airplanes with reciprocating engines, and the J Division was for turbojet powered airplanes.

The race course was laid out as a parallelogram, with two 10-mile (16.1 kilometer) sides, and two 5-mile (8.0 kilometer) sides. There were two 75° turns and two 105° turns.

In addition to the Thompson Trophy, the race winner would receive $20,000 in prize money (about $265,400 in 2017 dollars). There were additional $2,000 prizes for the leader of each lap. A pilot who set a speed record during the race would win the Allegheny-Ludlum Trophy and $2,000.

Entrants for the 1946 race included many well-known air racers, test pilots and combat pilots. They included Cook Cleland, a U.S. Navy dive bomber pilot and test pilot; Woodrow W. (“Woody”) Edmondson, an aerobatic pilot; Howard Clifton (“Tick”) Lilly, a test pilot for the National Advisory Committee for Aeronautics (NACA, predecessor of NASA); Alvin Melvin (“Tex”) Johnston, an experimental test pilot with the Bell Aircraft Corporation; Anthony W. (“Tony”) LeVier, Chief Engineering Test Pilot for the Lockheed Aircraft Corporation, and an experienced pylon racer; Earl Hill Ortman, test pilot for Douglas Aircraft Company, and also an experienced racer; Howard L. Pemberton; Bruce Raymond; Robert Swanson; Charles (“Chuck”) Tucker, who had flown P-40s with the “Flying Tigers” in China, and an Army Air Corps test pilot; George Schwarz Welch, the Army Air Corps hero of Pearl Harbor, and test pilot for North American Aviation, Inc.; and Sylvester Joseph (“Steve”) Wittman, an aircraft designer and air racer.

Before the war, the races used specially-constructed racing aircraft and production civil aircraft. Following the war, the expense of developing a purpose-built, competitive air racer was no longer feasible, so surplus military fighters were used.

Of the twelve airplanes competing in the 1946 Thompson Race, there was one Bell Aircraft Corporation P-39Q Airacobra; four Bell P-63 Kingcobras; one Goodyear Aircraft Corporation FG-1D Corsair (a licensed variant of the Vought-Sikorsky F4U Corsair); a Lockheed Aircraft Corporation P-38L Lightning; and five North American Aviation, Inc., P-51D Mustangs.

Bell Aircraft Corporation

Jack Woolams, Chief Test Pilot for Bell Aircraft Corporation, Experimental Test Pilot Tex Johnston and Bell’s Chief Engineer, Robert Morris Stanley, had determined that a properly prepared Bell P-39 Airacobra could outrun and outfly a North American Aviation P-51 Mustang in the Thompson race.

A Bell Aircraft mechanic was sent to inspect surplus P-39s in storage at Ponca City, Oklahoma. He selected two nearly-new P-39Q Airacobras, each with less than 50 hours flight time. Woolams and Johnston paid $3,000 for the two fighters and they were flown back to the Bell plant at Buffalo, New York.

Jack Woolams’ Cobra I was a P-39Q-10-BE, U.S. Army Air Corps serial number 42-20733. Tex Johnston’s Cobra II was also a P-39Q-10-BE, 42-20869 (Bell serial number 26E-324).

The Bell P-39 Airacobra was a single-engine, single-place low-wing monoplane with retractable tricycle landing gear. An Allison V-1710 V-12 engine was mounted behind the cockpit in an unusual mid-engine configuration, with a drive shaft passing under the cockpit floor and turning the propeller through a remotely-mounted 1.8:1 gear reduction unit. This allowed the fighter to be armed with a large 37 mm autocannon which fired through the propeller hub.

Bell P-39Q-20-BE Airacobra 44-3887 at the National Museum of the United States Air Force)

The P-39Q was the final production version of the Airacobra. It was 30 feet, 2 inches (9.195 meters) long with a wingspan of 34 feet, 0 inches (10.363 meters) overall height of 12 feet, 5 inches (3.785 meters). The P-39Q had an empty weight of 5,645 pounds (2,561 kilograms), and maximum gross of 8,300 pounds (3,765 kilograms).

