Tag Archives: Bomber

17 March 1947

North American Aviation XB-45 45-59479 in flight. (U.S. Air Force)

17 March 1947: The prototype of the United States’ first jet-powered bomber, the North American Aviation XB-45 Tornado, 45-59479, made a one-hour first flight at Muroc Army Air Field (later known as Edwards Air Force Base) with company test pilot George William Krebs at the controls.

The photographs below show the XB-45 parked on Muroc Dry Lake. Notice that the windows over the bombardier’s compartment in the nose are painted on.

The North American Aviation XB-45 Tornado was a four-engine prototype bomber. It had a high-mounted straight wing and tricycle landing gear. It was 74 feet, 0 inches (22.555 meters) long with a wingspan of 89 feet, 6 inches (27.279 meters) and overall height of 25 feet, 2 inches (7.671 meters). It had an empty weight of 41,876 pounds (18,995kilograms) and maximum takeoff weight of 82,600 pounds (37,467 kilograms).

North American Aviation XB-45 Tornado 45-59479 parked on the dry lake bed at Muroc Army Airfield, California. (U.S. Air Force)
North American Aviation XB-45 Tornado 45-59479 parked on Muroc Dry Lake. (U.S. Air Force)
North American Aviation XB-45 45-59479 makes a low pass over the runway. (U.S. Air Force)

The three prototypes were powered by four Allison-built General Electric J35-A-4 turbojet engines, installed in nacelles which were flush with the bottom of the wings. The J35 was a single-shaft engine with an 11-stage axial-flow compressor section and a single-stage turbine. The J35-A-4 was rated at 4,000 pounds of thrust (14.79 kilonewtons). The engine’s maximum speed was 8,000 r.p.m. The J35 was 14 feet, 0 inches (4.267 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter, and weighed 2,400 pounds (1,089 kilograms).

The maximum speed of the XB-45 was 494 miles per hour (795 kilometers per hour) at Sea Level and 516 miles per hour (830 kilometers per hour) at 14,000 feet (4,267 meters). The service ceiling was 37,600 feet (11,461 meters).

North American Aviation XB-45 45-59479 as a test bed for rocket assisted take-off, 24 September 1958. (U.S. Air Force)

The production B-45A Tornado was heavier and had better performance. It was operated by two pilots and carried a bombardier/navigator and a tail gunner. It was 75 feet, 4 inches (22.962 meters) long with a wingspan of 89 feet, 0 inches (27.127 meters) and overall height of 25 feet, 2 inches (7.671 meters).

The B-45A had a total wing area of 1,175 square feet (109.2 square meters). The leading edges were swept aft 3° 30′. Their angle of incidence was 3° with -3° 30′ twist and 1° dihedral.

The bomber’s empty weight was 45,694 pounds (20,726 kilograms) and maximum takeoff weight was 91,775 pounds (41,628 kilograms).

Cutaway illustration of the North American Aviation B-45 Tornado showing internal structure and arrangement. (U.S. Air Force)

The B-45A was powered by four General Electric J47-GE-13 turbojet engines. The J47 was an axial-flow turbojet with a 12-stage compressor and single stage turbine. It had a normal power rating of 4,320 pounds of thrust (19.216 kilonewtons) at 7,370 r.p.m.; military power, 5,200 pounds (23.131 kilonewtons) at 7,950 r.p.m. (30-minute limit); and maximum power rating of 6,000 pounds(26.689 kilonewtons) at 7,950 r.p.m., with water/alcohol injection (5-minute limit). The engine was 12 feet, 0.0 inches (3.658 meters) long, 3 feet, 3.0 inches (0.991 meters) in diameter and weighed 2,525 pounds (1,145 kilograms).

The B-45A Tornado had a cruise speed of 393 knots (452 miles per hour/728 kilometers per hour), and maximum speed of 492 knots (566 miles per hour (911 kilometers per hour) at 4,000 feet (1,219 meters). Its service ceiling was 46,800 feet (14,265 meters) and it had a maximum range of 1,886 nautical miles (2,170 statute miles/3,493 kilometers).

The bomb load was 22,000 pounds (9,979 kilograms). (It was capable of carrying the Grand Slam bomb.) Two Browning .50-caliber AN-M3  machine guns were mounted in the tail for defense, with 600 rounds of ammunition per gun.

