First produced in 1977, the Learjet 28 and 29 models were created as successors to the Learjet 25. The Lear 28 and 29 are identical apart from the 29’s additional long-range fuel tank, which reduces the aircraft’s capacity to four passengers with two pilots. The Lear 28 and 29 were the first Learjets to feature winglets, creating what they called the “Longhorn” wing that ended up being featured on later models.
Only five Lear 28s and four Lear 29s were produced before the project was cancelled in 1982, due to a lack of interest from aircraft buyers thanks in large part to their noise and fuel consumption. Like many older model Learjets, the Lear 28 and 29 are not permitted to fly in the United States without an FAA-approved hush kit or the installation of modified noise compliant engines due to an FAA mandate that went into effect on December 31, 2015.
Both the Lear 28 and Lear 29 are powered by General Electric CJ610-8A engines. They each have a normal cruise speed of 441 knots. The Lear 28 has a range of 1,450 nautical miles and the Lear 29 has a range of 1,550 nautical miles. Both models have a climb rate of 6,950 feet per minute and require 2,998 feet of runway to takeoff and 2,734 feet to land.
In 1988, deliveries of the Learjet 31 began. The Lear 31, which was created as the successor to the 29, essentially combined the best features of the Lear 35/36, the 28/29 and the 55. It comes equipped with the same engines and fuselage as the Lear 35/36 and the Longhorn wing featured on the 28/29 and 55. In 1990, Learjet became a subsidiary of Bombardier, and the Lear 31A variant was announced. The biggest difference between the original 31 and the 31A is in the cockpit, as the 31A comes equipped with a more advanced Bendix King avionics system (now Honeywell). Bombardier also created an extended range version, dubbed the Lear 31A/ER.
The Lear 31 and its variants are powered by Garrett (now Honeywell) TFE731-2-3B engines, some of which have been upgraded with TFE731-2C-3B engines. They have a normal cruise speed of 429 knots, a range of 1,250 nautical miles (1,800+ for the ER model), a climb rate of 5,480 feet per minute, and require 3,705 feet of runway to takeoff and 3,208 to land.
In 1974, the Learjet 35 and 36 models were introduced. The 36 is identical to the 35, with the exception of a larger fuselage fuel tank on the 36 that increases its range by about 500 nautical miles while reducing its passenger capacity. Compared to the 25, the 35 and 36 are more powerful and produce significantly less noise, in addition to undergoing some design improvements. Both the 35 and 36 were replaced with their “A” variants in 1976, which come equipped with upgraded TFE-731-2-2B engines.
Both the Lear 35A and 36A have a normal cruise speed of 425 knots. The 36A has a range of 2,700 nautical miles compared to 1,990 for the 35A. They each have climb rate of 4,760 feet per minute, while the 35A has a takeoff distance of 6,143 feet and a landing distance of 3,309 feet and the 36A has a takeoff distance of 5,168 feet and a landing distance of 3,309 feet.