Daily Archives: June 12, 2017

12 June 1994

Boeing test pilots John E. Cashman and Kenny Higgins with WA001 at Paine Field. (Boeing)
Boeing test pilots John E. Cashman and Kenny Higgins with WA001 at Paine Field. (Boeing)

12 June 1994: At 11:45 a.m., Boeing test pilots John E. Cashman and Kenny Higgins took the first Boeing 777-200 airliner, line number WA001, FAA registration N7771, on its first flight. Before taking off from Paine Field, Boeing’s president, Phil Condit, told Cashman, “Good luck, John. And no rolls!”, referring to the famous incident when Alvin M. “Tex” Johnston rolled the Model 367–80 prototype of the 707 airliner over Lake Washington, 6 August 1955.

The 777’s first test flight lasted 3 hours, 48 minutes. This was the longest first flight of any of Boeing’s airliners. It reached a maximum altitude of 19,000 feet (5,791 meters) and accomplished all tests on the flight plan, including shutting down and restarting an engine in flight.

Boeing 777-200 N7771, line number WA001, on its first flight, 12 June 1994. The chase plane is a Northrop T-38A Talon. (AP)
Boeing 777-200 N7771, line number WA001, on its first flight, 12 June 1994. The chase plane is a Northrop T-38A Talon. (AP)

The Boeing 777-200 is operated by two pilots and, depending on its configuration can carry 314 to 440 passengers. It is 209 feet, 1 inch (63.729 meters) long with a wingspan of 199 feet, 11 inches (60.935 meters) and overall height of 60 feet, 9 inches (18.517 meters). The fuselage has a diameter of 20 feet, 4 inches (6.198 meters). The airliner has an empty weight of 297,300 pounds (134,853 kilograms) and maximum takeoff weight of 545,000 pounds (247,208 kilograms).

WA001 was originally powered by two Pratt & Whitney PW4074 two-spool high-bypass-ratio turbofan engines which produce 77,000 pounds of thrust, each. Production airliners were equipped with PW4077 engines with the same thrust. General Electric and Rolls-Royce turbofans could also be ordered.

Boeing 777s have a cruise speed of 0.84 Mach (560 miles per hour, 901 kilometers per hour) and maximum speed of 0.89 Mach (590 miles per hour, 950 kilometers per hour). The service ceiling is 43,100 feet (13,137 meters). The 777-200 has a maximum range of 6,027 miles (9,700 kilometers) with maximum payload aboard.

Boeing 777 WA001, N7771. (Boeing)
Boeing 777 WA001, N7771. (Boeing)

The 777 series was the most comprehensively tested airplane in history. Nine aircraft were used in the test program. WA001 was in testing until April 1997, by which time it had accumulated 1,729 flight hours and another 1,033 hours of ground testing.

Purchased by Cathay Pacific, the first “Triple Seven” was completely refurbished and equipped for passenger service, configured as a 777-267. The engines were replaced by two Rolls-Royce RB211 Trent 884B-17 high-bypass turbofan engines. These engines are rated at 85,430 pounds of thrust for takeoff (5 minutes limit). Because of their lighter weight, the empty weight of the airliner was reduced approximately 7,500 pounds (3,400 kilograms). The airliner was rolled out of the factory for the second time 31 October 2000, and was delivered to the Cathay Pacific on 6 December. It is registered B-HNL, and remains in service.

Cathay Pacific's Boeing 777-267, Bankok, Thailand, 1 January 2014. (Teeawut Wongdee)
Cathay Pacific’s Boeing 777-267, B-HNL, landing at Bankok, Thailand, 1 January 2014. (Teerawut Wongdee)

The 777 was produced in the 777-200 configuration, followed the 777-200ER (“extended range”) and 777-200LR (“longer range”) variants, a longer 777-300ER and a 777F freighter. A tanker version has been proposed. Eighty-eight 777-200 airliners were built before production halted in favor of the -200ER and -200LR models.

