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

14 October 1944

Ann Gilpin Baumgartner, circa 1944. (National Air and Space Museum)

14 October 1944: Ann Gilpin Baumgartner, a member of the Women Airforce Service Pilots (WASPs) assigned as Assistant Operations Officer of the Fighter Section, Flight Test Division, at Wright Field, Dayton, Ohio, made an evaluation flight of the Bell YP-59A Airacomet, becoming the first woman to fly a jet-propelled airplane.

The Airacomet was designed and built by the Bell Aircraft Corporation as an interceptor, powered by two turbojet engines. There were three XP-59A prototypes. The first one flew at Muroc Army Airfield on 1 October 1942. The Army Air Corps had ordered thirteen YP-59A service test aircraft. The first of these flew in August 1943 at Muroc.

The Bell YP-59A was conventional single place airplane with retractable tricycle landing gear. It was primarily of metal construction, though the control surfaces were fabric-covered. Its dimensions differed slightly from the XP-59A, having shorter wings with squared of tips, and a shorter, squared, vertical fin. There were various other minor changes, but the exact specifications of the YP-59As are uncertain.

Bell YP-59A-BE Airacomet 42-108775 at Wright Field. (U.S. Air Force)

The primary difference, though, was the change from the General Electric I-A turbojet to the I-16 (later designated J31-GE-1). Both were reverse-flown engines using a single-stage centrifugal compressor and a single-stage turbine. The I-16 produced 1,610 pounds of thrust (7.16 kilonewtons). They were 6 feet, 0 inches long, 3 feet, 5.5 inches in diameter and weigh 865 pounds (392 kilograms),

Even with the two I-16s producing 720 pounds of thrust (3.20 kilonewtons) more than the the XP-59A’s I-A engines, the YP-59A’s performance did not improve. Engineers had a lot to learn about turbojeft engine inlet design.

The YP-59A had a maximum speed of 409 miles per hour (658 kilometers per hour) at 35,000 feet (10,668 meters), and its service ceiling was 43,200 feet (13,167 meters).

Bell YP-59A-BE Airacomet 42-108775 at Wright Field. (U.S. Air Force)

The P-59 was ordered into production and Bell Aircraft Corporation built thirty P-59A and twenty P-59B fighters. These were armed with one M4 37mm autocannon with 44 rounds of ammunition and three Browning AN-M2 .50-caliber machine guns with 200 rounds per gun.

Although a YP-59A had set an unofficial altitude record of 47,600 feet (14,508 meters), the Airacomet was so outclassed by standard production fighters that no more were ordered.

Bell YP-59A-BE Airacomet 42-108775 at Wright Field. (U.S. Air Force)
Ann G. Baumgartner stands on the wing of a North American Aviation T-6 Texan. (U.S. Air Force)

Ann Gilpin Baumgartner was born 27 Aug 1918, at the U.S. Army Hospital, Fort Gordon, Augusta, Georgia. She was the daughter of Edgar F. Baumgartner, engineer and patent attorney, and Margaret L. Gilpin-Brown Baumgartner. After graduating from Walnut Hill High School, Natick, Massachussetts, she studied pre-med at Smith College, Northampton, Massachussetts. She played soccer and was on the swimming team. She graduated in 1939.

Miss Baumgartner worked as a reporter for The New York Times. She took flying lessons at Somerset Hills Airport, Basking Ridge, New Jersey, and soloed after only eight hours. She then bought  Piper Cub to gain flight experience.

Ann G. Baumgartner, WASP Class 43-W-3. (U.S. Air Force)

After being interviewed by Jackie Cochran, Baumgartner joined the Women Airforce Service Pilots (WASPs) 23 March 1943, a member of Class 43-W-3, graduating 11 September 1943 with Class 43-W-5. She was then assigned to Camp Davis Army Airfield, Holly Ridge, North Carolina, where she towed targets for anti-aircraft artillery training.

