Tag Archives: First Flight

8 December 1962

Bell YOH-4 N73999 (U.S. Army serial number 62-4202. (U.S. Army)
Bell Model 206 N73999 (U.S. Army YOH-4-BF 62-4202) at the Bell Helicopter Company plant, Hurst, Texas. (Bell Helicopter Co.)
Bell YHO-4-BF. (U.S. Army)
Bell YHO-4. (Bell Helicopter Co.)

8 December 1962: At the Bell Helicopter Company plant at Hurst, Texas, the first Model D-250, N73999 (YHO-4-BF 62-4202) made its first flight.

The United States military had requested proposals from 25 aircraft manufacturers for a Light Observation Helicopter (LOH) to be powered by a gas turbine engine. Eventually, helicopters proposed by three companies were selected for flight testing. These were the Bell YHO-4, the Fairchild Hiller FH-1100, designated as YHO-5, and the Hughes Aircraft Company Model 369, designated YHO-6.

In 1962, U.S. military aircraft designations were standardized between services, and the three helicopters were redesignated YOH-4, YOH-5 and YOH-6. Bell Helicopter had also changed its internal company designation for their proposal from D-250 to Model 206. All three were powered by an Allison T63-A-5 turboshaft engine rated at 250 shaft horsepower (Allison 250-C18).

Bell 206 N73999 (YHO-4-BF-62-4202). (U.S. Army)
Bell 206 N73999 (YHO-4-BF 62-4202). Note the stabilizer bar. (U.S. Army)
A prototype Bell YOH-4 Light Observation Helicopter hovers in ground effect. The vertical fin has been changed from the original ventral configuration. (U.S. Army)

After the fly-off, the Hughes OH-6A Cayuse was selected for production. With the LOH classification, the OH-6 earned the nickname “Loach.”  Modern variants of the OH-6, now the AH-6 and MH-6 “Little Bird,” remain in service with United States special operations forces.

Bell Helicopter tried to market their Model 206 as a light civil aircraft, but its utilitarian appearance made it a hard sell. The helicopter was redesigned as the Model 206A and given the name JetRanger. This became one of the most successful aircraft ever built and it remained in production until 2011.

The first Bell 206A JetRanger, N8560F. (Bell Helicopter Co.)
The first Bell 206A JetRanger, N8560F. (Bell Helicopter Co.)

As the Vietnam War escalated, the need for helicopters increased. Hughes Aircraft had limited production capacity so the U.S. Army ordered a version of the redesigned Bell YOH-4 as the OH-58A Kiowa (Bell Model 206A-1). Though similar in appearance to the civil Bell 206A JetRanger, the OH-58A has significant differences and few parts are interchangeable between models. The Kiowa’s main rotor blades and tail boom are longer than the JetRanger’s. The rotor system turns at a slower r.p.m. Landing skids are mounted differently. The OH-58A has a lower maximum gross weight. There are internal differences as well, for example, the main transmission of the OH-58A has only three planetary gears while the 206B uses four, giving it a greater torque capacity.

The OH-58 Kiowa was continuously upgraded to the OH-58D Kiowa Warrior, with advanced targeting and communications capabilities. The D model uses a composite four-bladed “soft-in-plane” main rotor. Military variants of the civil Bell 206B-3 JetRanger III have been used as training helicopters for the U.S. Navy (TH-57 Sea Ranger) and U.S. Army (TH-67 Creek). The U.S. Army has now retired all of its OH-58s. The final flight of an OH-58D Kiowa Warrior took place in September 2017.

The first production Bell OH-58A-BF Kiowa, 68-16687. (U.S. Army)
The first production Bell OH-58A-BF Kiowa, 68-16687. (Bell Helicopter Co.)

The YOH-4A prototype is in storage at the U.S. Army Aviation Museum, Fort Rucker, Alabama. Because of an error is assigning serial numbers, this aircraft carries a manufacturer’s data plate with the military serial number 62-4201,¹ however, the correct serial number, 62-4202, is painted on the airframe exterior.

A flight of Bell OH-58D Kiowa Warriors scouting in a war zone. (U.S. Army)
A flight of Bell OH-58D Kiowa Warriors scouting in a war zone. (U.S. Army)

¹ Serial number 62-4201 had already been assigned to a Lockheed C-140B-LM JetStar.