41 B-45As were modified the the “Back Breaker” configuration, which enabled them to be armed with nuclear weapons.

The B-45 served with both the United States Air Force and the Royal Air Force. 143 were built, including the three XB-45 prototypes.

On 20 September 1948, the first production B-45A-1-NA Tornado, 47-001, was put into a dive to test the airplane’s design load factor. During the dive, an engine exploded, which tore off several cowling panels. These hit the horizontal stabilizer, damaging it. The B-45 pitched up, and both wings failed due to the g load. The prototype had no ejection seats and test pilots George Krebs and Nicholas Gibbs Pickard, unable to escape, were both killed.

George William Krebs

George William Krebs was born in Kansas City, Missouri, 5 March 1918. He was the first of three children of William J. Krebs, an advertising executive, and Betty Schmitz Krebs. He attended Southwest High School, graduating in 1935.

Krebs studied at the Massachussetts Instititute of Technology (M.I.T.) at Cambridge, Massachussetts. He was a member of the Sigma Chi fraternity.

In 1940, Krebs was the owner of a Luscombe airplane distributorship in Kansas City. He had brown hair, blue eyes and a ruddy complexion. He was 5 feet, 9 inches tall (1.75 meters) and weighed 135 pounds (61 kilograms).

George Krebs married Miss Alice Bodman Neal at Kansas City, Missouri, 26 December 1942. They had one son, William John Krebs II, born 1944.

During World War II, Krebs was employed as a test pilot at the North American Aviation, Inc., B-25 Mitchell medium bomber assembly plant at Kansas City, Kansas. Prior to taking over the XB-45 project, he was the chief test pilot at K.C.

North American Aviation B-25 Mitchell medium bombers near completion at the Kansas City, Kansas, bomber plant. (Alfred T. Palmer)
Nicholas Gibbs Pickard

Nicholas Gibbs Pickard was born at Brooklyn, New York, 5 November 1916. He was the second of three children of Ward Wilson Pickard, a lawyer, and Alice Rossington Pickard.

During World War II, Pickard served as a ferry pilot for the Royal Air Force Transport Command.

On 21 January 1944, Captain Pickard married Miss Kathleen Baranovsky at Montreal, Quebec, Canada. They had two daughters, Sandra and Manya.

Following the war, Pickard was employed as a test pilot by North American Aviation.

Nicholas Gibbs Pickard was buried at the Pacific Crest Cemetery, Redondo Beach, California.

The tenth production North American Aviation B-45A-1-NA Tornado, 47-011, in flight. (U.S. Air Force)

© 2019, Bryan R. Swopes

1 March 2003

Star of Abilene, Rockwell B-1B, 83-0065, after its last flight, 1 March 2003. (U.S. Air Force)
Star of Abilene, Rockwell B-1B 83-0065, after its last flight, Dyess AFB, 1 March 2003. (U.S. Air Force)

1 March 2003: The Star of Abilene, the first operational Rockwell B-1B Lancer supersonic heavy bomber, serial number 83-0065, made its final flight at Dyess Air Force Base, Abilene, Texas. It was delivered to the 96th Bombardment Group, Heavy, Strategic Air Command at Dyess on 7 July 1985, and was retired after 17 years, 7 months, 23 days of service.

83-0065 is preserved at the Dyess Linear Air Park, which displays over 30 airplanes along the main road of the air base, showing a chronological progression of Air Power.

The B-1B is 147 feet, 2.61 inches (44.8719 meters) long, with the wing span varying from 86 feet, 8.00 inches (26.4160 meters) at 67.5° sweep to 136 feet, 8.17 inches (41.6603 meters) at when fully extended to 15° sweep. It is 33 feet, 7.26 inches (10.2428 meters) high to the top of the vertical fin. The bomber’s empty weight is approximately 180,500 pounds (81,873 kilograms). Its maximum weight in flight is 477,000 pounds (216,634 kilograms). The internal payload is up to 75,000 pounds (34,019 kilograms).