More than 1,400 777s of all models have been delivered by Boeing. As of January 2016, there were 176 777-300ER and 42 777F freighters on order. Recently, Boeing cut the production rate from 100 “Triple-Sevens” per year to 84 airplanes. The next version is the 777-9X, planned for production in 2021.

Boeing 777 final assembly line. (archive.com)
Boeing 777 final assembly line. (archive.com)

© 2016, Bryan R. Swopes

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12 June 1979

Bryan Allen flies Gossamer Albatross across the English Channel.
Bryan Allen flies Gossamer Albatross across the English Channel. (Don Monroe via Bryan Allen)

12 June 1979: The human-powered airplane, Gossamer Albatross, built by AeroVironment, Inc., of Simi Valley, California, flew across the English Channel from The Warrens, near Folkstone, Kent, England, to Cap Griz-Nez, France, 22.26 miles (35.82 kilometers) in 2 hours, 49 minutes. He established two Fédération Aéronautique Internationale (FAI) World Record: Straight Distance, 35.82 kilometers (22.26 miles)¹ ; Duration, 2 hours, 49 minutes.²

The pilot/powerplant of Gossamer Albatross was long-distance bicyclist Bryan Lewis Allen. Allen pedaled at a constant 75 r.p.m.

Bryan Lewis and Paul Macready, London, 16 May 1979. (Getty Images/United News/Popperfoto)
Bryan Lewis and Paul MacCready, London, 16 May 1979. (Getty Images/United News/Popperfoto)
Gossamer Albatross arrives at France, 12 June 1978. (AeroEnvironment)
Gossamer Albatross arrives at France, 12 June 1978. (AeroEnvironment, Inc.

The aircraft was designed by Paul Beattie MacCready, Jr., Ph.D., and weighed just 70 pounds (31.8 kilograms), empty.

The two-way radio link failed right after takeoff. Unexpected winds made the flight an hour longer than planned and Allen used all of his water. Batteries powering the instruments ran down. A chase boat was prepared for Allen to abort the flight, but he continued to France.

Bryan Lewis Allen was born 13 October 1952 at Tulare, California. He attended Tulare Union High School and then College of the Sequoias and California State University, Bakersfield, earning a bachelor of science degree. Allen is employed as a software engineer for the Mars Reconnaissance Orbiter at the NASA Jet Propulsion Laboratory, Pasadena, California.

Paul Beattie MacCready, Jr., was born 29 September 1925. He graduated from Yale University with a bachelor’s degree in physics, and then earned a master’s in physics from the California Institute of Technology, Pasadena, California. In 1952, Caltech awarded MacReady a doctorate in aeronautics.

The Robert J. Collier Trophy. (Smithsonian Institution, National Air and Space Museum)
The Robert J. Collier Trophy. (Smithsonian Institution, National Air and Space Museum)

Dr. MacReady received the Collier Trophy for 1979 from the National Aeronautic Association, “For the concept, design and construction of the Gossamer Albatross, which made the first man-powered flight across the English Channel—with special recognition to Bryan Allen, the pilot.”

Dr. Paul B. MacReady died 25 August 2007 at Pasadena, California.

The Gossamer Albatross is a human-powered high-wing canard monoplane constructed primarily of carbon fiber tubing, expanded polystyrene foam, Mylar® and Kevlar®, with wire bracing. A single pilot in a gondola provides power to a two-bladed fixed-pitch propeller, pedaling at 75 r.p.m., through a bicycle-type gear-reduction drive mechanism.

The airplane is 50 feet, 6 inches (15.392 meters) long, with a wingspan of 93 feet, 10 inches (28.600 meters) and overall height of 16 feet, 4 inches (4.978 meters). It has an empty weight of 70 pounds (31.8 kilograms), and a gross weight at takeoff of 215 pounds (97.5 kilograms). Its maximum speed is 15 miles per hour (24 kilometers per hour).

