Rockwell International B-1B Lancer 82-0001 takes off for the first time at Air Force Plant 42, Palmdale, California. (U.S. Air Force)
18 October 1984: The first production Rockwell International B-1B Lancer, serial number 82-0001, a supersonic four-engine strategic bomber with variable sweep wings, made its first flight from Air Force Plant 42, Palmdale, California.
Rockwell test pilot Mervyn Leroy Evenson (Colonel, U.S.Air Force, retired) was the aircraft commander, with co-pilot Lieutenant Colonel Leroy Benjamin Schroeder; Major S.A. Henry, Offensive Systems Officer; Captain D.E. Hamilton, Defensive Systems Officer.
Rockwell International B-1B takeoff on Oct. 25, 1986. Note the lit afterburners. (U.S. Air Force)
After 3 hours, 20 minutes, the B-1B landed at Edwards Air Force Base where it would enter a flight test program.
Rockwell B-1B 82-0001 parked at the Rockwell International Corp. facility, Palmdale, California, 3 September 1984. (MSGT Mike Dial, U.S. Air Force)
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).
Rockwell International B-1B Lancer. (U.S. Air Force)
“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.
A Rockwell B-1B Lancer drops Mk. 82 bombs from its three weapons bays. (U.S. Air Force)
100 B-1B Lancers were built between 1983 and 1988. As of September 2021, 45 B-1B bombers remained the active Air Force inventory. The Air Force plans upgrades to the aircraft and to keep it in service until 2033.
To comply with the START weapons treaty, B-1B 82-0001 was scrapped at Ellsworth Air Force Base, South Dakota, in the mid-1990s.
A Rockwell International B-1B Lancer in flight. (U.S. Air Force)
First flight, Sikorsky YUH-60A 73-21650 at Stratford, Connecticut, 17 October 1974. (Sikorsky, a Lockheed Martin Company)
17 October 1974: Sikorsky Chief Pilot James R. (Dick) Wright and project chief test pilot John Dixson made the first flight of the prototype YUH-60A, 73-21650, at the company’s Stratford, Connecticut, facility. This helicopter was the first of three prototypes.
Early flight testing revealed excessive vertical vibrations associated with the main rotor. Extensive engineering and flight testing determined that this was caused by air flow upward through the rotor system and around the transmission and engine cowlings. The purpose of the low-mounted main rotor was to aid in fitting inside transport aircraft with minimal disassembly. It was necessary to increase the height of the mast and reshape the cowlings to achieve an acceptable level of vibration.
After eight months of testing, the U.S. Army selected the YUH-60A for production over its competitor, the Boeing Vertol YUH-61A. In keeping with the Army’s tradition of naming helicopters after Native Americans, the new helicopter was named Black Hawk, who was a 17th Century leader of the Sauk (or Sac) people.
Sikorsky YUH-60A 73-21650 at roll-out, 28 June 1974, with low main rotor, large-area tail rotor pylon and swept stabilator. (Sikorsky, a Lockheed Martin Company)
The Sikorsky Model S-70 (YUH-60A) was designed to meet the requirements of the U.S. Army Utility Tactical Transport Aircraft System (UTTAS). It had a 3-man crew and could carry an 11-man rifle squad. The helicopter could be transported by a Lockheed C-130 Hercules.
The three UTTAS prototypes were 63 feet, 6 inches (19.355 meters) long, with rotors turning. The span of the horizontal stabilizer was 15 feet, 0 inches (4.572 meters). The prototypes’ overall height was 16 feet, 10 inches (5.131 meters).
The three Sikorsky YUH-60A UTTAS prototypes. A fourth prototype, an S-70, was built and retained by Sikorsky for internal research and development and demonstrations. (Vertical Flight Society)
The YUH-60A had an empty weight of 11,182 pounds (5,072 kilograms) and gross weight of 16,750 pounds (7,598 kilograms). The helicopter had a structural load factor of 3.5 Gs. With 1,829 pounds (830 kilograms) of fuel, it had an endurance of 2 hours, 18 minutes.
The YUH-60A had a four-blade fully-articulated main rotor with elastomeric bearings. It had a diameter of 52 feet, 0 inches (15.850 meters). During flight testing, the diameter was increased to 52 feet, 4 inches (15.951 meters), and finally to 52 feet, 8 inches (16.053 meters). The blades were built with titanium spars and used two different airfoils and a non-linear twist (resulting in a net -16.4°). The outer 20 inches (0.508 meters) were swept aft 20°. These characteristics improved the helicopter’s maximum speed and hover performance. The main rotor turned counterclockwise, as seen from above (the advancing blade is on the right) at 258 r.p.m. The blade tip speed was 728 feet per second (222 meters per second). During flight testing it was decided to change the main transmission gear reduction ratio in order to operate the engines at a slightly increased r.p.m. At the higher r.p.m., the engines produced an additional 50 horsepower, each.
Sikorsky YUH-60A 73-21650 (c/n 70-001), right profile. In this photograph, the prototype has been modified closer to the production variant. The rotor mast is taller, the vertical fin has been decreased in size, a variable-pitch stabilator has replaced the fixed horizontal stabilizer, the engine cowlings have been redesigned, and the crew side window is the two-piece version. (U.S. Army Aviation Museum)
The four-bladed bearingless tail rotor was positioned on the right side of the tail rotor pylon in a tractor configuration. The tail rotor diameter was 11 feet (3.353 meters), and turned 1,214 r.p.m., rotating clockwise as seen from the helicopter’s left (the advancing was blade below the axis of rotation). The blade tip speed was 699 feet per second (213 meters per second). The tail rotor blades had -18° of twist. Because the Black Hawk’s engines are behind the transmission, the aircraft’s center of gravity (c.g.) is also aft. The tail rotor plane is inclined 20° to the left to provide approximately 400 pounds of lift (1.78 kilonewtons) to offset the rearward c.g.
Cutaway illustration of the T700-GE-700 turboshaft engine. (Global Security)
Power was supplied by two General Electric T700-GE-700 modular turboshaft engines, rated at 1,622 shaft horsepower at 20,900 r.p.m. Np, at Sea Level under standard atmospheric conditions. The T700 has a 5-stage axial-flow, 1-stage centrifugal-flow compressor, with a 2-stage axial-flow gas producer and 2-stage axial-flow power turbine. The T700 is 3 feet, 11 inches (1.194 meters) long, 2 feet, 1 inch (0.635 meters) in diameter and weighs 437 pounds (198 kilograms). The helicopter’s main transmission was designed for 2,828 horsepower. The engines are derated to the transmission limit.
The YUH-60A had a cruise speed of 147 knots (169 miles per hour/272 kilometers per hour) at 4,000 feet (1,219 meters) and 95 °F. (35 °C.). It could climb at 450 feet per minute (2.29 meters per second) at the same altitude and air temperature.
Sikorsky YUH-60A prototype, 73-21650, late configuration. (Vertical Flight Society)
While operating with an Army crew on the night of 9 August 1976, YUH-60A 73-21650 developed a significant vibration. An emergency landing was made. Because of darkness and mist, the pilots thought they were landing in a corn field, but it was actually a pine tree plantation. The helicopter’s rotors cut down more than 40 trees with trunk diameters up to 5 inches (12.7 centimeters).
Close inspection by Army and Sikorsky personnel found that the only visible damage was to the four main and four tail-rotor blades other than nicks and dents to the airframe that were of no structural concern. All gearboxes and engines turned freely, and all flight controls responded properly. ¹ The blades were replaced on-site and the helicopter was flown out the following day.
73-21650 crashed into the Housatonic River near the Stratford plant at 9:10 a.m., Friday, 19 May 1978, killing all three Sikorsky employees on board, pilots Albert M. King, Jr., John J. Pasquarello, and flight engineer John Marshall.
During routine maintenance an airspeed sensor for the all-flying tailplane had been disconnected. As the Black Hawk transitioned from hover to forward flight, the all-flying tailplane remained in the hover position and forced the helicopter’s nose to pitch down to the point that recovery was impossible.
A Sikorsky YUH-60A and Boeing Vertol YUH-61A hover for the camera. (U.S. Army)
The Black Hawk has been in production since 1978. More than 4,000 of the helicopters have been built and the type has been continuously improved. The current production model is the UH-60M.
Sikorsky is a Lockheed Martin Company.
A Sikorsky UH-60M Black Hawk in flight. (Sikorsky, a Lockheed Martin Company)Sikorsky’s UH-60M Black Hawk for the U.S. Army, seen here in the Military Hangar at Sikorsky Aircraft in Stratford, Connecticut, 20 February 2008. (Sikorsky, a Lockheed Martin Company)
¹ Black Hawk: The Story of a World Class Helicopter, by Ray D. Leoni, American Institute of Aeronautics and Astronautics, Reston, Virginia, 2007, Chapter 8 at Page 173.
The Boeing XB-15 takes off on its first flight, Boeing Field, 15 October 1937. (U.S. Air Force)
15 October 1937: Test pilot Edmund Turney (“Eddie”) Allen, a consulting engineer to Boeing, and Major John D. Korkille, Air Corps, United States Army, made the first flight of the prototype Boeing XB-15, 35-277, at Boeing Field, Seattle, Washington. Major Corkille reported that the airplane “handled easily and maneuvered readily.”
The flight deck of the Boeing XB-15. The radio operator’s station is on the left, and the navigator’s on the right. (The Boeing Company)
The Boeing Model 294, designated XB-15 by the Air Corps, was an experimental airplane designed to determine if a bomber with a 5,000 mile (8,047 kilometers) range was possible. It was designed at the same time as the Model 299 (XB-17), which had the advantage of lessons learned by the XB-15 design team. The XB-15 was larger and more complex than the XB-17 and took longer to complete. It first flew more than two years after the prototype B-17.
The Boeing Model 294 (XB-15) at Boeing Field, Seattle, Washington. The prototype bomber was rolled out for engine tests, 27 September 1937. (The Boeing Company)
Designers had planned to use an experimental 3,421.19-cubic-inch-displacement (56.063 liter) liquid-cooled, supercharged and turbosupercharged Allison V-3420 twenty-four cylinder, four-bank “double V” engine which produced a maximum of 2,885 horsepower at 3,000 r.p.m. The engine was not available in time, however, and four air-cooled Pratt & Whitney R-1830 (Twin Wasp) engines were used instead. With one-third the horsepower, this substitution left the experimental bomber hopelessly underpowered as a combat aircraft.
Boeing XB-15 35-277. (U.S. Air Force)Boeing XB-15 35-277. (U.S. Air Force)Boeing XB-15 35-277. (U.S. Air Force)
The XB-15 was a very large four-engine mid-wing monoplane with retractable landing gear. It was of aluminum monocoque construction with fabric-covered flight control surfaces. The XB-15 had a ten-man crew which worked in shifts on long duration flights.
Boeing XB-15 35-277
The prototype bomber was 87 feet, 7 inches (26.695 meters) long with a wingspan of 149 feet (45.415 meters) and overall height of 18 feet, 1 inch (5.512 meters). The airplane had an empty weight of 37,709 pounds (17,105 kilograms) and maximum takeoff weight of 70,706 pounds (32,072 kilograms)—later increased to 92,000 pounds (41,730 kilograms).
As built, the XB-15 was powered by four air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engines, rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. The engines turned three-bladed controllable-pitch propellers through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
These gave the experimental airplane a maximum speed of 197 miles per hour (317 kilometers per hour) at 5,000 feet (1,524 meters) and a cruise speed of 152 miles per hour (245 kilometers per hour) at 6,000 feet (1,829 meters). The service ceiling was 18,900 feet (5,761 meters) and maximum range was 5,130 miles (8,256 kilometers).
The Boeing XB-15 experimental long-range heavy bomber flies in formation with a Boeing YP-29 pursuit. (U.S. Air Force)
The bomber could carry a maximum of 12,000 pounds (5,443 kilograms) of bombs in its internal bomb bay, and was armed with three .30-caliber and three .50-caliber machine guns for defense.
Only one XB-15 was built. During World War II it was converted to a transport and redesignated XC-105. In 1945 it was stripped and abandoned at Albrook Field, Territory of the Canal Zone, Panama.
The XB-15 set several Fédération Aéronautique Internationale (FAI) world records: On 30 July 1939, the XB-15 carried 14,135 kilograms (31,162 pounds) to an altitude of 2,000 meters (6,562 feet) over Fairfield, Ohio.¹ The same flight set a second record by carrying 10,000 kilograms (22,046 pounds) to an altitude of 8,228 feet (2,508 meters).² On 2 August 1939, the XB-15 set a World Record for Speed Over a Closed Circuit of 5000 Kilometers With 2000 Kilogram Payload, at an average speed of 267.67 kilometers per hour (166.32 miles per hour).³
14 October 1964: The first prototype Sikorsky YCH-53A Sea Stallion, Bu. No. 151613, made its first flight at the Sikorsky plant at Stratford, Connecticut. (Sikorsky Model S-65, serial number 65001.)
The Bridgeport Telegram reported:
Brief First Flight Made By CH-53A at Sikorsky
The Sikorsky-Marine Corps CH-53A, designed as the free world’s largest and fastest transport helicopter, took off for the first time Wednesday at the Sikorsky Aircraft plant here. The aircraft was hovered within the flight field in its preliminary phase of the test program.
The brief flight exceeded expectations and project engineers and pilots expressed satisfaction with the CH-53A’s overall performance. More than twice the forces expected in actual high-performance flight were induced during ground tests prior to flight with far better results than ever before experienced at this early stage of a test program. Tie-down tests, started during the summer to check for components, structure and systems function, also provided “very satisfactory” results.
The CH-53A will be capable of speed of more than 200 miles an hour and will carry payloads of up to nine tons. It is powered by two General Electric T-64-6 turboshaft engines of 2,850 horsepower each. It will be flown by a three-man crew and will carry 38 fully-equipped troops. For medical evacuation duties, the CH-53A will carry 24 patients.
—The Bridgeport Telegram, Vol. LXXIII, No, 250, Saturday, 17 October 1964, Page 3, Columns 6–7
The fuselage of the YCH-53A was similar in configuration to the smaller CH-3C (S-61R). It used the dynamic components from the CH-37 Mojave (S-56) and CH-54A Tarhe (S-64).
U.S. Marine Corps Sikorsky CH-53A Sea Stallion (Wikimedia)
The Sikorsky CH-53A Sea Stallion is a twin-engine heavy-lift transport helicopter operated by two pilots. It is 88 feet, 2.4 inches (26.883 meters) with rotors turning. The fuselage is 67 feet, 2.4 inches (20.483 meters) long and 8 feet, 10 inches (2.692 meters) wide. The six-blade fully articulated main rotor is 72 feet, 2.7 inches (22.014 meters) in diameter and turns counterclockwise as seen from above. (The advancing blade is on the helicopter’s right.) Main rotor speed is 185 r.pm. The four-blade semi-articulated tail rotor has a diameter of 16 feet (4.877 meters) and is placed on the left side of the tail rotor pylon in a pusher configuration. It turns clockwise as seen from the helicopters left. (The advancing blade is below the axis of rotation.) Overall height (rotors turning) of the Sea Stallion is 24 feet, 10.8 inches (7.599 meters). The tail rotor speed is 792 r.p.m.
The CH-53A is powered by two General Electric T64-GE-6 turboshaft engines rated at 2,850 shaft horsepower, each. Performance of the CH-53D (T64-GE-413, 3,925 s.h.p) has a maximum speed (Vne) of 130 knots (241 kilometers per hour) service ceiling of 16,750 feet (5,105 meters) and range with maximum payload of 540 miles (870 kilometers)
Two YCH-53A prototypes were built, followed by 139 CH-53A Sea Stallion production models.
The CH-53 was developed into the three-engine CH-53E Super Stallion. The current production variant is the CH-53K King Stallion.
Sikorsky HH-53B 66-14428, Super Jolly Green Giant, first flight at Stratford, Connecticut, 15 March 1967. (Sikorsky Historical Archives)Sikorsky CH-53E Super Stallion at Mojave, California, 9 September 2007. (Alan Redecki/Wikipedia)This photograph by Alan Radecki of a Sikorsky CH-53E Super Stallion taking off at Mojave, California, 20 September 2007, is too exciting not to include. (Akradecki/Wikipedia)Sikorsky CH-53K King Stallion at West Palm Beach, Florida, 2 March 2017. (Lance Corporal Molly Hampton, United States Marine Corps)
The Curtiss-Wright XP-40 prototype, 38-10, on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives) 16_008532
14 October 1938: At Buffalo, New York, test pilot Everett Edward Elliot made the first flight in the new Curtiss-Wright Corporation’s Model 75P, a prototype for a single-engine pursuit plane which had been designated XP-40 by the U.S. Army Air Corps.
Curtiss-Wright’s Chief Engineer, Donovan Reese Berlin, had taken the tenth production P-36A Hawk, Air Corps serial number 38-10, and had its air-cooled radial engine replaced with the Harold Caminez-designed, liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C13 (V-1710-19).