Miss Baumgartner  was transferred to Wright Field, Dayton, Ohio (now, Wright-Patterson Air Force Base), where she flew the B-24 Liberator and B-29 Superfortress heavy bombers, P-38 Lightning, P-47 Thunderbolt, YP-59A Airacomet, P-82 Twin Mustang fighters, and the Luftwaffe Junkers Ju 88 medium bomber.

While at Wright Field, Miss Baumgartner met Major William Price Carl, who was an engineer associated with the P-82. They were married 2 May 1945, and would have two children.

Miss Baumgartner was released from service 20 December 1944, when the WASPs were disbanded. Following World War II, she was employed as an instrument flight instructor for United Air Lines.

After they retired, Mr. and Mrs. Carl sailed the Atlantic Ocean aboard their sailboat, Audacious.

Mrs. Carl was the author of A WASP Among Eagles and The Small World of Long-Distance Sailors.

Ann Gilpin Baumgartner Carl died at Kilmarnock, Virginia, 20 March 2008, at the age of 89 years. She and her husband, who had died one month earlier, were buried at sea.

Mrs. Ann Baumgartner Carl (1918–2008)

© 2017 Bryan R. Swopes

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14 October 1938

The Curtiss-Wright XP-40 prototype, 38-10, on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives) 16_008532

14 October 1938: At Buffalo, New York, test pilot Everett Edward Elliot made the first flight in the new Curtiss-Wright Corporation’s Model 75P, a prototype for a single-engine pursuit plane which had been designated XP-40 by the U.S. Army Air Corps.

Curtiss-Wright’s Chief Engineer, Donovan Reese Berlin, had taken the tenth production P-36A Hawk, Air Corps serial number 38-10, and had its air-cooled radial engine replaced with the Harold Caminez-designed, liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C13 (V-1710-19).

Donovan Reese Berlin. (Niagara Aerospace Museum)

The V-1710-19 was a single overhead cam (SOHC) 60° V-12 engine with four valves per cylinder and a compression ration of 6.65:1. It had a Normal Power rating of 910 horsepower at 2,600 r.p.m. at Sea Level, and 1,060 horsepower at 2,950 r.p.m. for Takeoff. At 10,000 feet (3,048 meters), the V-1710-19 had Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m., and Military Power rating of 1,150 horsepower at 2,950 r.p.m. The engine required 100/130-octane aviation gasoline. It drove a three-bladed Curtiss Electric constant-speed propeller through a 2:1 gear reduction. The V-1710-19 was 8 feet, 1.75 inches (2.483 meters) long, 3 feet, 4.75 inches (1.035 meters) high and 2 feet, 4.94 inches (0.735 meters) wide. It weighed 1,320 pounds (599 kilograms).

Curtiss-Wright XP-40 38-10 (SDASM 16_008531)

At 1,829.39-cubic-inches (29.978 liters), the original Pratt & Whitney Twin Wasp S1C1-G (R-1830-17) 14-cylinder radial engine had greater displacement and produced 80 horsepower more for takeoff than the Allison V-12. The long, narrow V-12, though, allowed for a much more streamlined engine cowling for higher speed and greater efficiency.

XP-40 16_008533
Curtiss-Wright XP-40 prototype. (SDASM 16_008534)
The Curtiss XP-40 prototype at Langley Field in the original configuration. (NASA)
The Curtiss-Wright XP-40 in the original configuration at Langley Field. (NASA)
Everett Edward Elliot (1907–1981).

In the early testing, the XP-40 was much slower than expected, reaching only 315 miles per hour (507 kilometers per hour). (The P-36A Hawk had a maximum speed of  313 miles per hour). Engineers experimented with different placement for the coolant radiator, oil coolers and the engine air intake. The Air Corps project officer, Lieutenant Benjamin Scovill Kelsey, had the prototype sent to the National Advisory Committee for Aeronautics (NACA) Research Center at Langley Field, Virginia, where the full-size airplane was placed inside a wind tunnel.

Over a two-month period, NACA engineers made a number of improvements. The radiator was moved forward under the engine and the oil coolers utilized the same air scoop. The exhaust manifolds were improved as were the landing gear doors.

