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

17 August 1942

A flight of Boeing B-17E Flying Fortress bombers forms up over England, 1942. “Yankee Doodle,” 41-9023, is just to the left of center. (U.S. Air Force)
Brigadier General Ira C. Eaker (Margaret Bourke-White/LIFE)

17 August 1942: Mission No. 1. The United States VIII Bomber Command made its first heavy bomber attack on Nazi-occupied Europe when eighteen Boeing B-17E Flying Fortress four-engine bombers of the 97th Bombardment Group (Heavy), based at RAF Polebrook, Northamptonshire, England, headed for the railroad marshaling yards at Rouen-Sotteville, France. This was the largest and most active railroad yard in northern France.

The group began takeoffs at 1530 hours. It was escorted by several squadrons of Royal Air Force Supermarine Spitfire fighters.

While six B-17s flew along the French coast as a diversion, twelve bombers flew to Rouen and were over the target from 1739 to 1746. From an altitude of 23,000 feet (7,010 meters), they dropped 39,000 pounds (17,690 kilograms) of general purpose bombs.

Accuracy was good. One of the aim points, the locomotive shops, was destroyed by a direct hit. The overall results were moderate.

Rouen-Sotteville target assesment photograph. (U.S. Air Force)
Rouen-Sotteville target assessment photograph. (U.S. Air Force)

All of the bombers returned to their base, with the first landing at 1900. Two B-17s had been damaged. American gunners claimed damage to one Luftwaffe airplane.

brigadier General Ira C. Eaker commanded the raid from this Boeing B-17E Flying Fortress, 41-9023, Yankee Doodle, here being serviced between missions. (U.S. Air Force)
Brigadier General Ira C. Eaker commanded Mission No. 1 from this Boeing B-17E Flying Fortress, 41-9023, Yankee Doodle, shown here being serviced between missions. This bomber survived the War. (U.S. Air Force)

The raid was commanded by Brigadier General Ira C. Eaker aboard Yankee Doodle, B-17E 41-9023, leading the second flight of six B-17s. The 97th Bombardment Group Commander, Colonel Frank A. Armstrong, Jr., flew as the co-pilot of the lead ship, Butcher Shop, B-17E 41-2578, with pilot Major Paul W. Tibbets, Jr. Major Tibbets was in command of the 97th’s 340th Bombardment Squadron. (He would later command the 509th Composite Group and fly the B-29 Superfortress Enola Gay.)

Colonel Frank A. Armstrong in the pilot's position of a Boeing B-17 (Imperial War Museum, Roger Freeman Collection, Object Number FRE 890)
Colonel Frank Alton Armstrong, Jr., Air Corps, United States Army, commanding the 97th Bombardment Group (Heavy), in the pilot’s position of a Boeing B-17E Flying Fortress. (Imperial War Museum)

The Boeing B-17E Flying Fortress was a major redesign. A new aft fuselage was used, incorporating larger vertical and horizontal stabilizers. A tail turret was added. A power-operated gun turret was added at dorsal and ventral positions.

The Boeing B-17E Flying Fortress was a four-engine heavy bomber operated by a flight crew of ten. It was 73 feet, 10 inches (22.504 meters) long with a wingspan of 103 feet, 9-3/8 inches (31.633 meters) and an overall height of 19 feet, 2 inch (5.842 meters). Its empty weight was 32,350 pounds (14,674 kilograms), 40,260 pounds (18,262 kilograms) gross weight, and the maximum takeoff weight was 53,000 pounds (24,040 kilograms).

