Tag Archives: Dayton Air Show

3 September 1954

Major John L. Armstrong, U.S. Air Force, standing on the wing of his record-setting F-86H-1-NH  Sabre. (Jet Pilot Overseas)

3 September 1954: At the Dayton Air Show, being held for the first time at the James M. Cox Municipal Airport, Major John L. (“Jack”) Armstrong, U.S. Air Force, flew his North American Aviation F-86H-1-NH Sabre, 52-1998, to a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 500 Kilometers Without Payload, averaging 1,045.206 kilometers per hour (649.461 miles per hour). ¹

Similar to the F-86H-1-NA Sabre flown by Captain Armstrong, this is F-86H-10-NH 53-1298. (U.S. Air Force)
Similar to the F-86H-1-NH Sabre flown by Captain Armstrong, this is F-86H-10-NH 53-1298. (U.S. Air Force)

The North American Aviation F-86H was a fighter-bomber variant of the famous Sabre Jet day fighter. It was equipped with a much more powerful General Electric J73-GE-3 turbojet engine. The engine was larger that the J47 used in previous F-86 models, and this required a much larger air intake and airframe modifications. The fuselage was 6 inches deeper and two feet longer than the F-86F. This accommodated the new engine and an increase in fuel load. The tail surfaces were changed with an increase in the height of the vertical fin and the elevators were changed to an “all-flying” horizontal stabilizer. The first F-86Hs built retained the six Browning AN-M3 .50 caliber machine guns of the F-86F, but this was quickly changed to four Pontiac M39 20 millimeter revolver cannon.

Another view of North American Aviation F-86-10-NH Sabre 53-1298. This fighter bomber i similar to the airplane flown by Colonel Armstrong to set a world speed record. (U.S. Air Force)
Another view of North American Aviation F-86-10-NH Sabre 53-1298. This fighter bomber is similar to the airplane flown by Major Armstrong to set a world speed record. (U.S. Air Force)

The F-86H Sabre was 38 feet, 10 inches (11.836 meters) long with a wingspan of 39 feet, 1 inch (11.913 meters) and overall height of 14 feet, 11 inches (4.547 meters). Empty weight was 13,836 pounds (6,276 kilograms) and gross weight was 24,296 pounds (11,021 kilograms).

The F-86H was powered by a General Electric J73-GE-3D or -3E engine, a single-spool, axial-flow, turbojet engine, which used a 12-stage compressor section with variable inlet vanes, 10 combustion chambers and 2-stage turbine section. It produced 8,920 pounds of thrust (39.68 kilonewtons) at 7,950 r.p.m. (%-minute limit). The J73 was 12 feet, 3.2 inches (3.739 meters) long, 3 feet, 0.8 inches (0.935 meters) in diameter and weighed 3,650 pounds (1,656 kilograms).

The F-86H had a maximum speed of 601 knots (692 miles per hour/1,113 kilometers per hour) at Sea Level and 536 knots (617 miles per hour (993 kilometers) at 35,000 feet (10,668 meters). The fighter bomber had an initial rate of climb of 12,900 feet per minute (65.53 meters per second) and it could reach 30,000 feet (9,144 meters) in 5.7 minutes. The service ceiling was 50,800 feet (15,484 meters). With a full load ofbombs, the F-86H had a combat radius of 350 nautical miles (402 statute miles/648 kilometers) at 470 knots (541 miles per hour (870 kilometers per hour). The maximum ferry range was 1,573 nautical miles (1,810 statute miles/2,913 kilometers).

F-86H Sabres (after the first ten production airplanes) were armed with four Pontiac M39 20 mm autocannon with 150 rounds of ammunition per gun. In ground attack configuration, it could carry a maximum bomb load of 2,310 pounds (1,048 kilograms), or one 12–24 kiloton Mark 12 “Special Store” that would be delivered by “toss bombing.”

The F-86H Sabre became operational in 1954. 473 F-86H Sabres were built before production ended. By 1958 all that remained in the U.S. Air Force Inventory were reassigned to the Air National Guard. The last one was retired in 1972.

North American Aviation F-86H Sabre. (U.S. Air Force)

John Leroy Armstrong was born in Orange County, California, 19 July 1922. He was the fourth child of Milton Williams Armstrong, an engineer, and Olive M. Meyer Armstrong. As a child, he was called “Jake.”

Major Armstrong had been a fighter pilot during World War II, flying Lockheed P-38 Lightnings, initially with the 554 Fighter Training Squadron, 496th Fighter Training Group.

On 13 March 1944, Armstrong made a forced landing at North Killingholme when his fighter ran out of fuel.

2nd Lieutenant Armstrong was assigned to the 79th Fighter Squadron, 20th Fighter Group based at RAF Kings Cliffe, Northamptonshire, England, 26 March 1944. He flew the Lockheed P-38 Lightning.