Allison Division of General Motors

The production P-39Q was powered by a liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Company V-1710-E19 (V-1710-85) single overhead camshaft (SOHC) 60° V-12 engine with four valves per cylinder and a compression ratio of 6.65:1. The V-1710-85 had a continuous power rating of 810 horsepower at 2,600 r.p.m. at Sea Level, and 1,000 horsepower at 2,600 r.p.m. at 14,000 feet (4,267 meters). The engine’s takeoff power rating was 1,200 horsepower at 3,000 r.p.m., and its military power rating was 1,125 horsepower at 3,000 r.p.m., at 14,600 feet (4,450 meters). 100/130 octane aviation gasoline was required. The Allison drove a three-bladed Aeroproducts Division A632S-C1 hydraulically-operated constant-speed propeller with a diameter of 11 feet, 7 inches (3.531 meters) through a 2.23:1 gear reduction. The V-1710-85 was 16 feet, 2.00 inches (4.928 meters) long, 3 feet, 1.56 inches (0.954 meters) high, and 2 feet, 5.28 inches (0.744 meters) wide. It weighed 1,435 pounds (651 kilograms).

Cutaway illustration showing the unusual mid-engine arrangement of the Bell P-39 Airacobra. (Allison Division of General Motors)

The Bell P39Q had a maximum speed of 385.0 mph (619.6 kilometers per hour) at 11,000 feet (3,353 meters). Its service ceiling was 34,900 feet (10,638 meters), absolute ceiling, 35,700 feet (10,881 meters), and its range was 1,075 miles (1,730 kilometers).

The P-39Q was armed with one Browning M4 37 mm autocannon with 30 rounds of explosive ammunition, and four Browning AN-M2 .50-caliber machine guns, with two in the nose with 200 rounds per gun, and one mounted under each wing in pods with 300 rounds per gun.

The Bell Aircraft Corporation built 9,558 P-39s. 4,905 of these were P-39Qs. 705 were the P-39Q-10-BE variant.

Jack Woolams (left) and Tex Johnston pose with their air racers, Cobra I and Cobra II, at the Bell Aircraft Corporation plant, August 1946. (airrace,com)

Bell Aircraft provided hangar space for the two Airacobras, and assigned an engineer and five mechanics to the project. Cobra I was painted red with black accents. It was issued Civil Aeronautics Administration experimental registration NX92847. Its race number, 75, was painted on the wings and fuselage. Cobra II was painted yellow with black trim, and registered NX92848. Its race number was 84.

Both airplanes were stripped of armament, armor and self-sealing fuel tanks. The landing gear was modified to reduce its retraction time from 22 seconds to just 4 seconds. The standard fabric-covered ailerons, rudder and elevators were covered with sheet aluminum. Adjustable trim tabs were deleted. Gyroscopic instruments were removed. The pitot tube was moved from the left wing tip and placed on a long boom projecting through the propeller hub. Thin, light-weight Goodyear fuel bladders were installed, not only reducing weight, but increasing the Airacobras’ fuel capacity by 10%. The roll-down side windows of the P-39 were replaced by fixed Plexiglas panels.

Bell P-39Q-10-BE NX92848, Cobra II, Tex Johnston’s Thompson Trophy Race winner. (San Diego Air and Space Museum Archives)

Engineers at Allison recommended that a modified Allison XV-1710-135 (E31) engine be used. The modified engines used an increased-diameter supercharger impeller and undersized pistons to reduce cylinder wall friction. Using 140-octane Mobil aviation gasoline, they produced 2,000 horsepower at 3,200 r.p.m. with 86 inches (291 kilopascals) of manifold pressure. The high power output required that the engine be provided with a continuous injection of a precisely-measured water and ethyl/methyl alcohol solution above 57 inches (193 kilopascals) of manifold pressure. An 85 gallon (322 liter) tank for the injection mixture was placed in the nose.

Tex Johnston’s Thompson Trophy-winning Bell P39Q Airacobra, “Cobra II.” (San Diego Air and Space Museum Archives)

The increased power of the modified XV-1710-135 required that the P-39’s standard three-bladed propeller be replaced by a four bladed unit from the P-63 Kingcobra. This was an Aeroproducts A624S constant-speed propeller with hollow steel blades. Its diameter was 11 feet, 0 inches (3.531 meters). The propeller gear reduction ratio remained the same, at 2.23:1, as did the remote gear box, at 1.8:1.