© 2017, Bryan R. Swopes

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8 December 1945

Floyd Carlson, chief Test Pilot for the Bell Aircraft Corporation, hovers the world's first civil-certified helicopter, NC1H, Serial Number One. (Niagara Aerospace Museum)
Floyd William Carlson, Chief Test Pilot, Bell Aircraft Corporation, hovers the world’s first civil-certified helicopter, NC1H, Serial Number One. (Niagara Aerospace Museum)

8 December 1945: At the Bell Aircraft Corporation Wheatfield Plant, Niagara Falls, New York, the first Model 47 helicopter, NX41962, was rolled out. Designed by Arthur M. Young, the Model 47 was based on Young’s earlier Model 30. The helicopter made its first flight on the same day.

The Civil Aviation Administration (C.A.A.), predecessor of the Federal Aviation Administration, had never certified a helicopter, so Bell worked with government officials to develop civil certification standards. The Bell 47 received the C.A.A. Type Certificate H-1 on 8 March 1946 and the first helicopter’s registration was assigned changed to NC1H.

Bell Model 47 NX41962, Serial Number 1, at Bell’s Wheatfield Plant, early 1946. (Bell Helicopter via “Floyd W. Carlson, Helicopter Pioneer”)

The Bell 47 series was constructed of a welded tubular steel airframe with a sheet metal cockpit and a characteristic plexiglas bubble. In the original configuration, it had a four-point wheeled landing gear, but this was soon replaced with a tubular skid arrangement. It was a two-place aircraft with dual flight controls.

The first Bell Model 47 had an overall length (with rotors turning) of 39 feet, 7½ inches (12.078 meters). The main rotor diameter was 33 feet, 7 inches (10.236 meters). The length of the fuselage, from the front of the plexiglass bubble canopy to the trailing edge of the tail rotor disc, was 29 feet, 3½ inches (8.928 meters). The tail rotor had a diameter of 5 feet, 5 inches (1.676 meters). The helicopter’s height, to the top of the main rotor mast, was 9 feet, 2-7/16 inches (2.805 meters).

NC1H had an empty weight of 1,393 pounds (632 kilograms). Its gross weight was 2,100 pounds (953 kilograms).

Bell Aircraft Corp. test pilot Floyd W. Carlson demonstrates the stability of the Model 47 by taking his hands off of the flight controls during a hover. (Bell Helicopter)

The Bell 47’s main rotor is a two-bladed, under-slung, semi-rigid assembly that would be a characteristic of helicopters built by Bell for decades. The blades were constructed of laminated wood, and covered with fabric. A stabilizer bar was placed below the hub and linked to the flight controls through hydraulic dampers. This made for a very stable aircraft. The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the right.) The tail rotor is positioned on the right side of the tail boom in a tractor configuration. It rotates counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)

Power was supplied by an air-cooled, normally-aspirated, 333.99-cubic-inch-displacement (5.473 liter) Franklin Engine Company 6V4-175-B3 vertically-opposed six cylinder engine, serial number 17008, rated at 178 horsepower at 3,000 r.p.m. Power was sent through a centrifugal clutch to a gear reduction transmission which turned the main rotor through a two-stage planetary gear system. The transmission also drove the tail rotor drive shaft, and through a vee-belt/pulley system, a large fan to provide cooling air for the engine.

The new helicopter had a cruise speed of 75 miles per hour (121 kilometers per hour) and a maximum speed (Vne) of 80 miles per hour (129 kilometers per hour). NC1H had a service ceiling of 11,400 feet (3,475 meters).

The Bell 47 gained fame during the Korean War as a rescue helicopter, transferring wounded soldiers directly to Mobile Army Surgical Hospitals placed near the front lines. Here, a wounded soldier is offloaded from an H-13D-1 Sioux. (U.S. Army)
The Bell 47 gained fame during the Korean War as a rescue helicopter, transferring wounded soldiers directly to Mobile Army Surgical Hospitals placed near the front lines. Here, a wounded soldier is offloaded from an H-13D-1 Sioux. (U.S. Army) 
The manufacturer's data plate for Bell Model 47, Serial Number 1. (Niagara Museum of Aeronautics)
The manufacturer’s data plate for Bell Model 47, Serial Number 1. (Niagara Museum of Aeronautics)

The Bell 47 was produced at the plant in New York, and later at Fort Worth, Texas. It was steadily improved and remained in production until 1974. In military service the Model 47 was designated H-13 Sioux, (Army and Air Force), HTL (Navy) and HUG (Coast Guard).  The helicopter was produced under license by Agusta, Kawasaki and Westland. More than 7,000 were built worldwide and it is believed that about 10% of thoe remain in service.

