The successful bidder for the production contract was a colorful Russian immigrant, Alexander de Seversky (1894-1974). He was the president, designer, and test pilot of
his own airplane company, with a fellow immigrant, Alexander Kartveli (1896-1974), as the chief engineer. In 1933, Seversky built an advanced all-metal low-wing monoplane on twin floats. Piloting it himself, Seversky set a new world’s speed record for amphibians, and then reworked his craft as a landplane.
His demonstrations won his company its first contracts: for three SEV-3M military amphibians for Colombia, and 30 BT-8s, the first Air Corps monoplane basic trainers. The first SEV-3M appeared in August 1935 with a 440-hp Wright Whirlwind R-975, sliding canopy over the two cockpits, and two guns.
Using the same one-piece semi-elliptical wing, Seversky had completed a second prototype as a two-seat fighter with deep wheel pants. The SEV-2XP used a 775-hp Wright GR-1670-5, and was the only sample plane built for the two-place competition. But it was damaged on the way to Wright Field and didn’t arrive until June 18, 1935, too late for the specified May date.
When he realized the Army was more interested in single-seat fighters, Seversky replaced the rear seat with a baggage compartment, and retracted the wheels backwards into fairings under the wings. Next, an 850-hp
XR-1820-G5 Wright Cyclone, the single-row radial used
by Army bombers, replaced the twin-row radial. The fuel tank was integral with the center section of the Seversky wing, whose shape remained the same for the whole
The resulting Sev-1XP returned to Wright Field on August 15, demonstrated a 289-mph top speed, and won the favor of the evaluation board. But Curtiss protested that the competition was unfair since, among other things, the Seversky had arrived late after changing to the larger engine. Army officials were not entirely happy with the result, either.
For one thing, only two of the companies interested in fighter design had actually provided prototypes. General Frank M. Andrews, GHQ Air Force commander, complained that the selection board did very little test flying, and recommended more thorough suitability trials.
Assistant Secretary of War Harry H. Woodring set a new date, April 15, 1936, for pursuit proposals, giving the builders a chance to improve their craft. Four builders responded with sample aircraft painted blue and yellow. Consolidated sent the seventh PB-2A (P-30A) modified as a single-seater with a 700-hp Curtiss V-1570-61, the only inline engine in the competition. But that was old technology, with an airframe too big for the power, and the price, $44,000 each for 25, too high for the Air Corps. The Vought V-141 was too small to have the growth potential of the Seversky and Curtiss ships.
Although the Hawk 75 reappeared in April powered by a single-row Wright XR-1820-39 Cyclone, Seversky again stepped up to an 850-hp Pratt & Whitney Twin Wasp R-1830-9 twin-row radial. While the power was the same, the smaller diameter of the Twin Wasp reduced drag and improved visibility.
As it turned out, the Air Corps decided to standardize on the Twin Wasp for production pursuits, and use the Cyclone, because of its lower fuel consumption, on bombers. Seversky won a contract, approved June 30, 1936, for 77 P-35 pursuits, while Curtiss had to be content, for the time being, with three Y1P-36s on a service test contract. To raise capital and get factory space in Farmingdale, Long Island, Seversky sold stock in his company. These investors would take control away from him in less than three years.
Major Seversky and Frank Sinclair used the original SEV-1 prototype as a personal plane and racer in 1937. A larger contract was to be awarded from bids opened April 2, 1937, so another prototype was built and Seversky challenged Curtiss again when he flew his AP-1 to Wright in March, 1937. Actually a preproduction P-35, the AP-1 had a bulged windshield, and the retracting wheels fully enclosed in fairings. But this time Curtiss got the contract.
The AP-1 was having various problems, including landing gear failures, Seversky’s Farmingdale factory was behind schedule, and General H.H. Arnold was, by April 15, complaining that the company “misrepresented the performance” of its planes in advertising.
Seversky had trouble producing his P-35s. The first true P-35 arrived late at Wright Field on May 7, 1937, (contract date had been January 30) with what became the standard windshield. In July, the second P-35 appeared with practical open-sided wheel fairings and added more dihedral to the wing. Making these changes delayed deliveries so that only four Army P-35s had been accepted by the end of 1937, along with six variants built for others.