Rockwell B-1B 83-0065, Star of Abilene, flies over Dyess Air Force Base, 7 July 1985. (Reporter-News)

The bomber is powered by four General Electric F101-GE-102 turbofan engines, mounted in two-engine nacelles under the wing roots. These are rated at 17,390 pounds of thrust (23.578 kilonewtons) and produce 30,780 pounds (41.732 kilonewtons) with “augmentation.” The engine has two fan stages, a 9-stage axial-flow compressor and a 3-stage turbine. The F101-GE-102 is 15 feet, 0.7 inches (4.590 meters) long, 4 feet, 7.2 inches (1.402 meters) in diameter and weighs 4,460 pounds (2,023 kilograms).

“The Bone” has a maximum speed of Mach 1.2 at Sea Level (913 miles per hour, or 1,470 kilometers per hour). The service ceiling is “over 30,000 feet” (9,144 meters). The Lancer’s maximum range is “intercontinental, unrefueled.”

It can carry up to 84 Mk.82 500-pound (226.8 kilogram) bombs, 24 Mk.84 2,000-pound (907.2 kilogram) bombs or other weapons in three weapons bays. The B-1B was built with the capability to carry 24 B61 thermonuclear bombs, though, since 2007, the fleet no longer has this capability.

100 B-1B Lancers were built between 1983 and 1988. As of May 2018, 62 B-1B bombers are in the active Air Force inventory. The Air Force plans upgrades to the aircraft and plans to keep it in service until 2036.

Star of Abilene, Rockwell B-1B 83-0065, after its last flight, Dyess AFB, 1 March 2003. (U.S. Air Force)
Star of Abilene, Rockwell B-1B 83-0065, after its last flight, Dyess AFB, 1 March 2003. (U.S. Air Force)

© 2019, Bryan R. Swopes

24 January 1961

Boeing B-52G-75-BW Stratofortress 57-6471, similar to 58-0187. The numeral "3" on the vertical fin and the white cross-in-back square on the top of the fuselage identify this B-52 as a Boeing flight test aircraft. (U.S. Air Force)
Boeing B-52G-75-BW Stratofortress 57-6471, similar to 58-0187. The numeral “3” on the vertical fin and the white cross-in-back square on the top of the fuselage identify this B-52 as a Boeing flight test aircraft. (U.S. Air Force)

24 January 1961: “Keep 19,” a Boeing B-52G-95-BW Stratofortress, serial number 58-0187, of the 4241st Strategic Wing, was on a 24 hour airborne alert mission off the Atlantic Coast of the United States. The bomber was commanded by Major Walter S. Tulloch, U.S. Air Force, with pilots Captain Richard W. Hardin and First Lieutenant Adam C. Mattocks. Other crewmembers were Major Eugene Shelton, Radar Navigator; Captain Paul E. Brown, Navigator; First Lieutenant William H. Wilson, Electronics Warfare Officer; Major Eugene H Richards, Electronics Warfare Instructor; Technical Sergeant Francis R. Barnish, Gunner. It was armed with two Mark 39 thermonuclear bombs, each with an explosive yield of 3–4 megatons.

The B-52 refueled in flight from an air tanker. The tanker’s crew notified Major Tulloch that the B-52’s right wing was leaking fuel. The leak was severe and more than 5,400 gallons (37,000 pounds/17,000 kilograms) of jet fuel was lost in less than three minutes. The B-52 headed for Seymour Johnson Air Force Base in North Carolina.

Boeing B-52G-95-BW Stratofortress 58-0190, the same type as Keep 19. (U.S. Air Force)

As they descended, the unbalanced condition made the bomber increasingly difficult to control. The bomber went out of control and Major Tulloch ordered the crew to abandon the doomed ship. Five crewmen ejected and one climbed out through the top hatch. (Lieutenant Mattocks is believed to be the only B-52 crewmember to have successfully escaped through the upper hatch.)

58-0187 broke apart and exploded. Its wreckage covered a two square mile (5.2 square kilometers) area. Three crewmen, Majors Shelton and Richards, and Sergeant Barnish, were killed.

As the B-52 broke up, its two Mark 39 bombs fell free of the bomb bay. One buried itself more than 180 feet (55 meters) deep. The other’s parachute retarding system operated properly and it touched down essentially undamaged. It was quickly safed by an explosive ordnance team and hauled away.

One of teh two Mk 39 bombs that fell from the B-52 as it broke up near Goldsboro, South Carolina, 24 January 1961.
One of the two Mk 39 bombs that fell from the B-52 as it broke up near Goldsboro, North Carolina, 24 January 1961. The parachute retarding  system had deployed, allowing the bomb to touch down with minimal damage.

