Tag Archives: Glenn L. Martin Company

20 December 1934

December 20, 2024AviationFirst Flight, Flying Boat, Glenn L. Martin Company, Martin M-130, Pan American Airways System, Pratt & Whitney Twin Wasp S2A5-G, Prototype, William K. ("Ken") EbelBryan Swopes

“This photograph of the Clipper, aloft at the mouth of the Middle River, was taken from another plane by Robert F. Kniesche, Sun staff photographer.” (The Sun (Baltimore), Vol. 196–D, Friday 21 December 1934, Page 30, Columns 3–5 )

20 December 1934: William K. (“Ken”) Ebel lifted off from Middle River, Maryland, taking the Martin M-130 “Clipper” for its first flight. The M-130 was airborne for approximately 1 hours. Flying at 1,200 feet (366 meters), it reached 160 miles per hour (257 kilometers per hour).

Three-view illustration of the Martin M-130. (Flight, The Aircraft Engineer & Airships, Vol. XXVII, No. 1361, 24 January 1935, Page 99)

NC14716, named China Clipper, was the first of three Martin M-130 four-engine flying boats built for Pan American Airways. It was used to inaugurate the first commercial transpacific air service from San Francisco to Manila in November, 1935. Built at a cost of $417,000 by the Glenn L. Martin Company in Baltimore, Maryland, it was delivered to Pan Am on October 9, 1935.

The airplane was operated by a flight crew of 6 to 9, depending on the length of the flight, plus cabin staff, and could carry 18 passengers on overnight flights or a maximum 36 passengers.

Cutaway illustration of Pan American Airways’ Martin M-130 China Clipper. (Detail from larger image. NASM SI-89-1216-A. Full image at: https://airandspace.si.edu/multimedia-gallery/7135hjpg)

The Martin M-130 was 90 feet, 10.5 inches (27.699 meters) long with a wingspan of 130 feet, 0 inches (39.624 meters). It was 24 feet, 7 inches (7.493 meters) high. The total wing area was 2,315 square feet (215 square meters), including the “sea wings”. Its maximum takeoff weight was 52,252 pounds (23,701 kilograms).

Martin M-130 under construction, 24 May 1934. (SFO Museum)

The flying boat was powered by four air-cooled, supercharged Pratt & Whitney Twin Wasp S2A5-G two-row 14-cylinder radial engines with a compression ratio of 6.7:1. They had a normal power rating 830 horsepower at 2,400 r.p.m., and 950 horsepower at 2,550 r.p.m. for takeoff. They drove three-bladed Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The S2A5-G was 3 feet, 11.88 inches (1.216 meters) in diameter, 4 feet, 8.75 inches (1.441 meters) long, and weighed 1,235 pounds (560 kilograms).

The airplane had a cruise speed of 130 miles per hour (209 kilometers per hour) and a maximum speed of 180 miles per hour (290 kilometers per hour). The M-130’s service ceiling was 10,000 feet (3,048 meters). Its range was 3,200 miles (5,150 kilometers).

A Martin M-130, X14714, undergoing ground testing at the Glenn L. Martin Co. plant at Middle River, Maryland, 30 November 1934. (Lockheed Martin)

Martin M-130 X14714, 30 November 1934. (SFO Museum)

William Kenneth Ebel was born at Orangeville, Illinois, 2 January 1899. He was the first of two sons of Willam Henry Ebel, a farmer, and Nora Agnes Rubendall Ebel.

Ken Ebel attended Heidelberg College at Tiffin, Ohio. While at Heidelberg, on 1 October 1918, he enlisted as a private in the Student Army Training Corps (S.A.T.C.). With World War I coming to an end in November, Private Ebel was discharged 20 December 1918. Ebel graduated from Heidelberg in 1921 with a bachelor of arts degree.

Ebel returned to military service, enlisting as a private in the 104th Squadron (Observation), Maryland National Guard, based at Baltimore, Maryland.

Ebel continued his college education at the Case School of Applied Science in Cleveland, Ohio. In 1923, he earned a bachelor of science degree in mechanical engineering (B.S.M.E.)

On 11 September 1923, Private Ebel was appointed an aviation cadet, graduating from primary flying school on 3 June 1924. He received a commission as a 2nd lieutenant, Officers Reserve Corps (O.R.C.), United States Army, on 12 June 1925.