When they had finished, Lieutenant Kelsey flew the modified XP-40 back to Curtiss. Its speed had been increased to 354 miles per hour (570 kilometers per hour), a 12% improvement.

By December 1939 the airplane had been further improved and was capable of 366 miles per hour (589 kilometers per hour).

The Curtiss-Wright XP-40 prototype in a wind tunnel at Langley Field, 24 April 1939. (NASA)
Curtiss XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, April 1939. (NASA)
Curtiss-Wright XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, 24 April 1939. (NASA)

The Curtiss Hawk 75P, XP-40 38-10, was 31 feet, 1 inch (9.574 meters) long with a wingspan of 37 feet, 4 inches (11.354 meters) and overall height of 12 feet, 4 inches (3.734 meters). It had an empty weight of 5,417 pounds (2,457.1 kilograms) and maximum gross weight of 6,870 pounds (3,116.2 kilograms).

The prototype had a maximum speed of 342 miles per hour (550 kilometers per hour) at 12,200 feet (3,719 meters) with a gross weight of 6,260 pounds (2,839.5 kilograms). Its range was 460 miles (740 kilometers) flying at 299 miles per hour (481 kilometers per hour) with 100 gallons (378.5 liters) of fuel. With 159 gallons (601.9 liters) and with speed reduced to 200 miles per hour (322 kilometers per hour), the XP-40 had a maximum range of 1,180 miles (1,899 kilometers).

The prototype was armed with two air-cooled Browning AN-M2 .50-caliber machine guns mounted above the engine and synchronized to fire forward through the propeller arc.

The Air Corps placed an initial order for 524 P-40s. This was the largest single order for airplanes by the U.S. military up to that time. The first production model was the P-40 Warhawk, armed with two .50-caliber machine guns. There was only one P-40A variant which was a P-40 modified as a camera aircraft. The definitive pursuit model was the P-40B Warhawk, which retained the two .50-caliber guns of the P-40 and added two Browning M2 .30-caliber machine guns to each of the wings.

A Curtiss-Wright P-40B Warhawk, 79th Pursuit Squadron, 20th Pursuit Group, Hamilton Field, California, 1940. (U.S. Air Force)

The P-40B was best known as the airplane flown by the American Volunteer Group fighting for China against the Japanese. They were called the “Flying Tigers”. Between 1939 and 1945, Curtiss built 13,738 P-40s in many configurations. They flew in combat in every theater of operations during World War II.

A Curtiss-Wright Hawk 81-A3 (Tomahawk IIb) of the American Volunteer Group, Kunming, China, 1942. (U.S. Air Force)

© 2018, Bryan R. Swopes

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12 October 1944

1st Lieutenant Chuck Yeager. (American Air Museum in Britain)

12 October 1944: During World War II, First Lieutenant Charles Elwood Yeager, Air Corps, Army of the United States (A.U.S.), was a P-51 Mustang fighter pilot assigned to the 363d Fighter Squadron, 357th Fighter Group, stationed at RAF Leiston (USAAF Station 373), near the village of Theberton, Suffolk, England.

Recently promoted from the warrant rank of Flight Officer, Lieutenant Yeager—as one of the most experienced pilots in the group— was leading the 357th on a bomber escort mission against Bremen, Germany. While the Group’s 362nd and 364th Fighter Squadrons remained with the B-24 bombers, Yeager and the 363d patrolled 50 to 100 miles (80 to 160 kilometers) ahead.

At 25,000 feet (7,620 meters) over Steinhuder Meer, northwest of Hanover, Yeager sighted a group of Messerschmitt Bf 109 fighters (also called the Me 109). He was soon able to count 22. Yeager and his squadron of 16 Mustangs circled and attacked out of the sun.