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

The V-1710-E31 was longer, at 17 feet, 4.00 inches (5.283 meters), and heavier, than the E19 because of an outboard reduction gear box. It was 3 feet, 0.75 inches (0.933 meters) high, with the same 2 foot, 5.28 inch (0.744 meters) width. It weighed 1,500 pounds (680 kilograms).

Jack Woolams’ P-39 Cobra I leads a P-51D Mustang around a pylon turn during qualifying, August 1946. (LIFE Magazine via Jet Pilot Overseas)

When race qualifications were held, Tex Johnston was placed first with his yellow Cobra II. His average speed was 409.091 mph (658.368 kilometers per hour). George Welch was second with his P-51D, number 37. Jack Woolams and Cobra I were third.

Jack Valentine Woolams

Jack Valentine Woolams was killed on 30 August, two days before the race, when his Cobra I crashed into Lake Ontario while returning to the Bell plant for an engine change. The Airacobra’s windshield may have collapsed at over 400 miles per hour (644 kilometers per hour).

The race was held on Sunday, 1 September 1946. Tex Johnston, leading the field, took off and retracted his landing gear, climbing to 300 feet (91 meters). As he approached the first turn, he rolled Cobra II into a 4G turn (75.5° angle of bank) and dove to 60 feet (18 meters). As he made the turn, he was already pulling far ahead of the other racers.

George Welch dropped out when his Merlin engine began overheating. Tony LeVier’s P-38 Lightning, race number 3, held on to second place. By the ninth lap, Tex Johnston was passing the airplanes at the back of the field.

On the final turn, Johnston rolled into a 90° bank, and at only 50 feet (15 meters) above the ground, passed inside a Bell P-63 Kingcobra at 430 miles per hour (692 kilometers per hour) to win the race. His average speed for the ten laps was 373.908 mph (601.746 kilometers per hour).

After winning the 1946 Thompson Trophy Race, test pilot Tex Johnston kisses his wife, DeLores. (LIFE Magazine via Jet Pilot Overseas.)
Tex Johnston with the Thompson Trophy, 1946 National Air Races, Cleveland, Ohio. (LIFE Magazine)

Tony LeVier and his Lightning were in second place at 370.193 mph (595.768 kilometers per hour). Finishers 3, 4 and 5 were P-51D Mustangs. Number 6 was the lone FG-1D Corsair, followed by another P-51D. Proving that Woolams, Johnston and Stanley knew their airplane, the final three finishers were the three remaining P-63 Kingcobras.

An oil-streaked, race-winning Bell P-39Q Airacobra, NX92848, Tex Johnston’s Cobra II. The modified Allison engine’s undersized pistons allowed excessive blow-by. (San Diego Air and Space Museum Archives)

Cobra II competed in the 1947 Thompson Trophy Race. Flown by Bell Aircraft Corp. test pilot Gerald A. (“Jay”) Demming, and carrying the race number 11, it finished in third place behind two Goodyear F2G-1 Super Corsairs. Demming’s average speed was 367.625 miles per hour (591.635 kilometers per hour).

In the 1948 Thompson race, Cobra II, still carrying the number 11, was flown by Charles Brown. For this year, the race was twenty laps of a shorter, 15 mile (24.1 kilometer) course. Cobra II had qualified in first place with an average speed of 418.300 miles per hour (673.189 kilometers per hour). Brown led the race for 18 laps. His highest speed for a single lap was 413.907 miles per hour (666.119 kilometers per hour). He had to land, though, when the modified Allison engine began losing power. The race was won by a P-51D Mustang.

Bell P-39Q-10-BE Airacobra NX92849
Cobra II at the 1947 National Air Races, with race number 11. It was flown in the Thompson Trophy race by Bell test pilot Jay Demming, who placed third.

The history of Cobra II is elusive until it was purchased by Ed Maloney in 1960. It was sold to Michael D. Carroll in 1967. Carroll was the owner of Signal Trucking Co., and lived in Palos Verdes, California. The Airacobra was now registered N9824. Carroll had the airplane’s wings shortened by 4 feet per side (1.2 meters), and renamed it Cobra III.