Recovery of the buried bomb was very difficult. After eight days, the ordnance team had recovered most of the bomb, including the 92 detonators and conventional explosive “lenses” of the “primary,” the first stage implosion section. The uranium-235/plutonium-239 “pit”—the very core of the bomb— was recovered on 29 January. The “secondary,” however, was never found.

Most of the Mark 39 bomb was uncovered from an excavation at the farm field near Goldsboro, North Carolina. (U.S. Air Force)

The secondary contains the fusion fuel, but it cannot detonate without the explosion of the primary. Although the secondary remains buried, there is no danger of an explosion.

“During a B-52 airborne alert mission structural failure of the right wing resulted in two weapons separating from the aircraft during aircraft breakup at 2,000 – 10,000 feet altitude. One bomb parachute deployed and the weapon received little impact damage. The other bomb fell free and broke apart upon impact. No explosion occurred. Five of the eight crew members survived. A portion of one weapon, containing uranium, could not be recovered despite excavation in the waterlogged farmland to a depth of 50 feet. The Air Force subsequently purchased an easement requiring permission for anyone to dig there. There is no detectable radiation and no hazard in the area.”

An accident of this type, involving the loss of nuclear weapons is known by the military code name BROKEN ARROW. Though official statements were that there was no danger that either of the bombs could have exploded, others indicate that five of the six steps (or six of seven) required for a thermonuclear detonation did occur. Only the aircraft commander’s arming switch had not been activated.

Bomb, Mark 39Y1 Mod 2, P/N 300611-00, serial number 4215, at the National Museum of the United States Air Force. Behind it is a Convair B-36 Peacemaker ten-engine strategic bomber. (U.S. Air Force)

The Mark 39 was a two-stage, radiation-implosion thermonuclear bomb. It was in production from 1957–1959, with more than 700 built. It was fully fused, meaning it could be detonated by contact with the ground, as an air burst, or “lay down”— a series of parachutes would slow the bomb and it would touch down on its target before detonating. This allowed the bomber time to get clear.

The Mark 39 was considered a light weight weapon, weighing 6,500–6,750 pounds (2,950–3,060 kilograms). The bomb’s length was approximately 11 feet, 8 inches (3.556 meters), with a diameter of 2 feet, 11 inches (0.889 meters). The explosive yield of the Mark 39 was 3–4 megatons. (For reference, the 1956 nuclear weapons test at Bikini Atoll, Redwing Cherokee, had a yield of 3.8 megatons.)

Fireball from detonation of TX-15 weapon, Operation Redwing Cherokee, 21 May 1956. (Nuclear Weapons Archive)

The Mark 39 was withdrawn from service in the mid-1960s and replaced with the more powerful Mk 41.

© 2018, Bryan R. Swopes

21 January 1987

Rockwell B-1B Lancer 85-0073, Wings of Freedom, lands at Ellsworth AFB, South Dakota, 21 January 1987. (U.S. Air Force)
General John T. Chain, Jr., U.S. Air Force
General John T. Chain, Jr., U.S. Air Force

21 January 1987: The first Rockwell International B-1B Lancer was delivered to the 28th Bomb Wing at Ellsworth Air Force Base, South Dakota. The airplane, serial number 85-0073, was named Wings of Freedom. It was flown to Ellsworth by General John T. Chain, Jr., Commander in Chief, Strategic Air Command.

100 B-1B Lancers were built by Rockwell International’s aircraft division at Air Force Plant 42, Palmdale, California, between 1983 and 1988

The Rockwell International B-1B Lancer is a supersonic intercontinental bomber capable of performing strategic or tactical missions. It is operated by a flight crew of four.

The B-1B is 147 feet, 2.61 inches (44.8719 meters) long, with the wing span varying from 86 feet, 8.00 inches (26.4160 meters) at 67.5° sweep to 136 feet, 8.17 inches (41.6603 meters) at when fully extended to 15° sweep. It is 33 feet, 7.26 inches (10.2428 meters) high to the top of the vertical fin. The bomber’s empty weight is approximately 180,500 pounds (81,873 kilograms). Its maximum weight in flight is 477,000 pounds (216,634 kilograms). The internal payload is up to 75,000 pounds (34,019 kilograms).