A flight of three Luftwaffe Messerschmitt Me 109 fighters, 20 July 1944. (Bundsarchive Bild 101l-676-7975-36)
A flight of three Luftwaffe Messerschmitt Me 109 fighters, 20 July 1944. (Bundsarchive Bild 101l-676-7975-36)

As Chuck Yeager maneuvered his P-51D Mustang, named Glamorous Glenn II, to fire at a trailing Bf 109, the German fighter suddenly turned left and collided with his wingman. Both pilots bailed out of their fighters and the two Bf 109s went down.

It was almost comic, scoring two quick victories without firing a shot. . . By now, all the airplanes in the sky had dropped their wing tanks and were spinning and diving in a wild, wide-open dogfight. I blew up a 109 from six hundred yards—my third victory—when I turned to see another angling in behind me. Man I pulled back the throttle so damned hard I nearly stalled, rolled up and over, came in behind and under him, kicking right rudder and simultaneously firing. I was directly underneath the guy, less than fifty feet, and I opened up that 109 as if it were a can of Spam. That made four. A moment later, I waxed a guy’s fanny in a steep dive; I pulled up at about 1,000 feet; he went straight into the ground.

Yeager, An Autobiography, by Chuck Yeager and Leo Janos, Bantam Books, New York, 1985, at Page 57.

1st Lieutenant Charles E. Yeager with “Glamorous Glenn II,” at USAAF Station 157, Raydon, Suffolk, England, 17 October 1944. (American Air Museum in Britain)

Lieutenant Yeager’s official report of the air battle reads (in part):

“H. Five Me. 109s destroyed

“I. I was leading the Group with Cement Squadron and was roving out to the right of the first box of bombers. I was over STEINHUDER LAKE when 22 Me. 109s crossed in front of my Squadron from 11:00 O’Clock to 1:00 O’Clock. I was coming out of the sun and they were about 1½ miles away at the same level of 25,000 feet. I fell in behind the enemy formation and followed them for about 3 minutes, climbing to 30,000 feet. I still had my wing tanks and had close up to around 1,000 yards, coming within firing range and positioning the Squadron behind the entire enemy formation. Two of the Me. 109s were dodging over to the right. One slowed up and before I could start firing, rolled over and bailed out. The other Me. 109, flying his wing, bailed out immediately after as I was ready to line him in my sights. I was the closest to the tail-end of the enemy formation and no one, but myself was in shooting range and no one was firing. I dropped my tanks and then closed up to the last Jerry and opened fire from 600 yards, using the K-14 sight. I observed strikes all over the ship, particularly heavy in the cockpit. He skidded off to the left. I was closing up on another Me. 109 so I did not follow him down. Lt. STERN, flying in Blue Flight reports this E/A on fire as it passed him and went into a spin. I closed up on the next Me. 109 to 100 yards, skidded to the right and took a deflection shot of about 10°. I gave about a 2 second burst and the whole fuselage split open and blew up after we passed. Another Me. 109 to the right had cut his throttle and was trying to get behind. I broke to the right and quickly rolled to the left on his tail. He started pulling it in and I was pulling 6″G”. I got a lead from around 300 yards and gave him a short burst. There were hits on wings and tail section He snapped to the right 3 times and bailed out when he quit snapping at around 18,000 feet. I did not blackout during this engagement due to the efficiency of the “G” suit. Even though I was skidding I hit the second Me. 109 by keeping the bead and range on the E/A. To my estimation the K-14 sight is the biggest improvement to combat equipment for Fighters up to this date. The Me. 109s appeared to have a type of bubble canopy and had purple noses and were a mousey brown all over. I claim five Me 109s destroyed.

“J. Ammunition Expended: 587 rounds .50 cal MG.

“Charles E. Yeager, 1st Lt, AC.”

Lieutenant Yeager had destroyed five enemy fighters during a single battle. He became “an Ace in one day” and was awarded the Silver Star. Of the twenty-two Me 109s, the 363rd had destroyed eight without losing a single Mustang.

Yeager’s Glamorous Glenn II had previously been assigned to Captain Charles K. Peters and named Daddy Rabbit. Flown by another pilot, Second Lieutenant Horace Roycroft, 44-13897 was destroyed six days later when it crashed in bad weather. Lieutenant Roycroft was killed.

North American Aviation P-51D-5-NA 44-13366 on a test flight near the North American plant at Inglewood, California. This is from the same production block as Yeager's Glamorous Glenn II.
North American Aviation P-51D-5-NA 44-13366 on a test flight near the North American plant at Inglewood, California. This fighter is from the same production block as Yeager’s Glamorous Glenn II.

The P-51D was the predominant version of the North American Aviation World War II fighter. It was a single-seat, single-engine fighter, initially designed for the Royal Air Force. The P-51D was 32 feet, 3.5 inches (9.843 meters) long, with a wingspan of 37 feet (11.278 meters). It was 13 feet, 4.5 inches (4.077 meters) high. The fighter had an empty weight of 7,635 pounds (3,463 kilograms) and a maximum takeoff weight of 12,100 pounds (5,489 kilograms).

The P-51D was powered by a right-hand tractor, liquid-cooled, supercharged, 1,649-cubic-inch-displacement (27.04-liter) Packard V-1650-3 or -7 Merlin single overhead cam (SOHC) 60° V-12 engine with Military Power ratings of 1,380 horsepower at Sea Level, turning 3,000 r.p.m with 60 inches of manifold pressure (V-1650-3), or 1,490 horsepower at Sea Level, turning 3,000 r.p.m. with 61 inches of manifold pressure (V-1650-7). These engines were versions of the Rolls-Royce Merlin 63 and 66, built under license by the Packard Motor Car Company of Detroit, Michigan. The engine drove a four-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 11 feet, 2 inches (3.404 meters) through a 0.479:1 gear reduction.

A Packard Motor Car Company V-1650-7 Merlin V-12 aircraft engine at the Smithsonian Institution National Air and Space Museum. This engine weighs 1,715 pounds (778 kilograms) and produces 1,490 horsepower at 3,000 r.p.m. Packard built 55,873 of the V-1650 series engines. Continental built another 897. The cost per engine ranged from $12,548 to $17,185. (NASM)
A Packard Motor Car Company V-1650-7 Merlin V-12 aircraft engine at the Smithsonian Institution National Air and Space Museum. This engine weighs 1,715 pounds (778 kilograms) and produces 1,490 horsepower at 3,000 r.p.m. Packard built 55,873 of the V-1650 series engines. Continental built another 897. The cost per engine ranged from $12,548 to $17,185. (NASM)

The P-51D with a V-1650-7 Merlin had maximum speed at Sea Level of 323 miles per hour (520 kilometers per hour) at the Normal Power setting of 2,700 r.p.m. and 46 inches of manifold pressure, and 375 miles per hour (604 kilometers per hour) at War Emergency Power, 3,000 r.p.m with 67 inches of manifold pressure (5 minute limit). At altitude, using the Military Power setting of 3,000 r.p.m. and 61 inches of manifold pressure (15 minute limit), it had a maximum speed of 439 miles per hour (707 kilometers per hour) at 28,000 feet (8,534 meters). With War Emergency Power the P-51D could reach 442 miles per hour (711 kilometers per hour) at 26,000 feet (7,925 meters).

The P-51D could climb to 20,000 feet (6,096 meters) in 6.4 minutes, and to its service ceiling, 41,600 feet (12,680 meters), in 28 minutes. The airplane’s absolute ceiling was 42,400 feet (12,924 meters).

With 180 gallons (681 liters) internal fuel, the maximum range of the P-51D was 1,108 miles (1,783 kilometers).

Armorers carry AN/M2 Browning .50-caliber machine guns and belts of linked ammunition to a P-51 Mustang. (U.S. Air Force)
Armorers carry Browning AN-M2 .50-caliber machine guns and belts of linked .50-caliber ammunition to a P-51 Mustang. (U.S. Air Force)

The P-51D was armed with six electrically-heated Browning AN-M2 .50-caliber machine guns, with three mounted in each wing. 400 rounds of ammunition were provided for the inner pair of guns, and 270 rounds for each of the other four guns, for a total of 1,880 rounds of ammunition. This was armor piercing, incendiary, and tracer ammunition. The fighter could also carry a 1,000 pound (453.6 kilogram) bomb under each wing in place of drop tanks, or up to ten rockets.

North American Aviation P-51D Mustang. (U.S. Air Force)
North American Aviation P-51D Mustang. (U.S. Air Force)

A total of 8,156 P-51Ds were produced by North American at Inglewood, California, and Dallas, Texas, and another 200 by the Commonwealth Aircraft Corporation, Melbourne, Australia.

The North American Aviation P-51D Mustang remained in service with the United States Air Force until 27 January 1957, when the last aircraft were retired from the 167th Fighter Squadron, West Virginia National Guard.

North American Aviation P-51D-25-NT Mustang 44-84900 at NACA Langley Memorial Aeronautical Laboratory, circa 1945–1952. (NASA)

© 2018, Bryan R. Swopes

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1 October 1942

Bell XP-59A Airacomet 42-108784, first flight at Muroc Dry Lake, 1 October 1942. (U.S. Air Force)

1 October 1942: At Muroc Dry Lake, in the high desert north of Los Angeles, California, Bell Aircraft Corporation’s Chief Test Pilot, Robert Morris Stanley, made the first flight of the top secret prototype turbojet-powered fighter, the Bell XP-59A Airacomet, serial number 42-108784. Weather was “C.A.V.U.” (Ceiling and Visibility Unrestricted) and wind was from the west at 20 miles per hour (9 meters per second).

Bell Aircraft Corporation Chief Test Pilot Robert M. Stanley in the cockpit of an XP-59A Airacomet. (National Museum of the United States Air Force)

In his report, Stanley wrote:

“4.     All take-offs were made using 15,000 r.p.m. on both engines with flaps fully up and with the airplane pulled off the ground at about 80 to 90 m.p.h. Throttle was applied promptly and acceleration during take-off appeared quite satisfactory. The run was estimated to be in the vicinity of 2,000 feet, possibly more. The first flight reached an altitude of approximately 25 feet, and landing was made using partial power without flaps. This take-off had the wind approximately 60° on the right bow and must be considered a cross-wind take-off.

“5.     Aileron and elevator action appear satisfactory, although the rudder force appears undesirably light causing the airplane to yaw somewhat for very light pedal pressures. Left rudder was needed for take-off due to cross wind.”

—Bell Aircraft Corp. Pilot’s Report 27-923-001, at Page 1-12, by Robert M. Stanley, 1 October 1942

Bell XP-59A Airacomet 42-108784 disguised with a false propeller. (U.S. Air Force)
One of the three Bell XP-59A prototypes, circa 1942. (U.S. Air Force)
Bell Aircraft Corporation XP-59A Airacomet 42-108784. (U.S. Air Force photo)
Bell Aircraft Corporation P-59 Airacomet with updated national insignia, after August 1943. (U.S. Air Force photo)
Bell Aircraft Corporation XP-59A Airacomet 42-108784. (U.S. Air Force photo)

Stanley made three more flights that day, as high as 100 feet (30.5 meters). The following day, Army Air Corps test pilot Colonel Laurence C. Craigie conducted the “official” first flight, reaching an altitude of 10,000 feet (3,048 meters).

A Bell XP-59A Airacomet prototype in flight near Muroc Army Airfield, 1942. (U.S. Air Force)

Three XP-59A prototypes were built. The number one ship, 42-108784, was affectionately nicknamed Miss Fire, because of the initial difficulty in getting the engines to start.

The Bell XP-59A was conventional single-place airplane with retractable tricycle landing gear. It was primarily of metal construction, though the control surfaces were fabric-covered. The prototype was 38 feet, 10 inches (11.836 meters) long with a wingspan of 49 feet, 0 inches (14.935 meters) and overall height of 12 feet, 3¾ inches (3.753 meters), at rest. The leading edge of the wings were swept aft  7°. The angle of incidence was +2° with -2° twist and 2½° dihedral. The horizontal stabilizer had a span of 16 feet, 8 inches (5.080 meters). Its angle of incidence was +1½° with no dihedral. The vertical fin had 0° offset. The empty weight of the XP-59A was 7,319 pounds (3,320 kilograms) and its maximum gross weight was 10,089 pounds (4,576 kilograms).