In 2010, the type certificates for all Bell 47 models was transferred to Scott’s Helicopter Service, Le Sueur, Minnesota, which continues to manufacture parts and complete helicopters.

After certification testing and demonstrations, NC1H was one of two Bell 47s used for flight training. The first Bell 47, s/n 1, crashed at Niagara Falls Airport, 3 April 1946.

While hovering out of ground effect, a student inadvertently oversped the main rotor. The main rotor hub separated and the helicopter dropped to the ground. Both the student and instructor were injured. Damage to NC1H was extensive and the helicopter was scrapped. The registration, NC1H, was reassigned to Bell 47 s/n 11.

© 2016, Bryan R. Swopes

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2 December 1936

Boeing YB-17 Flying Fortress 36-149. (U.S. Air Force)
Boeing YB-17 Flying Fortress 36-149. (U.S. Air Force)

2 December 1936: The first Boeing YB-17, U.S. Army Air Corps serial number 36-149, made its first flight.

Although the prototype Boeing Model 299, NX13372, had crashed at Wright Field, Ohio, 30 October 1935, the Army had ordered thirteen Y1B-17 service test aircraft, serials 36-149–36-161. Prior to the model’s first flight, this designation was changed to YB-17. (The “-1-” in the original Y1B-17 designation indicated that the service test bombers were ordered using funding other than the normal appropriations for new aircraft.)

Boeing YB-17. (U.S. Air Force)
Boeing YB-17 36-149. (U.S. Air Force)

The YB-17 had several improvements over the Model 299, which was retroactively designated XB-17. There was a long carburetor intake on top of the engine nacelles which visually distinguishes the YB-17 from the follow-on YB-17A. The main landing gear has one strut rather than the two of the Model 299.

Boeing YB-17 36-149. (U.S. Air Force)
Boeing YB-17 36-149. (U.S. Air Force)

The Boeing Model 299B, designated YB-17 by the Army Air Corps, was 68 feet, 4 inches (20.828 meters) long with a wingspan of 103 feet, 9 inches (31.633 meters) and the overall height was 18 feet, 4 inches (5.588 meters). It had an empty weight of 24,465 pounds (11,097 kilograms), gross weight of 34,880 pounds (15,821 kilograms) and maximum takeoff weight of 42,600 pounds (19,323 kilograms).

Boeing Y1B-17 at Hamilton Field, Calif. (U.S. Air Force photo)
A Boeing YB-17 at Hamilton Army Airfield, north of San Francisco, California.  (U.S. Air Force photo)

Instead of the Pratt & Whitney engines installed on the 299, the YB-17 had four air-cooled, supercharged 1,823.129-cubic-inch-displacement (29.876 liter) Wright Aeronautical Division Cyclone 9 R-1820G5 (R-1820-39) nine-cylinder radial engines with a compression ratio of 6.45:1. They turned three-bladed Hamilton Standard constant-speed propellers through a 16:11 gear reduction drive, in order to match the engines’ effective power range with the propellers. The R-1820-39 was rated at 805 horsepower at 2,100 r.p.m., at Sea Level, and 930 horsepower at 2,200 r.p.m., at Sea Level, for takeoff. The R-1820-39 was 45-7/16 inches (1.154 meters) long and 54¼ inches (1.378 meters) in diameter, and weighed 1,198 pounds (543.4 kilograms).

The cruise speed of the YB-17 was 217 miles per hour (349 kilometers per hour) and the maximum speed was 256 miles per hour (412 kilometers per hour) at 14,000 feet (4,267 meters). Its service ceiling was 30,600 feet (9,327 meters) and the maximum range was 3,320 miles (5,343 kilometers). The YB-17 could carry 8,000 pounds (3,629 kilograms) of bombs. Defensive armament consisted of five .30-caliber air-cooled Browning machine guns.

Boeing YB-17 36-149. (U.S. Air Force)
Boeing YB-17 36-149. (U.S. Air Force)

36-149 was damaged in a landing accident 7 December 1936. It was repaired and then flown to Wright Field, Dayton, Ohio, 11 January 1937. After testing at Wright Field, 36-149 was delivered to the 2nd Bombardment Group, Langley Field, Virginia. By 1938 the bomber was back at Wright Field for additional tests.

