17 February 1996, 20:43:27 UTC

NEAR/Delta II lifts off from Cape Canaveral Air Force Station Launch Complex 17 at 3:30 a.m., EST, 17 February 1996. (NASA)
NEAR/Delta II D232 lifts off from Cape Canaveral Air Force Station Launch Complex 17 at 3:43 a.m., EST, 17 February 1996. (NASA)

17 February 1996, 20:43:27 UTC: The National Aeronautics and Space Administration/Johns Hopkins University Applied Physics Laboratory space probe NEAR—Near Earth Asteroid Rendezvous—was launched aboard a three-stage McDonnell Douglas Delta II rocket from Launch Complex 17 at the Cape Canaveral Air Force Station, Cape Canaveral, Florida.

The purpose of the 5-year-long mission was to study several near-Earth asteroids, including 253 Mathilde and 433 Eros.

The space probe was renamed NEAR Shoemaker in honor of Eugene Merle (“Gene”) Shoemaker, Ph.D., a well-known planetary scientist who dies in a vehicle collision in Australia, 18 July 1997.

Near-Earth Asteroid 253 Mathilde photographed from a distance of 1,200 kilometers, 27 June 1997. (NASA)

NEAR Shoemaker made its closest approach to 253 Mathilde on 27 June 1997, passing the asteroid at a distance of approximately 1,200 kilometers (746 miles) at 35,748 kilometers per hour (22,213 miles per hour). More than 500 photographic images, along with sensor data, were transmitted to Earth. The space probe’s main engine was then ignited to send it on a new trajectory to 433 Eros.

NEAR Shoemaker was placed into an orbit around 433 Eros on 14 February 2000. NEAR Shoemaker photographed and studied the asteroid for nearly a year, and then on 12 February 2001, after completing 230 orbits, made a soft landing on its surface.

Near-Earth asteroid 433 Eros photographed by the NEAR-Shoemaker space probe. (NASA)

The McDonnell Douglas Delta II 7925-8 Orbital Launch Vehicle is a three-stage, liquid-fueled rocket. It is 125 feet, 4 inches (38.201 meters) long, 8 feet, 0 inches (2.438 meters) in diameter, and weighs approximately 480,000 pounds (217,724 kilograms). At the time, the Delta II was the smallest rocket used to launch a planetary mission.

The first stage is a Thor/Delta XLT-C (“long-tank Thor”), which is 85 feet, 5½ inches (26.048 meters) long, 8 feet, 0 inches (2.438 meters) in diameter, and weighs 224,600 pounds (101,877 kilograms) when fully fueled. The stage is powered by one liquid-fueled Rocketdyne RS-27A rocket engine, rated at 236,992 pounds of thrust (1,054.193 kilonewtons). Fueled with 10,000 gallons (37,854 liters) of RP-1/LOX propellant and oxidizer, the engine has 4 minutes, 25 second burn time.

Surrounding the Thor are nine Alliant Techsytems (ATK) GEM-40 (Graphite-Epoxy Motor) solid fuel boosters. They are 42 feet, 6 inches (12.957 meters) long, and 3 feet, 4 inches (1.018 meters) in diameter, and weigh 28,671 pounds ( kilograms). Each booster produces 110,800 pounds of thrust (492.863 kilonewtons), and have 1 minute, 4 second burn time. Six of the nine GEM-40s are ignited at launch, and the remaining three ignite after the first six burn out.

The second stage is a McDonnell Douglas Delta K, which is 19 feet, 3 inches (5.867 meters) long, 8 feet, 0 inches (2.438 meters) in diameter, and weighs 15,331 pounds ( kilograms). The Delta K is powered by one Aerojet AJ10-118K liquid-fueled rocket engine which produces 9,800 pounds of thrust (43.593 kilonewtons). It has a 7 minute, 11 second burn time.

The third stage is a McDonnell Douglas PAM-D (Payload Assist Module), powered by a Thiokol Propulsion Star 48B solid rocket motor, which produces 15,000 pounds of thrust (66.723 kilonewtons), and has a burn time of 1 minute, 27 second burn time.