Donovan Reese Berlin. (Niagara Aerospace Museum)
The V-1710-19 was a single overhead cam (SOHC) 60° V-12 engine with four valves per cylinder and a compression ration of 6.65:1. It had a Normal Power rating of 910 horsepower at 2,600 r.p.m. at Sea Level, and 1,060 horsepower at 2,950 r.p.m. for Takeoff. At 10,000 feet (3,048 meters), the V-1710-19 had Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m., and Military Power rating of 1,150 horsepower at 2,950 r.p.m. The engine required 100/130-octane aviation gasoline. It drove a three-bladed Curtiss Electric constant-speed propeller through a 2:1 gear reduction. The V-1710-19 was 8 feet, 1.75 inches (2.483 meters) long, 3 feet, 4.75 inches (1.035 meters) high and 2 feet, 4.94 inches (0.735 meters) wide. It weighed 1,320 pounds (599 kilograms).
Curtiss-Wright XP-40 38-10 (SDASM 16_008531)
At 1,829.39-cubic-inches (29.978 liters), the original Pratt & Whitney Twin Wasp S1C1-G (R-1830-17) 14-cylinder radial engine had greater displacement and produced 80 horsepower more for takeoff than the Allison V-12. The long, narrow V-12, though, allowed for a much more streamlined engine cowling for higher speed and greater efficiency.
XP-40 16_008533Curtiss-Wright XP-40 prototype. (SDASM 16_008534)The Curtiss-Wright XP-40 in the original configuration at Langley Field. (NASA)Everett Edward Elliot (1907–1981).
In the early testing, the XP-40 was much slower than expected, reaching only 315 miles per hour (507 kilometers per hour). (The P-36A Hawk had a maximum speed of 313 miles per hour). Engineers experimented with different placement for the coolant radiator, oil coolers and the engine air intake. The Air Corps project officer, Lieutenant Benjamin Scovill Kelsey, had the prototype sent to the National Advisory Committee for Aeronautics (NACA) Research Center at Langley Field, Virginia, where the full-size airplane was placed inside a wind tunnel.
Over a two-month period, NACA engineers made a number of improvements. The radiator was moved forward under the engine and the oil coolers utilized the same air scoop. The exhaust manifolds were improved as were the landing gear doors.
When they had finished, Lieutenant Kelsey flew the modified XP-40 back to Curtiss. Its speed had been increased to 354 miles per hour (570 kilometers per hour), a 12% improvement.
By December 1939 the airplane had been further improved and was capable of 366 miles per hour (589 kilometers per hour).
The Curtiss-Wright XP-40 prototype in a wind tunnel at Langley Field, 24 April 1939. (NASA)Curtiss-Wright XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, 24 April 1939. (NASA)
The Curtiss Hawk 75P, XP-40 38-10, was 31 feet, 1 inch (9.574 meters) long with a wingspan of 37 feet, 4 inches (11.354 meters) and overall height of 12 feet, 4 inches (3.734 meters). It had an empty weight of 5,417 pounds (2,457.1 kilograms) and maximum gross weight of 6,870 pounds (3,116.2 kilograms).
The prototype had a maximum speed of 342 miles per hour (550 kilometers per hour) at 12,200 feet (3,719 meters) with a gross weight of 6,260 pounds (2,839.5 kilograms). Its range was 460 miles (740 kilometers) flying at 299 miles per hour (481 kilometers per hour) with 100 gallons (378.5 liters) of fuel. With 159 gallons (601.9 liters) and with speed reduced to 200 miles per hour (322 kilometers per hour), the XP-40 had a maximum range of 1,180 miles (1,899 kilometers).
The prototype was armed with two air-cooled Browning AN-M2 .50-caliber machine guns mounted above the engine and synchronized to fire forward through the propeller arc.
The Air Corps placed an initial order for 524 P-40s. This was the largest single order for airplanes by the U.S. military up to that time. The first production model was the P-40 Warhawk, armed with two .50-caliber machine guns. There was only one P-40A variant which was a P-40 modified as a camera aircraft. The definitive pursuit model was the P-40B Warhawk, which retained the two .50-caliber guns of the P-40 and added two Browning M2 .30-caliber machine guns to each of the wings.
A Curtiss-Wright P-40B Warhawk, 79th Pursuit Squadron, 20th Pursuit Group, Hamilton Field, California, 1940. (U.S. Air Force)
The P-40B was best known as the airplane flown by the American Volunteer Group fighting for China against the Japanese. They were called the “Flying Tigers”. Between 1939 and 1945, Curtiss built 13,738 P-40s in many configurations. They flew in combat in every theater of operations during World War II.
A Curtiss-Wright Hawk 81-A3 (Tomahawk IIb) of the American Volunteer Group, Kunming, China, 1942. (U.S. Air Force)