The bomber is powered by four General Electric F101-GE-102 turbofan engines, mounted in two-engine nacelles under the wing roots. These are rated at 17,390 pounds of thrust (17.355 kilonewtons) and produce 30,780 pounds (136.916 kilonewtons) with “augmentation.” The engine has two fan stages, a 9-stage axial-flow compressor and a 3-stage turbine. The F101-GE-102 is 15 feet, 0.7 inches (4.590 meters) long, 4 feet, 7.2 inches (1.402 meters) in diameter and weighs 4,460 pounds (2,023 kilograms).

“The Bone” has a maximum speed of Mach 1.2 at Sea Level (913 miles per hour, or 1,470 kilometers per hour). The service ceiling is “over 30,000 feet” (9,144 meters). The Lancer’s maximum range is “intercontinental, unrefueled.”

A Rockwell B-1B drops Mk. 82 bombs from its three weapons bays. (U.S. Air Force)

It can carry up to 84 Mk.82 500-pound (226.8 kilogram) bombs, 24 Mk.84 2,000-pound (907.2 kilogram) bombs or other weapons in three weapons bays. The B-1B was built with the capability to carry 24 B61 thermonuclear bombs, though, since 2007, the fleet no longer has this capability.

100 B-1B Lancers were built between 1983 and 1988. As of May 2018, 62 B-1B bombers are in the active Air Force inventory. The Air Force plans upgrades to the aircraft and plans to keep it in service until 2036.

After 21 years of service, 85-0073 was retired to The Boneyard at Davis-Monthan Air Force Base, Tucson, Arizona, 24 March 2008.

Rockwell B-1B Lancer, 85-0073, Wings of Freedom, at Ellsworth AFB, South Dakota, 21 January 1987. (U.S. Air Force)
Rockwell B-1B Lancer, 85-0073, Wings of Freedom, at Ellsworth AFB, South Dakota, 21 January 1987. (U.S. Air Force)

© 2019, Bryan R. Swopes

17 January 1932

At the lower left corner of this image, the shadow of a Curtiss B-2 Condor can be seen as it prepares to drop supplies at the Navajo reservation near Winslow, Arizona, 17 January 1932. (Davis-Monthan Aviation Field Register)
At the lower left corner of this image, the shadow of a Curtiss B-2 Condor can be seen as it prepares to drop supplies at the Navajo reservation near Winslow, Arizona, 17 January 1932. (Davis-Monthan Aviation Field Register)

17 January 1932: The 11th Bombardment Squadron, U.S. Army Air Corps, commanded by 1st Lieutenant Charles H. Howard and based at March Field, Riverside, California, flew six Curtiss B-2 Condor bombers to drop food and supplies to the Navajo reservation near Winslow, Arizona. A severe winter storm had isolated the community and caused the deaths of thousands of livestock.

More than 30,000 pounds (13,600 kilograms) of food was dropped to support the 20,000 people of the Navajo and Hopi nations effected by the winter storms.

Lieutenant Howard and the 11th Bombardment Squadron won the Mackay Trophy for the most meritorious flight of the year. This was the first time that the Mackay was awarded to a group.

First Lieutenant Charles H. Howard, U.S. Army Air Corps. (U.S. Air Force)

Charles Harold Howard was born at Ashland, Oregon, 29 December 1892. He was the first of two children of Charles B. Howard, a telegraph operator, and Mary Ann Kincaid Howard.

Howard enlisted as a private in the Signal Corps, United States Army, 23 November 1917. He served with Company C, 322nd Field Signal Battalion, and the Aviation Section, Signal Corps. He was commissioned as a second lieutenant, Air Service, 7 November 1918.

In 1920, Lieutenant Howard was an instructor at the Air Service Flying School at Love Field, Dallas, Texas. In a reorganization of the Air Service, his commission was vacated 15 September 1920 and he was appointed a second lieutenant, Air Service, with date of rank retroactive to 1 July 1920. Howard was promoted to first lieutenant, 30 August 1924.

Captain Howard was killed in an aircraft accident near Bryan Mill, Texas, 25 October 1936. His remains were buried at the Mountain View Cemetery, Ashland, Oregon. Howard Air Force Base, Panama, was named in his honor.