On 10 August 1968, Carroll and Cobra III took of from Long Beach Airport (LGB), enroute to Orange County Airport (SNA), at nearby Santa Ana, California. At 11:15 a.m., the racer crashed at the Seal Beach Naval Weapons Station. Carroll bailed out, but his parachute did not open and he was killed. His body was located 125 feet (38 meters) from the wreckage. There was no post-crash fire. Lieutenant Commander Jack Kellicott, U.S. Navy, said that the airplane had run out of fuel.

Tex Johnston left Bell Aircraft Corporation and moved on to Boeing in Seattle, initially testing the swept-wing XB-47 Stratojet. He made the first flights of the YB-52 and XB-52 Stratofortress; the Model 367-80 (the “Dash 80”), which he notoriously rolled over Lake Washington, 6 August 1955; the KC-135A Stratotanker; and the Model 707 airliner. As Boeing’s Chief of Flight Test, Tex Johnston set the standard by which modern flight testing is carried out.

Alvin Melvin (“Tex”) Johnston, Chief of Flight Test. (The Boeing Company)

Highly recommended: Tex Johnston, Jet-Age Test Pilot, by A.M. “Tex” Johnston with Charles Barton, Smithsonian Books, Washington, D.C., 1991

© 2017, Bryan R. Swopes

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24 August 1942

Captain Marion E. Carl, USMC, with a Grumman F4F-3 Wildcat. (U.S. Navy)

24 August 1942: Flying a Grumman F4F Wildcat, Lieutenant Marion Eugene Carl, United States Marine Corps, a 27-year-old fighter pilot assigned to Marine Fighter Squadron 223 (VMF-223) based at Henderson Field, Guadalcanal Island, shot down four enemy airplanes in one day. They were a Mitsubishi A6M “Zeke” fighter, a Mitsubishi G4M1 “Betty” medium bomber and two Nakajima B5N2 “Kate” torpedo bombers. Carl had previously shot down an A6M during the Battle of Midway, less than three months earlier. He now had five aerial combat victories, making him the Marine Corps’ first ace.

Captain Carl was awarded the Navy Cross (his second) for his actions in the Solomon Islands from 24 August to 9 September 1942.

Marion Carl’s fighter was a Grumman F4F-4 Wildcat, designed by Robert Leicester Hall as a carrier-based fighter for the United States Navy. The F4F-4 was a single-place, single-engine, mid-wing monoplane with retractable landing gear.

Grumman F4F-4 Wildcat. (U.S. Navy)

The F4F-4 was 29 feet, 9-3/8 inches (9.077 meters) long, with a wingspan of 38 feet, 0 inches (11.582 meters) and overall height of 12 feet, 1-3/8 inches (3.693 meters). Unlike the preceding F4F-3, the F4F-4 had folding wings for storage aboard aircraft carriers. With the wings folded, the airplane was 14 feet, 4 inches (4.369 meters) wide. Its empty weight was 5,895 pounds (2,674 kilograms), and the gross weight was 7,975 pounds (3,617 kilograms).

The F4F-4 was powered by an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp SSC7-G (R-1830-86) two-row, 14-cylinder radial engine with a compression ratio of 6.7:1. The R-1830-86 had a normal power rating of 1,100 at 2,550 r.p.m., from Sea Level to 3,300 feet (1,006 meters), and 1,000 horsepower at 2,550 r.p.m. at 19,000 feet (5,791 meters). It was rated at 1,200 horsepower at 2,700 r.p.m. for takeoff. The engine turned a three-bladed Curtiss Electric propeller with a diameter of 9 feet, 9 inches (2.972 meters) through a 3:2 gear reduction. The R-1830-86 was 4 feet, 0.19 inches (1.224 meters) in diameter, 5 feet, 7.44 inches (1.713 meters) long, and weighed 1,560 pounds (708 kilograms).

The F4F-4 had a maximum speed of 284 miles per hour (457 kilometers per hour) at Sea Level, and 320 miles per hour (515 kilometers per hour) at 18,800 feet (5,730 meters). Its service ceiling was 34,000 feet (10,363 meters).

