Airliners powered by jet engines had just begun to consolidate their value to airline transport service in 1959 when William P. Lear, Sr. initiated the development of the Learjet. His aircraft design soon demonstrated the combination of form and function that makes an outstanding performer. The first Lear Jets, the Model 23s, were the founding products of the original Lear Jet Corporation and pioneers in the entirely new field of business and personal jet aviation. As an example of this transportation mode, it represents the ability to cruise above most weather, over long distances, and at high speed. Whether the business jet operates as a small airliner or as a more personal independent aircraft, it permits the movement of passengers and small cargo to airports both large and small around the globe.
Performance is the direct result of design and construction, and the design of the Model 23 was based on the known structural quality of a Swiss strike-fighter, the AFA P-16. The cabin of this smallest model Lear Jet seats up to nine persons, including pilots, and may be fully pressurized. The windshield and cabin windows are formed of stretched, laminated, acrylic plastic. The ailerons, elevators, and rudder are mechanically connected to the cockpit controls, while all trim surfaces are electrically operated. There is a small tab on the left aileron for roll and one on the rudder for yaw. The incidence angle of the horizontal stabilizer is changed for pitch trim control. The aircraft has spoilers for speed control on the upper surface of each wing panel forward of the flaps. These are actuated by hydraulic pressure, as is the fully retractable landing gear and multiple disc brakes on the dual mail wheels. As a matter of aerodynamic design, the fuselage narrows at each side as the wing and engine nacelles extend outward. This is a design concept known as "area rule" and is used to smooth the flow of air around these projections during high-speed flight.
On October 7, 1963, prototype Model 23, N801L, made the first flight of a Lear Jet. This original airplane flew 194 hours during 167 separate flights until it was destroyed following a test flight in June 1964. N802L completed its maiden flight of 1 hour, 30 minutes on March 5, 1964, just 135 days after construction began. With the cross-continent flight of a Model 23 on May 21, 1965, Lear Jets began to set formally recognized performance records. On this particular flight, pilots John M. Conroy and Clay Lacy, flying with five observers, covered 5,005 statute miles from Los Angeles to New York and back in 11 hours, 36 minutes. On December 14, 1965, another Model 23, flown by Henry Beaird and Ronald G. Puckett, with five other persons on board, left Wichita to climb to and reach an altitude of 40,000 feet in 7 minutes, 21 seconds. With an engine thrust-to-weight ratio of 1:2.2 pounds, a Model 23 can out climb an F-100 Super Sabre to 10,000 feet, and can be just as impressive on the way down.
The success of the basic Model 23 design and the expansion of the corporate and personal jet market inspired a number of derivative models with increased range, size, and speed. Between May 23 and 26, 1966, the first Model 24, also the 150th production Lear Jet built, flew around the world and set or broke eighteen international aviation records. With Henry Beaird as pilot-in-command, Rick King and John O. Lear as alternates, and John Zimmerman as an observer, the flight of this aircraft covered a straight-line distance of 22,992.8 statute miles in 50 hours, 39 minutes of flight.
Between May 17 and 19, 1976, during the American bicentennial year, Arnold Palmer and James Bir flew a Model 36 from Denver, Colorado, to set a round-the-world speed record. The flight time over a specifically recognized course was 48 hours and 48 minutes for an average speed of 400.23 mph. Flying a Model 28 on February 19-20, 1979, Neil Armstrong set five world records for an aircraft of this class: two for altitude achieved, two for sustained flight at 51,000 feet, and one for high-altitude time-to-climb.
The Lear Jet was a technological advance and a research tool that was significantly involved in the creation of business jet aviation. Gates Learjet produced the Learjet line until 1987 and Bombardier acquired it in 1990. The Learjet line closed in 2021.
The Museum's Lear Jet registration number N802L, is the second prototype Model 23. The factory retained it for continued testing and modification analysis until June 15, 1966, when, during testing of an experimental control-system modification, the aircraft encountered severe vibrations. This damaged the airframe and it was retired from flying status on June 17, 1966, after a total of 1,127 flying hours during 864 flights. Although the flying life of this aircraft came to an end, N802L continued to perform as a full-scale wind-tunnel model with the National Aeronautics and Space Administration. Following this, the aircraft was returned to the factory at Wichita, Kansas, for restoration. Gates Learjet Corporation donated the aircraft to the Museum on October 11, 1977.
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