Yearly Archives: 2025

31 January 1951

Charles F. Blair, jr. arrives at Heathrow. (Getty Images)

31 January 1951: Pan American World Airways Captain Charles F. Blair, Jr., flew a modified North American Aviation P-51C-10-NT Mustang, NX1202, named Excalibur III, from New York International Airport to London Airport in 7 hours, 48 minutes, with an average speed of 446 miles per hour (718 kilometers per hour). Captain Blair took advantage of the jet stream, flying as high as 37,000 feet (11,278 meters).

“At last, I was riding the jet stream, pushed by a tailwind exceeding 200 miles per hour. . . Above me, the sky was empty and blue; below the wings of my tiny aircraft a winter storm raged. Its upper canopy of white clouds gave it a look of complete innocence.”

The Salt Lake Tribune, Sunday, 3 June 1951, Page 115

This was Blair’s 401st Atlantic crossing.

Blair’s flight did not set an official record. No arrangements had been made to have officials of the Fédération Aéronautique Internationale (FAI) available to observe the flight.

Mrs. Charles Blair Jr. (right) with her two children, Suzanne, 16, and Christopher, 10 months, get the news of Capt. Blair’s safe arrival. (NEWS foto by Sam Platnik)

Interestingly, Excalibur III was impounded by HM Customs at the London Airport. Blair had not paid the £800 customs duty which would have allowed the Mustang to stay for six months. He would have had to fly the airplane back to the United States to avoid the aircraft being impounded.

The Chicago Daily Tribune reported the event:

LONE PILOT HOPS OCEAN IN LESS THAN 8 HOURS

LONDON, Jan. 31 (AP)— Air Line Capt. Charles Blair landed his scarlet Mustang fighter plane in a blaze of red flares tonight, chalking up a New York to London speed record of 7 hours 48 minutes. He clipped an hour and seven minutes off the old record.

     Blair said his only troubles during the flight were some icing in the early stages and a painfully tight pair of boots.

     As he climbed from the cockpit of the flying gas tank named Excalibur III and waved to a cheering crowd at London airport he winced and declared: “The first thing I do is get these boots off.”

Aided by Tail Winds

     Blair left New York’s Idlewild airport at 3:50 a.m. Chicago time [09:50 UTC] and was clocked in here at 5:38 p.m. British time [11:38 a.m. Chicago time]. [17:38 UTC]

     A Pan American Airways pilot, Blair took the time record from a Pan American Stratocruiser which made the eastward Nov. 22, 1949, with 24 passengers, in 8 hours and 55 minutes. Strong tail winds helped in both cases.

     Blair, tall, dark, married, and 41, brought no luggage, but had a shaving kit and a tooth brush in a small leather bag.

     His plane is powered by a Packard built Rolls-Royce Merlin engine and was modified to hold 863 gallons of gasoline inside wings and fuselage without external tanks. He said the plane cost $25,000 to buy and revamp.

Averages 450 M. P. H.

     Blair told newsmen at London airport: “It was a very good crossing. It wasn’t as fast as I expected, but after Gander, N.F., I had a tail wind of 130 miles an hour. But the weather wasn’t too good and there was some ice.”

     Blair’s average speed was about 450 miles an hour and he made much of the jaunt at 37,000 feet.

     He said the trip had a dual purpose, to break the record and to study the effect of high velocity winds on airliners in the lower stratosphere.

     Blair will fly back to New York as a passenger in a Stratocruiser. He has to return by Saturday. On that day he will fly a planeload of passengers from New York to London.

Chicago Daily Tribune, Volume CX—No. 28, Thursday, February 1, 1951, Part 1, at Page 6, Columns 4 and 5.

Blair was presented the Harmon International Trophy by President Harry S. Truman in a ceremony at the White House, 18 November 1952. The Harmon awards are for “the most outstanding international achievements in the art and/or science of aeronautics for the previous year, with the art of flying receiving first consideration.”