Continuing to serve as a reserve officer, in 1926 Ebel went to work as an engineer for the Glenn L. Martin Company, then located in Cleveland, Ohio. As a test pilot and engineer, Ebel flew the Martin M-130 four-engine flying boar

2nd Lieutenant Ebel,still with the 104th Squadron, Maryland National Guard, was promoted to the rank of 1st lieutenant on 21 December 1928. The U.S. Army advanced his rank to 1st lieutenant, Air Corps, 15 February 1929.

On 21 October 1929, William K. Ebel married Miss Florence E. Sherck at Seneca, Ohio. They would have two children, William Kenneth, Jr., and Lydia Lynn Ebel.

While testing a Martin BM-2 dive bomber, on 11 August 1932, W.K. Ebel “leaped to safety in a parachute Friday when a bombing plane he was testing failed to come out of a spin and crashed at Dahlgren, Virginia. The plane was going through its final tests before being delivered to the navy. It was wrecked in the crash.” Ebel became Member No. 495 of The Caterpillar Club.

On Thursday, 20 December 1934, Chief Pilot Ken Ebel took the new four-engine Martin M-130 flying boat, Pan American Airways System’s Hawaii Clipper, for its first flight from Middle River, Maryland. He also made the first flight of the M-156 “Russian Clipper” in 1935.

Ebel was promoted to captain, Air Corps, on 5 January 1935. On 21 August, he delivered the new Martin Model 146 “mystery bomber” to Wright Field for evaluation by the Bombardment Board.

In 1948, Ken Ebel became director of the Airplane Division of the Curtiss-Wright Corporation in Columbus, Ohio. Soon after, Curtiss-Wright sold its airplane division to North American Aviation. In 1950, the U.S. Navy’s primary submarine builder, the Electric Boat Company, appointed Ebel as Vice Pressident of Engineering for its Canadair Ltd., aircraft manufacturing subsidiary in Montreal, Quebec, Canada. (In 1952, after acquiring Convair, the corporation reorganized as General Dynamics.

Ebel returned to the United States in 1961 and served as a consultant for General Dynamics in Washington, D.C. Ebel retired in 1963, purchasing the Mount Pleasant Orchards near Baltimore.

Mrs. Ebel died in 1968. He later married Helene H. Topping.

William Kenneth Ebel, Ph.D., died at the Greater Baltimore Medical Center, 12 July 1972.

27 November 1933

November 27, 2024Aviation33-140, Bomber, c/n 508, Glenn L. Martin Company, Martin B-10B, Martin Model 123, Martin Model 139, Martin XB-907, Martin XB-907A, Martin YB-10, Wright Aeronautical Division R-1820-25, Wright Cyclone SGR-1820-F2Bryan Swopes

Martin YB-10 (Model 139), 33-140. (U.S. Air Force)

27 November 1933: The United States Army Air Corps accepted the Glenn L. Martin Company’s first service test YB-10 bomber, serial number 33-140. This was the first all-metal monoplane bomber with an internal bomb bay, retractable landing gear, rotating gun turret and enclosed cockpit. It flew faster than pursuit aircraft of the day.

The prototype Martin Model 123 (XB-907) in flight, 1932. (U.S. Air Force)

There had been a single prototype, the Martin Model 123. It was powered by two Wright R-1820-19 engines rated at 600 horsepower, each. This was designated XB-907 by the U.S. Army Air Corps when tested at Wright Field in 1932. Recommendations for modifications were made, and Martin upgraded the prototype to the XB-907A configuration, which was then designated XB-10 by the Air Corps. The Army then ordered 48 production airplanes.

Martin XB-907A (XB-10 33-139). (U.S. Air Force)

The first group of 14 airplanes were designated YB-10. The YB-10 (Martin Model 139) had enclosed canopies for the pilot and top gunner, and a nose turret. The crew consisted of a pilot, radio operator and three gunners.

These airplanes were powered by two air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.876 liter) Wright Cyclone SGR-1820-F2 (R-1820-25) 9-cylinder radial engines with a compression ratio of 6.4:1, which were rated at 750 horsepower at 1,950 r.p.m. at Sea Level. The engines turned three-bladed Hamilton Standard adjustable-pitch propellers through a 16:11 gear reduction. The R-1820-25 was 3 feet, 11–13/16 inches (1.214 meters) long, 4 feet, 5-¾ inches (1.365 meters) in diameter, and weighed 1,047 pounds (475 kilograms).