Lt. John L. Armstrong, 79th Fighter Squadron, 20th Fighter Group, with a Lockheed P-38 Lightning, 1944. (The 20th Fighter Group Project)

The 79th transitioned to the P-51 Mustang. Armstrong was promoted to first lieutenant 26 June 1944. He was officially credited with having destroyed one enemy Focke-Wulf Fw 190. On 28 August 1944, while flying his 30th combat mission, his North American Aviation P-51D-5-NA Mustang, 44-13791, Guardian Angel, was shot down by anti-aircraft gunfire while he was attacking a railway roundhouse at Bad Greuznach, Germany. Armstrong bailed out but was captured. He was held as a prisoner of war at Stalag Luft I at Barth, Western Pomerania. Armstrong was returned to U.S. military control in June 1945.

Major Armstrong had been awarded the Distinguished Flying Cross, the Air Medal with five oak leaf clusters (six awards), the Purple Heart, the Prisoner of War Medal, World War II Victory Medal, and the European-African-Middle Eastern Campaign Medal.

Two days after setting the speed record, Jack Armstrong was attempting to increase his record speed. The Sabre broke up in flight and Major Armstrong was killed.

John Leroy Armstrong’s remains were buried at the Loma Vista Memorial Park, Fullerton, California, 11 September 1954.

This exhibit at the National Museum of the United States Air Force, Wright-Patterson AFB, ohio, commemorates Major Armstrong's record-setting flight. His flight helmet is included in the display. (U.S. Air Force)
This exhibit at the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio, commemorates Major Armstrong’s record-setting flight. His flight helmet is included in the display. Visible behind the display case is North American Aviation F-86H-10-NH Sabre 53-1352.  (U.S. Air Force)

¹ FAI Record File Number 8860

© 2018, Bryan R. Swopes

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2 September 1953

Captain Russell M. Dobyns, United States Air Force, with his YH-21 Workhorse. (FAI)
Captain Russell M. Dobyns, United States Air Force, with his YH-21 Work-Horse. (FAI)

2 September 1953: At the Dayton Air Show, Captain Russell Martin Dobyns, United States Air Force, flew a Piasecki YH-21-PH Work-Horse tandem rotor helicopter to an altitude of 6,739 meters (22,110 feet), setting an Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload for reciprocating-engine helicopters.¹ This record still stands.

Two days later, Captain Dobyns flew his H-21 over a 3-kilometer course. Making four passes, two in each direction, he averaged 236.19 kilometers per hour (146.76 miles per hour). This established a second FAI world record.²

Piasecki YH-21-PH Workhorse, 50-1235, FAI World Altitude Record holder. (FAI)
Piasecki YH-21-PH Workhorse, 50-1235, FAI World Altitude Record holder. (FAI)

The Piasecki YH-21 Work-Horse made its first flight at Morton Grove, Pennsylvania, just over four months earlier, on 11 April 1952. It was a single-engine, tandem rotor transport helicopter. The Piasecki Helicopter Corporation built 18 pre-production YH-21-PH helicopters, followed by three production variants, the H-21A, H-21B and H-21C. Major Dobyns’ record-setting YH-21 was the fourth pre-production aircraft.

In 1962, the helicopter was redesignated CH-21. In U.S. Army service, the H-21 was named Shawnee, in accordance with the Army’s tradition of naming its aircraft after Native American tribes.

The H-21A could be flown by a single pilot, although it was normally operated by two pilots, with a flight mechanic (crew chief), and could carry a maximum of 16 persons, including crew members.

With rotors turning, the ship’s overall length was 86 feet, 5 inches (26.340 meters) (86 feet, 4 inches for the H-21B). The helicopter was 52 feet, 2 inches (15.900 meters) long with its blades folded, and it was 16 feet, 0 inches (4.877 meters) high.

Each three-bladed rotor had a diameter of 44 feet, 0 inches (13.411 meters). The angle in the fuselage was intended to provide adequate vertical clearance between the intermeshing fore and aft rotor assemblies. (Later tandem rotor helicopters use raised pylons.) The rotor blades were constructed of wood around a steel spar and covered with 3-ply mahogany plywood. The airfoil is symmetrical. Each blade is 19 feet, 6.50 inches (5.956 meters) long and 1 foot, 6.00 inches (0.457 meters) wide. There is 5° 37′ of negative twist from the blade root to tip. The individual rotor blades weigh 178 pounds (80.74 kilograms).

The forward rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The rear rotor turns the opposite direction. Normal operating speed for the main rotors was 235 to 260 r.p.m. (233–350 r.p.m. in autorotation, with a transient droop to 210 r.p.m.). At 250 r.p.m., the blades’ tip speed is 594 feet per second (181 meters per second). The counter-rotating rotors cancelled out engine torque, eliminating any need for a tail rotor.

