Lieutenant Stewart R. Graham, USCG, in cockpit of Sikorsky HNS-1 near Gander, Newfoundland, September 1946. (U.S. Coast Guard)
April 6, 1949: Lieutenant Stewart Ross Graham, United States Coast Guard, and his crewman, Aviation Metalsmith 2nd Class (AM2) Robert McAuliffe, completed the longest unescorted helicopter flight on record. They flew a Sikorsky HO3S-1G, serial number 51-234, from the Coast Guard Air Station, Elizabeth City, North Carolina, to Coast Guard Air Station Port Angeles, Washington, via San Diego, California, covering a distance of 3,750 miles (6,035 kilometers) in 57.6 flight hours over 11 days.
Lieutenant Graham was the first pilot to fly a helicopter from a ship. On 16 January 1944, he flew a Sikorsky YR-4B, serial number 46445, from the deck of a British freighter, SS Daghestan, while in convoy from New York to Liverpool. After 30 minutes, he returned to the freighter. He was a pioneer in the use of the helicopter by the Coast Guard and the Navy.
U.S. Coast Guard Sikorsky HO3S-1G 51-232, sister ship of 51-234. (U.S. Coast Guard)
The HO3S (Sikorsky S-51) was a second-generation helicopter, capable of carrying a pilot and up to three passengers. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.
The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left.
The helicopter’s fuselage was 41 feet, 7.5 inches (12.687 meters). The main rotor had a diameter of 48 feet (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.2.565 meters) giving the helicopter an overall length of 57 feet, 1 inch (17.399 meters). It was 13 feet, 1.5 inches (4.001 meters) high. The landing gear tread was 12 feet (3.7 meters).
The S-51 had an empty weight of 4,050 pounds (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).
The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The S-51 had a maximum speed (Vne) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).
Sikorsky built 220 helicopter of the S-51 series.
U.S. Coast Guard HO3S-1G, serial number 51-238, sister ship of Lieutenant Graham’s record-setting helicopter. (USCG/Smithsonian Institution)
The prototype Sikorsky S-51 commercial helicopter, NX92800, in flight between Bridgeport and East Hartford, Connecticut, 1946. (Sikorsky Historical Archive)
16 February 1946: The Sikorsky S-51 prototype, NX92800, made its first flight. The test pilot was Dimitry D. (“Jimmy”) Viner, who later made the first civilian rescue using a helicopter. The S-51 was the first helicopter intended for commercial use, though it was also widely used by military services worldwide. (The prototype was later delivered to Aéronavale, French Naval Aviation.)
Dimitry D. (“Jimmy”) Viner with a Sikorsky S-51, the civil version of the R-5. (Sikorsky Historical Archive)
The S-51 was a commercial version of the Sikorsky R-5 series military helicopters. It was a four-place, single engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.
The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)
Sikorsky S-51 three-view illustration with dimensions. (Sikorsky Historical Archives)
The helicopter’s fuselage was 41 feet, 1¾ inches (12.541 meters). The main rotor had a diameter of 48 feet, 0 inches (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.568 meters) giving the helicopter an overall length of 57 feet, ½ inch (17.386 meters). It was 12 feet, 11-3/8 inches (3.947 meters) high. The landing gear tread was 12 feet, 0 inches (3.658 meters).
The S-51 had an empty weight of 4,050 pounds (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).
Sikorsky S-51 NC92813, Los Angeles Airways, departs on a commercial flight, Los Angeles, California, 1947. (Los Angeles Times)
The helicopter was powered by a 986.749-cubic-inch-displacement (16.170 liter) air-cooled, supercharged, Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The S-51 had a maximum speed (VNE) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).
Of 220 helicopters in the S-51 series built by Sikorsky, 55 were commercial models. Westland built another 159 helicopters under license.
One of Los Angeles Airways’ Sikorsky S-51 helicopters takes off from roof of the the Terminal Annex Post Office, Los Angeles, California, 1 October 1947. (Los Angeles Times Photographic Archive/UCLA Library)Dimitry D. Viner, circa 1931
Дмитро Дмитрович Вінер (Dimitry Dimitrovich Viner) was born in Kiev, Ukraine, Imperial Russia, 2 October 1908. He was the son of Dimitry Nicholas Weiner and Helen Ivan Sikorsky Weiner, a teacher, and the sister of Igor Ivanovich Sikorsky.
At the age of 15 years, Viner, along with his mother and younger sister, Galina, sailed from Libau, Latvia, aboard the Baltic-American Line passenger steamer S.S. Latvia, arriving at New York City, 23 February 1923.
“Jimmy” Viner quickly went to work for the Sikorsky Aero Engineering Company, founded by his uncle, Igor Sikorsky.
Dimitry Viner became a naturalized United States citizen on 27 March 1931.