Martin YB-10 at Wright Field, 1933. (U.S. Air Force)

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

Martin YB-10, left profile. (U.S. Air Force)

Martin YB-10, right rear quarter view. (U.S. Air Force)

The bomber could carry two 1,130 pound (513 kilogram) bombs, or five 300 pound (136 kilogram) bombs in its internal bomb bay. Alternatively, a 2,000 pound (907 kilogram) bomb could be carried externally. There were three .30-caliber (7.62 mm) Browning M1919 machine guns for defense.

Martin B-10B in flight. (U.S. Air Force)

The first full scale production version was the B-10B, which was very similar to the service test YB-10s. These airplanes were 44 feet, 9 inches (13.640 meters) long with a wingspan of 70 feet, 6 inches (21.488 meters) and height of 15 feet, 5 inches (4.670 meters). The B-10B had an empty weight of 9,681 pounds (4,391 kilograms).

The engines installed in this variant were Wright Cyclone SGR-1820-F3 (R-1820-33), rated at 700 horsepower at 1,950 r.p.m. at Sea Level. Dimensions, weight and propeller gear reduction for this engine are the same as the R-1820-25, above.

The B-10B had a cruising speed of 193 miles per hour (311 kilometers per hour), and maximum speed of 213 miles per hour (343 kilometers per hour) at 10,000 feet (3,048 meters).

33-140 was converted to a B-10M for towing aerial targets and was assigned to the Tow Target Detachment at March Field, Riverside, California. Piloted by Robert E. Phillips, 33-140 was damaged in a taxiing accident, 8 April 1942.

25 November 1940

November 25, 2024Aviation40-1361, Al Malewski, B-26-MA, Bomber, c/n 1226, Ed Fenimore, First Flight, Glenn L. Martin Company, Martin B-26 Marauder, Martin M-130, Martin XPB2M-1 Mars, Medium Bomber, Middle River, Pratt & Whitney R-2800-5, Test Pilot, William K. ("Ken") Ebel, World War IIBryan Swopes

25 November 1940: Glenn L. Martin Company’s engineer and test pilot William Kenneth 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 engines idling. (U.S. Air Force)

The B-26 Marauder was 58 feet, 2.5 inches (17.742 meters) long with a wingspan of 65 feet, 0 inches (19.812 meters) ¹ and overall height of 19 feet, 10.3 inches (6.053 meters). At the root, the wings’ chord was 12 feet, 10.5 inches (3.924 meters), with an angle of incidence of 3° 30′. The wing center section had no dihedral, while the the outer panels had +1° 17′. The total wing area was 602 square feet (56 square meters). The bomber 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, constant-speed 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 326 miles per hour (525 kilometers per hour) at 14,250 feet (4,343 meters) with the engines turning 2,400 r.p.m. Its service ceiling was 25,000 feet (7,620 meters), and the absolute ceiling was 26,200 feet (7,986 meters).

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,” and also had several less polite nicknames. 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 of the wingspan and the size of the vertical fin and rudder. At the same time, an emphasis was made on airspeed control during training. During World War II, the Marauder had the lowest rate of combat losses of any American bomber.

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

201 B-26s were built before production switched to the B-26A. Glenn L. Martin Co. produced 5,288 Marauders between 1941 and 1945, with manufacturing taking place at Middle River, Maryland, and Omaha, Nebraska. The Marauder served in the Pacific, Mediterranean and European combat areas, with both the United States and several Allied nations. 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)

William Kenneth Ebel was born at Orangeville, Illinois, 2 January 1899. He was the first of two sons of Willam Henry Ebel, a farmer, and Nora Agnes Rubendall Ebel.

Ebel returned to military service, enlisting as a private in the 104th Squadron (Observation), Maryland National Guard, based at Baltimore, Maryland.

Ebel continued his college education at the Case School of Applied Science in Cleveland, Ohio. In 1923, he earned a bachelor of science degree in mechanical engineering (B.S.M.E.)

On 21 October 1929, William K. Ebel married Miss Florence E. Sherck at Seneca, Ohio. They would have two children, William Kenneth, Jr., and Lydia Lynn Ebel.

Martin M-130 NX14714 during engine testing. (Glenn L. Martin Co.)

Ebel was promoted to captain, Air Corps, on 5 January 1935. On 21 August, he delivered the new Martin Model 146 “mystery bomber” to Wright Field for evaluation by the Bombardment Board.

The Martin Model 146 medium bomber prototype at Wright Field for evaluation, 1935. (Ray Wagner Collection, San Diego Air & Space Museum Archives)

In 1942, Ken Ebel earned a doctorate (Ph.D.) in engineering from the Case School of Applied Science.

On 3 July 1942, Ken Ebel took the Martin XPB2M-1 Mars flying boat prototype for its first flight.

Martin XPB2M-1 Mars taxi test, 1942. (Charles M. Daniels Collection, San Diego Air & Space Museum Archives)

Ebel returned to the United States in 1961 and served as a consultant for General Dynamics in Washington, D.C. Ebel retired in 1963, purchasing teh Mount Pleasant Orchards near Baltimore.

Mrs. Ebel died in 1968. He later married Helene H. Topping.

William Kenneth Ebel, Ph.D., died at the Greater Baltimore Medical Center, 12 July 1972.

¹ The wing span was increased to 71 feet, 0 inches (21.641 meters) with the B-26B-10-MA.

22 November 1935

November 22, 2024AviationAir Mail, Airliner, c/n 558, China Clipper, Edwin Charles Musick, Flying Boat, Frederick Joseph Noonan, Glenn L. Martin Company, Martin M-130, NC14716, Pan American Airways, Robert Oliver Daniel Sullivan, Trans-Pacific Flight, Transoceanic FlightBryan Swopes

22 November 1935: The Pan American Airways flying boat, China Clipper, a Martin M-130, NC14716, departed Alameda, California (an island in San Francisco Bay) at 3:46 p.m., Friday, and arrived at Honolulu at 10:39 a.m., Saturday, completing the first leg of a five-day trans-Pacific flight to Manila in the Philippine Islands.

The aircraft commander was Captain Edwin Charles Musick, with First Officer Robert Oliver Daniel (“Rod”) Sullivan. The navigator was Frederick Joseph Noonan, who would later accompany Amelia Earhart on her around-the-world flight attempt. There were also a Second Officer and two Flight Engineers. The cargo consisted of 110,000 pieces of U.S. Mail.

Captain Edwin Musick and R.O.D. Sullivan, at the center of the image, next to the China Clipper before leaving San Francisco Bay with the first transpacific airmail, 22 November 1935. The three men at the right of the image are (left to right) Postmaster General James Farley; Assistant Postmaster General Harllee Branch; and Pan American Airways’ President Juan Trippe.

Pan Am personnel called the Clipper “Sweet Sixteen,” referring to its Civil Aeronautics Board registration number, NC14716. The airplane and Humphrey Bogart starred in a 1936 First National Pictures movie, “China Clipper.”

NC14716 was the first of three Martin M-130 four-engine flying boats built for Pan American Airways and was used to inaugurate the first commercial transpacific air service from San Francisco to Manila in November, 1935. Built at a cost of $417,000 by the Glenn L. Martin Company in Baltimore, Maryland, it was delivered to Pan Am on October 9, 1935. The airplane’s serial number was 558.

Pan American Airways’ Martin M-130m China Clipper, NC14716, over San Francisco, California. (Clyde Herwood Sunderland, Jr./Library of Congress 94509045)

The M-130 was operated by a flight crew of 6–9, depending on the length of the flight, plus cabin staff, and could carry 18 passengers on overnight flights, or a maximum 36 passengers.

Cutaway illustration of Pan American Airways’ Martin M-130 China Clipper. Detail from larger image. (National Air and Space Museum SI-89-1216-A)

Martin M-130 NC14716, right rear quarter view.

Martin M-130, NC14716, China Clipper, moored at some distant exotic locale. (Unattributed)

18 September 1959, 05:20:07 UTC

September 18, 2024Space FlightAerojet General AJ10-37, Allegany Ballistics Laboratory JATO X-248 A2, Cape Canaveral Air Force Station, General Electric Hermes X-405, Glenn L. Martin Company, LC-18A, NASA, Satellite, Satellite Launch Vehicle, Three-Stage Rocket, Vanguard 3, Vanguard SLV-7, Vanguard TV-4BUBryan Swopes

Vanguard 3 is launched aboard Vanguard SLV-7 from Launch Complex 18A at the Cape Canaveral Air Force Station, 12:20:07 a.m., EST, 18 September 1959. (NASA Marshall Space Flight Center MSFC-9139356)

18 September 1959: At 12:20:07 a.m., Eastern Standard Time (05:20:07 UTC), a three-stage Vanguard Satellite Launch Vehicle lifted off from Launch Complex 18A at the Cape Canaveral Air Force Station on the eastern coast of Florida. The rocket placed a 50 pound (22.7 kilogram) scientific satellite, Vanguard 3 (also known as Vanguard III) into Earth orbit. Orbital injection occurred at 05:29:49, 9 minutes, 35 seconds after launch, at 27,195 feet per second (98,239 meters per second). The orbit was inclined 33.350°. The satellite’s perigee, the closest point in its orbit to Earth, was 512.00 kilometers (318.142 statute miles), and its apogee, 3,750.00 kilometers (2,330.142 statute miles). The orbital period was 2 hours, 10 minutes, 9 seconds.