NEAR space probe inside a protective cover. A man at the lower left of the image provides scale. (NASA)
NEAR space probe inside a protective payload fairing. A man at the lower left of the image provides scale. (NASA)

The NEAR space probe was designed and built by the Johns Hopkins University Applied Physics Laboratory. The probe was equipped with an X-ray/gamma ray spectrometer, near-infrared imaging spectrometer and a multi-spectral CCD imaging camera, laser rangefinder and magnetometer. NEAR was 9 feet, ¼-inch (2.749 meters) long and weighed 1,803 pounds (817.8 kilograms). Power was supplied by four solar panels, capable of generating 400 watts.The main engine produced 450 Newtons (101 pounds) of thrust using hydrazine and nitrogen tetroxide. A system of 11 hydrazine thrusters and 4 reaction wheels  were used attitude control.

© 2019, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

17 February 1956

Lockheed YF-104A, 55-2955. (AFFTC History Office)

17 February 1956: Test pilot Herman Richard (“Fish”) Salmon made the first flight of the Lockheed YF-104A service test prototype, Air Force serial number 55-2955 (Lockheed serial number 183-1001). This airplane, the first of seventeen pre-production YF-104As, incorporated many improvements over the XF-104 prototype, the most visible being a longer fuselage.

Lockheed test pilots Anthony W. (“Tony”) LeVier, on the left, and Herman R. (“Fish”) Salmon, circa 1957. An F-104 Starfighter is in the background. (Jet Pilot Overseas)

On 28 February 1956, YF-104A 55-2955 became the first aircraft to reach Mach 2 in level flight.

The YF-104A was later converted to the production standard and redesignated F-104A.

Lockheed XF-104. (Lockheed-Martin)
Lockheed YF-104A Starfighter 55-2955 (183-1001), right profile. Note the increased length of the fuselage and revised air intakes, compared to the XF-104, above. Also, the XF-104’s nose gear retracts backward, while the YF-104A’s gear swings forward. (U.S. Air Force)

The Lockheed F-104A Starfighter is a single-place, single-engine, Mach 2 interceptor. It was designed by a team lead by the legendary Clarence L. “Kelly” Johnson. The F-104A is 54.77 feet (16.694 meters) long with a wingspan of 21.94 feet (6.687 meters) and overall height of 13.49 feet (4.112 meters). The total wing area is just 196.1 square feet (18.2 square meters). At 25% chord, the wings are swept aft 18° 6′. They have 0° angle of incidence and no twist. The airplane has a very pronounced -10° anhedral. An all-flying stabilator is placed at the top of the airplane’s vertical fin, creating a “T-tail” configuration.

The F-104A had an empty weight of 13,184 pounds (5,980.2 kilograms). The airplane’s gross weight varied from 19,600 pounds to 25,300 pounds, depending on the load of missiles and/or external fuel tanks.

Internal fuel capacity was 896 gallons (3,392 liters). With Sidewinder missiles, the F-104A could carry two external fuel tanks on underwing pylons, for an additional 400 gallons (1,514 liters). If no missiles were carried, two more tanks could be attached to the wing tips, adding another 330 gallons (1,249 liters) of fuel.

Lockheed F-104A Starfighter three-view illustration with dimensions. (Lockheed Martin)

The F-104A was powered by a single General Electric J79-GE-3B, -11A or -19 engine. The J79 is a single-spool, axial-flow, afterburning turbojet, which used a 17-stage compressor and 3-stage turbine. The J79GE-3B has a continuous power rating of 8,950 pounds of thrust (39.81 kilonewtons) at 7,460 r.p.m. Its Military Power rating is 9,600 pounds (42.70 kilonewtons) (30-minute limit), and 15,000 pounds (66.72 kilonewtons) with afterburner (5-minute limit). The engine is 17 feet, 3.2 inches (5.263 meters) long, 2 feet, 8.6 inches (0.828 meters) in diameter, and weighs 3,225 pounds (1,463 kilograms).

