Tag Archives: Allison Division of General Motors

23 April 1941

North American Aviation Mustang Mk.I AG348, prior to camouflage paint. (North American Aviation Inc.)
North American Aviation Mustang Mk.I AG345, c/n 73-3098, prior to camouflage paint. Note the short carburetor air intake compared to the photograph below. (North American Aviation Inc.)

23 April 1941: At North American Aviation’s Inglewood, California factory, test pilot Louis S. Wait takes the very first production Mustang Mk.I, AG345, (c/n 73-3098) for its first flight.

The Royal Air Force had contracted with NAA to design and build a new fighter with a 1,200 horsepower Allison V-1710 supercharged 12-cylinder engine. The first order from the British Purchasing Commission was for 320 airplanes, and a second order for another 300 soon followed.

The Mustang Mk.I (NAA Model NA-73) was a single-place, single-engine fighter primarily of metal construction with fabric control surfaces. It was 32 feet, 3 inches (9.830 meters) long with a wingspan of 37 feet, 5/16-inches (11.373 meters) and height of 12 feet, 2½ inches (3.721 meters). The airplane’s empty weight was 6,280 pounds (2,849 kilograms) and loaded weight was 8,400 pounds (3,810 kilograms).

North American Aviation Mustang Mk.I AG345 (North American Aviation Inc.)
North American Aviation Mustang Mk.I AG345 (North American Aviation Inc.)

The Mustang Mk.I was powered by a liquid-cooled, supercharged 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Company V-1710-F3R (V-1710-39) single overhead cam (SOHC) 60° V-12 engine with a compression ratio of 6.65:1. The -F3R had a Maximum Continuous Power rating of 880 horsepower at 2,600 r.p.m. at Sea level, and 1,000 horsepower at 11,000 feet (3,353 meters). It was rated at 1,150 horsepower at 3,000 r.p.m. for Take Off and Military Power. The Allison V-12 drove a 10 foot, 9 inch (3.277 meter) diameter, three-bladed Curtiss Electric constant-speed propeller through a 2.00:1 gear reduction. The V-1710-F3R was 7 feet, 4.38 inches (2.245 meters) long, 3 feet, 0.54 inches (0.928 meters) high, and 2 feet, 5.29 inches (0.734 meters) wide. It weighed 1,310 pounds (594 kilograms).

The Mustang Mk.I had a cruise speed of 311 miles per hour (500.5 kilometers per hour) at 75% power, and a maximum speed of 384 miles per hour (618 kilometers per hour) at 19,000 feet (5,791 meters). The airplane could reach 20,000 feet (6,096 meters) in 8.80 minutes. The service ceiling was 32,000 feet (9,754 meters) and its range was 640 miles (1,030 kilometers).

The Mk.I was equipped with four Browning AN-M2 .50-caliber machine guns, with one in each wing and two mounted in the nose under the engine. Four Browning .303 Mk.II machine guns were also installed, with two in each wing.

North American Aviation Mustang Mk.I AG345 (c/n 73-3098), front. (North American Aviation Inc.)
North American Aviation Mustang Mk.I AG345 (c/n 73-3098), front. (North American Aviation Inc.)

The Mk.I was 30 m.p.h. (48 kilometers per hour) faster than its contemporary, the Curtiss P-40 Warhawk, though both used the same engine. Below 15,000 feet (4,572 meters), the Mustang was also 30–35 m.p.h (48–56 kilometers per hour) faster than a Supermarine Spitfire, which had the more powerful Roll-Royce Merlin V-12.

Two Mustang Mk.Is, AG348 and AG354, were taken from the first RAF production order and sent to Wright Field for testing by the U.S. Army Air Force. These airplanes, assigned serial numbers 41-038 and 41-039, were designated XP-51. They would be developed into the legendary P-51 Mustang. In production from 1941 to 1945, a total of 16,766 Mustangs of all variants were built.

AG345 was retained by North American Aviation for long term testing. It was stricken off charge 3 December 1946.