The following is excerpted from the Davis-Monthan Aviation Field Register web site:

The Air Corps Newsletter of November 1, 1936 reports his passing and summarizes his flying career:

“An airplane accident on the night of October 25th, near Bryan’s Mill, Texas, cost the lives of Captain Charles H. Howard and Corporal Edward N. Gibson, Air Corps, both of whom were stationed at Langley Field, VA.

“Captain Howard, who enlisted in the Aviation Section, Signal Corps, during the World War, was an efficient and capable officer, an expert pilot, and was particularly well versed in the field of radio communications.

“. . . after serving for a brief period with Company C, 322nd Field Signal Battalion, Fort Lewis, Washington, he was transferred to Kelly Field, Texas, where he served with the 84th Aero Squadron. . .

“During the next four years, Captain Howard’s duties related mainly to radio communications. . . 

“In January 1926, Captain Howard was transferred to the Panama Canal Department, where he served for three years, being on duty with the 7th Observation Squadron at France Field for two years, and with the 25th Bombardment Squadron in the remaining year.

“From Panama, Captain Howard was transferred to Rockwell Field, Calif., when he was assigned to the 11th Bombardment Squadron. He also served as Communications Officer of the 7th Bombardment Group. Later, when the Squadron was transferred to March Field, Calif., he was placed in command thereof.”

It was during this time that he and his crew won the Mackay Trophy.

“During the summer of 1934, Captain Howard piloted one of the B-10 Bombardment planes in the Army Alaskan Flight, from Washington, D.C., to Fairbanks, Alaska, and return. This aerial expedition of ten B-10 airplanes was commanded by Brigadier General Henry H. Arnold. The flight was completed according to a prearranged schedule in exactly one month. In addition to his duties as pilot, Captain Howard served as Assistant Communications Officer of the expedition. . .

“Captain Howard had to his credit over 4,000 hours flying time. He was the author of various articles dealing most interestingly and convincingly with subjects in which he particularly specialized – Bombardment Aviation and Radio Communications.”

Davis-Monthan Aviation Field Register http://www.dmairfield.com/index.php

Curtiss B-2 Condor 28-399 of the 11th Bomb Squadron, in flight near San Diego, California, 1930. (U.S. Air Force photo)

The Curtiss B-2 Condor was a large (by contemporary standards) twin-engine biplane bomber, operated by a crew of five. It was 47 feet, 4.5 inches (14.440 meters) long with a 90 foot (27.432 meter) wingspan and overall height of 16 feet, 6 inches (5.029 meters). The airplane had an empty weight of 9,300 pounds (4,218.4 kilograms) and loaded weight of 16,591 pounds (7,525.6 kilograms).

The B-2 was powered by two liquid-cooled, normally-aspirated 1,570.381-cubic-inch-displacement (25.734 liter) Curtiss Conqueror V-1570-7 DOHC 60° V-12 engines producing 633 horsepower at 2,450 r.p.m., each, driving three-bladed propellers.

The bomber had a maximum speed of 132 miles per hour (212 kilometers per hour) at Sea Level and a range of 805 miles (1,296 kilometers).

Although the Condor’s service ceiling was 16,140 feet (4,920 meters), Lieutenant Howard flew one to 21,000 feet (6,400 meters) while conducting an experiment in cosmic ray research for Dr. Robert Andrews Millikan of Caltech, Pasadena, California. (“Service ceiling” is the altitude above which an aircraft can no longer maintain at least a 100 feet per minute/0.5 meters per second rate of climb.)

First Lieutenant Charles H. Howard, Air Corps, United States Army, and Dr. Robert A. Millikan of CalTech, with a Curtiss B-2 Condor bomber at March Field, 27 October 1932. (© Bettman/CORBIS)

Defensive armament consisted of six .30-caliber Lewis machine guns, with gunners’ positions at the nose and behind each engine. The B-2 could carry 2,500 pounds (1,134 kilograms) of bombs.

Including the XB-2 prototype, 13 B-2s were built, and a single B-2A. They were removed from service by 1934 as more modern designs became available.

A Curtiss B-2 Condor, serial number 28-399, in flight near Rockwell Field, San Diego, California. (U.S. Air Force)
A Curtiss B-2 Condor, serial number 28-399, 11th Bombardment Squadron, in flight near Rockwell Field, San Diego, California. (U.S. Air Force)

© 2019, Bryan R. Swopes