Boeing B-17E Flying Fortress 41-2587, 97th Bombardment Group, photographed 17 August 1942. (Imperial War Museum, Roger Freeman Collection, Object Number FRE 4053)
Boeing B-17E Flying Fortress 41-2578, 97th Bombardment Group, photographed 17 August 1942. (Imperial War Museum)

The B-17E was powered by four air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.875 liters) Wright Cyclone G666A (R-1820-65) nine-cylinder radial engines with turbochargers, producing 1,200 horsepower at 2,500 r.p.m. for takeoff and 1,000 horsepower at 2,300 r.p.m. at Sea Level. The Cyclones turned three-bladed constant-speed Hamilton-Standard Hydromatic propellers with a diameter of 11 feet, 7 inches (3.835 meters) though a 0.5625:1 gear reduction. The R-1820-65 was 47.59 inches (1.209 meters) long and 55.12 inches (1.400 meters) in diameter. It weighed 1,315 pounds (596 kilograms). 8,422 of these engines were produced by Wright Aeronautical Division and its licensees between February 1940 and August 1942.

The B-17E had a cruise speed of 195 miles per hour (314 kilometers per hour). Its maximum speed was 318 miles per hour (512 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 36,600 feet (11,156 meters).

With a normal fuel load of 2,490 gallons (9,426 liters) the B-17E had a maximum range of 3,300 miles (5,311 kilometers). Carrying a 4,000 pound (1,814 kilogram) bomb load, the range was 2,000 miles (3,219 kilometers).

Boeing B-17E Flying Fortress 41-2578, lead ship on the 17 August 1942 air raid on Rouen-Sotteville, France. By the end of the war, this airplane was the oldest, longest-serving B-17E in the USAAF.
Boeing B-17E Flying Fortress 41-2578, the lead ship on the 17 August 1942 air raid on Rouen-Sotteville, France, flown by Major Paul W. Tibbets, photographed at RAF Bovingdon, 1943. By the end of the war, this airplane was the oldest, longest-serving B-17E in the USAAF. (Imperial War Museum)

The B-17E Flying Fortress was armed with one .30-caliber Browning M2 Aircraft Machine Gun and eight Browning AN-M2 .50-caliber machine guns. The .30 was mounted in the nose.  Power turrets mounting two .50-caliber guns, each, were located at the dorsal and ventral positions. (The first 112 B-17Es were built with a remotely-operated turret in the belly position, sighted by a periscope. A manned ball turret replaced this.) Two machine guns were in a tail turret, and one on each side at the waist.

The maximum bomb load of the B-17E was 20,800 pounds (9,435 kilograms) over very short distances. Normally, 4,000–6,000 pounds (1,815–2,722 kilograms) were carried. The internal bomb bay could be loaded with a maximum of eight 1,000 pound (454 kilogram) or four 2,000 pound (907 kilogram) bombs.

The B-17 Flying Fortress first flew in 1935, and was in production from 1937 to 1945. 12,731 B-17s were built by Boeing. 512 of the total were B-17Es. The last one was completed 28 May 1942. Production shifted to the further-improved B-17F.

Boeing B-17E Flying Fortress 41-2509, flying over the Florida Keys, circa 1942. (Getty Images)

© 2017, Bryan R. Swopes

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9 August 1944

MEDAL OF HONOR

LINDSEY, DARRELL R. (Air Mission)

Rank and organization: Captain, U.S. Army Air Corps.

Place and date: L’Isle Adam railroad bridge over the Seine in occupied France, 9 August 1944.

Entered service at: Storm Lake, lowa. Birth: Jefferson, lowa.

G.O. No: 43, 30 May 1945.

