Tag Archives: Larry Therkelson

24 March 1939

Jackie Cochran with her Beechcraft D17W, NR18562. (FAI)
Jackie Cochran with her Beechcraft D17W, NR18562. (FAI)

24 March 1939: During a 2 hour, 26 minute flight over southern California, Jacqueline Cochran established a U.S. National Altitude Record for Women of 9,160 meters (30,052 feet). She flew a Beechcraft D17W “Staggerwing,” serial number 164, registered NR18562.

A National Aeronautic Association official, Larry Therkelson, took the recording barograph from the airplane and sent it to the N.A.A. headquarters in Washington, D.C., for certification. The record had previously been held by Ruth Rowland Nichols.¹

“Were I to make the simple statement that I climbed to an altitude of thirty-three thousand feet, that statement in and of itself would mean nothing because I have often gone higher than that. But when I add that I did this in 1937 in a fabric-covered biplane without heating, without pressurization and without an oxygen mask, the elements of an accomplishment are added. I nearly froze; the pipestem between my teeth through which I tried to get an oxygen supply from a tank and connecting tube was inadequate for the purpose, and I became so disoriented through lack of oxygen that it took over an hour to get my bearings and make a landing. The difference between the pressure my body was accustomed to on the ground and the atmospheric pressure at 33,000 feet was such that a blood vessel in my sinus ruptured. All this was a part of the cumulative evidence that led up to cabin pressurization and and mandatory use of the oxygen mask above certain altitudes.”

The Stars at Noon, by Jacqueline Cochran, Little, Brown and Company, Boston, 1954, Chapter IV at Pages 61–62.

According to the U.S. Centennial of Flight Commission, Jackie Cochran “. . . set more speed and altitude records than any other pilot.”

Beechcraft D17W Staggerwing NR18562, c/n 164, which Jackie Cochran used to set an altitude record, 24 March 1939. (Unattributed)
Beechcraft D17W Staggerwing NR18562, c/n 164, which Jackie Cochran used to set an altitude record, 24 March 1939, at the Beechcraft factory, Wichita, Kansas, 1937. (Beech Aircraft Corporation)

The Beechcraft Staggerwing got its name because its lower wing was placed ahead of the upper wing (negative stagger). It was a fast airplane for its time and set several speed and altitude records. The Beechcraft D17W was a special version of the D17 production model. Only two were built. Jackie Cochran purchased it from Beech for $20,145, and it had been delivered to her by famed aviator Frank Hawks.

The “Staggerwing” was a single-engine, four-place biplane with an enclosed cabin and retractable landing gear, flown by a single pilot. The basic structure was a welded tubular steel framework, with wood formers and stringers. The wings and tail surfaces were built of wood spars and ribs. The airplane was covered with doped fabric, except the cabin and engine, which were covered in sheet metal.

Beech Aircraft Corporation Model 17 “Staggerwings” under construction. (Beech B-111/U.S. Air Force)

The airplane was 26 feet, 10 inches (8.179 meters) long with a wingspan of 32 feet, 0 inches (9.754 meters) and overall height of 8 feet, 0 inches (2.438 meters). It had an empty weight of 2,540 pounds (1,152.1 kilograms) and loaded weight of 4,250 pounds (1,927.8 kilograms).

While most biplanes had staggered wings, the Staggerwing was unusual in having negative stagger. This not only increased the pilot’s field of vision, but improved the airplane’s stability in a stall. The leading edge of the Model 17 upper wing was 2 feet, 1–19/32 inches (0.65008 meters) aft of the lower wing. The leading edges had 0° 0′ sweep. Both wings had an angle of incidence of 5° 5′. The upper wing had no dihedral, but the lower wing had +1°. The mean vertical gap between the wings was 5 feet (1.52 meters), and the chord of both wings was 5 feet, 0 inches (1.524 meters). The total wing area was 269.5 square feet (25.04 square meters). The horizontal stabilizer had 0° incidence, while the vertical fin was offset 0° 43′ to the left of the airplane’s centerline.

Beech D17W NR18562. (Beechcraft)
Beechcraft D17W NR18562, c/n 164, carrying race number “13.” (Beech Aircraft Corporation)

The Staggerwing was offered with a selection of engines of different displacements and horsepower ratings. The standard Beechcraft D17S was equipped with an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liters) Pratt & Whitney Wasp Jr. A, a nine-cylinder radial engine producing 300 horsepower at 2,000 r.p.m at Sea Level. It had a maximum speed of 212 miles per hour (341 kilometers per hour), 670 mile (1,078 kilometer) range and service ceiling of 25,000 feet (7,620 meters).

The 1,343.804-cubic-inch-displacement (22.021 liter) Pratt & Whitney Wasp SC-G engine installed in Jackie Cochran’s D17W was an experimental version of the Wasp C with 5:4 propeller reduction gearing. It produced 600 horsepower at 2,850 r.p.m. for takeoff, and 525 horsepower at 2,700 r.p.m., up to 9,500 feet (2,896 meters). The SC-G never entered production.

Beechcraft D17W c/n 164, was impressed into military service at Tarrant Field, Texas, 12 March 1943. Assigned to the United States Army Air Corps, it was given the designation UC-43K Traveler and Air Corps serial number 42-107277. It was turned over to the Reconstruction Finance Corporation, 22 November 1944, for sale to the civil market. The airplane was now powered by a 971.930-cubic-inch displacement (15.927 liter) Wright R-975-5 Whirlwind nine-cylinder radial and was redesignated Beechcraft D17R. The Staggerwing was sold to the Carver Pump Company, Muscatine, Iowa, and registered NC50958.

The record-setting Beechcraft Staggerwing crashed at Avenger Field, Sweetwater, Texas, 15 December 1945.

Jackie Cochran's beechcraft D17W, NV18562, c/n 164, carrying the race number "33" circa 1937. (Unattributed)
Jackie Cochran’s Beechcraft D17W, NX18562, c/n 164, carrying the race number “33” circa 1937. (Unattributed)

¹ FAI Record File Number 12228: 8,761 meters (28,743 feet), 6 March 1931.

© 2019, Bryan R. Swopes

15 September 1939

Jackie Cochran with her record-setting Seversky AP-7A, NX1384. (FAI)

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

Jackie Cochran with the Seversky AP-7A, NX1384. Her racing number, 13, has not yet been painted on the fuselage. (San Diego Air and Space Museum Archive)
Jackie Cochran with the Seversky AP-7A, NX1384. Her racing number, 13, has not yet been painted on the fuselage. (San Diego Air and Space Museum Archive)

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.


     “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.


      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

Jackie Cochran’s Seversky AP-7, NX1384, at the Union Air Terminal, Burbank, California, September 1939. (Unattributed)

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.

Seversky AP-7 NX1384, seen from below. In this early configuration, the landing gear folds rearward. (San Diego Air & Space Museum Archives)

¹ FAI Record File Number 12027

© 2018, Bryan R. Swopes