The 5670kg gross weight limit to which the Lear Jet 23 had been developed proved in practice to be an unnecessary constraint. Most operators were already using two-man crews and, subsequently, CAB licensing requirements for low-capacity jet aircraft were eased. This allowed Lear to take advantage of the basic strength of the design to develop a new version, to FAR.25 standards, with a gross weight of 6123kg. Announced in October 1965, the Learjet 24 introduced among other improvements increased cabin pressurisation for operation at higher altitude. The first Learjet 24 was flown on 24 February 1966 and gained certification the following month. In 1967 Bill Lear's holdings in Lear Jet Corporation were acquired by the Gates Rubber Company. As a result, in January 1970 the Lear Jet Corporation was renamed the Gates Learjet Corporation. A year earlier the company had started delivery of a new Learjet 24B, differing primarily by having uprated 1338kg thrust General Electric CJ610-6 engines. A lighter-weight Learjet 24C was then under development, but this was abandoned in December 1970 in favour of the Learjet 24D. This offered greater range as a result of increased fuel capacity and certification for operation at a higher gross weight. It was recognisable externally by deletion of the non-structural bullet at the junction of the horizontal and vertical tail surfaces and by having square instead of oval cabin windows. A Model 24D/A was also available with take-off weight restricted to 5669kg.

In 1976 these two versions were superseded by the Learjet 24E and Learjet 24F, introducing a new cambered wing and aerodynamic improvements to reduce stall and approach speeds. Although the two models were generally similar, the Learjet 24F differed by having almost 18 per cent greater fuel capacity. Production of the Learjet 24E was terminated during 1979, and that of the Learjet 24F during 1980, 258 model 24s having been built.

3-View

A three-view drawing (1280 x 650)