Medal of Honor
Medal of Honor

Citation: On 9 August 1944, Capt. Lindsey led a formation of 30 B-26 medium bombers in a hazardous mission to destroy the strategic enemy held L’lsle Adam railroad bridge over the Seine in occupied France. With most of the bridges over the Seine destroyed, the heavily fortified L’Isle Adam bridge was of inestimable value to the enemy in moving troops, supplies, and equipment to Paris. Capt. Lindsey was fully aware of the fierce resistance that would be encountered. Shortly after reaching enemy territory the formation was buffeted with heavy and accurate antiaircraft fire. By skillful evasive action, Capt. Lindsey was able to elude much of the enemy flak, but just before entering the bombing run his B-26 was peppered with holes. During the bombing run the enemy fire was even more intense, and Capt. Lindsey’s right engine received a direct hit and burst into flames. Despite the fact that his ship was hurled out of formation by the violence of the concussion, Capt. Lindsey brilliantly maneuvered back into the lead position without disrupting the flight. Fully aware that the gasoline tanks might explode at any moment, Capt. Lindsey gallantly elected to continue the perilous bombing run. With fire streaming from his right engine and his right wing half enveloped in flames, he led his formation over the target upon which the bombs were dropped with telling effect. Immediately after the objective was attacked, Capt. Lindsey gave the order for the crew to parachute from the doomed aircraft. With magnificent coolness and superb pilotage, and without regard for his own life, he held the swiftly descending airplane in a steady glide until the members of the crew could jump to safety. With the right wing completely enveloped in flames and an explosion of the gasoline tank imminent, Capt. Lindsey still remained unperturbed. The last man to leave the stricken plane was the bombardier, who offered to lower the wheels so that Capt. Lindsey might escape from the nose. Realizing that this might throw the aircraft into an uncontrollable spin and jeopardize the bombardier’s chances to escape, Capt. Lindsey refused the offer. Immediately after the bombardier had bailed out, and before Capt. Lindsey was able to follow, the right gasoline tank exploded. The aircraft sheathed in fire, went into a steep dive and was seen to explode as it crashed. All who are living today from this plane owe their lives to the fact that Capt. Lindsey remained cool and showed supreme courage in this emergency.

Strike photo, L’Isle-Adam Railroad Bridge, 9 August 1944. (U.S. Air Force)

Darrell Robbins Lindsey was born 30 December 1919 at Jefferson, Iowa. He was the second of two sons of Jesse Lyle Lindsey, a civil engineer, and Grace Alice Puffer Lindsey. Darrell Lindsey grew up in Iowa, where he attended Fort Dodge High School, graduating in 1938. He then studied at Buena Vista College at Storm Lake, before transferring to Drake University in Des Moines.

Aviation Cadet Darrell Robbins Lindsey, circa 1942.

Immediately following the United States’ entry into World War II, 16 January 1942, Lindsey enlisted as an aviation cadet in the U.S. Army Air Corps. He trained as a pilot and on graduating from flight school, was commissioned as a second lieutenant, 27 August 1942.

Lieutenant and Mrs. Darrell R. Lindsey, circa 1942.

Following his commissioning, Lieutenant Lindsey married Miss Evelyn Scott of Storm Lake, Iowa.

Lieutenant Lindsey next trained as a bombardier at Kirtland Field, New Mexico. He was promoted to first lieutenant and was assigned to a Martin B-26 Marauder operational training unit, the 314th Bombardment Squadron (Medium), at MacDill Army Airfield, near Tampa, Florida. He was promoted to captain in December 1943.

Captain Lindsey was assigned to the 585th Bombardment Squadron (Medium), 394th Bombardment Group (Medium), as a B-26 aircraft commander and flight leader. The unit deployed to Europe in February 1944. The 585th was initially stationed at RAF Boreham (AAF-161) in Essex, but in July 1944, moved to RAF Holmsley South (AAF-455), Hampshire, England.

The bombing mission against the L’Isle-Adam Railroad Bridge on 9 August 1944 was Captain Lindsey’s 46th combat mission. Army Air Corps records indicate that at the time of his death, he had flown a total of 1,497:00 hours. 143 hours were in combat.

Captain Lindsey’s remains were buried at an unknown location. In 1959, a cenotaph memorializing Captain Lindsey was placed at Jefferson Cemetery, Jefferson, Iowa.

The Medal of Honor was presented to Captain Lindsey’s widow, Mrs. Evelyn Scott Lindsey, 9 August 1945, by Major General Robert B. Williams, commanding Second Air Force. In November 1946, Lindsey Air Station at Wiesbaden, Germany, was named in his honor.