The F-104A had a maximum speed of  1,150 knots (1,323 miles per hour/2,130 kilometers per hour) at 35,000 feet (10,668 meters). The Starfighter’s initial rate of climb was 60,395 feet per minute (306.8 meters per second) and its service ceiling was 59,600 feet (18,166 meters).

The Lockheed F-104 was armed with an electrically-powered General Electric T-171E-3 (later designated M61) Vulcan 6-barrel rotary cannon, or “Gatling Gun.” The technician has a belt of linked 20 mm cannon shells. (SDASM)

Armament was one General Electric M61 Vulcan six-barreled revolving cannon with 725 rounds of 20 mm ammunition, firing at a rate of 4,000 rounds per minute. An AIM-9B Sidewinder infrared-homing air-to-air missile could be carried on each wing tip.

Lockheed YF-104A 55-2955 with landing gear retracting. (Lockheed Martin via International F-104 Society)

Lockheed built 153 of the F-104A Starfighter initial production version. A total of 2,578 F-104s of all variants were produced by Lockheed and its licensees, Canadair, Fiat, Fokker, MBB, Messerschmitt,  Mitsubishi and SABCA. By 1969, the F-104A had been retired from service. The last Starfighter, an Aeritalia-built F-104S ASA/M of the  Aeronautica Militare Italiana, was retired in October 2004.

While conducting flame-out tests in 55-2955, 25 April 1957, Lockheed  engineering test pilot John A. (“Jack”) Simpson, Jr., made a hard landing  at Air Force Plant 42, Palmdale, California, about 22 miles (35 kilometers) southwest of Edwards Air Force Base. After a bounce, the landing gear collapsed, and the Starfighter skidded off the runway. 55-2955, nick-named Apple Knocker, was damaged beyond repair. “Suitcase” Simpson was not hurt.

Lockheed F-104A 55-2955 was damaged beyond repair, 25 April 1967. (U.S. Air Force photograph via International F-104 Society))

© 2019, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

16 February 1967

Wilfried von Englehardt tests the Bölkow-Entwicklungen KG Bo-105 V-2, D-HECA in an out-of-ground effect hover, with engine cowlings removed, 16 February 1967. (Eurocopter)
Wilfried von Engelhardt tests the prototype Bölkow-Entwicklungen KG Bo-105 V-2, D-HECA, in an out-of-ground effect hover with engine cowlings removed, 16 February 1967. (Airbus Helicopters Deutschland GmbH)
Wilfried von Englehardt (Académie de l’Air et de l’Espace)
Wilfried von Engelhardt (Académie de l’Air et de l’Espace)

16 February 1967: At Ottobrun, Germany, test pilot Wilfried von Engelhardt made the first flight of the Bölkow-Entwicklungen KG Bo-105 prototype V-2, D-HECA, a twin-engine, rigid rotor helicopter. Baron von Engelhardt took off at 5:04 p.m. The flight lasted 20 minutes. D-HECA was the second prototype. The first one was destroyed by ground resonance during pre-flight testing.

Messerschmitt AG merged with Bölkow-Entwicklungen KG in June 1968, becoming  Messerschmitt-Bölkow. The following year, the new company merged with Blohm & Voss to become Messerschmitt-Bölkow-Blohm KG, or MBB. The Bo-105 A entered production in 1970. A number of civil and military variants followed.

The Bo-105 is a 5-place light helicopter powered by two turboshaft engines. It has a four-bladed rigid (or hingeless) main rotor. This gives it a high degree of maneuverability, and it is capable of performing aerobatic maneuvers. The two-bladed tail rotor is mounted high on a pylon and gives exceptional ground clearance for a helicopter of this size. There are two “clam shell” doors located at the rear of the cabin section, giving access to a large flat floor. The helicopter has been widely used by military, law enforcement and as an air ambulance.

