The Kellett Kl-X rotor m front of a Krieder-Reisner Aircraft, (now Fairchitd) where ii was built. (Kellett Photo)
der, air-cooled Velie M-5 radial engine giving 65 HP at 1900 rpm. The propeller for the Szekley was 6 feet in diameter. There is no record of the diameter propeller used on the Velie, but it is assumed to be the same diameter.
Tests began October 14, 1930, apparently at Philadelphia Municipal Airport, on October 15. The Kl-X was moved to Pitcairn Field. Larger wheels from Pitcairn's Cierva C-19 were installed and the taii skid shortened I-V2 inches to increase the ground angle. The RH landing gear failed on the first run with these wheels. Reports show tests were discontinued on December 3, 1930. In spite of the fact that the 65 hp Velie was installed early in November 1930, the Kl-X never left the ground.
Gross weight 775 lbs.
Empty weight 545 lbs*
*E. weight increased 87 lbs. with Velie engine.
Estimated performance with Szekley: Maximum speed 65 mph
Minimum speed N.A.
Absolete ceiling 6000 ft.
Taxi run for takeoff 200ft.
Landing run 25 ft.
Vertical descent 14.5 feet per second
There was no means provided to spin the rotor up mechanically so all attempts to take off had to be made by taxiing faster and faster to build up rotor RPM. One straight run could not be made. Rpm was lost each time on turns and down wind runs. The final test report says, "Air speed 58 mph rotor 150 rpm—-no tendency to take off Broke tailskid Tests discontinued".
Kellett Kl-X fuselage and landing gear.
K-2 autogiro used by steel pier in Atlantic City, an amusement pier
Undaunted, Kellett went on to design a machine similar to the Pitcairn and Cierva style, which had been successful. The differences were that Kellet's was a side-by-side seater, had larger blade area and a much simpler landing gear.
The first flight was on April 24, 1931 by Jim Ray, Pitcairn's chief test pilot. Approval by the Department of Commerce (1931's FAA) was obtained under a "group 2" type certificate # 2431 on May 27, 1931, just about a month after the first flight. Joe Juptner's Volume 5, shows K-2 having ATC437, The Chief of the Department of Commerce, Gilbert Budwjg, flew the K-2 and complained of lack of aileron control at low speeds and slow rate of climb. Flight test notes fail to show any corrective work done between flights. Approval was granted on the promise that the aileron control would be improved.
The Autogiro was flown to Washington for the evaluation by the Department of Commerce. A note on the test report says it took 3V2 hours to fly from Philadelphia to Washington against a 20 mile per hour wind. The return trip required about two hours. The distance is about 130 miles.
The fuselage was gas welded of steel tubing using square tubes for longerons. It was lightly faired on the sides with deep fairing on the top with no fairing on tho
A much simpler landing gear than the Pitcairn models was designed. A long-travel oleo shock strut was attached to the bottom of the wing at the front spar. The lower end was attached to the axle. A drag brace took the taxiing and aft loads. These were attached to a cabin assembly under the fuselage. The axle and drag braces faired into a streamline shape with balsa wood on the aft Side which was wrapped with airplane fabric and doped.
The entire tail assembly was made from wood resulting in a very light structure. Spars were solid spruce, the ribs were light plywood web members with spruce cap strips and a few vertical members. The trailing edged of the rudder and elevators were round aluminum tubes which were pressed into a streamlined shape.
Wing beams were box spars with spruce longitudinal and vertical members. The web members were three-ply mahogany with a 45 degree face grain. Ash blocks were built into the spars at points of heavy loads. Most ribs were made of square spruce cap strips and diagonals; some were made with spruce cap strips and mahogany plywood members. The airfoil, a RAF 30 was symmetrical in shape.
The wings were braced to the fuselage with
Kellett personnel in /9,'i/ at factory in Philadelphia Municipal Airport. Top row: (in frontof windshield) Elliot Daland, formerly of Huff-Daland; to the right of Daland is Chuck Miller. Middle row: Directly below Daland Hugh Mulvey; seated directly belou Miller, Ralph McC (arret); Front row: third from left, Guy Miller, test pilot; Wallace Kellett; Rod Kellett; Unknown. Kellett K-i autogiro in background (Kellett Photo
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