In addition to the Medal of Honor, Captain Lindsey was awarded the Distinguished Flying Cross, the Air Medal with eight oak leaf clusters (nine awards), and the Purple Heart.

Martin B-26B-55-MA Marauder 42-96153 of the 397th Bombardment Group (Medium), at Peronne Advanced Landing Ground (A-72), France, January 1945. This is the same type as the B-26 flown by Captain Darrell R. Lindsey, 9 August 1944. (U.S. Air Force)

Captain Lindsey’s B-26 was a Glenn L. Martin Company B-26B-55-MA Marauder, serial number 42-96101, built at Baltimore, Maryland. It carried the squadron identification markings 4T N on its fuselage.

The Martin B-26 first flew 25 November 1940. The B-26 was a twin-engine medium bomber designed with high speed as a primary objective. Production of the new airplane was considered so urgent that there were no prototypes. All aircraft were production models.

Martin B-26B-55-MA Marauder 42-96142, 596th Bombardment Squadron (Medium), 397th Bombardment Group (Medium). This is the same type aircraft flown by Captain Lindsey in the attack against the L’Isle-Adam Railroad Bridge. (U.S. Air Force)

The B-26B was 58 feet, 3 inches (17.755 meters) long with a wingspan of 71 feet, 0 inches (21.641 meters) and overall height of 21 feet, 6 inches (6.533 meters). It had an empty weight of 24,000 pounds (10,886 kilograms) and gross weight of 37,000 pounds (16,783 kilograms).

The B-26B-55-MA was powered by two air-cooled, supercharged, 2,804.461-cubic-inch-displacement (45.956 liter), Pratt & Whitney Double Wasp 2SB-G (R-2800-43) two-row, 18-cylinder radial engines with a compression ratio of 6.65:1. The R-2800-43 had a Normal Power rating of 1,600 horsepower at 2,400 r.p.m. to 5,700 feet (1,737 meters), 1,450 horsepower at 2,400 r.p.m. at 13,000 feet (3,962 meters). Its Takeoff Power rating was 2,000 horsepower at 2,700 r.p.m. The Military Power rating was the same as Takeoff Power up to 2,700 feet (823 meters), and 1,600 horsepower at 2,700 r.p.m. to 13,500 feet (4,115 meters). They turned 13 foot, 6 inch (4.115 meter) diameter four-bladed Curtiss Electric propellers through a 2:1 gear reduction. The R-2800-43 was 6 feet, 3.72 inches (1.923 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 2,300 pounds (1,043 kilograms). All R-2800-43 engines were built by the Ford Motor Company.

The B-26B had a maximum speed of 270 miles per hour (435 kilometers per hour) at Sea Level, and 282 miles per hour (454 kilometers per hour) at 15,000 feet (4,572 meters). The airplane’s service ceiling was 21,700 feet (6,614 meters). It’s maximum ferry range was 2,850 miles (4,587 kilometers).

The B-26B was armed with 11 air-cooled Browning AN-M2 .50-caliber machine guns. One was at the nose on a flexible mount, two fixed guns were on each side of the fuselage in “blister packs,” there were two flexible guns in the waist. A power-operated dorsal gun turret had two, as did the tail turret.

A maximum of four 2,000 pound (907 kilograms) bombs could be carried in the bomb bay.

Martin B-26F-1-MA of the 397th Bomb Group in flight at bomb release. (U.S. Air Force)

When the B-26 entered service, it quickly gained a reputation as a dangerous airplane and was called “the widowmaker.” The airplane had relatively short wings with a small area for its size. This required that landing approaches be flown at much higher speeds than was normal practice. With one engine out, airspeed was even more critical. Some changes were made, such as a slight increase on wingspan and the size of the vertical fin and rudder, and an emphasis was made on airspeed control during training. The Marauder had the lowest rate of combat losses of any American bomber.