Messerschmitt-Bölkow-Blohm Bo-105 V-2, D-HECA. (Eurocopter)
Bölkow-Entwicklungen KG prototype Bo-105 V-2, D-HECA, during flight testing. (Airbus Helicopters Deutschland GmbH )

The Bo-105 is 11,86 meters (38 feet, 10.9 inches ) long with rotors turning. The fuselage is 8,81 meters (28 feet, 10.9 inches) long, with a maximum width of 1,58 meters (5 feet, 2.2 inches). The helicopter’s overall height is 3.00 meters (9 feet, 10 inches). The helicopter has an empty weight of approximately 1,276 kilograms (2,813 pounds), depending on installed equipment, and maximum takeoff weight of 2,100–2,500 kilograms (5,512 pounds), depending on variant.

The diameter of the main rotor is 9,84 meters (32 feet, 3.4 inches). The main rotor follows the American practice of turning counter-clockwise as seen from above. (The advancing blade is on the right.) It operates at 416–433 r.p.m. (361–467 r.p.m. in autorotation). The tail rotor diameter is 1,90 meters (6 feet, 2.8 inches). It turns clockwise as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.)

Three-view illustration of the Messerschmitt-Bölkow-Blohm Bo-105 LS (lengthened cabin section). (Nordic Helicopters)

The prototype was powered by two Allison 250-C18 turboshaft engines, with increasingly more powerful 250-C20, -C20B and C-28C engines being added through the production run. The Allison 250-C18 is a 2-spool, reverse-flow, gas turbine engine with a 6-stage axial-flow, 1-stage centrifugal-flow, compressor section, and a 4-stage axial-flow turbine (2-stage gas producer, and 2-stage power turbine). The 250-C18 is rated at 317 shaft horsepower at 51,600 r.p.m., N1 (6,000 r.p.m. N2).

The helicopter’s cruise speed is 127 miles per hour (204 kilometers per hour) and maximum speed (VNE) is 135 knots (155 miles per hour/250 kilometers per hour) at Sea Level. The service ceiling is 17,000 feet (5,180 meters). The Bo-105 C has a maximum fuel capacity of 580.0 liters (153.22 U.S. gallons), of which 570.0 liters (150.58 U.S. gallons) are usable. The range is 691 miles (1,112 kilometers.

The original Type Certificate for the Bölkow Bo-105 A was issued 13 October 1970. Since then, the Bo-105 series has been produced in Germany, Canada, Spain, Indonesia and the Philippines. More than 1,500 were built.

Wilfried von Englehart tests the Bölkow-Entwicklungen KG Bo-105 V-2, D-HECA, at Ottobrun, Germany, 16 February 1967. (Eurocopter)
Wilfried von Engelhardt tests the Bölkow-Entwicklungen KG Bo-105 V-2, D-HECA, at Ottobrun, Germany, 16 February 1967. (Airbus Helicopters Deutschland GmbH)
Charles (“Chuck”) Aaron demonstrates the aerobatic capability of the Messerschmitt-Bölkow-Blohm Bo-105 CBS-4, N154EH. (Red Bull)
Baron von Engelhardt’s parents

Wilhelm Friedrich Franz Eugen Baron von Engelhardt was born at Schloss Liebenberg, north of Berlin, Germany, 11 September 1928. He was the son of the Rudolf Robert Baron von Engelhardt and Ingeborg Maria Alexandrine Mathilde Baroness Engelhardt (Gräfin zu Eulenbrug), and the grandson of Friedrich-Wend Fürst zu Eulenburg-Hertefeld, Count of Sandels.

Wilhelm von Engelhardt had an early interest in aviation.  His stepfather, Generalmajor Carl-August von Schoenebeck, a World War I ace, commanded the Luftwaffe flight test agency at Flugplatz Rechlin-Lärz, Rechlin, Germany. Von Englehardt was able to meet a number of well known German pilots, some of whom were guests at the family home. At the age of 16, he began flight training in gliders.

With the approach of the Soviet Red Army, von Engelhardt and his family fled to Austria. (General Shoenebeck was held as a prisoner of war until 1948.) He trained in hotel management in Salzburg. Following his release from Allied custody, General Schoenebeck formed Luftfahrt-Technik, a distributor for several aircraft manufacturers, including Hiller Helicopters.