Vanguard 3 being installed on the Vanguard SLV-7 launch vehicle by NASA engineer R.J. Andryshak (left) and D.R. Corbin. (NASA)

Contained inside the satellite’s 1 foot, 8.0 inch (50.8 centimeter) diameter magnesium spherical outer shell were sensors and transmitters. The satellite collected data on the Earth’s magnetic field, the Van Allen Radiation Belt, micrometeorite impacts on the satellite, and measured drag acting to slow the satellite in its orbit. The 2 foot, 2 inch (0.66 meter) cone-shaped structure at the top of the satellite contains a magnetometer.

Vanguard 3 transmitted data for 84 days before its batteries failed. It is estimated that it will remain in orbit around the Earth for 300 years.

The Vanguard Satellite Launch Vehicle was a three-stage rocket, using liquid fuel for the first and second stages, while the third stage used a solid fuel rocket motor. It was built by the Glenn L. Martin Company at Baltimore, Maryland. The rocket had a total length of 71 feet, 6.721 inches (21.8115 meters), including the payload fairing. SLV-7 (also known as TV-4BU) was an unused test article. The all-up vehicle weighed 23,143 pounds (10,497.488 kilograms) at the time of the firing signal.

A Vanguard rocket (TV-2) at the Cape Canaveral Air Force Station, Launch Complex 18A. (Dan Beaumont Space Museum)

The Vanguard first stage was powered by a General Electric Hermes X-405 (LR50-GE-1) engine, fueled by liquid oxygen and Shell Oil Company Jet B (a naptha-kerosene fuel used for turbojet engines in cold weather conditions). The propellant system was pressurized with helium. Hydrogen peroxide was used to drive the engine’s turbopump. The X-405 weighed 425 pounds (192.8 kilograms) and produced 27,835 pounds of thrust (123.816 kilonewtons) at Sea Level. The first stage was 39 feet, 7.243 inches (12.0712 meters) long and 3 feet, 9 inches (1,143 meters) in diameter. Its empty weight was 1,599 pounds (725.29 kilograms). The stage had a burn time of 2 minutes, 30 seconds.

The second stage was 18 feet, 7.54 inches (5.6779 meters) long and 2 feet, 8 inches (0.8128 meters) diameter, and had an empty weight 1,013 pounds (459.49 kilograms). It was powered by an Aerojet General AJ10-37 engine, fueled by a hypergolic mixture of white inhibited fuming nitric acid (WIFNA) and unsymmetrical dimethylhydrazine (UDMH). The engine weighed 386 pounds (175.09 kilograms). It produced 7,500 pounds (33.362 kilonewtons) thrust in vacuum. It had a burn time of 2 minutes.

The Vanguard SLV-7 third stage was 5 feet, 10.29 inches (1.7854 meters) long and 2 feet, 8 inches (0.8128 meters) in diameter. It weighed 50.9 pounds (23.09 kilograms) burn time 37 seconds. The engine was a solid fuel Allegany Ballistic Laboratory ¹ JATO X-248 A2, originally designed for rocket assisted takeoff for fixed wing aircraft. The engine was 4 feet, 10.2 inches (1.478 meters) long, 1 foot, 6.0 inches (0.457 meters) in diameter, and weighed 203 pounds (92.1 kilograms). It produced 3,070 pounds (13.656 kilonewtons) of thrust and had a burn time of 37 seconds.

Vanguard third stage X-248 A2 solid rocket motor (NASM A19680576000).

The satellite was enclosed in a conical phenolic plastic fairing, which had a titanium tip.. The fairing was 12 feet, 6.72 inches (3.8283 meters) long. The cone angled 20° from its axis.

Third stage was left attached to the satellite. The total mass placed in orbit was 94.6 pounds (42.91 kilograms).

¹ Allegany Ballistics Laboratory was a Naval Sea Systems Command (NAVSEA) facility, operated by the Hercules Powder Company.

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