The Glenn L. Martin Co. produced 5,288 Marauders between 1941–1945. It served in the Pacific, Mediterranean and European combat areas. When it was removed from service at the end of World War II, the “B-26” designation was reassigned to the Douglas A-26 Invader, a light twin-engine bomber.

© 2017, Bryan R. Swopes

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6 August 1945

Major Richard Ira Bong, United States Army Air Forces. (U.S. Air Force)

6 August 1945: After serving three combat tours flying the Lockheed P-38 Lightning in the Southwest Pacific, Major Richard Ira Bong, Air Corps, United States Army, was assigned as an Air Force acceptance test pilot for new Lockheed P-80 Shooting Star jet fighters at the Lockheed Air Terminal, Burbank, California.

The P-80A was a brand new jet fighter, and Major Bong had flown just 4 hours, 15 minutes in the type during 12 flights.

Shortly after takeoff in P-80A-1-LO 44-85048, the primary fuel pump for the turbojet engine failed. A back-up fuel pump was not turned on. The Shooting Star rolled upside down and Bong bailed out, but he was too low for his parachute to open and he was killed. The jet crashed at the intersection of Oxnard Street and Satsuma Avenue, North Hollywood, California, and exploded.

Site of the crash of Major Richard I. Bong’s Lockheed P-80A-1-LO fighter, 44-85048, at Oxnard Street and Satsuma Avenue, North Hollywood, California. (Contemporary news photograph)
This graphic appeared in the Los Angles Times, 7 August 1945, at Page 3. (Los Angeles Times)
General Douglas MacArthur with Major Richard I. Bong.
General Douglas MacArthur with Major Richard I. Bong.

Richard I. Bong was known as the “Ace of Aces” for scoring 40 aerial victories over Japanese airplanes between 27 December 1942 and 17 December 1944 while flying the Lockheed P-38 Lightning. He was awarded the Medal of Honor, which was presented by General Douglas MacArthur, 12 December 1944. [The following day, General MacArthur was promoted to General of the Army.]

The citation for Major Bong’s Medal of Honor reads: “For conspicuous gallantry and intrepidity in action above and beyond the call of duty in the Southwest Pacific area from 10 October to 15 November 1944. Though assigned to duty as gunnery instructor and neither required nor expected to perform combat duty, Major Bong voluntarily and at his own urgent request engaged in repeated combat missions, including unusually hazardous sorties over Balikpapan, Borneo, and in the Leyte area of the Philippines. His aggressiveness and daring resulted in his shooting down eight enemy airplanes during this period.”

General of the Army Henry H. (“Hap”) Arnold and Major Richard I. Bong, circa 1945.

The Lockheed P-80-1-LO was the United States’ first operational jet fighter. It was a single-seat, single-engine low-wing monoplane powered by a turbojet engine. The fighter was designed by a team of engineers led by Clarence L. (“Kelly”) Johnson. The prototype XP-80A, 44-83020, nicknamed Lulu-Belle, was first flown by test pilot Tony LeVier at Muroc Army Air Field (now known as Edwards Air Force Base), 8 January 1944.

Lockheed P-80A-1-LO shooting Star 44-85004, similar to the fighter being test flown by Richard I. Bong, 6 August 1945. (U.S. Air Force)

The P-80A was a day fighter, and was not equipped for night or all-weather combat operations. The P-80A was 34 feet, 6 inches (10.516 meters) long with a wingspan of 38 feet, 10.5037 inches (11.84919 meters) ¹ and overall height of 11 feet, 4 inches (3.454 meters).

The leading edges of the P-80A’s wings were swept aft 9° 18′ 33″. They had an angle of incidence of +1° at the root and -0° 30′ at the tip. There was 3° 50′ dihedral. The total wing area was 237.70 square feet (22.083 square meters).

The fighter had an empty weight of 7,920 pounds (3,592 kilograms) and a gross weight of 11,700 pounds (5,307 kilograms). The maximum takeoff weight was 14,000 pounds (6,350 kilograms).

Lockheed P-80 Shooting Star production, alongside P-38 Lightnings. (SDASM)

Early production P-80As were powered by either an Allison J33-A-9 or a General Electric J33-GE-11 turbojet engine. The J33 was a licensed version of the Rolls-Royce Derwent. It was a single-shaft turbojet with a 1-stage centrifugal compressor section and a 1-stage axial-flow turbine. The -9 and -11 engines were rated at 3,825 pounds of thrust (17.014 kilonewtons). The J33s were 8 feet, 6.9 inches (2.614 meters) long, 4 feet, 2.5 inches (1.283 meters) in diameter and weighed 1,775 pounds (805 kilograms).

The P-80A had a cruising speed of 445 miles per hour (716 kilometers per hour) at 20,000 feet (6,096 meters). Its maximum speed was 548 miles per hour (882 kilometers per hour) at 2,700 feet (823 meters) and and 501 miles per hour (806 kilometers per hour) at 34,700 feet (10,577 meters).² The service ceiling was 45,000 feet (13,716 meters).

Lockheed P-80A-1-LO Shooting Star 44-85155, similar to the jet fighter which Major Bong was flying, 6 August 1945. (U.S. Air Force)

The P-80A Shooting Star was armed with six air-cooled Browning AN-M2 .50-caliber aircraft machine guns mounted in the nose.

Dick Bong poses with “Marge,” his Lockheed P-38J Lightning. A large photograph of his fiancee, Miss Marjorie Vattendahl, is glued to the fighter’s nose.

¹ Wing span with rounded wing tips. P-80As with squared (“clipped”) tips had a wing span of 37 feet, 7.5037 inches (11.46819 meters).

² Several hundred of the early production P-80 Shooting stars had all of their surface seams filled, and the airplanes were primed and painted. Although this process added 60 pounds (27.2 kilograms) to the empty weight, the decrease in drag allowed a 10 mile per hour (16 kilometers per hour) increase in top speed. The painted surface was difficult to maintain in the field and the process was discontinued.

© 2018, Bryan R. Swopes

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31 July 1923: Browning Machine Gun, Caliber .50, AN-M2

This photograph shows SSGT Maynard H. Smith with a Browning .50-caliber machine gun at the left waist position of a B-17 Flying Fortress. (U.S. Air Force)

31 July 1923: The original patent application, Serial No. 654,955, for the legendary Browning .50-caliber machine gun was filed with the United States Patent Office on 31 July 1923. Patent Number 1,628,226 was issued to the estate of John Moses Browning by the Patent Office on 10 May 1927.

The majority of United States combat aircraft during World War II were armed with the Browning Machine Gun, Caliber .50, AN-M2. The machine gun could be mounted as a fixed weapon in the aircraft’s wings or nose, in flexible mounts, or power-operated turrets.

Three Browning .50-caliber machine guns and belted ammunition installed in the left wing of a Vought-Sikorsky F4U-1 Corsair, 11 August 1942. (Vought-Sikorsky)

“The  basic aircraft Browning machine gun, cal. .50, AN-M2. . . is an automatic, recoil-operated, belt-fed, air-cooled machine gun. The metallic link disintegrating belt is used in all firing of the gun. The gun is designed for all cal. .50 aircraft machine gun installations. By properly repositioning some of the component parts, ammunition may be fed into the gun from either the right or the left side.”

TM9-225 War Department Technical Manual, BROWNING MACHINE GUN, CALIBER .50, AN-M2, AIRCRAFT, BASIC, 28 January 1947, Section II., Paragraph 3. General, at Page 2

Illustration of the basic .50-caliber Browning machine gun, AN-M2. (War Department)
John Moses Browning

The Browning Machine Gun (“BMG”) was designed by John Moses Browning, who had also designed the Automatic Pistol, Caliber .45, M1911, the standard sidearm of the U.S. military for 74 years;  the Rifle, Caliber .30, Automatic, Browning, M1918 (best known as the “Browning Automatic Rifle” or “BAR”); the Browning Machine Gun, Caliber .30, M1919; and the Browning Hi-Power, a 9 × 19 mm double-action semiautomatic pistol designed for Fabrique National (FN) of Herstal, Belgium.