Gossamer Albatross is in the collection of the Stephen F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum.

Gossamer Albatross at teh National Air and Space Museum. (NASM)
Gossamer Albatross at the National Air and Space Museum. (NASM)

¹ FAI Record File Number 392

² FAI Record File Number 393

© 2017, Bryan R. Swopes

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12 June 1955

Prototype Cessna 172 N41678, serial number 612. (Flying Magazine, December 1955, Volume 57, Number 6, at Page 22)

12 June 1955:  On Sunday morning, 12 June 1955, Cessna Aircraft Company test pilot Emil Brown (“Fritz”) Feutz, took off from Cessna Aircraft Field (CEA), southeast of Wichita, Kansas, with the new prototype Model 172, N41678, and flew west to a grass runway near Kingman, Kansas, approximately 48 miles (78 kilometers) to the west. Also on board was an observer, D.G. Underwood. The airplane was stored in a small hangar. Feutz conducted the flight and certification testing at Kingman.

This color photograph of the prototype Cessna 172, N41678, was featured in a 1956 sales brochure. (Cessna Airplane Co. via cessna.org)
A prototype Cessna 170C, this is 170B serial number 609, N37892. (Cessna Aircraft Co.)

N41678, serial number 612, was originally a prototype for the Model 170C “tail-dragger.” It featured new, straight tail surfaces, in place of the classic rounded style. The airplane was then modified with tricycle-configuration landing gear. With the airplane in a horizontal attitude, the pilot had better visibility while on the ground. Taxiing, takeoff and landing were much easier. Flight testing showed that the increased drag slowed the 172 by about 5 miles per hour (8 kilometers per hour) when compared to the 170.

The Civil Aeronautics Administration (predecessor to the Federal Aviation Administration) approved the airplane’s type certificate, 3A12, on 4 November 1955.

The Cessna 172 was an immediate success, with 1,174 being produced in 1956. Total production of the original model was 3,808, before production changed to the Model 172A in 1960. During the 1960s, Cessna began marketing the airplane with the name Skyhawk.

The 172 was in production from 1956 until 1986, when product liability lawsuits made the cost of the airplane unaffordable. Production resumed in 1996 and continues today. More than 44,000 have been built in at least 24 variants by Cessna and its licensee, Reims Aviation Industries, in France. This is greater than any other aircraft type, and only the Lockheed C-130 Hercules has been in production longer.

N41678, the first Cessna 172. (Cessna Aircraft Co.)

The Cessna 172 is a single-engine, four-place, high-wing, all-metal light airplane with fixed tricycle landing gear. The first production airplane was serial number 28000, registered N5000A. (This airplane is currently registered to an owner in Quincy, Illinois.) The list price in 1956 was $8,995.

Dimensions of the first Cessna 172 have been elusive. The current production model, the 172S, is 27 feet, 2 inches (8.280 meters) long, with a wingspan of 36 feet, 1 inch (10.998 meters) and height of 8 feet, 11 inches (2.718 meters). Certified in the Normal Category, the original Model 172 had an empty weight of 1,290 pounds (585 kilograms), and gross weight of 2,200 pounds (998 kilograms). It was also certified in the Utility Category as a 2-place airplane, with a maximum gross weight reduced to 1,950 pounds (885 kilograms).

Continental O-300 (Flying Magazine)

The Cessna 172 was powered by an air-cooled, normally-aspirated, 301.370 cubic inch (4.939 liter) Continental O-300-A ¹ six-cylinder, horizontally-opposed, overhead valve engine. It has two valves per cylinder, a compression ratio of 7.0:1, and is rated at 145 horsepower at 2,700 r.p.m. using 80/87-octane aviation gasoline. The O-300-A is a right-hand tractor, direct-drive engine which turns a two-bladed, fixed-pitch, metal propeller with a diameter of 6 feet, 4 inches (1.930 meters). It is  2 feet, 1115/32 inches (0.9009 meters) long, 2 feet, 7½ inches (0.800 meters) wide and 2 feet, 313/32 inches (0.6961 meters) high. This engine weighs 268 pounds (121.6 kilograms), dry.