Captain Charles F. Blair, Jr., American Overseas Airlines.

Charles Francis Blair, Jr., was born 19 July 1909 at Buffalo, New York, the second child of Charles F. Blair, an attorney, and Grace Ethelyn McGonegal Blair. He entered the University of Vermont, where is father was a member of the Board of Trustees, as a freshman in 1927. He was a member of the Phi Delta Theta (ΦΔΘ) fraternity.

Blair was commissioned as an ensign in the United States Naval Reserve, 16 August 1932.

On 6 September 1932, Ensign Blair married Miss Janice Evelyn Davis at Wallingford, Vermont. They would have two children, Suzanne, born in 1934, and Christopher Noel, born in 1950. The Blairs would later divorce.

He was promoted to lieutenant, junior grade, 16 August 1937. During World War II, he served as a transport pilot in the U.S. Navy.

On 18 November 1952, Blair was one of three aviators to be awarded the Harmon Trophy. The presentation was made by President Harry Truman in a ceremony in The White House Rose Garden.

Blair resigned from the Naval Reserve in 1952 and the following year he accepted a commission in the U.S. Air Force Reserve with the rank of colonel. In 1959, Blair was promoted to brigadier general.

While serving as a reserve officer, Charlie Blair continued his civilian career as an airline pilot for United Airlines, American Overseas Airlines, and then with Pan American.

On 12 March 1968, Captain Blair married to actress Maureen O’Hara, whom he had met during one of his 1,575 transatlantic crossings. It was the fourth marriage for both.

Captain Blair made his final flight with Pan American in July 1969. He had flown more than 45,000 hours and traveled more than 10,000,000 miles.

Blair was the author of Thunder Above (Henry Holt & Co., 1956), a novel co-written with A.J. Wallis and filmed as “Beyond the Curtain,” starring Richard Green and Eva Bartok, in 1960. He also wrote Red Ball in the Sky (Random House, 1969), an account of his career in aviation.

Brigadier General Charles Francis Blair, Jr., died 2 September 1978 in an airplane accident. His remains were interred at the Arlington National Cemetery.

Captain Charles F. Blair, Jr., checks his astrocompass shortly before beginning his transpolar flight, 29 May 1951. (Smithsonian Institution)

Excalibur III is a Dallas, Texas-built North American Aviation P-51C-10-NT Mustang, one of a group of 400 fighters which had been contracted on 5 March 1943. Its North American Aviation serial number is 111-29080, and the U.S. Army Air Force assigned it serial number 44-10947.

After World War II, 44-10947 was transferred to the Reconstruction Finance Corporation (a Depression-era agency of the United States government) at Searcy Field (SWO), Stillwater, Oklahoma. It was purchased by Paul Mantz, 19 February 1946, and the Civil Aeronautics Administration registered it as NX1202. Mantz had the Mustang painted red and named it Blaze of Noon. (Mantz was a movie pilot and aerial coordinator for the 1947 Paramount Pictures movie, “Blaze of Noon,” which was based on the Ernest K. Gann novel, Blaze of Noon, published in 1946.)

Paul Mantz flew NX1202 to win the 1946 and 1947 Bendix Trophy Races. Flown by Linton Carney and renamed The Houstonian, NX1202 placed second in the 1948 Bendix race, and with “Fish” salmon in the cockpit, it took third place in 1949.

Paul Mantz in the cockpit of “Blaze of Noon,” P-51C-10-NT Mustang 44-10947, NX1202. (Hans Greehoff Photographic Collection, Smithsonian Institution, National Air and Space Museum, NASM-HGC-1100)
North American Aviation P-51C Mustang NX1202, now named “The Houstonian.” The modified fighter flew in the 1948 Bendix Trophy Race, finishing in second place. (NASM)
Test pilot Herman “Fish” Salmon awaits the starter’s signal at the beginning of the 1949 Bendix Trophy Race on Rosamond Dry Lake, California, in the modified North American Aviation P-51C Mustang, NX1202. Salmon finished in third place. (San Diego Air and Space Museum Archive)

Paul Mantz had set several speed records with the Mustang before selling it to Pan American World Airways, Inc., Blair’s employer. Blair named the Mustang Stormy Petrel, but later changed it to Excalibur III.

To increase the Mustang’s range for these long-distance flights, Mantz had removed the standard 90-gallon pressure-molded Firestone self-sealing tanks from each wing and converted the entire wing to a fuel tank (what is known as a “wet wing”).

The P-51B and P-51C Mustang are virtually Identical. The P-51Bs were built by North American Aviation, Inc, at Inglewood, California. P-51Cs were built at North American’s Dallas, Texas plant. They were 32 feet, 2.97 inches (9.829 meters) long, with a wingspan of 37 feet, 0.31-inch (11.282 meters) and overall height of 13 feet, 8 inches (4.167 meters) high. The fighter had an empty weight of 6,985 pounds (3,168 kilograms) and a maximum gross weight of 11,800 pounds (5,352 kilograms).

North American Aviation P-51C-10-NT 44-10947, "Excalibur III", at the Steven F. Udvar-Hazy Center, National Air and Space Museum.
North American Aviation P-51C-10-NT 44-10947, “Excalibur III,” at the Steven F. Udvar-Hazy Center, National Air and Space Museum.

P-51Bs and Cs were powered by a right-hand tractor, liquid-cooled, supercharged, 1,649-cubic-inch-displacement (27.04-liter) Packard V-1650-3 or -7 Merlin single overhead cam (SOHC) 60° V-12 engine which produced 1,380 horsepower at Sea Level, turning 3,000 r.p.m at 60 inches of manifold pressure (V-1650-3) or 1,490 horsepower at Sea Level, turning 3,000 r.p.m. at 61 inches of manifold pressure (V-1650-7). (Military Power rating, 15 minute limit.) These were license-built versions of the Rolls-Royce Merlin 63 and 66. The engine drove a four-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 11 feet, 2 inches (3.404 meters) through a 0.479:1 gear reduction.

The P-51B/C had a cruise speed of 362 miles per hour (583 kilometers per hour) and the maximum speed was 439 miles per hour (707 kilometers per hour) at 25,000 feet (7,620 meters), slightly faster than the more numerous P-51D Mustang. The service ceiling was 41,900 feet (12,771 meters). With internal fuel the combat range was 755 miles (1,215 kilometers).

Identical to the Inglewood, California-built North American Aviation P-51B Mustang, this is a Dallas, Texas-built P-51C-1-NT, 42-103023. (North American Aviation, Inc.)
Identical to the Inglewood, California-built North American Aviation P-51B Mustang, this is a Dallas, Texas-built P-51C-1-NT, 42-103023. (North American Aviation, Inc.)

In military service, armament consisted of four Browning AN-M2 .50-caliber machine guns, mounted two in each wing, with 350 rounds per gun for the inboard guns and 280 rounds per gun for the outboard.

1,988 P-51B Mustangs were built at North American’s Inglewood, California plant and another 1,750 P-51Cs were produced at Dallas, Texas. This was nearly 23% of the total P-51 production.

Though the P-51D with its bubble canopy was built in far greater numbers during World War II, the earlier P-51B and P-51C Mustangs were actually faster, so many surplus airplanes were used for racing and record attempts after the war.

In 1952, Pan American World Airways donated Excalibur III to the Smithsonian Institution. The airplane’s registration was cancelled 4 June 1952. Today, completely restored, it is on display at the Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Charles F. Blair, Jr.'s North American Aviation P-51C-10-NT Mustang, Excalibur III, at the Steven F. Udvar-Hazy Center, National Air and Space Museum. (NASM)
North American Aviation P-51C-10-NT Mustang, Excalibur III, at the Steven F. Udvar-Hazy Center, National Air and Space Museum. (NASM)

A British PATHÉ news film of Blair’s arrival at London can be seen on YouTube at https://www.youtube.com/watch?v=LdRbIQdnyQo

© 2019, Bryan R. Swopes

30 January 1934

Osoaviakhim-1, 30 January 1934. (RIA Novosti/Science Source)
П. Ф. Федосеенко (Pavel Fyodorovich Fedoseyenko)

30 January 1934: At approximately 9:00 a.m. a large gas balloon lifted off from Matilovo, near Moscow, and ascended toward the stratosphere. Three aeronauts were aboard: Pavel Fyodorovich Fedoseyenko, Ilya Davydovich Usyskin, and Andrei Bogdanovich Vasenko. The balloon was named Osoaviakhim 1.

Buoyancy was provided by gaseous hydrogen. When fully expanded, the balloon had a volume of approximately 25,000 cubic meters (882,867 cubic feet) and a diameter of 177 feet (54.95 meters).

The three passengers and scientific instruments were carried in a welded sheet metal sphere hanging from cables below the envelope. The gondola was considered air-tight, and with its passengers, equipment and ballast, weighed about 2,000 kilograms (4,409 pounds).

The equipment and experiments carried aboard Osoaviakhim 1 were provided by the Main Physical Observatory, Ioffe Physical-Technical Institute, and the State Radium Institute, all located in Leningrad, Russian Soviet Federative Socialist Republic. They were designed to measure cosmic rays, determine the makeup of the upper atmosphere, and measure magnetic effects. Photographs of the ground were also to be taken.

А.Б.Васенко (Andrei Vasenko)

As the balloon rose, the crew maintained radio contact with ground stations. At about 11:45, they reported that they had reached about 67,600 feet (20,600 meters). At 12:23, Osoaviakhim 1 had reached its peak altitude, 22,000 meters (72,178 feet).

While in the stratosphere, sunlight was not damped as it would have been in the lower, denser troposphere. It caused the hydrogen within the envelope to heat to approximately 54 °C. (129 °F.) above the temperature of the surrounding air. The hydrogen expanded the envelope beyond its limits and was released through pressure relief valves.

During the descent, the remaining hydrogen cooled and contracted. The balloon gradually lost buoyancy and the rate of descent increased. The crew had released all of the ballast in order to reach the peak altitude and now had no way to lighten ship to slow the balloon’s descent. After passing through 12,000 meters (39,370 feet), the rate of descent began to dramatically increase, and by 8,000 meters (26,247 feet), the balloon was torn away from the spherical gondola, which then entered a free fall.

И.Д.Усыскин (Il’ia Usyskin)

Osoaviakhim 1 struck the ground near Potijsky Ostrog, about 470 kilometers (292 miles) east of Matilovo. All three men were killed. A watch belonging to Vasenko was stopped at 4:23. Presumably, this was the time at which the impact occurred.

A state funeral was held 2 February. The ashes of the three aeronauts were interred in the Kremlin wall. The three urns were carried by the most prominent leaders of the Communist state, Joseph Vissarionovich Stalin, General Secretary of the Communist Party of the Soviet Union; Kliment Yefremovich Voroshilov, People’s Commissar for Defense; and Vyacheslav Mikhailovich Molotov, Chairman of the Council of People’s Commissars.

Fedoseyenko, Usyskin, and Vasenko were named Heroes of the Soviet Union.

Although Osoaviakhim 1 rose higher than than the 18,665 meter record ¹ set by Century of Progress (Commander Thomas Greenhow Williams Settle, United States Navy, and Major Chester Fordnay, United States Marine Corps), 20 November 1933, its peak altitude was not recognized as a record by the Fédération Aéronautique Internationale (FAI). At the time, the Union of Soviet Socialist Republics was not a member nation of the FAI.

Osoaviakhim stratospheric balloon. (Georgy N. Bibikov/The State Russian Museum)

¹ FAI Record File Number 10645

2018, Bryan R. Swopes

29 January 1936

Grumman F3F-1, Bu. No. 0211, s/n 274. (San Diego Air & Space Museum, Roger Bilstein Collection 00032)

29 January 1936: The first production Grumman F3F-1, Bureau of Aeronautics serial number (“Bu. No.”) 0211 (Grumman Model G-11, serial number 271), was delivered to the United States Navy at NAS Anacostia, Washington, D.C. The F3F series was the last biplane fighter in service with the U.S. Navy.

The production F3F-1 aircraft were preceded by three XF3F-1 prototypes. Interestingly, all three prototypes had the same Grumman serial number, 257, and were assigned Bu. No. 9727. Two of these crashed.

The F3F-1 was built by the Grumman Aircraft and Engineering Corporation at Farmingdale, New York, in factory space rented from Fairchild Aircraft Company. It was a single-bay wire-braced biplane with manually-operated retractable landing gear and an enclosed cockpit with a sliding canopy. It had an arresting hook for landing aboard aircraft carriers.

The airplane had an aluminum monocoque fuselage with fabric covered wings, ailerons, rudder and elevators. The vertical fin and horizontal stabilizer were of metal construction. The ailerons were positioned on the upper wing. The wings for the F3F-1 and F3F-2 were built by the Brewster Aeronautical Corporation under a subcontract.

Grumman F3F-1 Bu. No. 0264. (U.S. Navy, Naval History and Heritage Command, 80-G-462080)

The F3F-1 was 23 feet, 3½ inches (7.099 meters) long. The upper wing had a span of 32 feet (9.754 meters) and a chord of 5 feet (1.524 meters). The lower wing’s span was 29 feet, 6 inches (8.992 meters) with a 4 foot (1.219 meters) chord. The total wing area was 260.6 square feet (24.2105 square meters). Both wings used a NACA CYH airfoil. The upper wing had no dihedral, but the lower wing had 2° dihedral. The vertical gap between the wings was 5 feet (1.524 meters) and the wings were staggered 2 feet, 7-1/16 inches (0.7889875 meters). The aircraft had an overall height of 10 feet, 6 inches (3.200 meters) with the thrust line level, and 8 feet 6 inches (2.591 meters) in three point attitude (not including the propeller).

Grumman F3F1 Bu. No. 0259, assigned to Fighting Squadron Three (VF-3). (U.S. Navy)

The F3F-1 was powered by an air-cooled, supercharged, 1,534.94-cubic-inch-displacement (25.153 liters) Pratt & Whitney R-1535-84 Twin Wasp Junior. This was a two-row, 14-cylinder radial engine, with a compression ratio of 6.75:1, requiring 87-octane gasoline. The direct drive engine turned a two-blade adjustable pitch Hamilton Standard propeller. The R-1535-84 was rated at 650 horsepower at 2,200 r.p.m. at 7,500 feet (2,286 meters), and 700 horsepower at 2,250 r.p.m. for takeoff. It was 3 feet, 8-1/8 inches (1.1208 meters) long, 3 feet, 6-3/8 inches (1.107 meters) in diameter, and weighed 959 pounds (434 kilograms).

The F3F-1 had a fuel capacity of 110 U.S. gallons (416 liters) in a 75 gallon (284 liter) main, and 35 gallon (132 liter) auxiliary tank. Its gross weight was 4,116 pounds (1,867 kilograms).

The F3F series was armed with one M1919 .30-caliber Browning machine gun with 500 rounds of ammunition, and one M2 .50-caliber Browning machine gun with 200 rounds. It could also carry a 110 pound (50 kilogram) bomb on a centerline bomb rack.

The F3F-1 had a maximum speed of 231 miles per hour (372 kilometers per hour) at 7,500 feet (2,286 meters). It could climb at 1,900 feet per minute (9.65 meters per second) and had a service ceiling of 29,500 feet (8,992 meters).

Flight of three Grumman F3F-1 from Fighting Squadron Four (VF-4), “The Red Rippers.” Note the gun cameras mounted on the upper wing. (SDA&SM Catalog # 16_003713)

The U.S. Navy ordered 54 F3F-1 fighters in August 1935. The final airplane in this series was modified to the XF3F-2, substituting a Wright Cyclone XR-1820-22 engine, rated at 850 horsepower at 2,100 r.p.m., and 950 horsepower at 2,200 r.p.m. for takeoff. This engine installation reduced the length of the airplane to 23 feet, 1-5/8 inches (7.052 meters).

A total of 147 F3F-1, -2 and -3 fighters were built. The type was retired in 1943.

The first F3F-1, Bu. No. 0211, crashed at sea near NAS Miami in March 1942.

Grumman F3F-1, Bu. No. 0252, assigned to Fighting Squadron Four (VF-4). The airplane is shown with the canopy open. (U.S. Navy)

© 2025, Bryan R. Swopes

29 January 1926

Mrs. Macready with her husband, Lieutenant John Arthur Macready, shortly before his altitude record flight, 29 January 1926. (George Rinhart via Daedalians)

29 January 1926: At McCook Field, near Dayton, Ohio, First Lieutenant John Arthur Macready, Air Service, United States Army, took off in an experimental airplane, the Engineering Division XCO-5. Macready was attempting to exceed the existing Fédération Aéronautique Internationale world altitude record of 12,066 meters (39,587 feet), which had been set by Jean Callizo at Villacoublay, France, 21 October 1924.¹

The official observers of the National Aeronautic Association were Orville Wright (co-inventor with his brother Wilbur, of the airplane); George B. Smith of Dayton; and Levitt Luzurne Custer (inventor of the statoscope, the original barometric altimeter).

The Dayton Daily News reported:

    Every part of the plane functioned perfectly. . . with the exception of the supercharging apparatus. The plane climbed to 25,000 feet in less than 45 minutes. The remainder of the flight was a fight against the dropping pressure in the motor.

     In taking off, the altitude plane required approximately 50 feet and immediately began a steep ascent. Throughout the test the several hundred people who had congregated to see the flight start could find the plane by a long line of white vapor, which trailed in the wake of the ship in the rare atmosphere.

     On other tests the plane has shown sea level pressure at approximately 32,000 feet. The super-charger showed a steadily declining pressure after 25,000 feet, indicating its lack of sufficient capacity for the motor. . .

Dayton Daily News, Vol. XL, No. 162, January 29, 1926, Page 1, Column 7, and Page 2, Column 2

Lieutenant John A. Macready, 28 September 1921. “The cold, though a severe drain on the system with the best protection possible, is more easily met. To prepare for it, Lieutenant Macready wears over his uniform, a heavy suit of woollen underwear and over that a thick heavily padded, leather-covered suit of down and feathers. Then, fur-lined gloves, fleece-lined moccasins over the boots, and a leather head mask lined with fur, which, with the oxygen mask, completely covers the face, completes the costume. The goggles are coated on the inside with anti-freezing gelatine supposed to function to 60 degrees below zero, Fahrenheit.” (NASM)

Lieutenant Macready reported, “My watch stopped at 30,000 feet and I believe it was frozen, because just before landing it started again.” He observed a temperature of -62 °C. (-79.6 °F.) at 34,600 feet (10,546 meters), which he said then increased to -56 °C. (-68.8 °F.) at 36,000 feet (10,973 meters).

When the airplane was inspected after landing at McCook Field, it was found that a crack had developed in the supercharger intercooler, allowing the supercharged air to escape. This resulted in a significant loss of power, and prevented Macready from passing Callizo’s record.

Lieutenant Macready reported that the Fédération Aéronautique Internationale altimeter (one of two altimeters in the airplane’s cockpit) had indicated that he had reached a maximum of 36,200 feet (11,034 meters). When the sealed barograph was sent to the Bureau of Standards in Washington, D.C., for calibration, it indicated a peak altitude of 38,704 feet (11,797 meters). This was 269 meters (883 feet) lower than the existing world record, but it did establish a new United States national altitude record.

Letter from Orville Wright to the National Aeronautic Association, 11 March 1926.
Engineering Division XCO-5, A.S. 23-1204. (U.S. Air Force)

The XCO-5 was a prototype two-place, single-engine, two-bay biplane, a reconnaissance and observation variant of the TP-1 fighter. It was built by the Engineering Division at McCook Field. The airplane carried project number P305 painted on its rudder.

The XCO-5’s wings were built specifically for flight at very high altitude, using an airfoil (Joukowsky StAe-27A) designed by Professor Nikolay Yegorovich Zhukovsky (Николай Егорович Жуковский), head of the Central AeroHydroDynamics Institute (TsAGI) at Kachino, Russia. The two-bay biplane wings had a significant vertical gap and longitudinal stagger. The lifting surface was 600 square feet (55.742 square meters). The upper wing had dihedral while the lower wing did not.

The XCO-5 was 25 feet, 1 inch long (7.645 meters) with a wingspan of 36 feet (10.973 meters) and height of 10 feet (3.048 meters). The empty weight was 2,748 pounds (1,246 kilograms) and the gross weight was 4,363 pounds (1,979 kilograms).

The XCO-5 was powered by a water-cooled, 1,649.34-cubic-inch-displacement (27.028 liter) Liberty 12 single overhead cam (SOHC) 45° V-12 engine. It produced 408 horsepower at 1,800 r.p.m. The L-12 is a right-hand tractor, direct-drive engine. As installed on A.S. 23-1204, the engine turned a specially-designed, two-bladed, ground-adjustable, forged aluminum propeller with a diameter of 10 feet, 6 inches (3.200 meters). The Liberty 12 was 67.375 inches (1.711 meters) long, 27.0 inches (0.686 meters) wide, and 41.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms).

Also installed on A.S. 23-1204 was an experimental supercharger. FLIGHT explained:

Since the Liberty engine, which delivers 400 h.p. at sea level, has an output of but 50 h.p. at 35,000 feet unsupercharged, a supercharger is a prime requisite of altitude work. The General Electric Form F, 20,000-ft. side type supercharger used in previous tests, with certain modifications, has been installed. The supercharger is an air compressor which keeps the air pressure in the carburettor at sea level pressure at heights where, owing to the natural decrease in the air pressure, the horsepower gradually falls away but to a fraction of its original output. In former supercharger installations, much difficulty was experienced with pre-ignition of the engine. This often became so pronounced that the plane had to be brought to earth. It was suspected that a richer mixture with the supercharger at altitude was necessary. This was found to be true but the principal difficulty was the overheating of the mixture due to the heat generated in the supercharger itself. Due to the increase in temperature created by the compression in the supercharger, it was necessary to interpose an intercooler between the supercharger outlet and the carburettor in order to obtain satisfactory engine performance. The intercooler, in the form of a honeycomb radiator, was placed on the side of the aeroplane. It was also found that the poor conductivity of the air at high altitudes, additional radiating surface for engine cooling was required. This, with the correction of mixture, put an end to pre-ignition.

FLIGHT, The Aircraft Engineer & Airships, No. 893. (No. 5, Vol. XVIII.), 4 February 1926, Page 69, Column 1

The XCO-5 has a maximum speed of 129 miles per hour (208 kilometers per hour) at Sea Level, and a cruise speed of 117 miles per hour (188 kilometers per hour).

Lieutenant John A. Macready, USAAS, stands in front of the Engineering Division-built XCO-5. (U.S. Air Force)

¹ FAI Record File Number 8384, Gourdou-Leseurre GL.40, 300 c.v. Hispano Suiza

See also: John Arthur Macready (14 October 1887–15 September 1979) [TDiA No. 1,500]

© 2019, Bryan R. Swopes