The basic weapon had an overall length of 56.25 inches (1.429 meters) and weighed 61.00 pounds (27.67 kilograms). The barrel is cylindrical, and 36.00 inches (0.91 meters) long. It is surrounded by a barrel jacket with ventilation holes to dissipate heat. The bore has 8 rifled-grooves with a right-hand twist, making one complete turn in every 15.00 inches (0.381 meters).

The basic AN-M2 gun could be modified to be manually fired with the substitution of a “spade grip” back plate. It could also be changed from left-hand ammunition feed to right hand by reversing some internal parts.

The M2 machine gun had a rate of fire of 750 to 850 rounds per minute.

Armorers load disintegrating-link belts of .50-caliber ammunition for the eight machine guns of a Republic P-47 Thunderbolt. (U.S. Air Force)

Ammunition is ball, armor-piercing, armor-piercing-incendiary, tracer, blank (no bullet), and dummy. The armor-piercing cartridge, M2, has a muzzle velocity of 2,840 feet per second (866 meters per second) and maximum range of 7,275 yards (6,652 meters). Some .50-caliber rounds have muzzle velocities as high as 3,450 feet per second (1,052 meters per second), though most range from 2,730 fps to 2,900 fps (832–884 m/s). The ammunition produces chamber pressures of approximately 55,000 pounds per square inch (3,792 bar).

A gunner fires the two Browning .50-caliber machine guns of a B-17’s ball turret. (U.S. Air Force)

The .50 BMG cartridge is 5.45 inches (13.843 centimeters) long (NATO 12.7 × 99). The rimless, tapered bottleneck case is 3.91 inches (9.931 centimeters) long, with diameters of 0.560 inches (14.224 millimeters) at the neck, 0.735 inches (18.669 millimeters) at the shoulder, and 0.804 inches (20.422 millimeters) at the base. The bullet is 2.31 inches (58.67 millimeters) long, with a maximum diameter of 0.510 inches (12.954 millimeters) and weighs 706.7 grains (1.6 ounces, 45.8 grams).

Lieutenant Clark Gable with a belt of linked .50-caliber machine gun cartridges. The colored tips of the bullets identify armor piercing, incendiary or tracer ammunition.
Armorers carry Browning AN-M2 .50-caliber machine guns and belts of linked ammunition to a P-51 Mustang. (U.S. Air Force)

© 2018, Bryan R. Swopes

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8 July 1941

Fortress Mark I, AN521 ‘WP-K’, of No. 90 Squadron RAF based at West Raynham, Norfolk, preparing for take off at Hatfield, Hertfordshire, during an inspection of newly-arrived American aircraft by the Chief of the Air Staff and the US Air Attache. (Photograph by Flight Lieutenant Bertrand John Henry Daventry, Royal Air Force/CH 2873, Imperial War Museum)
Boeing Fortress Mark I AN521, ‘WP-K’, (U.S.A.A.F. serial number 40-2052) of No. 90 Squadron R.A.F., based at West Raynham, Norfolk, preparing for take off at Hatfield, Hertfordshire, during an inspection of newly-arrived American aircraft by the Chief of the Air Staff and the U.S. Air Attache. Photograph by Flight Lieutenant Bertrand John Henry Daventry, Royal Air Force. © IWM (CH 2873)

00DD3437_5056_A318_A85F9DA3980B669B8 July 1941: Three Royal Air Force Boeing Fortress Mk.I heavy bombers departed from their base at RAF Watton to attack Wilhelmshaven, Germany. This was a daylight bombing mission, with the airplanes flying at 30,000 feet (9,144 meters). One bomber diverted to a secondary target because of engine trouble, while the remaining two Fortresses continued to the primary target.

At the very high altitudes flown, the defensive heavy machine guns that gave the airplane its name froze due to the low temperatures and could not be fired. (In standard atmospheric conditions, the temperature at 30,000 feet would be -45 °C., or -49 °F.)

"Vertical aerial reconnaissance of Wilhelmshaven." © IWM (HU 91201)
“Vertical aerial reconnaissance of Wilhelmshaven.” © IWM (HU 91201)

All three aircraft returned safely to their base. The mission was completely ineffective, however.

This was the very first use of the Boeing B-17 Flying Fortress in combat.

Fortress B.I WP-F
Fortress B.I AN530, WP-F (U.S.A.A.F. B-17C 40-2066) (Royal Air Force)

The Boeing Model 299H, designated B-17C, was the second production variant ordered by the U.S. Army Air Corps. 38 were built by Boeing for the U.S. Army Air Corps, but 20 were transferred to Great Britain’s Royal Air Force, designated Fortress Mk.I. (Boeing Model 299T.) They were initially assigned to No. 90 Squadron, Bomber Command. (A 1941 book, War Wings: Fighting Airplanes of the American and British Air Forces, by David C. Cooke, Robert M. McBride & Company, New York, refers to the B-17C in British service as the “Seattle,” which is in keeping with the R.A.F.’s system of naming bombers after cities.)

Of the 20 Fortress Mk.I bombers, 8 were lost in combat or in accidents.

Boeing Fortress Mk.I AN529 at Heathfield, Scotland, after arrival from United States, May 1941. © Imperial War Museum E(MOS) 276

The Boeing B-17C/Fortress Mk.I was 67 feet, 10-9/16 inches (20.690 meters long with a wingspan of 103 feet, 9 inches (31.633 meters) and the overall height was 15 feet, 4½ inches (4.686 meters). The B-17C had an empty weight of 30,900 pounds (14,016 kilograms). The maximum design gross weight was 47,500 pounds (21,546 kilograms).

The B-17C was powered by four air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.876 liters) Wright Cyclone G666A (R-1820-65)¹ nine-cylinder radial engines with a compression ratio of 6.70:1. The engines were equipped with remote General Electric turbochargers capable of 24,000 r.p.m. The R-1820-65 was rated at 1,000 horsepower at 2,300 r.p.m. at Sea Level, and 1,200 horsepower at 2,500 r.p.m. for takeoff. The engine could produce 1,380 horsepower at War Emergency Power. 100-octane aviation gasoline was required. The Cyclones turned three-bladed, constant-speed, Hamilton-Standard Hydromatic propellers with a diameter of 11 feet, 7 inches (3.835 meters) though a 0.5625:1 gear reduction. The R-1820-65 engine is 3 feet, 11.59 inches (1.209 meters) long and 4 feet, 7.12 inches (1.400 meters) in diameter. It weighs 1,315 pounds (596 kilograms).

Crew members of a No. 90 "RAF Fortress crew at RAF Polebrook July 19, 1941." (IWM CH 3090)
“RAF Fortress crew at RAF Polebrook July 19, 1941.” © IWM (CH 3090)

The B-17C had a maximum speed of 323 miles per hour (520 kilometers per hour) at 25,000 feet (7,620 meters). Its service ceiling was 37,000 feet (11,278 meters) and the maximum range was 3,400 miles (5,472 kilometers).

The Fortress Mk.I could carry 4,800 pounds (2,177 kilograms) of bombs in an internal bomb bay. Defensive armament consisted of one Browning AN-M2 .30-caliber air-cooled machine gun at the nose and four Browning AN-M2 .50-caliber heavy machine guns in dorsal, ventral and waist positions.

Fortress I AN528 (Getty Images/Three Lions)
Royal Air Force Fortress Mk.I AN528 (B-17C 40-2064) prior to being camouflaged. (Getty Images/Three Lions)

© 2018, Bryan R. Swopes

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