The H-21A had an empty weight was 7,966 pounds (3,613 kilograms), with a gross weight of 11,500 pounds (5,216 kilograms) and maximum overload weight of 13,500 pounds (6,123 kilograms). It could carry a maximum external load of 3,000 pounds (1,361 kilograms).

ARVN troops wait while a U.S. Army CH-21C Shawnee lands. (LIFE Magazine)
ARVN troops wait while a U.S. Army CH-21C Shawnee lands. (Larry Burrows/LIFE Magazine)

The H-21 was powered by a single air-cooled, supercharged, 1,823.13-cubic-inch-displacement (29.876 liter) Wright Aeronautical Division Cyclone 863C9WD1 (R-1820-103) nine-cylinder radial, mounted inside the fuselage at midship, and drove the front and rear rotors in opposite directions through drive shafts and gear boxes.

The Wright R-1820-103 engine was rated at 1,275 horsepower at 2,500 r.p.m., and 1,425 horsepower at 2,700 r.p.m., for takeoff. (Installed in the H-21A, the engine was restricted to a 30-minute limit above 2,500 r.p.m.) This direct-drive engine had a compression ratio of 6.80:1 and required 100/130 aviation gasoline. The engine was 4 feet, 0.50 inches (1.232 meters) long, 4 feet, 6.95 inches (1.396 meters) in diameter, and weighed 1,350 pounds (612 kilograms). Wright built 971 R-1820-103s from November 1950 through 1957.

The H-21A had a maximum speed of 100 knots (115 miles per hour/185 kilometers per hour) and could hover sideways at up to 40 knots (46 miles per hour/74 kilometers per hour). The helicopter could land and take off from sloped surfaces up to 20°.

Under standard atmospheric conditions, at a gross weight of 11,500 pounds, the H-21A could hover in ground effect (HIGE) at approximately 9,500 feet (2,896 meters), and out of ground effect (HOGE) at about 6,750 feet (2,057 meters).

The H-21A had an internal fuel capacity of 300 U.S. gallons (1,136 liters), giving a maximum range under cruise conditions of 481 nautical miles (554 statute miles/891 kilometers) at 10,000 feet (3,048 meters). Its service ceiling was 19,200 feet (5,852 meters).

The U.S. Air Force immediately ordered 32 H-21A helicopters for Search and Rescue operations. The Workhorse was well suited to cold weather operations and it was widely used in Alaska, Canada, and the Antarctic. Another 163 H-21B models were ordered as a troop transport. The U.S. Army ordered a similar H-21C variant.

In 1955, Piasecki became Vertol and eventually Boeing Vertol. The company would continue to produce tandem rotor helicopters such as the H-46 Sea Knight and the CH-47 Chinook, which is still in production.

Russell M. Dobyns, 1942. (Volunteer)

Russell Martin Dobyns was born in Norton, Virginia, 2 July 1921. He was the son of Bridie Witten Dobyns, a grocery salesman, and Zollie Russell Martin Dobyns. He attended Norton High School in Norton, Virginia, graduating in 1940. He then entered the University of Tennessee at Knoxville, as a member of the Class of 1944. Dobyns was a member of the Pi Kappa Alpha (ΠΚΑ).

Russell Dobyns enlisted as an aviation cadet in the Air Corps, United States Army, on 16 June 1942. He had brown hair, blue eyes, was 5 feet, 6 inches (1.68 meters) tall, and weighed 150 pounds (68 kilograms). Trained as a pilot, he was discharged 29 August 1943, and then commissioned as a second lieutenant, 30 August 1943.

During World War II, Lieutenant Dobyns flew 32 combat missions over Europe as a pilot of a B-17 Flying Fortress heavy bomber.

Returning to the United States, Dobyns married his wife, Ada, in 1945. They would have a son, Russell Martin Dobyns, Jr., born 25 November 1946.

Following the war, Dobyns remained in the military until being released from active duty 30 March 1950. Less than three months later, he was recalled to active duty because of teh Korean War. Major Dobyns retired from the Air Force 5 February 1964.

Entering civilian life, Dobyns was employed as an aeronautical engineer by the Lockheed Aircraft Corporation at Marietta, Georgia.

Major Dobyns’ son, Russell, a Lance Corporal, United States Marine Corps, was killed in action in the Quang Tri Province of Vietnam, 10 May 1969.

Russell Martin Dobyns, Sr., died in Fulton County, Georgia, 17 August 2007. His remains were interred at the Arlington Memorial Park, Sandy Springs, Georgia.

Piasecki H-21B Workhorse -03433 at Elmendorf Air Foce Base, Alaska, circa 1960. (U.S. Air Force)
Piasecki H-21B Workhorse 53-4334 at Elmendorf Air Force Base, Alaska, circa 1963. This helicopter was later registered N6796 by the FAA. (U.S. Air Force)

¹ FAI Record File Number 2185

² FAI Record File Number 13102

© 2017, Bryan R. Swopes

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