The Learjet 25 was the best-selling early private jet. Developed at a time when the private flying market was still new, it set the way for later Learjet developments.

The Learjet 23 - one of the first private jets

The concept of an exclusive jet for personal use instead of shared commercial flying arose in the 1950s. Lockheed was the first to launch such an aircraft, with the Lockheed JetStar in 1957. This four-engine jet was originally designed for a military contract, carrying up to 10 passengers and two crew. Lear Jet (the company at that time was branded as Lear Jet, rather than the one-word term it later became) soon followed with the Learjet 23, flying in 1964.

Photo: Shutterstock / OLEG PLESHKOV

This aircraft was capable of high-speed flight and had space for just four to six passengers. It also introduced the unusual two-panel cockpit window that remained a feature of most Learjet aircraft.

The Learjet 24 and Learjet 25

The Learjet 23 was a successful development. The specifications matched what people wanted in the early days of the private industry (much more so than the Lockheed jet, which was not further developed). Equally importantly, the image and brand became popular. Celebrities and VIPs wanted to be seen flying in the Learjet, which further helped market it for private and business flying. Just over 100 aircraft were delivered up to 1966.

Photo: RAF-YYC via Wikimedia

Learjet quickly followed with an updated aircraft, the Learjet 24 (pictured above). This offered improved engines and increased maximum takeoff weight. It was introduced in 1966, replacing the Learjet 23 in production, and 259 aircraft were delivered up to 1977.

The company also saw a market for a larger private jet. It also launched the Learjet 25 as a stretched version of the Learjet 24 in 1966. It used the same design and engines as the Learjet 24, but the fuselage was lengthened by 1.27 meters, taking passenger capacity up to eight. Additional windows easily distinguish this lengthened cabin.

Photo: Aeroprints.com via Wikimedia

With the larger aircraft proving popular, Learjet kept the Model 25 in production for around 16 years. Over this time, several modified variants were developed. The Learjet 25B brought the first design improvements in 1970. The Learjet 25C the same year offered higher fuel capacity. The Learjet 25D was a longer-range model, using upgraded engines (General Electric CJ610-8A upgraded from the CJ610-6) and featured an increased operational flight ceiling.

The most successful early Learjet

Learjet's view of the market wanting a larger aircraft was right, and the Learjet 25 was the best-selling of these three early jets. By the time production ended in 1982 (much later than the Learjet 24), 369 Learjet 25 aircraft had been delivered.

As well as private ownership and charter operators, Learjet 25s have seen use with NASA in the United States and militaries in several countries, including Argentina, Bolivia, Mexico, and Peru.

Photo: Public Domain via Wikimedia

The next jets to be developed (with Learjet now merged with Gates Aviation Corporation) were the Model 35 and Model 36, from 1973. The Learjet 28 followed in 1977 and was based on the same fuselage design as the Learjet 25 but with a new wing design. It, and the related longer-range Learjet 29, were not very successful. Later developments moved away from the early design.

Would you like to discuss more about the history, design, or use of the Learjet 25 (or any of the other early Learjet models)? Feel free to do so in the comments section.