21 September 1937: Jackie Cochran flew the Seversky Aircraft Corporation SEV-S1, civil registration NR18Y, over a 3 kilometer course at Detroit Wayne County Airport, Romulus, Michigan, averaging 470.40 kilometers per hour (292.29 miles per hour). This was a new Fédération Aéronautique Internationale (FAI) world speed record.¹
The Seversky SEV-S1 Executive was an improved version of the P-35 fighter, which was designed by Major Alexander P. de Seversky. The P-35 was the first U.S. Army Air Corps single-engine airplane to feature all-metal construction, an enclosed cockpit and retractable landing gear.
The airplane had been built as the SEV-2XP, a two-place monoplane with fixed landing gear, and powered by an air-cooled, supercharged 1,666.860-cubic-inch-displacement (27.315 liter) Wright Aeronautical Division GR1670 two-row, 14-cylinder radial engine.
The SEV-2XP was to be a second entry, along with the SEV-1XP, to enter a fly-off against the Curtiss 75 Hawk for the Air Corps fighter contract in 1935. It was damaged, though, while en route Wright Field. The prototype was rebuilt as a single-place airplane with retractable landing gear and a 1,000-horsepower Wright Cyclone GR-1820G4 nine-cylinder engine. In this configuration, the airplane was designated SEV-1XP.
After the Air Corps demonstrations, which resulted in an order for 100 Seversky P-35s, NX18Y was again repowered, this time with an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engine. The R-1830-11 had a compression ratio of 6.7:1 and was rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. 87-octane aviation gasoline was required. The engine turned a three-bladed Hamilton-Standard controllable-pitch propeller through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
With the Twin Wasp, NR18Y’s designation was changed to SEV-S1. Frank Sinclair, Seversky’s chief test pilot, flew it in the 1937 Bendix Trophy Race and the Thompson Trophy Race. (Jackie Cochran flew a Beech Staggerwing in the ’37 Bendix, beating Sinclair and NX18Y by 33 minutes.) Sinclair went on to place fourth in the Thompson pylon race. The Seversky averaged 252.360 miles per hour (406.134 kilometers per hour).
15 September 1939: Jackie Cochran set a Fédération Aéronautique Internationale (FAI) World Speed Record flying a Seversky AP-7A, civil registration NX1384, over a 1,000 kilometer course, from Burbank, California, to San Mateo, approximately 20 miles (32 kilometers) south of San Francisco, and back to Burbank. Her average speed was 492.34 kilometers per hour (305.93 miles per hour).¹
The Los Angeles Times reported:
Woman Flyer Sets Air Record
Jacqueline Cochran Betters Speed Mark for 1000 Kilometers
Streaking a path across the hills to the north of Union Air Terminal, a tiny silver pursuit plane yesterday roared a successful climax to Jacqueline Cochran’s bid for a new 1000-kilometer speed record. Her time: 2h. 2m. for an average of 309 m.p.h. to San Mateo and return.
The slim, brown-eyed pilot, America’s No. 1 woman speed flyer, settled her sleek Seversky on the runway, braked the ship to a stop and pulled off her helmet to loose a flood of tawny hair before the propeller blades stopped turning.
STARTS AFTER LUNCH
“Whew!” she said. “Has anyone got a cigarette?”
It was shortly after lunch that Miss Cochran, clad in green slacks and coat, climbed into her 1200-horsepower ship and thundered down the runway to climb in circles to 10,000 feet. Loosing a trail of blue smoke at this altitude she was officially clocked on the course by Larry Therkelson, Southland representative of the National Aeronautic Association, who checker her in again at the same level 2h. and 2m. later.
KEEPS PLANE HIGH
After entering the course, Miss Cochran said, she nosed her low-wing monoplane upward again, climbing to 15,000 feet. At San Mateo, she dropper to 10,000 feet again to circle a pylon, and climbed back to the higher level for the return race.
Miss Cochran said she used oxygen almost continuously during the flight.
It was the second time the comely woman flyer attempted to shatter her own record of 203 m.p.h., her first try last Aug. 26 having gone awry because N.A.A. officials were unable to clock her as she swung above Union Air Terminal at 14,700 feet.
—Los Angeles Times, Vol. LVIII, Saturday, 16 September 1939, Page 6, Column 6
The Seversky AP-7 was an improved civil version of the Seversky P-35 fighter, which was the first U.S. Army Air Corps single engine airplane to feature all-metal construction, an enclosed cockpit and retractable landing gear. It was designed by Major Alexander Nikolaievich Prokofiev de Seversky, a World War I Russian fighter ace.
Cochran’s AP-7A was a specially-built racer, modified from the original AP-7 with a new, thinner, wing and different landing gear arrangement. It was powered by a an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engine rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. The engine turned a three-bladed Hamilton-Standard controllable-pitch propeller through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
This is the same airplane in which she won the 1938 Bendix Trophy.
1 September 1938: Jackie Cochran departed the Union Air Terminal, Burbank, California, at 3:00 a.m., flying her Seversky AP-7, NX1384, c/n 145. Her destination was Cleveland, Ohio, the finish line for the Bendix Trophy Race, 2,042 miles (3,286 kilometers) away.
NX1384 was built by the Seversky Aircraft Corporation of Farmingdale, Long Island, New York, especially for Jackie Cochran. It had been flown from the factory to Burbank by Major de Seversky just two days earlier. His flight set an East-to-West Transcontinental Speed Record of 10 hours, 2 minutes, 55.7 seconds.
The AP-7 racer was an improved version of Major Alexander Nikolaievich Prokofiev de Seversky’s P-35A fighter, which was the U.S. Army Air Corps’ first all-metal single-engine airplane with an enclosed cockpit and retractable landing gear.
Cochran’s AP-7 was powered by an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engine rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. The engine turned a three-bladed Hamilton-Standard controllable-pitch propeller through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
“Finally the P-35 arrived. I decided that I didn’t want to take it into the air for a test even if I could. The racing officials impounded it because it was a prototype and there was some kind of rule about untested planes. I would test it en route. . . Finally, I got to sit in the cockpit. I began to study all the instruments by the hour. I can almost see them still.
“There are about a hundred or more buttons, levers, and other gadgets to push, pull or twirl. . . I close my eyes and reach for everything in the dark. And I keep at this until I can get to them blindfolded and with no false moves. . .
“I finally see Cleveland. . . (a)nd am going so fast that I pass the airport and come in from the wrong side. . . Have I won? The crowds are cheering. It’s a standing ovation. . . I have won the Bendix.”
— Jackie Cochran: An Autobiography, by Jacqueline Cochran and Maryann Bucknum Brinley, Bantam Books, New York 1987, Pages 160–165.
“I often wonder what is meant exactly by a considered risk. . . In my case I never could ponder over the risks too much because I had to take a fast plane whenever it became available to me and make the best of it. I won the 1938 Bendix Race in a Seversky pursuit plane which I had never flown until that night, when, with a heavy overload of gas, I took off in the race. The plane was delivered from the factory to me just two days before the race and under the rules it had to be immediately impounded. It was a prototype that had not yest been tested. I tested it en route during the race. Its feature was that it had wings that were in effect integrated tanks so that most of the wings could be filled with fuel, thus adding range. It developed in flight that the fuel from the right wing would not properly feed the engine. By force on the stick I had to hold that wing much higher than the other from time to time in order to drain the fuel from that right wing into the left wing and from the left wing into the engine. When I got the plane back to the factory after the race a large wad of wrapping paper was discovered near the outlet of the right-wing tank. No wonder the drainage had been bad. How, for example, could that risk be properly considered i advance? The paper in the tank could have been sabotage. Some thought so at the time. More likely it was paper pasted on the inside of the wing during manufacture which had not been removed and which worked loose from the action of the gasoline and the vibration of the plane.”
—The Stars at Noon, by Jacqueline Cochran. Little, Brown and Company, Boston, 1954, at Pages 65–66
Jackie Cochran was the third pilot to leave Burbank, but the first to arrive at Cleveland. Her elapsed time for the flight from California to Ohio was 8 hours, 10 minutes, 31.4 seconds, for an average speed of 249.774 miles per hour (401.895 kilometers per hour). For her first place finish, Ms. Cochran won a prize of $12,500.
After being congratulated on her win by Vincent Bendix and other race officials, Cochran had her Seversky monoplane refueled. She then got back in to its cockpit and took off for Floyd Bennett Field, new York. She landed there 10 hours, 12 minutes, 55 seconds after leaving Burbank. This was a new West-to East Transcontinental Speed Record.
29 August 1938: At 7:37 a.m., Alexander Nikolaevich Prokofiev-Seversky departed Floyd Bennett Field, Brooklyn, New York, flying a Seversky AP-7 Pursuit, NX1384, an all-metal monocoque monoplane of his own design and manufacture, enroute to the Lockheed Air Terminal, Burbank, California, a distance of 2,457 miles (3,954 kilometers). He completed the flight in 10 hours, 2 minutes, 55.7 seconds, setting a new speed record for an East-to-West Transcontinental Flight. Major Seversky refueled during a 30-minute stop at Kansas City.
Larry Therkelson of the National Aeronautic Association was the official timer for the record attempt.
The Los Angeles Times reported:
SEVERSKY SETS RECORD
Flies across Country in Few Minutes More than Ten Hours
Maj. Alexander P. (Sascha) de Seversky, who flew fighting planes for the Czar of Russia and now builds pursuit ships for the American Army, yesterday notched another hour off the already incredibly narrow time-space separating the Atlantic and Pacific coasts.
In a “civilianized” fighter made at his Long Island factory, de Seversky thrashed along the 2600-mile airway from Floyd Bennett Field, N.Y., to Union Air Terminal, Burbank, in ten hours, three minutes, seven seconds, better than 260 miles per hour.
START AND FINISH
He had gobbled a husky breakfast of oatmeal, orange juice and toast in Manhattan as dawn arose over the skyscrapers (at 3:37 a.m. P.S.T.)
Under a blazing Southland sun that shot the mercury to 100 deg. at Burbank, he toyed with a chicken sandwich fifteen minutes after he set his pursuiter’s trim wheels down at exactly 1:40:07 p.m.
De Seversky was greeted—warmly—by Jacqueline Cochran, America’s No. 1 woman speed flyer for whom he was ferrying the all-metal monoplane to Los Angeles. She will retrace his course in the small hours of Saturday, seeking the lion’s share of the $30,000 Bendix Trophy purse.
It was, he said, “Practically nothing.”
In a new age of aeronautics, when pilots break records just in the day’s work during routine assignments, de Seversky stands with the best of ’em.
His time and speed would have been materially bettered if he’d been “trying,” he admitted. At Kansas City, plopping down into TWA’s hangars for refueling, he wasted a precious twenty-nine minutes while mechanics tinkered with his tricky gasoline system.
“Once I was traveling more than 300 miles an hour,” De Seversky admitted.
MERELY A WARM-UP
How much faster he could have flown, the esrtwhile White Russian declined to say—”Wait until ‘Jacky’ starts for Cleveland in the Bendix race,” he interposed.
“I used oxygen part of the way, especially when I climbed to 16,000 over the Kansas prairies during a hailstorm,” he said. “This whole flight was nothing but a warm-up. I could have flown nonstop. Instead, I tried different wing loadings and paused at Kansas City. Sometimes I throttled down to less than 240 miles an hour.”
Two hundred and forty!
Between bites of chicken sandwich, De Seversky pointed out that his 1200-horsepower plane can soar 3000 miles without refilling its wing-to-wing tanks that carry 540 gallons of high octane fuel. That, he observed, carries huge military significance.
“We are learning in the Army,” this builder of the nation’s fastest pursuit ships declared, “that bombardment craft are vulnerable to attack from the air unless properly convoyed.
Turn to Page 5, Column 2
Record Upset by Seversky
Continued from First Page
So—the ‘flying fortress’ that cruises 5000 miles must be accompanied by pursuit ships that can go equally as far nonstop. To Europe from America, for example.
THREE UNDER WAY
“In the United States at least three such planes are underway today. I am building one. Others may be twin-engined—such as the ship being readied at the Lockheed plant—and capable of terrific speeds.”
By Christmas of this year, de Seversky promised, a standard military fighter, soon to be released to Air Corps testers, will crack the long-sought-after 400-miles-an-hour mark.
BENDIX MARK SEEN
De Seversky was cool as he braked his craft to a halt under the gaze of Larry Therkelson, official National Aeronautic Association timer. He removed his earphones, slipped out of his jumper and asked, “When’s lunch?” To statements that he had knocked Roscoe Turner’s five-year-old record of 11h. 30m. silly, he only shrugged.
OTHERS IN RACE
Others in the Bendix race will be Frank Fuller and Miss Cochran in Seversky planes, Robert Perlick, Glendale, in a Beechcraft; Robert Hinschey and Charles LaJotte, Glendale, in a Sparton; Ross Hadley, Burbank, in a Beechcraft; George Armistead, Los Angeles, in a Q.E.D. Special; Bernarr Macfadden, New York publisher, and Ralph Francis, former TWA pilot, in a Northrop Gamma; Paul Mantz, Burbank, in a Lockheed Orion; Frank Cordova, New York, in a Bellanca; Lee Gehlbach, New York, in a Wedell-Williams, and Max Constant, Burbank, in a Beechcraft.
—Los Angeles Times, Vol. LVII, Tuesday Morning, 30 August 1938, Page 1, Column 5, and Page 5, Column 2
NX1384 was built especially for Jackie Cochran. The AP-7 racer was an improved version of Seversky’s P-35A fighter, which was the U.S. Army Air Corps’ first all-metal single-engine airplane with an enclosed cockpit and retractable landing gear.
Cochran’s AP-7 was powered by an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney Twin Wasp S1B3-G (R-1830-11) two-row 14-cylinder radial engine with a compression ratio of 6.7:1. It was rated at 850 horsepower at 2,450 r.p.m. at 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. The engine turned a three-bladed Hamilton-Standard controllable-pitch propeller through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
Two days later, 1 September 1938, Jackie Cochran flew this same airplane to win the Bendix Trophy Race from Burbank to Cleveland, Ohio, a distance of 2,042 miles (3,286 kilometers). Her winning time was 8 hours, 10 minutes, 31.4 seconds, for an average speed of 249.774 miles per hour (401.895 kilometers per hour). After a 40 minute refueling stop, and being congratulated for her Bendix win, she flew on to Bendix, New Jersey, setting a West-to-East Transcontinental Speed Record with a total elapsed time of 10 hours, 7 minutes, 1 second.
The Seversky AP-7 and its military version, the P-35, would be developed over the next few years to become the Republic P-47 Thunderbolt.
2 August 1939: The Boeing Model 294, designated by the U.S. Army Air Corps as the XB-15, serial number 35-277, flown by a crew led by Major Caleb Vance Haynes, set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 5000 Kilometers With 2000 Kilogram Payload, when they flew the experimental long range heavy bomber a distance of 3,109 miles at an average speed of 267.67 kilometers per hour (166.32 miles per hour) while carrying a payload of 2,000 kilograms (4,409.25 pounds).¹
The other members of the XB-15 crew were Captain William D. Old, Walter G. Bryte, Jr., A.C. Brandt, Master Sergeant Adolph Cattarius, Staff Sergeant William J. Heldt, Technical Sergeant Daniel L. Spicer and Staff Sergeant James E. Sands.
The Boeing Model 294, designated XB-15 by the Air Corps, was an experimental airplane designed to determine if a bomber with a 5,000 mile range was possible. It was designed at the same time as the Model 299 (XB-17), which had the advantage of lessons learned by the XB-15 design team. The XB-15 was larger and more complex than the XB-17 and took longer to complete. It first flew more than two years after the prototype B-17.
Designers had planned to use an experimental 3,421.194-cubic-inch-displacement (56.063 liter) liquid-cooled, supercharged and turbosupercharged Allison V-3420 twenty-four cylinder, four-bank “double V” engine. It produced a maximum of 2,885 horsepower at 3,000 r.p.m. The engine was not available in time, however, and four air-cooled Pratt & Whitney R-1830 (Twin Wasp) engines were used instead. With one-third the horsepower, this substitution left the experimental bomber hopelessly underpowered as a combat aircraft. (The Douglas XB-19 was retrofitted with V-3420s in 1942, and re-designated XB-19A.)
The XB-15 was a very large four-engine mid-wing monoplane with retractable landing gear. It was of aluminum monocoque construction with fabric-covered flight control surfaces. The XB-15 had a ten-man crew which worked in shifts on long duration flights.
The prototype bomber was 87 feet, 7 inches (26.695 meters) long with a wingspan of 149 feet (45.415 meters) and overall height of 18 feet, 1 inch (5.512 meters). The airplane had an empty weight of 37,709 pounds (17,105 kilograms) and maximum takeoff weight of 70,706 pounds (32,072 kilograms)—later increased to 92,000 pounds (41,730 kilograms).
The XB-15’s wings used a symmetrical airfoil and were very highly tapered (4:1 from root to tip). They had an angle of incidence of 4½° and 4½° dihedral. The total area was 2,780 square feet (258.271 square meters). A contemporary aeronautical publication wrote, “The airfoil provides constant center of pressure, minimum profile drag with flaps up and high maximum lift with flaps down.” The XB-15’s wings were adapted by Boeing for the Model 314 Clipper flying boat.
As built, the XB-15 was equipped with four air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.978 liter) Pratt & Whitney R-1830-11 (Twin Wasp S1B3-G) two-row 14-cylinder radial engines with a compression ratio of 6.7:1. The R-1830-11 was rated at 850 horsepower at 2,450 r.p.m. and 5,000 feet (1,524 meters), and 1,000 horsepower at 2,600 r.p.m. for take off. They turned three-bladed controllable-pitch propellers through a 3:2 gear reduction. The R-1830-11 was 4 feet, 8.66 inches (1.439 meters) long with a diameter of 4 feet, 0.00 inches (1.219 meters), and weighed 1,320 pounds (599 kilograms).
The experimental airplane had a cruise speed of 152 miles per hour (245 kilometers per hour) at 6,000 feet (1,829 meters), and a maximum speed of 200 miles per hour ( kilometers per hour) at 5,000 feet (1,524 meters). The service ceiling was 18,900 feet (5,761 meters) and maximum range was 5,130 miles (8,256 kilometers).
The bomber could carry a maximum of 12,000 pounds (5,443 kilograms) of bombs in its internal bomb bay, and was armed with three .30-caliber and three .50-caliber machine guns for defense .
Only one XB-15 was built. During World War II it was converted to a transport and re-designated XC-105. In 1945 35-277 was stripped and abandoned at Albrook Field, Territory of the Canal Zone, Panama.