The Cessna 172 has a Maneuvering Speed (VC) of 115 miles per hour (185 kilometers per hour), and Maximum Speed with Flaps Extended (VFC) of 100 miles per hour (161 kilometers per hour). The Maximum Structural Cruising Speed (VNO) is 140 miles per hour (225 kilometers per hour), and the Never Exceed speed (VNE) is 160 miles per hour (257 kilometers per hour). (Speeds are Calibrated Air Speed, CAS.)

There are two 21-gallon (79.5 liter) fuel tanks in the wings, with 37 gallons (140 liters) usable. The airplane has a maximum range at cruse speed of 481 statute miles (774 kilometers) kilometers. The service ceiling is 15,100 feet (4,602 meters).

A very early production Cessna 172, serial number 28008, registered N5008A. (Cessna Aircraft Co./Ed Coates Collection)

Emil Brown Feutz was born at Wichita, Kansas, 1 July 1923. He was the son of Wallace Frederic Feutz and Lelah Mae Brown Feutz. He attended the Missouri Military Academy, a private college preparatory school at Mexico, Missouri.

Emil Brown Feutz. (The 1942 Savitar)

In 1941, “Buddie” Feutz entered the University of Missouri, Columbia, Missouri, as an engineering student. He was a member of the Sigma Nu (ΣΝ) fraternity.

Feutz was a member of the Class of 1945, but World War II interrupted his college plans. He enlisted in the United States Army at Jefferson Barracks, south of St. Louis, Missouri, on 25 January 1943. U.S. Army records say that was 6 feet, 0 inches (1.828 meters) tall and weighed 143 pounds (65 kilograms).

On 18 September 1949, Emil Feutz married Miss Dorothy Jean Estep, who was also at the University of Missouri, and an employee of LIFE Magazine. They would have four children.

Following the war, Feutz returned to the University of Missouri. He was a member of the American Society of Mechanical Engineers and the Engine Club. He graduated with a Bachelor of Science Degree in Mechanical Engineering (B.S.M.E.) in 1952.

E.B. “Fritz” Feutz. (SETP)

Fritz Feutz worked as an aerodynamicist and flight test engineer for the Beech Aircraft Corporation, 1950 to 1953. He flew as a test pilot for Cessna from 1953 until 1957, then went to the McDonnell Aircraft Company at St. Louis, Missouri. In 1961, Feutz founded his own company, Testair, Inc., also in St. Louis. He was a member of the Society of Experimental Test Pilots.

Emil Brown Feutz died at his home in Columbia, Missouri, 1 September 2013, at the age of 90 years. He was buried at Elmwood Cemetery, Mexico, Missouri.

The new Cessna 172 was featured on the cover of the December 1955 issue of FLYING. (Ziff-Davis Publications)

¹ “0-300-A is similar to C145-2 except parts material and ignition component substitutions.”TYPE CERTIFICATE DATA SHEET NO. E-253

© 2017, Bryan R. Swopes

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12 June 1937

Amelia Earhart’s Lockheed Electra 10E NR16020 at El Fasher, Anglo-Egyptian Sudan, 12 June 1937. (Purdue University Libraries, Archives and Special Collections)

12 June 1937: Leg 14. Amelia Earhart and Fred Noonan fly the Lockheed Electra 10E Special, NR16020, from Fort-Lamy in French Equatorial Africa, to El Fasher, Anglo-Egyptian Sudan, a distance of approximately 700 miles (1,127 kilometers). A leak in one of the Electra’s landing gear struts took several hours to deal with.

Because of the late start we made the objective of that day’s flight El Fasher, in Anglo-Egyptian Sudan. With a following wind we negotiated the journey to something over three hours. As expected, thanks to the day’s heat, which caught up to us, it was particularly bumpy flying, with a particularly desolate region below us.” —Amelia Earhart

© 2016, Bryan R. Swopes

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12 June 1922

Albert William Stevens (Belfast Historical Society and Museum)

12 June 1922: Captain Albert William Stevens, Air Service, United States Army, made a high altitude parachute jump from a twin-engine Martin GMB bomber flying at 24,206 feet (7,378 meters) over McCook Field, Ohio.

A contemporary magazine article described the jump:

The greatest recorded parachute jump made from an airplane was accomplished by Capt. Albert W. Stevens a year or more ago. He fell 24,200 feet—almost five miles—landing 25 miles away from the point above which he jumped and suffering no injury in his descent, beyond a couple of dislocated toes.

Popular Science Monthly, November 1924, Vol. 105, No. 5, at Page 152, Column 2.

The Army and Navy Register published this very informative report:

PARACHUTING FROM 24,206 FEET

     Hurtling four and one-half miles through space was the recent experience of Capt. A. W. Stevens, Air Service, stationed at McCook Field, Dayton Ohio, in a parachute jump on June 12 last from the high altitude of 24,206 feet from a supercharged Martin bomber, piloted by Lieut. Leigh Wade, with Sergeant Roy Lanham as the other passenger. Capt. Stevens’ fall lasted approximately 20 minutes, and the oscillations of the chute, due to the prevailing winds, made him thoroughly seasick by the time half of the descent was over. In his official report to the chief of the Air Service, Capt. Stevens says:

    “The pack-cord was ripped about ten feet below the fuselage of the bomber. The parachute opened instantly and was fully open in less than 100 feet below the plane (estimated). The writer has made several jumps before, viz., from 1,500 feet, at 85 miles per hour; 1,500 feet at 65 miles per hour, and 5,600 feet at 65 miles per hour. Although the plane speed is estimated by the pilot at 110 miles per hour, the shock of opening was less, if anything, than on the previous jumps by the writer at lower altitudes and speed—due very likely to the lower density of the atmosphere.

     “The writer had complete confidence that the parachute would open fully—sooner or later. The only question with him was whether the passage of the silk fabric through the cold, rarefied upper air might generate enough static electricity to hold the folds of the ‘chute tight together for a time, until when it did open the shock might result in a rupture, either of the operator’s body, or of the shroud lines. This fear was groundless as the ‘chute opened instantly—or practically so. The ‘chute used had the vents sewed right; it had been tested with both 100 and 200-pound weights in the usual manner over McCook Field from about 600 feet altitude.

     “The time of descent was not over 20 minutes, from the writer’s estimate. It may have been less than 20 minutes, but was over 15 minutes. The writer would like to make another jump from still higher altitude, 40,000 feet or more, when he recovers from a few broken foot bones, and if this is done, a recording barograph will be carried as part of the jumper’s equipment. Needless to say, a comparatively windless day is best to choose for a thing of this kind, as the ‘chute may get caught in a down current on a windy day and land twice as hard as usual. Also, the jumper from high altitudes is burdened with heavy flying clothing, which increases his weight considerably.

     “Attention is called to the fact that the parachute averaged a ground speed of one and one-half miles a minute, based on a travel of 30 miles and a time of descent of less than 20 minutes. The ordinary time of descent is about 1,000 feet per minute at ordinary altitudes; for instance, in the 5,600-foot jump previously referred to, the time was six minutes. In the thin upper air the ‘chute undoubtedly falls faster, especially when it is oscillating and spilling air, as was the case all the way down on the recent jump.

     “Ten minutes of such oscillation will upset anything but a cast-iron stomach. In the writer’s case, he was thoroughly seasick by the time half of the descent was over. He could get little relief by closing his eyes, and if his eyes were open the landscape below heaved and tipped in all directions. It is of interest to note that temporary relief was experienced by fixing the eyes for a few seconds on the center of the parachute, this being the only point in space reasonably at rest with respect to the body of the jumper.

     “It is inadvisable to open the second ‘chute for the purpose of checking oscillation, as one then loses control of movement. With a single ‘chute it is possible to change the direction of one’s flight very considerably, even on a windy day. On a calm day one can do much better, even to the extent of picking out a particular field in which to land. On a windy day the air currents carry you irresistibly ahead, and the best that can be done is to side-slip to the right or to the left of the line of flight.

     “About the land: if one imagines that he has just jumped from a twelve-foot wall and crouches in a jumping position, he will be in the best position for landing. Too great a tension of the leg muscles may result in ruptured tendons or broken foot bones. You are sure to collapse in a pile on the ground; it is better to relax with that in view, and thereby get a more even distribution of bruises. The jumper should face the way he is traveling; to accomplish this it is possible to make the ‘chute revolve, earlier in the drop, by taking a few of the shroud lines and pulling diagonally, with the idea of working a “propeller” surface into one point of the ‘chute circumference. The second ‘chute may be pulled about 50 to 75 feet before landing, chiefly to get rid of the extra weight. If pulled earlier, the two ‘chutes will soon stand well apart, at 60 degrees or more, and will spill air between them, so that the jumper will fall nearly as fast as ever, and with practically no control.

     “The bomber carried four recording barographs, as well as indicating altimeters. The result of McCook Field laboratory measurements showed that the elevation was 24,206 feet.

     “It was the intention of Lieut. Wade to take the plane, relieved of 250 pounds of weight, still higher, but one of the superchargers developed trouble and it was necessary to cut the flight short.”

ARMY AND NAVY REGISTER, The U.S. Military Gazette, Vol. LXIII, No. 2195, 12 August 1922 at Page 162

1st Lieutenant Albert William Stevens, Air Service, United States Army, circa 1921. Lieutenant Williams is wearing the badge of an aerial observer. The decoration beneath is the Victory Medal with four campaign stars. (Albert W. Stevens Collection)

Albert William Stevens (née Whitten) was born at Belfast, Maine, 13 March 1886, the third child of Nathan Whitten, a blacksmith and wagon builder, and Alice C. Anderson Whitten. His mother died of “consumption” (tuberculosis) when Albert was five months old. He was adopted by Albert J. Stevens and Nancy M. Trimble Stevens, and his name became Albert William Stevens.

Stevens attended the University of Maine at Orono, Maine. He graduated in 1907 with a Bachelor of Science (B.S.) degree. He earned a Masters degree in electrical engineering  from the university in 1909. He then worked as a mining engineer in Alaska, California, Idaho and Montana.

Stevens enlisted in the U.S. Air Service in Idaho, January 1918. Because of his experience in photography, which began while he was in college, Stevens was assigned to the Aerial Photography School at Cornell University, Ithaca, New York. He was commissioned as a First Lieutenant, Aviation Section, Signal Officers Reserve Corps, 18 February 1918. Sent to Europe as part of the American Expeditionary Forces, Stevens commanded the 6th Photo Section, 88th Aero Squadron. He flew in the major campaigns of the final months of the War.

In this photograph of officers of the 88th Aero Squadron in France, 1918, Lieutenant Stevens is in the front row, fifth from right. The airplane is an Avion Salmson Type 2 A.2. (United States Air Force)

He was an acknowledged expert in the field of aerial photography. Lieutenant Stevens was wounded and awarded the Purple Heart. Following the War, he was promoted to Captain, Air Service, 21 February 1919. His commission was vacated 18 September 1920, and he was appointed a Captain, Air Service, United States Army, effective 1 July 1920. On 18 November 1922, Stevens was discharged as a Captain, then re-appointed a First Lieutenant. He returned to the rank of Captain, Air Service, 10 February 1925. On 16 June 1936, he was promoted to the temporary rank of Major, United States Army Air Corps. This rank became permanent 12 June 1939. In 1940, Major Stevens took command of the Photographer’s School, Air Corps Technical School, Lowry Field, Denver, Colorado. He advanced to the temporary rank of Lieutenant Colonel, 30 December 1940. This rank became permanent 15 October 1941. He was retired from the Air Corps for medical reasons, 30 April 1942.