Viner married Miss Irene Regina Burnett. They had a son, Nicholas A. Viner.
On 29 November 1945, Jimmy Viner and Captain Jackson E. Beighle, U.S. Army, flew a Sikorsky YR-5A to rescue two seamen from an oil barge which was breaking up in a storm off of Fairfield, Connecticut. This was the first time that a hoist had been used in an actual rescue at sea.
A Sikorsky R-5 flown by Jimmy Viner with Captain Jack Beighle, lifts a crewman from Texaco Barge No. 397, aground on Penfield Reef, 29 November 1945. (Sikorsky Historical Archive)
In 1947, Viner became the first pilot to log more than 1,000 flight hours in helicopters.
Dimitry Dimitry Viner died at Stratford, Connecticut, 14 June 1998, at the age of 89 years.
The Hughes XH-17, 50-1842, before its first flight, 23 October 1952. (Old Machine Press/LIFE Magazine)
23 October 1952: At Culver City, California, Hughes Tool Company Aircraft Division test pilots Gale Joseph Moore and Chalmer Donald Bowen,¹ with flight test engineer Wallace Marion, took the Hughes XH-17, U.S. Air Force serial number 50-1842, for its official first flight. At a height of 20 to 40 feet (6 to 12 meters) above the runway, the helicopter maneuvered for about nine minutes. It reached a speed of 45 miles per hour (72 kilometers per hour), flew backwards, and rotated 360°. (The helicopter had actually become briefly airborne for the first time 16 September 1952.) The crew nicknamed the aircraft “The Monster.”
The Hughes XH-17 airborne 19 September 1952, during a “bounce drill.” (Los Angeles Times, 20 September 1952, Page 1, Columns 3–6)
According to the Los Angeles Times, “Although it was termed a “first flight,” the great machine had previously been airborne frequently in recent weeks at the Hughes strip in Culver City. . . Its fledgling flights have been witnessed by thousands of persons from nearby highways. . . .” Test pilot Moore did not call these flights, referring to them as “bounce drills.”
From left to right: Rea E. Hopper, Chief Engineer, Hughes Aircraft; Howard Robard Hughes, Jr.; Clyde Jones, Director of Engineering; Warren Reed, Assistant; Colonel Carl E. Jackson, U.S. Air Force, Air Research and Development Headquarters, Baltimore, Maryland; Gale Joseph Moore, pilot; Chalmer Donald Bowen, co-pilot; and Marion Wallace, flight test engineer. (Old Machine Press/LIFE Magazine)
The XH-17 was primarily built by the Kellett Aircraft Corporation, a manufacturer of autogyros at Upper Derby, Pennsylvania, in response to a 1946 U.S. Army Air Forces request for a heavy lift helicopter, and originally designated XR-17. It was redesignated XH-17 in June 1948. When Kellett entered bankruptcy, the incomplete helicopter was purchased by the Hughes Tool Company for $250,000 and moved to Culver City, California in 1949.
The Hughes XH-17 was a single main rotor tip-jet-driven helicopter with an auxiliary tail rotor for yaw control. The main rotor diameter was 130 feet (39.624 meters).² The fuselage was 53 feet, 4 inches (16.256 meters) long, and the helicopter had an overall height of 30 feet, 1 inch (9.169 meters). The main rotor turned counter-clockwise, as seen from above (the advancing blade is on the right), at 88 r.p.m. The main rotor blade was 12 inches (30.38 centimeters) thick and had a chord of 4 feet, 10 inches (1.473 meters). Each blade weighed approximately 5,000 pounds (2.268 kilograms) and was fully articulated. Unlike a normal helicopter, the tip-jet-driven blades do not produce torque which needs to be counteracted by a tail rotor. However, an auxiliary tail rotor was used for yaw control. With a diameter of 8 feet, 8 inches (2.642 meters), it was borrowed from a Sikorsky S-55, and turned clockwise as seen from the helicopter’s left side (the advancing blade is below the axis of rotation).
The XH-17’s empty weight was 28,562 pounds (12,956 kilograms), and its maximum takeoff weight (MTOW) was 43,500 pounds (19,731 kilograms). On 15 December 1955, the helicopter lifted a trailer van weighing 7,800 pounds (3,538 kilograms), at that time the heaviest load ever lifted by a helicopter.
The XH-17 was powered by two modified General Electric J35 (7E-TG-180-XR-17A) turbojet engines, mounted on each side of the fuselage. The engines were rated at 1,740 horsepower, each. Bleed air from the engines’ compressors was directed through ducts to the rotor blades to exit through the blade tips. Fuel was injected through GE 33F pressure jet burners and ignited to produce thrust to drive the rotors.
The XH-17 had a cruise speed of 85 miles per hour (137 kilometers per hour), and a maximum speed of 90 miles per hour (145 kilometers per hour) at 8,000 feet (2,438 meters). The helicopter’s service ceiling was 13,100 feet (3,993 meters). With a maximum fuel capacity of 635 U.S. gallons (2,404 liters), the XH-17 had a maximum range of only 30 miles (48 kilometers)
The XH-17 was grounded in December 1955 when its main rotor blades reached their design limit, 10 flight hours. The helicopter was later scrapped.
Gale Joseph Moore, was born at Mauston, Wisconsin, 24 January 1921. He was second of four children of of George Joseph Moore, a dairyman, and Amy Dell Priessnitz Moore. By 1940, the family had moved to Inglewood, California, where Moore worked in a dairy with his father.
Moore attended John C. Fremont High School in Los Angeles, graduating in 1938, and Compton Community College, in Compton, California.
Moore registered for Selective Service (conscription), 15 February 1942, at Hawthorne, California. He was described as having a light complexion, red hair and hazel eyes. He was 5 feet, 11½ inches (1.82 meters) tall and weighed 145 pounds (66 kilograms).
Moore joined the United States Army Air Forces. He trained as a pilot and was commissioned a second lieutenant at Douglas Army Airfield, Arizona, in June 1943. Pilots at Douglas trained on the North American Aviation B-25 Mitchell twin-engine medium bomber. After the war, he left the service as a first lieutenant.
Gale Joseph Moore married Miss Patricia Elise Diehl at the Little Chapel of the Dawn, Santa Monica, California, 13 January 1948. They had one child, Richard D. Moore. They later divorced.
During 1948, Moore joined Los Angeles Airways to fly the Sikorsky S-51.
The Los Angeles Times, 2 October 1947 published photo caption: “NEW MAIL SERVICE — Los Angeles Airways helicopter shown landing on the roof of Terminal Annex Post office yesterday to inaugurate helicopter air-mail service, the first of its kind in the United States. Two flights daily are planned on this run with another to start Oct. 16.” (L.A. Times Photo Archive/UCLA)
On 2 October 1956, Moore took the prototype Hughes Model 269, N78P, for its first flight. This helicopter was later adopted by the United States Army as the TH-55A Osage.
Moore next married Thais E. Hildebrand, three years his senior, in California, 15 December 1961.
Gale Joseph Moore died 18 Nov 2015, at Fernley, Nevada, at the age of 93 years. His remains were interred at the Northern Nevada Veterans Memorial Cemetery in Fernley.
Chalmer Donald Bowen and Gale Joseph Moore. (Pauline Annette DiSipio)
Chalmer Donald Bowen was born 21 August 1912 at Delta, Iowa. He was the third of five children of Perman Montague Bowen, a farmer, and Martha (“Mattie”) Esther Taylor Bowen. He attended Van Buren and Wilson schools in Cedar Rapids, Iowa, and graduated from the State University of Iowa.
Bowen married Miss Emma Louise Brink at Cedar Rapids, 17 August 1931. They would have two sons. Mrs. Bowen died in 1988.
In 1940, Bowen worked for the Quaker Oats Company in Cedar Rapids as a package room laborer. He registered for conscription 16 October 1940. At that time he was described as having a light brown complexion, with brown hair and blue eyes. He was 5 feet, 7 inches (1.70 meters) tall, and weighed 165 pounds (75 kilograms). He then moved to Burbank, California, in 1942, where he was employed as a flight engineer by the Lockheed Aircraft Company.
Bowen worked as a pilot for Hughes Aircraft for 31 years. He had acted as Howard Hughes’ co-pilot for the only flight of the Hughes H-4 “Spruce Goose,” 2 November 1947.
Charles Donald Bowen died at Montrose, Colorado, 28 February 2011. His remains were interred at Cedar Memorial Park, Cedar Rapids, Iowa.
¹ The rotor diameter has been variously described as being 125 feet (38.1 meters) and 136 feet (41.45 meters).
A Los Angeles Airways Sikorsky S-51 helicopter takes off from the roof of the Terminal Annex Post Office, 1 October 1947. The Los Angeles Times published this photograph 2 October 1947 with the following caption: “NEW MAIL SERVICE — Los Angeles Airways helicopter shown landing on the roof of Terminal Annex Post office yesterday to inaugurate helicopter air-mail service, the first of its kind in the United States. Two flights daily are planned on this run with another to start Oct. 16.” (Los Angeles Times Photographic Archive/UCLA Library)
1 October 1947: Los Angeles Airways began regularly scheduled air mail service in Los Angeles, using the Sikorsky S-51 helicopter.
“. . . the U.S. Civil Aeronautics Board awarded LAA the route authorities to operate local air mail services in Southern California using the Sikorsky S-51. Before long, LAA was operating a twice-a-day mail service between the main downtown post office and Los Angeles International Airport along with a small package air express service.
“With a fleet of five S-51s, LAA’s first year of operations resulted in 700 tons of mail being carried with approximately 40,000 landings throughout the Los Angeles metropolitan area. The small operation maintained a 95% reliability rate and by the time it began its small package air express service in 1953, it was annually moving nearly 4,000 tons of mail a year.
“In July 1951 the CAB awarded LAA’s reliable helicopter operation the rights for passenger services which started in November 1954 with larger Sikorsky S-55 helicopters while the smaller S-51s continued the mail and small package services. . . .”
The S-51 was a commercial version of the Sikorsky R-5 series of military helicopters. It was a four-place, single-engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction. The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left.
The helicopter’s fuselage was 41 feet, 7.5 inches (12.687 meters) long. The main rotor had a diameter of 48 feet (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.565 meters), giving the helicopter an overall length of 57 feet, 1 inch (17.399 meters). It was 13 feet, 1.5 inches (4.001 meters) high. The landing gear tread was 12 feet (3.7 meters). The S-51 had an empty weight of 4,050 pounds (1,837 kilograms) and maximum takeoff weight of 5,500 pounds (2,495 kilograms). Fuel capacity was 100 gallons (378.5 liters).
The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The S-51 had a maximum speed (Vne) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).
Of 220 helicopters in the S-51 series built by Sikorsky, 55 were commercial models.
A Los Angeles Airways Sikorsky S-51. The main rotor hub is covered. (Viewliner)
A U.S. Air Force Sikorsky H-5F lifts off during the Korean War. (U.S. Air Force)
4 August 1950: During the Battle of the Pusan Perimeter, wounded soldiers were evacuated from the battlefield by helicopter for the first time when a Sikorsky H-5F of Detachment F, 3rd Emergency Rescue Squadron,¹ Air Rescue Service, United States Air Force, flew Private 1st Class Claude C. Crest, Jr., U.S. Army, from the Sengdang-ni area to an Army hospital. By the end of combat in 1953, 21,212 soldiers had been medevaced by helicopters.
Only the second military helicopter, the H-5 was frequently flown overloaded and outside of its center of gravity limits. The helicopter was not armed, though the pilot normally carried an M1911 .45-caliber semi-automatic pistol, and the crewman, a .30-caliber M1 Carbine.
Eleven commercial Sikorsky S-51 helicopters had been purchased by the Air Force in 1947 and designated R-5F. This was later changed to H-5F. It was a four-place, single-engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction. The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs, covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) Its normal operating range was 175–195 r.p.m. The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)
Sikorsky S-51 three-view drawing with dimensions. (Sikorsky Historical Archives)
The helicopter’s fuselage was 41 feet, 1¾ inches (12.541 meters) long. The main rotor had a diameter of 48 feet, 0 inches (14.630 meters) and the tail rotor diameter was 8 feet, 5 inches (2.565 meters),² giving the helicopter an overall length of 57 feet, ½ inch (17.386 meters) with rotors turning. It was 12 feet, 11–3/8 inches (3.947 meters) high. The tricycle landing gear had a wheel base of 10 feet, 1 inch (3.073 and the tread was 12 feet, 0 inches (3.658 meters). The S-51 had an empty weight of 4,050 pounds (1,837 kilograms) and maximum gross weight of 5,300 pounds (2,404 kilograms) below 1,000 feet (305 meters) MSL.³ Fuel capacity was 100 gallons (379 liters).
The H-5F was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4 ) which was placed in the fuselage behind the crew compartment with the crankshaft vertical. The R-985-AN-5 was a direct-drive, nine-cylinder radial engine with a compression ratio of 6:1. It required 91-octane aviation gasoline and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The H-5F had a maximum speed (VNE) of 107 knots (123 miles per hour/198 kilometers per hour). Range was 275 miles (443 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914 meters).
Sikorsky H-5, Korea. (U.S. Air Force)
¹ Reorganized as the 3rd Air Rescue Squadron 10 August 1950.
² An 8 foot, 9 inch (2.667 meter) all-metal two-blade tail rotor assembly became standard with the H-5G, and was available to retrofit earlier helicopters.
³ The maximum gross weight had to be reduced 150 pounds (68 kilograms) for each additional 1,000 feet of altitude.
April 6, 1949: Lieutenant Stewart Ross Graham, United States Coast Guard, and his crewman, Aviation Metalsmith 2nd Class (AM2) Robert McAuliffe, completed the longest unescorted helicopter flight on record. They flew a Sikorsky HO3S-1G, serial number 51-234, from the Coast Guard Air Station, Elizabeth City, North Carolina, to Coast Guard Air Station Port Angeles, Washington, via San Diego, California, covering a distance of 3,750 miles (6,035 kilometers) in 57.6 flight hours over 11 days.
The HO3S (Sikorsky S-51) was a second-generation helicopter, capable of carrying a pilot and up to three passengers. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.
The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