North American Aviation Mustang Mk.I AG345, the first production airplane built for the Royal Air Force. (North American Aviation, Inc.)
North American Aviation Mustang Mk.I AG345, the first production airplane built for the Royal Air Force. (North American Aviation, Inc.)

© 2018, Bryan R. Swopes

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20–21 April 1964

Lockheed L-100 Hercules N1130E, in flight. Both outboard engines are shut down and the propellers feathered. (Lockheed Martin)

20–21 April 1964: Nearly ten years after the first flight of the Lockheed YC-130 Hercules prototype, the Lockheed Model 382, serial number 3946, the commercial version of the military C-130E, made the longest first flight in history when it flew for 25 hours, 1 minute, after taking off from Marietta, Georgia.

The flight crew, led by Chief Production Pilot Joe Garrett, flew the Hercules in a racetrack pattern over Georgia and Alabama, and for all but 36 minutes of the flight, the outboard engines were shut down and their propellers feathered.

The Lockheed Model 382 was certified by the Federal Aviation Administration 16 February 1965.

Lockheed personnel celbrate the 25 hour, 1 minute first flight of the commercial L100 Hercules. (Lockheed Martin)
Lockheed personnel celebrate the 25 hour, 1 minute first flight of the commercial L-100 Hercules. (Lockheed Martin)

The L-382 was powered by four Allison 501-D22 turboprop engines, rated at 3,755 shaft horsepower at 13,820 r.p.m., and driving four-bladed Hamilton Standard Hydromatic constant-speed, reversible-pitch propellers with a diameter of 13 feet, 6 inches (4.115 meters). at 1,020 r.p.m.

Maximum operating altitude 32,600 feet (9.936 meters)

N1130E at Fairbanks, leased to Alaska Airlines. (Lockheed Martin)
N1130E at Fairbanks, leased to Alaska Airlines, 1965. (Lockheed Martin)

N1130E was retained by Lockheed as a demonstrator, however it was briefly leased to Alaska Airlines in March 1965, and returned the following month.

The L-382 was converted to the L382E-44K-20 standard in April 1968, with a 5 foot, 0 inch (1.524 meters) segment added to the fuselage behind the cockpit, and a 3 foot, 4 inch (1.016 meter) section behind the wing.

N1130E's fuselage was cut in two places to accommodate an 8 foot, 4 inch ( meter) stretch. (Lockheed Martin)
N1130E’s fuselage was cut in two places to accommodate an 8 foot, 4 inch (2.540 meter) stretch. (c-130hercules.net)
N1130E after conversion to the L100-20 configuration, at Lockheed-Burbank Airport, 1968. (Unattributed)
N1130E after conversion to the L100-20 configuration, at Lockheed-Burbank Airport, 1968. (c-130hercules.net)

N1130E was leased to Delta Air Lines in October 1968, and returned after six months.

Lockheed sold N1130E to Pepsico Airlease Corporation, who leased the freighter to Flying W Airways. It was reregistered as N50FW. In March 1973 Pepsico sold it to Philippine Aerotransport and it was operated for the Philippine government, first as PI-97, and then RP-97.

The first commercial Lockheed L-100, s/n 3946, in service with the Republic of the Philippines. (Ken Fielding via flickr)
The first commercial Lockheed L-100, s/n 3946, in service with the Republic of the Philippines. (Ken Fielding via flickr)

After sixty-four years, the Lockheed Hercules remains in production, and both military and civil versions are in service worldwide.

Lockheed Martin Model 382J Super Hercules (Lockheed Martin)
Lockheed Martin Model 382J Super Hercules, N100J. (Lockheed Martin)

© 2018, Bryan R. Swopes

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16 April 1949

Prototype Lockheed YF-94 48-356, first flight, 16 April 1949. (U.S. Air Force)
Prototype Lockheed YF-94 48-356, first flight, 16 April 1949. (U.S. Air Force)
Anthony M. "Tony" LeVier.
Anthony M. “Tony” LeVier.