Stevens married Ruth E. Fischer at Rockville, Maryland, 8 August 1938.

Captain Stevens was a pioneering aviator, balloonist and aerial photographer. Using infrared film, he made the first photograph that showed the curvature of the Earth. He also took the first photograph of the Moon’s shadow on the surface of the Earth during an eclipse.

Stevens made a series of high-altitude balloon flights, and on 11 November 1935 he and Captain Orvil A. Anderson ascended to 22,066 meters (72,395 feet) aboard Explorer II, establishing a Fédération Aéronautique Internationale (FAI) world record. ¹

Lieutenant Colonel Andrew William Stevens, United States Army Air Forces (Retired), died at Redwood City, California, 26 March 1949, at the age of 63 years. He is buried at the Golden Gate National Cemetery, San Bruno, California.

Major Albert W. Stevens, U.S. Army Air Corps, circa 1936. Major Stevens is wearing the wings of an aerial observer. The ribbons beneath represent the Purple Heart, the World War I Victory Medal with four campaign stars, and the Distinguished Flying Cross with one oak leaf cluster (a second award).
1st Lieutenant Leigh Wade, Air Service, U.S. Army

1st Lieutenant Leigh Wade, Captain Stevens’ pilot, flew a Douglas World Cruiser Boston in the U.S. Army’s around the world flight, April–September 1924, for which he was awarded the Distinguished Service Medal. He reached the rank of Major General and remained in the United States Air Force until retiring, 1 November 1955.

The Martin GMB (also referred to as the Martin MB-1) was a twin-engine biplane designed as a reconnaissance airplane with a secondary role as a bomber. It had a crew of three. The bomber entered service in 1918 and was the first U.S.-built bomber to enter production.

The GMB was 44 feet, 10 inches (13.665 meters) long with a wingspan of 71 feet, 5 inches (21.768 meters) and height of 14 feet, 7 inches (4.445 meters). The airplane had an empty weight of 6,702 pounds (3,040 kilograms) and a gross weight of 10,225 pounds (4,638 kilograms).

A Martin MB-1 bomber, A.S. 39059, (P-104) at Wright Field. (U.S. Air Force)
A Martin GMB bomber, A.S. 39059 (P-104). (U.S. Air Force)

The bomber was powered by two water-cooled, normally-aspirated, 1,649.336-cubic-inch-displacement (27.028 liter) Liberty L-12 single overhead cam (SOHC) 45° V-12 engine with a compression ratio of 5.4:1. The Liberty produced 408 horsepower at 1,800 r.p.m. The L-12 as a right-hand tractor, direct-drive engine. It turned turned a two-bladed fixed-pitch wooden propeller. The Liberty 12 was 5 feet, 7.375 inches (1.711 meters) long, 2 feet, 3.0 inches (0.686 meters) wide, and 3 feet, 5.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms). The engines on Stevens’ airplane were supercharged to increase its altitude capability.

The GMB had a cruise speed of 92 miles per hour (148 kilometers per hour) and maximum speed of 105 miles per hour (169 kilometers per hour) at Sea Level. Its service ceiling was 10,300 feet (3,140 meters). Range for the standard airplane was 390 miles (628 kilometers).

Twenty-two GMBs were built by the Glenn L. Martin Company.

Martin MB-1 A.S. , P=106. (U.S. Air Force)
Martin GMB bomber A.S. 62950 (P-106). (U.S. Air Force)

¹ FAI Record File Number 10654

© 2017, Bryan R. Swopes

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