“In the summer of 1938, Bill [Captain William C. Bentley, Jr., U.S. Army Air Corps, a B-17 test pilot at Langley Field] and his aircrew flew back to Seattle to pick up an additional aircraft, YB-17 tail number 36-149 from Boeing. This aircraft was different from the original thirteen. During its assembly phase at Boeing, it was packed with additional instruments for recording purposes. Once delivered to Langley, the plane was going to be subjected to a variety of stress tests in order to determine how much damage the plane could take and still operate. During its flight to Langley, Bill arrived over the field in a thunderstorm. The strength of the storm flipped the plane upside down, a stress never envisioned by the designers for such a large aircraft, much less one loaded to capacity with measuring instrumentation and a full crew. Using his fighter pilot training, Bill flew the aircraft at its maximum altitude then performed a slow roll to bring the airplane into its proper attitude. After recovering from a harrowing spin, Bill got control of the plane and landed successfully.

“Much to the crew’s amazement, the wings were slightly bent and some rivets were missing. But the measuring instrumentation had recorded all of the stress placed on the plane. . . .”

—The Touch of Greatness: Colonel William C. Bentley, Jr., USAAC/USAF, by Stewart W. Bentley, Jr., Ph.D. , AuthorHouse, Bloomington, Indiana, 2010, Chapter 2 at Page 45.

(This meant that a fourteenth YB-17, which had been built specifically as a static test article, could be completed as a Y1B-17A, 37-369.)

In October 1940 36-149 was transferred to the 19th Bombardment Group at March Field, California. Finally, on 11 February 1942, it was transferred to the Air Park at Amarillo Army Air Field, a B-17 training base in Texas. It was written off 11 December 1942.

After several years of testing, the YB-17 went into production as the B-17 Flying Fortress. By the end of World War II, 12,731 B-17s had been built by Boeing, Douglas and Lockheed Vega.

Boeing YB-17 36-139 arrives at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-139 arrives at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-149 at Langley Field, Virginia, 1 March 1937. (U.S. Air Force)
Boeing YB-17 36-149 at the Golden Gate International Exposition, Treasure Island, California, ca. 1939. (Stephen Fisher)

© 2017, Bryan R. Swopes

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25 November 1940

The first Martin Marauder, B-26-MA 40-1361, takes off for the first time at Middle River, Maryland, 25 November 1940. (U.S. Air Force)
The first Martin Marauder, B-26-MA 40-1361, takes off for the first time at Middle River, Maryland, 25 November 1940. (U.S. Air Force)

25 November 1940: Glenn L. Martin Company’s test pilot William K. (“Ken”) Ebel, co-pilot Ed Fenimore and flight engineer Al Malewski made the first flight of the first B-26 Marauder, Army Air Corps serial number 40-1361.

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-26-MA Marauder 40-1361, right profile, with bomb bay doors open. (U.S. Air Force)
Martin B-26-MA Marauder 40-1361, right profile, with engines idling. (U.S. Air Force)

The Marauder was 56 feet, 0 inches (17.069 meters) long with a wingspan of 65 feet, 0 inches (19.812 meters) and overall height of 19 feet, 10 inches (6.045 meters). It had an empty weight of 21,375 pounds (9,696 kilograms) and gross weight of 32,025 pounds (14,526 kilograms).

The prototype was powered by two air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter), Pratt & Whitney R-2800-5 two-row, 18-cylinder radial engines with a compression ratio of 6.65:1. The R-2800-5 had a Normal Power rating of 1,500 horsepower at 2,400 r.p.m. to 7,500 feet (2,286 meters) and a Takeoff/Military Power rating of 1,850 horsepower at 2,600 r.p.m. to 2,700 feet (823 meters). They turned 13 foot, 6 inch (4.115 meter) diameter four-bladed Curtiss Electric propellers through a 2:1 gear reduction. The R-2800-5 was 6 feet, 3.72 inches (1.923 meters) long, 4 feet, 4.06 inches (1.322 meters) in diameter, and weighed 2,270 pounds (1,030 kilograms).

40-1361 had a maximum speed of 315 miles per hour (507 kilometers per hour) at 15,000 feet (4,572 meters). Its service ceiling was 25,000 feet (7,620 meters).

Martin B-26-MA Marauder 40-1361, the first production airplane, 25 November 1940. (U.S. Air Force)
Martin B-26-MA Marauder 40-1361, the first production airplane, 25 November 1940. (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.

Prototype Martin B-26 40-1361 taxiing. (U.S. Air Force)
Prototype Martin B-26 40-1361 taxiing. (U.S. Air Force)

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 twin-engine light bomber.