16 April 1949: At Van Nuys Airport, California, test pilot Tony LeVier and flight test engineer Glenn Fulkerson made the first flight of the Lockheed YF-94 prototype, serial number 48-356. The aircraft was the first jet-powered all-weather interceptor in service with the United States Air Force and was the first production aircraft powered by an afterburning engine.

Two prototypes were built at Lockheed Plant B-9, located on the east side of Van Nuys Airport. Two TF-80C-1-LO (later redesignated T-33A) Shooting Star two-place trainers, 48-356 and 48-373, were modified with the installation of air intercept radar, an electronic fire control system, radar gun sight, four Browning AN-M3 .50-caliber (12.7 × 99 NATO) aircraft machine guns and a more powerful Allison J33-A-33 turbojet engine with water-alcohol injection and afterburner. The rear cockpit was equipped as a radar intercept officer’s station.

Right side profile of the Lockheed YF-94A Starfire prototype, 48-356, during its first flight, 16 April 1949. (San Diego Air & Space Museum Archives)
Right side profile of the Lockheed YF-94 prototype, 48-356, during its first flight, 16 April 1949. (San Diego Air & Space Museum Archives)

It was initially thought that the project would be a very simple, straightforward modification. However, the increased weight of guns and electronics required the installation of a more powerful engine than used in the T-33A. The new engine required that the aft fuselage be lengthened and deepened. Still, early models used approximately 80% of the parts for the F-80C fighter and T-33A trainer. The Air Force ordered the aircraft as the F-94A. Improvements resulted in an F-94B version, but the definitive model was the all-rocket-armed F-94C Starfire.

The Allison J33-A-33 was a single-shaft turbojet engine with a single-stage centrifugal-flow compressor, 14 combustion chambers and, a single-stage axial flow turbine. The engine was rated at 4,600 pounds of thrust (20.46 kilonewtons) and 6,000 pounds (26.69 kilonewtons) with afterburner. The J33-A-33 was 17 feet, 11.0 inches (5.461 meters) long, 4 feet, 1.3 inches (1.252 meters) in diameter and weighed 2,390 pounds (1,084 kilograms).

Originally a P-80C Shooting Star single-place fighter, 48-356 had been modified at Lockheed Plant B-9 in Van Nuys to become the prototype TF-80C two-place jet trainer (the designation was soon changed to T-33A), which first flew 22 March 1948. It was then modified as the prototype YF-94. 48-356 was later modified as the prototype F-94B. It is in the collection of the Air Force Flight Test Museum, Edwards Air Force Base, and is in storage awaiting restoration.

Underside of the prototype Lockheed YF-94A Starfire, 49-356, during its first flight, 16 April 1949. (San Diego air & Space Museum Archives)
Underside of the prototype Lockheed YF-94, 49-356, during its first flight, 16 April 1949. (San Diego Air & Space Museum Archives)

© 2017, Bryan R. Swopes

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14 April 1947

Douglas test pilot Gene May with a D-558-I Skystreak high-speed research airplane. (Douglas Aircraft Company)
Douglas Aircraft Company test pilot Eugene Francis May. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

14 April 1947: Douglas Aircraft Company test pilot Eugene Francis (“Gene”) May took the Number 1  U.S. Navy/NACA/Douglas D-558-I Skystreak high-speed research aircraft, Bu. No. 37970, for its first flight at at Muroc Army Airfield. The aircraft had been transported from the Los Angeles factory to Muroc by truck.

The Skystreak was a joint United States Navy/National Advisory Committee for Aeronautics (NACA) research aircraft designed to explore flight at high subsonic speed. The Phase I Skystreak was designed by a team led by Douglas Chief Engineer Edward Henry Heinemann. Flight testing was conducted at the NACA High Speed Flight Station at Muroc Army Airfield (later known as Edwards Air Force Base). Three D-558-Is were built, followed by the Phase II, swept-wing, Mach 2, D-558-II Skyrocket rocketplane.