While the F4F-3 Wildcat was armed with four air-cooled Browning AN-M2 .50-caliber machine guns, the F4F-4 had six. It carried 1,400 rounds of ammunition.

The prototype XF4F-1 made its first flight in 1935. It was substantially improved as the XF4F-2. The first production F4F-3 Wildcat was built in February 1940. The airplane remained in production through World War II, with 7,860 built by Grumman and General Motors Eastern Aircraft Division (FM-1 Wildcat).

According to the National Naval Aviation Museum, F4F Wildcats held a 9:1 ratio of victories over Japanese aircraft, with 1,006 enemy airplanes destroyed in combat.

Grumman F4F-3 Wildcat at Henderson Field
A Grumman F4F Wildcat at Henderson Field, Guadalcanal. There are 19 Japanese flags painted on the fuselage, suggesting that this is Major John L. Smith’s fighter. (U.S. Navy)

Marion Eugene Carl was born at Hubbard, Oregon, 1 November 1915. He was the second of four children of Herman Lee Carl, a dairy farmer, and Ellen Lavine Ellingsen Carl.

Carl graduated from Oregon State College at Corvallis, Oregon, and was commissioned as a second lieutenant in the United States Army Reserve, 31 May 1938. Lieutenant Carl soon resigned this commission to accept an appointment as an Aviation Cadet, United States Navy. He enlisted as a private, first class, Volunteer Marine Corps Reserve, 17 July 1938, and was designated a student Enlisted Naval Aviation Pilot assigned to the Naval Reserve Aviation Base, Squantum, Massachusetts. He entered flight school as an Aviation Cadet at Naval Air Station Pensacola near Pensacola, Florida, 26 July 1938.

Lieutenant Marion E. Carl, USMC, Naval Aviator. (U.S. Navy)

After completing flight training, Carl was commissioned as a Second Lieutenant, United States Marine Corps Reserve, 20 October 1939. He was then assigned to Marine Fighting Squadron One (VMF-1) at Brown Field, Quantico, Virginia.

In 1940, Lieutenant Carl returned to NAS Pensacola as a flight instructor. On 25 February 1941, Second Lieutenant Carl, U.S.M.C.R., was appointed a Second Lieutenant, United States Marine Corps.

Lieutenant Carl was transferred to VMF-221 at San Diego, California, as a fighter pilot. The unit was assigned to the aircraft carrier USS Saratoga (CV-3) for transportation to Marine Corps Air Station Ewa, Oahu, Territory of Hawaii. On 25 December 1941, VMF-221 was deployed to Midway Atoll.

Marion Carl and his squadron fought during the Battle of Midway. Flying a Grumman F4F-3 Wildcat, Bu. No. 1864,¹ on 4 June 1942, he shot down his first enemy airplane, a Mitsubishi A6M Zero fighter, and damaged two others. Lieutenant Carl was awarded the Navy Cross for his actions in that decisive battle.

Marion Carl was next assigned to VMF-223 under the command of Captain John L. Smith. The Marine fighter squadron was the first air unit to arrive at Henderson Field on the island of Guadalcanal in the Solomons, 20 August 1942. This was a critical airfield, originally built by the Japanese military but occupied by Allied forces. On 24 August, Lieutenant Carl became the Marine Corps’ first “ace.”

Carl was shot down in 9 September 1942 and was missing for five days. He was helped by islanders who eventually returned him to his base.

The squadron departed Guadalcanal 16 October 1942, and sailed to San Francisco, California. VMF-223 was credited with destroying 110½ enemy aircraft. Carl was credited with 16.

Lieutenant Carl married Miss Edna T. Kirvin at New York City, New York, 7 January 1943.

On 26 January, he took command of VMF-223. On 8 May 1943, Lieutenant Carl was promoted to the temporary rank of captain. The squadron was re-equipped with the new Vought-Sikorsky F4U-1 Corsair. Training in the new fighter took place at MCAS El Toro, in southern California.