With the assistance of General Schoenebeck, in the early 1950s von Engelhardt went to Paris, France, to train as a helicopter mechanic. He next became a helicopter pilot, then flight instructor, in 1958. He flew the Hiller 12, the Bell 47, and the gas turbine-powered Sud-Ouest Djinn. Von Engelhardt flew the SNCASE SE.3130 Alouette II in Papua New Guinea, 1961–1962, then returned to France where he trained as a test pilot at École du personnel navigant d’essais et de réception (EPNER) at Istres.

Von Engelhardt was recommended as test pilot for the Bölkow-Entwicklungen KG Bo-46, by the helicopter’s rotor system designer, Hans Derschmidt. The Bo-46 was an experimental high-speed helicopter. Von Engelhardt made the first liftoff of the prototype aircraft 14 February 1964.

Bölkow-Entwicklungen Bo-46 V-1, D-9514, with the Derschmidt rotor system. (Johan Visschedijk Collection, No. 6705/1000aircraftphotos.com)

Wilhelm von Engelhardt served as Bölkow’s chief test pilot, from 1962 to 1973. He then became the company’s sales director and director of customer service training.

With the Soviet occupation of eastern Germany, the village where Baron von Engelhardt was born was seized. It later came under the jurisdiction of the German Democratic Republic. Following the reunification of East and West Germany, the government of the Federal Republic of Germany held control of Schloss Liebenberg.

Schloss Liebenberg is now a hotel. (Michelin)

In 1996, without informing the local population, the Federal Office for Special Tasks Related to Unification, government’s privatization agency, placed the entire village, including the castle, the 13th century church, all the homes, farm buildings and stable, for sale. The asking price was so high that it was impossible for the villagers to come up with enough money to buy their home town. There was considerable outcry from the villagers, who said that they felt as if they, too, had been put on sale.

Baron von Engelhardt, who was living in a rented coach house on the estate that his family had owned for more than 300 years, gained international recognition for his attempts to negotiate a reasonable outcome.

With his wife, Evamaria, he edited and published Brücke über den Strom, (“Bridge over the Stream”), the letters of his cousin, Sigwart Botho Philipp August zu Eulenburg, Count of Eulenburg, a musical composer who was killed during World War I.

Wilhelm Friedrich Franz Eugen Baron von Engelhardt died 24 January 2015, at the age of 86 years.

Wilfried Baron von Englehardt 1928-2015)
Wilhelm Friedrich Franz Eugen Baron von Engelhardt (11 September 1928–24 January 2015)

© 2019, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

16 February 1946

The prototype Sikorsky S-51 commercial helicopter, NX19800, in flight between Bridgeport and East Hartford, Connecticut, 1946. (Sikorsky Historical Archive)
The prototype Sikorsky S-51 commercial helicopter, NX92800, in flight between Bridgeport and East Hartford, Connecticut, 1946. (Sikorsky Historical Archive)

16 February 1946: The Sikorsky S-51 prototype, NX92800, made its first flight. The test pilot was Dimitry D. (“Jimmy”) Viner, who later made the first civilian rescue using a helicopter. The S-51 was the first helicopter intended for commercial use, though it was also widely used by military services worldwide. (The prototype was later delivered to Aéronavale, French Naval Aviation.)

Dimitry D. ("Jimmy") Viner with a Sikorsky S-51, the civil version of the R-5. (Sikorsky Historical Archive)
Dimitry D. (“Jimmy”) Viner with a Sikorsky S-51, the civil version of the R-5. (Sikorsky Historical Archive)

The S-51 was a commercial version of the Sikorsky R-5 series military helicopters. It was a four-place, single engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.

The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)

Sikorsky S-51 three-view illustration with dimensions. (Sikorsky Historical Archives)

The helicopter’s fuselage was 41 feet, 1¾ inches (12.541 meters). The main rotor had a diameter of 48 feet, 0 inches (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.568 meters) giving the helicopter an overall length of 57 feet, ½ inch (17.386 meters). It was 12 feet, 11-3/8 inches (3.947 meters) high. The landing gear tread was 12 feet, 0 inches (3.658 meters).