The D-558-I carried extensive flight test instrumentation for its time. The wings had 400 orifices for air pressure sensors. During the test series, aircraft stability in the range of 0.82–0.99 Mach was investigated. One of the Skystreaks may have briefly exceeded Mach 1 as it came out of a dive.

Unlike some of the other experimental high speed aircraft of the time, it took off from the ground under its own power rather than being carried aloft by a mother ship. While those other aircraft could briefly reach much higher speeds, the D-558-I was able to fly for extended periods in the high-subsonic range, providing scientists and engineers with a tremendous amount of data.

The research airplane was a single-place, single-engine, low-wing monoplane with retractable tricycle landing gear. The fuselage of the D-558-I was constructed of an aluminum framework covered with sheet magnesium. It was designed for an ultimate load factor of 18 gs. The wings and tail surfaces were aluminum. The airplane was painted scarlet (not orange, like its contemporary, the Bell X-1) and was known as “the crimson test tube.” The D-558-I was 35 feet, 1.5 inches (10.706 meters) long with a wingspan of 25 feet, 0 inches (7.620 meters) and overall height of 12 feet, 1.6 inches (3.698 meters). Gross weight 10,105 pounds (4,584 kilograms). It carried 230 gallons (871 liters) of kerosene in its wings.

A Douglas D-558-I Skystreak being inspected by U.S. Navy personnel at the Douglas Aircraft Company plant in Los Angeles, California. [Modelers: Note the GREEN anti-glare panel.] (Getty Images/Bettman)
The D-558-I was powered by a single Allison J35-A-11 turbojet engine. The J35 was a single-spool, axial-flow turbojet with an 11-stage compressor section, 8 combustion chambers and single-stage turbine. The J35-A-11 was rated at 5,000 pounds of thrust (22.24 kilonewtons). The engine was 12 feet, 1.0 inches (3.683 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,455 pounds (1,114 kilograms).

Bu. No. 37970 made 101 of the 228 Phase I flights. It set a world speed record 1,031.178 kilometers per hour (640.744 miles per hour), flown by Commander Turner F. Caldwell Jr., U.S. Navy,  20 August 1947.¹ (Major Marion E. Carl, U.S. Marine Corps, flew the second Skystreak, Bu. No. 37971, to 1,047.356 kilometers per hour (650.797 miles per hour),² breaking Caldwell’s record.)

After Douglas completed the contractor’s test series, the Number 1 Skystreak was turned over to the NACA High Speed Flight Station and designated NACA 140. It was not as highly instrumented as the Number 2 and Number 3 Skystreaks and was not flown, but was used as a source for spare parts for the other D-558-Is.

Douglas D-558-I Skystreak Bu. No. 37970 is on display at the National Naval Aviation Museum, NAS Pensacola, Florida.

Douglas D-558-I Skystreak, Bu. No. 37970, at the National Naval Aviation Museum, Naval Air Station Pensacola, Florida. (U.S. Navy)

¹ FAI Record File Number 9864

² FAI Record File Number 9865

© 2017, Bryan R. Swopes

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27 March 1966

Test pilot Jack L. Zimmerman with the record-setting Hughes YOH-6A Light Observation Helicopter, 62-4213. (FAI)

27 March 1966: At Edwards Air Force Base in the high desert of southern California, Hughes Aircraft Company test pilot Jack Louis Zimmerman flew the third prototype YOH-6A Light Observation Helicopter, 62-4213, to set six Fédération Aéronautique Internationale (FAI) World Record for Altitude and Time-to-Climb. The records were set in two sub-classes, based on the helicopter’s take-off weight. Fifty-one years later, one of these records still stands.