In August, the squadron returned to combat in the Solomons. By the end of 1943, Major Carl’s total of enemy aircraft destroyed was 18½ with 3 damaged, making him the seventh highest-scoring Marine fighter pilot of World War II.

Major Marion E. Carl, USMC, commanding VMF-223 in 1943. The aircraft is a Vought F4U Corsair in which Carl shot down two enemy aircraft in December 1943. (U.S. Navy)

After the War Marion Carl was assigned as a test pilot at NAS Patuxent River, Maryland, testing jet aircraft on aircraft carriers. He was also the first Marine Corps pilot to fly a helicopter. Carl commanded the Marine’s first jet squadron, VMF-122, which flew the McDonnell FH-1 Phantom. He was promoted to lieutenant colonel 7 August 1947.

In May 1955, Colonel Carl commanded Marine Photo Reconnaissance Squadron One (VMJ-1). The squadron flew the McDonnell FH-2 Banshee from air bases on the island of Formosa (Taiwan) on secret missions over the People’s Republic of China.

At Muroc Army Air Field (now Edwards Air Force Base) Marion Carl tested the Douglas D-558-I Skystreak and D-558-II Skyrocket, setting world records for speed and altitude. He was promoted to colonel, 1 October 1956.

Major Marion E. Carl, USMC, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy)

By 1962 Colonel Carl was Director of Marine Corps Aviation. He was promoted to brigadier general, 1 June 1964. He commanded the First Marine Brigade during the Vietnam War and flew combat missions in jet fighters and helicopter gun ships.

Major General Marion E. Carl, United States Marine Corps.

Carl was promoted to major general in August 1967, with his date of rank retroactive to 1 June 1964. Carl commanded the 2nd Marine Aircraft Wing, then served as Inspector General of the Marine Corps from 1970 until 1973. When he retired in 1973, General Carl had accumulated more that 13,000 flight hours.

During his military career, Major General Carl was awarded the Navy Cross with two gold stars (three awards); The Legion of Merit with valor device and three gold stars (four awards); The Distinguished Flying Cross with four gold stars (five awards); and the Air Medal with two gold and two silver stars (twelve awards).

Tragically, General Carl was murdered in Roseburg, Oregon, 28 June 1998, as he defended his wife, Edna, during a home-invasion robbery. Mrs. Carl was wounded, but survived.

Major General Marion E. Carl, United States Marine Corps, is buried at Arlington National Cemetery.

A Mitsubishi A6M2 Model 21 "Zero" fighter takes off from an aircraft carrier of teh Imperial Japanese Navy.
A Mitsubishi A6M2 Type 0 Model 21 “Zero” fighter takes off from an aircraft carrier of the Imperial Japanese Navy. Marion Carl shot down one of these and damaged two others during the Battle of Midway, 4 June 1942. (Imperial Japanese Navy)
Mitsubisshi A6M3 Model 22 "Zeke" in the Solomon Islands, 1943. (Imperial Japanese Navy)
Mitsubishi A6M3 Type 0 Model 22 “Zeke” in the Solomon Islands, 1943. (This fighter is flown by Petty Officer 1st Class Hiroyoshi Nishizawa, one of the most successful fighter pilots of World War II.)  (Imperial Japanese Navy) 
A Mitsubishi G4M "Betty" takes off from Rabaul, 1942.
A Mitsubishi G4M1 Type 1 Model 11 “Betty” takes off from Rabaul, 1942.
Nakajima B5N Kate. Marion Carl shot down two of these light bombers, 24 August 1942.
Nakajima B5N2 Type 97 “Kate”. Marion Carl shot down two of these torpedo bombers, 24 August 1942.

¹ The fighter flown by Marion Carl to shoot down his first enemy airplane is often cited as Grumman F4F-3 Bu. No. 4000 (second bureau number series, 1935–1940). However, the entry in Carl’s certified pilot logbook for 4 June 1942 states the airplane he flew was F4F-3 Bu. No. 1864.

© 2017, Bryan R. Swopes

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19 August 1940

Vance Breese (SDA&SM)

19 August 1940: At Mines Field (now known as Los Angeles International Airport), the first North American Aviation B-25 twin-engine medium bomber, serial number 40-2165, took off on its first flight with test pilot Vance Breese at the controls and engineer Roy Ferren in the co-pilot’s position.

The airplane, North American model NA-62, serial number 62-2834, was developed from two earlier designs which had been evaluated by the U.S. Air Corps but rejected, and it was ordered into production without a prototype being built.

The first few B-25s built—sources vary, but 8–10 airplanes—were built with a constant dihedral wing. Testing at Wright Field showed that the airplane had a slight tendency to “Dutch roll” so all B-25s after those were built with a “cranked” wing, giving it the bomber’s characteristic “gull wing” appearance. The two vertical stabilizers were also increased in size.

40-2165 was retained by North American for testing while the next several aircraft were sent to Wright Field.

Roy Ferren (SDA&SM)

The B-25 was named Mitchell in honor of early air power advocate Brigadier General Billy Mitchell. A total of 9,984 B-25s, F-10 reconnaissance variants and U.S. Navy and Marine Corps PBJ-1 patrol bombers were built by North American Aviation at Inglewood, California and Kansas City, Kansas. The last one, a TB-25J, remained in service with the U.S. Air Force until 1960.

Twenty-three B-25s were built before the B-25A Mitchell went into production. The B-25 was operated by a crew of five. It was 54 feet, 1 inch (16.485 meters) long with a wingspan of 67 feet, 6.7 inches (20.592 meters) and overall height of 16 feet, 4 inches (4.978 meters). The empty weight was 17,258 pounds (7,828 kilograms) and the maximum gross weight was 28,557 pounds (12,953 kilograms).

Scale model of a North American Aviation B-25 medium bomber being tested in a wind tunnel. (4″ × 5″ Kodachrome transparency by Alfred Palmer)

The B-25 was powered by two air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.688 liter) Wright Aeronautical Division Cyclone 14 GR2600B665 (R-2600-9) two-row 14-cylinder radial engines which were rated at 1,500 horsepower at 2,400 r.p.m., and 1,700 horsepower at 2,600 r.p.m. for takeoff. These engines (also commonly called “Twin Cyclone”) drove three-bladed Hamilton Standard Hydromatic variable-pitch propellers through 16:9 gear reduction. The R-2600-9 was 5 feet, 3.1 inches (1.603 meters) long and 4 feet, 6.26 inches (1.378 meters) in diameter. It weighed 1,980 pounds (898 kilograms).

The medium bomber had a maximum speed of 322 miles per hour (518 kilometers per hour) at 15,000 feet (4,572 meters) and a service ceiling of 30,000 feet (9,144 meters). It could carry a 3,000 pound bomb load 2,000 miles (3,219 kilometers).

Defensive armament consisted of three air-cooled Browning M2 .30-caliber aircraft machine guns and one Browning AN-M2 .50-caliber machine gun.

After testing was completed, B-25 40-2165 was retained by North American and modified as a company transport. During a flight on 8 January 1945, it crash-landed. The airplane was damaged beyond repair.

Front view of the first North American B-25 Mitchell, 40-2165. The constant dihedral wing was used on the first nine airplanes built. (U.S. Air Force)
Front view of the first North American Aviation B-25 Mitchell medium bomber, 40-2165, at Mines Field, August 1940. The constant dihedral wing was used on the first nine airplanes built. (U.S. Air Force)
North American Aviation NA-62, B-25 Mitchell 40-2165, left front. (U.S. Air Force)
North American B-25 Mitchell 40-2165, left rear. (U.S. Air Force)
North American Aviation B-25 Mitchell 40-2165, left rear. (U.S. Air Force)
North American Aviation B-25A Mitchell medium bomber of the 34th Bombardment Squadron (Medium), 17th Bombardment Group (Medium), based at McChord Field, south of Tacoma, Washington, and Pendleton Army Airfiled, northwest of Pendleton, Oregon, circa 1941. (U.S. Air Force)
North American Aviation B-25A Mitchell medium bomber of the 34th Bombardment Squadron (Medium), 17th Bombardment Group (Medium), based at McChord Field, south of Tacoma, Washington, circa 1941. (U.S. Army Air Corps 10822 AC)

© 2017, Bryan R. Swopes

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