A cutaway display of a General Electric I-A turbojet engine. The compressor and turbine are on a single shaft (center). One of the combustion chambers is sectioned at the upper left. (National Museum of the United States Air Force)
A cutaway display of a General Electric I-A turbojet engine. The single-stage centrifugal compressor and single-stage axial-flow turbine are on a single shaft (center). One of the annular combustion chambers is sectioned at the upper left. (National Museum of the United States Air Force)

The experimental fighter was initially powered by two General Electric Type I-A centrifugal reverse-flow turbojet engines, serial numbers 170121 (left) and 170131 (right), each producing 1,250 pounds of thrust (5.561 kilonewtons) at 15,000 r.p.m. These were copies of the British Whittle W.2B engines. They were heavy, underpowered and unreliable.

Performance of the XP-59A was disappointing with a maximum speed of 350 miles per hour (563 kilometers per hour) at Sea Level and 389 miles per hour (626 kilometers per hour) at 35,160 feet (10,717 meters), significantly slower than many piston-engined fighters.

Three XP-59A prototypes and thirteen YP-59A preproduction airplanes were built. The P-59 was ordered into production and Bell Aircraft Corporation built thirty P-59A and twenty P-59B fighters. These were armed with one M4 37mm autocannon with 44 rounds of ammunition and three Browning AN-M2 .50-caliber machine guns with 200 rounds per gun.

Although a YP-59A had set an unofficial altitude record of 47,600 feet (14,508 meters), the Airacomet was so outclassed by standard production fighters that no more were ordered.

Lawrence D. ("Larry") Bell with his XP-59A Airacomet at Muroc Dry Lake. (Robert F. Dorr Collection)
Lawrence D. Bell with his XP-59A Airacomet at Muroc Dry Lake. (Robert F. Dorr Collection)

The race for a jet engine-powered fighter had been ongoing for several years, and the United States’ XP-59A was trailing behind. The first jet airplane, the Heinkel He 178, had made its first flight in Germany three years earlier, on 27 August 1939, though it was a proof-of-concept article, not an operational military aircraft. In the United Kingdom, the Gloster E/28.39, also a proof-of-concept aircraft, though more advanced than the Heinkel, made its first flight, 15 May 1941. The world’s first operational jet fighter, the Messerschmitt Me 262, made its first flight on 18 July 1942. It was nearly two years before production Me 262s entered combat, but they were devastating against bomber formations. The Gloster Meteor, the Allies’ first jet fighter, first flew 5 March 1943, and deliveries to fighter squadrons began in July 1944. The de Havilland DH.100 Vampire made its first flight 20 September 1943, but it did not become operational until after the end of World War II.

The XP-59A flew nearly five months before its British cousin, but would not be assigned to an operational squadron, the 445th Fighter Squadron, 412th Fighter Group, until June 1945.

The first American military jet aircraft, Bell XP-59A Airacomet 42-108784, was preserved by the Army at Muroc, and the engines at Wright Field, Ohio. In 1978, these were given to the Smithsonian Institution National Air and Space Museum where the prototype was later restored and placed on display.g9

The first American jet-powered aircraft, Bell XP-59A Airacomet 42-108784 on display at the National Air and Space Museum. (NASM)

© 2018, Bryan R. Swopes

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21 September 1942

A Boeing XB-29 takes off from Boeing Field, Seattle, Washington. (SDASM)
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!”

Eddie Allen lean’s out of a cockpit window following the first taxi test of the XB-29. (Boeing)

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 41-002. (SDASM)

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 XB-29 41-002. (SDASM)

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.

The B-29 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.

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)

© 2018, Bryan R. Swopes

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