The S-51 had an empty weight of 4,050 pounds (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).

Sikorsky S-51 NC92813, Los Angeles Airways, departs on a commercial flight, Los Angeles, California, 1947. (LAT)
Sikorsky S-51 NC92813, Los Angeles Airways, departs on a commercial flight, Los Angeles, California, 1947. (Los Angeles Times)

The helicopter was powered by a 986.749-cubic-inch-displacement (16.170 liter) air-cooled, supercharged, Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive,  nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.

The S-51 had a maximum speed (VNE) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).

Of 220 helicopters in the S-51 series built by Sikorsky, 55 were commercial models. Westland built another 159 helicopters under license.

One of Los Angeles Airways' Sikorsky S-51 helicopters takes off from roof of the the Terminal Annex Post Office, Los Angeles, California, 1 October 1947. (Los Angeles Times Photographic Archive/UCLA Library)
One of Los Angeles Airways’ Sikorsky S-51 helicopters takes off from roof of the the Terminal Annex Post Office, Los Angeles, California, 1 October 1947. (Los Angeles Times Photographic Archive/UCLA Library)
Dimitry D. Viner, circa 1931

Дмитро Дмитрович Вінер (Dimitry Dimitry Viner) was born in Kiev, Ukraine, Imperial Russia, 2 October 1908. He was the son of Dimitry Nicholas Weiner and Helen Ivan Sikorsky Weiner, a teacher, and the sister of Igor Ivanovich Sikorsky.

At the age of 15 years, Viner, along with his mother and younger sister, Galina, sailed from Libau, Latvia, aboard the Baltic-American Line passenger steamer S.S. Latvia, arriving at New York City, 23 February 1923.

“Jimmy” Viner quickly went to work for the Sikorsky Aero Engineering Company, founded by his uncle, Igor Sikorsky.

Dimitry Viner became a naturalized United States citizen  on 27 March 1931.

Viner married Miss Irene Regina Burnett. The had a son, Nicholas A. Viner.

On 29 November 1945, Jimmy Viner and Captain Jackson E. Beighle, U.S. Army, flew a Sikorsky YR-5A to rescue two seamen from an oil barge which was breaking up in a storm off of Fairfield, Connecticut. This was the first time that a hoist had been used in an actual rescue at sea.

A Sikorsky R-5 flown by Jimmy Viner with Captain Jack Beighle, lifts a crewman from Texaco Barge No. 397, aground on Penfield Reef, 29 November 1945. (Sikorsky Historical Archive)

In 1947, Viner became the first pilot to log more than 1,000 flight hours in helicopters.

Dimitry Dimitry Viner died at Stratford, Connecticut, 14 June 1998, at the age of 89 years.

© 2019, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

16 February 1932

Martin XB-907 in flight. (U.S. Air Force)

16 February 1932: First flight, Glenn L. Martin Co. Model 123, designated XB-907 by the U. S. Army Air Corps. It was powered by two Wright Cyclone SR-1820-E engines rated at 600 horsepower, each. The engines were covered by Townend rings to reduce drag and improve cooling.

Martin XB-907

The prototype was tested at Wright Field.  The airplane reached a maximum speed of 197 miles per hour (317 kilometers per hour) at 6,000 feet (1,829 meters). Recommendations for modifications were made, and Martin upgraded the prototype to the XB-907A configuration (Martin Model 139), which was then designated XB-10 by the Air Corps, with the serial number 33-139.

Martin XB-907A, right profile. (U.S. Air Force)

Martin increased the XB-907A’s wingspan from 62 feet, 2 inches (18.948 meters) to 70 feet, 7 inches (21.514 meters). The engines were upgraded to Wright R-1820-19s, rated at 675 horsepower. Full NACA cowlings were installed.

The Army then ordered 48 production airplanes.

The XB-907 would be developed into the Martin B-10 bomber.

U.S. Army Air Corps Martin B-10B of the 28th Bombardment Squadron, Philippine Islands 28 November 1939. (U.S. Air force)

© 2019, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather