The first production B-52A takes off from Boeing Field, 5 August 1954. (Boeing)
5 August 1954: The first production Boeing B-52A Stratofortress, B-52A-1-BO 52-001, made its first flight from Boeing Field, Seattle, Washington.
Boeing B-52A Stratofortress 52-001 rollout, 18 March 1954. (Boeing)
The B-52A differed from the XB-52 and YB-52 in that its cockpit was arranged for side-by-side seating, rather than the B-47-type tandem arrangement of the prototypes. It also had an inflight refueling system allowing it to receive fuel from an airborne KC-97 tanker.
Boeing B-52A Stratofortress 52-001 takes off from Boeing Field, 4 August 1954. (U.S. Air Force 021001-O-9999G-015)
52-001 was used as a service test aircraft along with sister ships 52-002 and 52-003. It was used to test the shorter vertical fin of the B-52G. It was permanently grounded at Chanute Air Force Base in the early 1960s.
Boeing B-52A-1-BO Stratofortress 52-001 during its first flight, 5 August 1954. (U.S. Air Force)
A prototype Agusta A109 Hirundo hovering in ground effect. (Agusta)
4 August 1971: At its Cascina Costa plant, near the Aeroporto di Milano-Malpensa, northwest of Milan, Italy, Agusta test pilot Ottorino Lancia made the first flight of the prototype Agusta A109 Hirundo, serial number 7101. Also on board was one of the helicopter’s designers, Paolo Bellevita.
The Agusta A109 is an 8-place, light, twin-engine helicopter with a four-blade, fully-articulated main rotor and retractable landing gear. It can be flown by one pilot and carry up to seven passengers. The helicopter is certified for flight in visual meteorological conditions. It was certified by Italy’s Ente Nazionale per l’Aviazione Civile (ENAC) on 28 May 1975, and by the U.S. Federal Aviation Administration the following month. The first production helicopters were delivered in 1976.
The original production variant A109 was 10.71 meters (35 feet, 2 inches) in length. The fuselage had a maximum width of 2.88 meters (9 feet, 5 inches) and the helicopter’s overall height was 3.30 meters (10 feet, 10 inches). The maximum gross weight was 2,450 kilograms, or 5,400 pounds.
The main rotor diameter of the A109 is 11.00 meters (36 feet, 1 inch), and turns counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) In normal operation, the main rotor turns 365–385 r.p.m. (95–100%). In autorotation, the range is 346–424 r.p.m. (90–110%). The two-bladed semi-rigid tail rotor had a diameter of 2.03 meters (6 feet, 8 inches). It is positioned on the left side of the tail boom in pusher configuration. The tail rotor turns clockwise, when seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.)
The A109 was powered by two Allison 250-C20B turboshaft engines. They are rated at 346 shaft horsepower (113% torque), each, for takeoff (five minute limit). With one engine inoperative (OEI), the maximum power of the remaining engine is 400 shaft horsepower (five minute limit) and 385 shaft horsepower, maximum continuous power.
The A109’s maximum speed (VNE) is 168 miles per hour (270 kilometers per hour). The maximum operating altitude is 15,000 feet (4,572 meters). The helicopter’s total useable fuel capacity is 550.0 liters (145.3 gallons).
A prototype Agusta A109 Hirundo in ground effect hover. (Agusta)
The A109 remains in production in both civil and military variants. It is produced in Italy by Leonardo S.p.A. (formerly, AgustaWestland) and in China by Jiangxi Change Agusta Helicopter Co., Ltd.
Boeing Model 299 X13372, photographed during its first flight, 28 July 1935. (The Boeing Company)Boeing’s Chief Test Pilot Leslie R. Tower.
28 July 1935, At Boeing Field, Seattle, Chief Test Pilot Leslie Ralph (“Les”) Tower and Louis Waite took off on the maiden flight of the Boeing Model 299, X13372,¹ a prototype four-engine long range heavy bomber. For approximately one-and-a-half hours, Tower flew back and forth between Tacoma and Fort Lewis. When he landed, he said, “It handles just like a little ship—a little bigger, of course.”
The Boeing Model 299 was a four-engine bomber operated by a crew of eight. It was designed to meet a U.S. Army Air Corps proposal for a multi-engine bomber that could carry a 2,000 pound (907 kilogram) bomb load a distance of 2,000 miles (3,219 kilometers) at a speed greater than 200 miles per hour (322 kilometers per hour). Design of the prototype began in June 1934 and construction was started 16 August 1934. The Air Corps designated it B-299, and later, XB-17. It did not carry a military serial number, being marked with civil experimental registration X13372.
The Boeing Model 299 with Mount Rainier. (U.S. Air Force)
The Model 299 was 68 feet, 9 inches (20.955 meters) long with a wingspan of 103 feet, 9–3/8 inches (31.633 meters) and height of 14 feet, 11–5/16 inches (4.554 meters). Its empty weight was 21,657 pounds (9,823 kilograms). The maximum gross weight was 38,053 pounds (17,261 kilograms).
The prototype was powered by four air-cooled, supercharged, 1,690.537-cubic-inch-displacement (27.703 liter) Pratt & Whitney Hornet S1E-G nine-cylinder radial engines with a compression ratio of 6.5:1. The S1E-G was rated at 750 horsepower at 2,250 r.p.m., and 875 horsepower at 2,300 r.p.m. for takeoff, using 87-octane gasoline. They turned 11 foot, 6 inch (3.505 meters) diameter, three-bladed, Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The S1E-G was 4 feet, 1.38 inches (1.254 meters) long, 4 feet, 6.44 inches (1.383 meters) in diameter and weighed 1,064 pounds (483 kilograms)
Boeing Model 299. (U.S. Air Force)
In flight testing, the Model 299 had a cruise speed of 204 miles per hour (328 kilometers per hour) and a maximum speed of 236 miles per hour (380 kilometers per hour) at 10,000 feet (3,048 meters). The service ceiling was 24,620 feet (7,504.2 meters). Its maximum range was 3,101 miles (4,991 kilometers). Carrying a 2,573 pounds (1,167 kilograms) load of bombs, the range was 2,040 miles (3,283 kilometers).
Boeing 299 X13372, all engines running.
The XB-17 could carry eight 500 pound (226.8 kilogram) bombs in an internal bomb bay. Defensive armament consisted of five air-cooled Browning .30-caliber machine guns.
Nose turret of the Boeing Model 299, photographed 24 July 1935. (The Boeing Company)
X13372 was destroyed when it crashed on takeoff at Wright Field, Dayton, Ohio, 30 October 1935. An Army Air Corps pilot making his first familiarization flight neglected to remove the control locks. This incident led directly to the creation of the ”check list” which is used by all aircraft crew members.
Waist gun position of the Boeing 299. (The Boeing Company)
Designated XB-17 by the Army Air Corps, this airplane and the YB-17 pre-production models that followed would undergo several years of testing and improvement before entering production as the B-17 Flying Fortress, a legendary airplane of World War II. By the end of the war 12,731 B-17s had been built by Boeing, Douglas and Lockheed Vega.
Boeing Model 299 X13372, designated XB-17, at Wright Field, Ohio, 1935. (U.S. Air Force)
Leslie Ralph Tower was born at Sisseton, South Dakota, 21 January 1903. He was the first of three children of Ralph R. Tower, a farmer who would later serve as a state senator for Montana, and Mayme Amanda Johnson Tower, a Swedish immigrant.
Les Tower attended high school at Polson, Montana, graduating in 1922. He then attended the University of Washington, where he studied engineering. He was a member of the Radio Club.
Tower enlisted in the United States Army as an aviation cadet, training at Brooks and Kelly airfields in Texas. He then served with the 2nd Bombardment Squadron at Langley Field, Virginia.
In 1925 Tower started working for Boeing as a draftsman, but soon began test flying new airplanes, which included the B-9 bomber and the Model 247 commercial airliner. He also demonstrated and delivered Boeing airplanes around the world.
On 20 August 1935, Tower and Louis Wait flew the Model 299 from Seattle to Dayton, approximately 2,100 miles, in 9 hours, 3 minutes, averaging 233 miles per hour (375 kilometers per hour).
Les Tower was aboard the XB-17 as an observer during the 30 October flight. He saw that the control locks had not been released and tried to reach them, but was unable. In the fire that followed the crash, Tower suffered severe burns to his face, right arm and both legs.
Leslie Ralph Tower died of his injuries 19 November 1935 at Miami Valley Hospital in Dayton. His remains were transported by train, escorted by Army airplanes, and were buried at Lakeview Cemetery, Polson, Montana.
¹ At that time, experimental and restricted category aircraft were prohibited from displaying the letter “N” at the beginning of their registration mark.
Irving L. Burrows prepares for the first flight of the pre-production YF-15A-1-MC Eagle air superiority fighter at Edwards Air Force Base, California. (U.S. Air Force)
27 July 1972: McDonnell Douglas Chief Experimental Test Pilot Irving L. Burrows made the first flight of the prototype YF-15A-1-MC Eagle, 71-0280, at Edwards Air Force Base, California.
Irving L. Burrows
The F-15A Eagle is a single-seat, twin-engine air superiority fighter, built by the McDonnell Douglas Corporation at St. Louis, Missouri. The fighter has outstanding acceleration and maneuverability. It is 63 feet, 9 inches (19.431 meters) long, with a wingspan of 42 feet, 9.75 inches (13.049 meters) and overall height of 18 feet, 7.5 inches (5.677 meters).
The first pre-production prototype McDonnell Douglas F-15 Eagle, YF-15A-1-MC 72-0280, on its first flight near Edwards Air Force Base, California, 27 July 1972. (U.S. Air Force)
The wings’ leading edges are swept to 45°. The angle of incidence is 0°. The wings have 1° anhedral. The total wing area is 608 square feet (56.5 square meters).
The F-15A has an empty weight of 25,780 pounds (11,694 kilograms), and maximum takeoff weight of 44,497 pounds (20,184 kilograms).
McDonnell Douglas YF-15A-1-MC Eagle 71-0280, with a McDonnell Douglas RF-4C Phantom II chase plane, in flight near Edwards AFB. (U.S. Air Force)
The fighter was powered by two Pratt & Whitney JTF22A-25A (F100-PW-100) turbofan engines. The F100 is a two-spool, axial-flow afterburning turbine engine with a 3-stage fan section; 10-stage compressor; single chamber combustion section; and 4-stage turbine (2 low- and 2 high-pressure stages). The F100-PW-100 has a maximum continuous power rating of 12,410 pounds of thrust (55.20 kilonewtons) and intermediate rating of 14,690 pounds (65.34 kilonewtons), (30 minute limit). Its maximum power rating is 23,840 pounds (106.05 kilonewtons) with afterburner (5 minute limit). The F100-PW-100 is 16 feet, 4.3 inches (4.986 meters) long, 3 feet, 10.5 inches (1.181 meters) in diameter, and weighs 3,179 pounds (1,442 kilograms).
An early production McDonnell Douglas F-15A-8-MC Eagle, 73-0090, at Luke Air Force Base, Arizona. The fighter is painted “air superiority blue.” (U.S. Air Force)
The Eagle is a Mach 2.5+ fighter. The cruise speed of the F-15A Eagle is 502 knots (578 miles per hour/930 kilometers per hour). It has a maximum speed of 1,434 knots (1,650 miles per hour/2,656 kilometers per hour) at 45,000 feet (13,716 meters)—Mach 2.503. The service ceiling is 63,050 feet (19,218 meters). It can climb 67,250 feet per minute (342 meters per second), and with a thrust-to-weight ratio of 1.15:1, the fighter could climb straight up.
The The F-15A’s combat radius is 638 nautical miles (734 statute miles/1,182 kilometers). Its maximum ferry range is 2,362 nautical miles (2,718 statute miles/4,374 kilometers).
A McDonnell Douglas F-15 Eagle over the White Sands Missile Range banks away from the camera to display its air-to-air missile armament, 1 May 1980.. (Technical Sergeant Frank Garzelnick, U.S. Air Force)
The F-15A is armed with one General Electric M61A1 Vulcan 20mm rotary cannon with 938 rounds of ammunition, four AIM-7F Sparrow radar-guided missiles and four AIM-9E/L Sidewinder infrared-homing missiles. The fighter could also carry a variety of bombs.
There were 12 pre-production F-15 aircraft, serial numbers 71-0280–71-0291. 384 F-15A fighters were built from 1972 to 1979, before production switched to the improved F-15C. The last F-15A Eagle in U.S. Air Force service, F-15A-19-MC 77-0098, was retired from the Oregon Air National Guard, 16 September 2009.
The last McDonnell Douglas F-15A Eagle in U.S. Air Force service. F-15A-19-MC 77-0098, prepares for its final flight from Portland, Oregon, to Davis-Monthan AFB, 16 September 2009. The pilot was LCOL Steve Beauchamp, 123rd Fighter Squadron, 142nd Fighter Wing, Oregon Air National Guard. (U.S. Air Force) 09016-F-8260H-184
The first YF-15A, 71-0280, is on display at Lackland Air Force Base, Texas.
Chief Test Pilot Fritz Wendel with the Messerschmitt Me 262 V3 prototype, PC+UC. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)Test Pilot Fritz Wendel (left) talks with Willy Messerschmitt after the maiden flight of Me 262 V3, 18 July 1942.