The first Martin Marauder, B-26-MA 40-1361, was written off after a belly landing at Patterson Field, Ohio, 8 August 1941.

Martin B-26 40-1361 with engines turning, 28 November 1940. (U.S. Air Force)
Martin B-26 40-1361 with engines turning, 28 November 1940. (U.S. Air Force)

© 2015, Bryan R. Swopes

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25 November 1940

The prototype DH.98 Mosquito, marked W4050, takes off on its first flight at Hatfield, 25 November 1940. (BAE Systems)
Geoffrey Roal De Havilland

25 November 1940: De Havilland Aircraft Company’s Chief Test Pilot, Geoffrey Roal de Havilland, Jr., and engineer John Walker, made the first flight of the DH.98 Mosquito prototype, E0234, at Hatfield, Hertfordshire, England. The multi-role combat aircraft was constructed primarily of layers of balsa covered with layers of birch, then a layer of doped cotton fabric. It was powered by two Rolls-Royce Merlin V-12 engines.

The DH.98 had been predicted to be 20 miles per hour (32 kilometers per hour) faster than the Supermarine Spitfire, but was actually much faster. In testing, the prototype reached 437 miles per hour (703 kilometers per hour). The construction materials took advantage of plentiful supplies of wood, and also made workers who were not in the standard metal aircraft industry able to take part.

The prototype de Havilland DH.98 Mosquito, W0234, outside the Assembly Building, 19 November 1940. (BAE Systems)

The prototype was rolled out 19 November 1040, painted overall yellow. It had a wingspan of 54 feet, 2 inches (16.510 meters). Its gross weight was 19,670 pounds (8,922 kilograms). The production Mosquito B. Mk.IV was 40 feet, 6 inches (12.344 meters) long with a wingspan of 54 feet, 2 inches (16.510 meters) and height of 12 feet, 6 inches (3.810 meters). Its empty weight was 15,318 pounds (6,948 kilograms) and the maximum weight was 21,462 pounds (9,735 kilograms).

W4050 was powered by two liquid-cooled, supercharged, 1,648.96-cubic-inch-displacement (27.01 liter) Rolls-Royce Merlin Mk.21 single overhead camshaft (SOHC) 60° V-12 engines, producing 1,460 horsepower at 3,000 r.p.m. at 10,000 feet (3028 meters), with 10 pounds (0.69 Bar) of boost, and driving three-bladed de Havilland Hydromatic propellers through a gear reduction.

The prototype DH.98 Mosquito,W4050, in the field behind Salisbury Hall (where it was designed and built) just before its first flight, 25 November 1940. (HistoryNet)

The Mk.IV had a cruise speed of 265 miles per hour (426 kilometers per hour) at 15,000 feet (4,572 meters) and maximum speed of 380 miles per hour (612 kilometers per hour) at 21,900 feet (6,675 meters). It was the world’s fastest operational airplane at the time.

The prototype had a service ceiling of 34,000 feet (10,363 meters) and range of 2,180 miles (3,500 kilometers).

Mosquito bomber variants could carry four 500 pound bombs, but had no other armament. Fighters were armed with four 20 mm cannon and four .303-caliber machine guns in the nose.

6,411 DH.98 Mosquitoes were built in England, 1,134 in Canada and 212 in Australia. It was produced in bomber, fighter, night fighter, fighter bomber and photo reconnaissance versions.

The prototype DH.98 Mosquito, W4050, at Hatfield, Hertfordshire. (Royal Air Force)

W4050’s (the prototype’s Royal Air Force identification) fuselage was damaged while taxiing at Boscombe Down, 24 February 1941, and had to be replaced with one intended for a second prototype, W4051. It remained at de Havilland and was used to test different engines, armaments and versions. After a series of tests conducted in December 1943, the prototype Mosquito was permanently grounded. It was used as an instructional airframe and later placed in storage.

In September 1958, W4050 was turned over to the de Havilland Aircraft Heritage Centre. Today, the restored prototype DH.98 Mosquito is at the museum at London Colney, Hertfordshire, England.

The Mosquito prototype with camouflauged upper surfaces as it appeared at Boscombe Down, (de Havilland Aircraft Museum)
The Mosquito prototype with camouflaged upper surfaces as it appeared at Boscombe Down, 1941. (de Havilland Aircraft Museum)

© 2017, Bryan R. Swopes

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