Hughes YOH-6A 62-4213 at Edwards Air Force Base, 1966. (FAI)

Zimmerman took the YOH-6A from the surface to a height of 3,000 meters (9,843 feet) in 4 minutes, 1.5 seconds (FAI Record File Number 9922); and to 6,000 meters (19,685 feet) in 7 minutes, 12 seconds (FAI Record File Number 9923). The helicopter reached an altitude in level flight of 8,061 meters (26,447 feet). (FAI Record File Numbers 9920 and 9921). 9921 remains the current record for helicopters in Sub-Class E-1b, with a takeoff weight of 500–1,000 kilograms (1,102–2,205pounds).

Beginning with a takeoff weight between 1,000–1,750 kilograms (2,205–3,858 pounds) (Sub-Class E-1c), Zimmerman took the “loach” to a height 3,000 meters (9,843 feet) in 5 minutes, 37 seconds. (FAI Record File Number 771). The helicopter reached an altitude of 5,503 meters (16,578 feet), without payload. (FAI Record File Number 772)

[The field elevation of Edwards Air Force Base (EDW) is 2,210 feet (704 meters) above Sea Level. If the time-to-altitude flights had been made at nearby NAS Point Mugu (NTD) on the southern California coast, which has a field elevation 13 feet (4 meters), the times might have been significantly reduced. The air temperature at Edwards, though, was much colder.]

One day earlier, 26 March, Allison Engine Company test pilot Jack Schweibold flew the same YOH-6A  to set three Fédération Aéronautique Internationale (FAI) World Records for Distance Over a Closed Circuit Without Landing of 2,800.20 kilometers (1,739.96 miles).¹ One week earlier, 20 March, Jack Zimmerman had set a Fédération Aéronautique Internationale (FAI) World Record for Distance Over a Closed Circuit Without Landing of 1,700.12 kilometers (1,056.41 miles).² Fifty-one years later, these four World Records still stand.

The Hughes Model 369 was built in response to a U.S. Army requirement for a Light Observation Helicopter (“L.O.H.”). It was designated YOH-6A, and the first aircraft received U.S. Army serial number 62-4211. It competed with prototypes from Bell Helicopter Company (YOH-4) and Fairchild-Hiller (YOH-5). All three aircraft were powered by a lightweight Allison Engine Company turboshaft engine. The YOH-6A won the three-way competition and was ordered into production as the OH-6A Cayuse. It was nicknamed “loach,” an acronym for L.O.H.

The third prototype YOH-6A, 62-4213, testing the XM-7 twin M60 7.62 weapons system. (U.S. Army)

The YOH-6A was a two-place light helicopter, flown by a single pilot. It had a four-bladed, articulated main rotor which turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) Stacks of thin stainless steel “straps” fastened the rotor blades to the hub and were flexible enough to allow for flapping and feathering. Hydraulic dampers controlled lead-lag. Originally, there were blade cuffs around the main rotor blade roots in an attempt to reduce aerodynamic drag, but these were soon discarded. A two-bladed semi-rigid tail rotor was mounted on the left side of the tail boom. Seen from the left, the tail-rotor rotates counter-clockwise. (The advancing blade is above the axis of rotation.)

The YOH-6A was powered by a T63-A-5 turboshaft engine (Allison Model 250-C10) mounted behind the cabin at a 45° angle. The engine was rated at 212 shaft horsepower at 52,142 r.p.m. (102% N1) and 693 °C. turbine outlet temperature for maximum continuous power, and 250 shaft horsepower at 738 °C., 5-minute limit, for takeoff. Production OH-6A helicopters used the slightly more powerful T63-A-5A (250-C10A) engine.

The Hughes Tool Company Aircraft Division built 1,420 OH-6A Cayuse helicopters for the U.S. Army. The helicopter remains in production as AH-6C and MH-6 military helicopters, and the MD500E and MD530F civil aircraft.

Hughes YOH-6A 62-4213 is in the collection of the United States Army Aviation Museum, Fort Rucker, Alabama.

U.S. Army Hughes YOH-6A prototype 62-4213 at Le Bourget, circa 1965.

¹ FAI Record File Numbers 786, 787 and 11656.

² FAI Record File Number 762.

© 2017 Bryan R. Swopes

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