18 July 1942: In the late 1930s, Germany began developing a fighter powered by a turbojet engine. In early 1942 the first two prototypes of the Messerschmitt Me 262 began flight testing. They had two BMW 003 jet engines mounted on the wings, but for safety, a piston engine and propeller were mounted in the nose.
At 8:40 a.m. on 18 July 1942, V3, the third prototype, call sign PC+UC, made its first pure-jet flight when it took off from Leipheim, Bavaria, with Messerschmitt’s Chief Test Pilot, Flugkapitän Fritz Wendel. (The first true turbojet-powered aircraft, the Heinkel He 178 V-1, first flew almost three years earlier, 27 August 1939).
This prototype was powered by two Junkers Jumo 004 turbojet engines. The Jumo 004 had an eight-stage axial flow compressor, six straight through combustion chambers and a single-stage turbine. It produced 1,850 pounds of thrust (8.23 kilonewtons).
Messerschmitt Me 262 V3, PC+UC, takes off on its first flight at Leipheim, 18 July 1942.
There were problems created by the airplane’s use of a tailwheel configuration. Turbulence from the wings and reflected jet exhaust blanked out the tail surface. When the Me 262 prototype reached flying speed, Wendel tapped the brakes. The tail popped up, free of the turbulence, and the jet fighter took off. Beginning with the fifth prototype, V5, all Me 262s were built with tricycle landing gear.
Messerschmitt Me 262 V3, PC+UC
The Messerchmitt Me 262 Schwalbe was the first production jet fighter, preceding the British Gloster Meteor Mk.III into operational service by about three months. It was a single-place, twin-engine airplane with the engines placed in nacelles under the wings. It was 10.6 meters (34 feet, 9.3 inches) long with a wingspan of 12.51 meters (41 feet, 5.2 inches) and overall height of 3.85 meters (12 feet, 7.6 inches). According to Fay, the fighter’s empty weight was 3,760 kilograms (8,289 pounds) and the maximum gross weight was 7,100 kilograms (15,653 pounds) at engine start.¹
The Me-262 wings had 6° dihedral. The leading edges were swept aft to 20°, while the trailing edges of the inner panels swept forward 8½° to the engine nacelle, then outboard of the engines, aft 5°. The purpose of the sweep was to keep the airplane’s aerodynamic center close to the center of gravity, a technique first applied to the Douglas DC-2. The total wing area was 21.7 square meters (233.6 square feet).
Messerschmitt test pilot Hans Fay told Allied interrogators that, for acceptance, the production Me 262 was required to maintain a minimum of 830 kilometers per hour (515 miles per hour) in level flight, and 950 kilometers per hour (590 miles per hour) in a 30° dive. The fighter’s cruise speed was 750 kilometers per hour (466 miles per hour).
A number of factors influenced the Me 262’s maximum range, but Fay estimated that the maximum endurance was 1 hour, 30 minutes. U.S. Air Force testing establish the range as 650 miles (1,046 kilometers) and service ceiling at 38,000 feet (11,582 meters).
The Jumo 004 was tested at the NACA Aircraft Engine research Laboratory, Cleveland, Ohio, in March 1946. (NASA)
The Me 262 A-1 was powered by two Junkers Jumo TL 109.004 B-1 turbojet engines. The 004 was an axial-flow turbojet with an 8-stage compressor section, six combustion chambers, and single-stage turbine. The 004 engine case was made of magnesium for light weight, but this made it vulnerable to engine fires. The engine was designed to run on diesel fuel, but could also burn gasoline or, more commonly, a synthetic fuel produced from coal, called J2. The engine was first run in 1940, but was not ready for production until 1944. An estimated 8,000 engines were built. The 004 B-1 idled at 3,800 r.p.m., and produced 1,984 pounds of thrust (8.825 kilonewtons) at 8,700 r.p.m. The engine was 2 feet, inches (0.864 meters) in diameter, 12 feet, 8 inches (3.861 meters) long, and weighed 1,669 pounds (757 kilograms).
Cutaway illustration of Jumo 004 engine.
The Me 262 A-1 was armed with four Rheinmetall-Borsig MK 108 30 mm autocannons with a total of 360 rounds of ammunition. (The Me 262 A-2 had just two autocannons with 160 rounds.) It could also be armed with twenty-four R4M Orkan 55 mm air-to-air rockets. Two bomb racks under the fuselage could each be loaded with a 500 kilogram (1,102 pounds) bomb.
1,430 Me 262s were produced. They first entered service during the summer of 1944. Luftwaffe pilots claimed 542 Allied airplanes shot down with the Me 262.
Messechmitt Me 262A-1, WNr. 1117111. (U.S. Air force)
