Learjet 23

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Learjet 23
Air Zoo Learjet II.JPG
A decommissioned and preserved Learjet 23
Type: Business jet
Design country:

United StatesUnited States United States


Lear Jet Corporation

First flight:

October 7, 1963

Production time:

1962 to 1966

Number of pieces:


The Learjet 23 is a twin-engine business aircraft in low-wing design that from the 1963 Lear Jet Corporation was established. The Learjet 23 was the first aircraft to be designed as a business jet from the start, making it the forerunner of all modern machines of this type.



Learstar , Lockheed Model 18 converted by Lear into a business jet . The D-CABO was one of two Lear aircraft that were delivered to Helmut Horten GmbH in 1956 .

As early as the 1950s, William P. Lear developed the Learstar , his first business jet . To do this, he equipped the airframe of a Lockheed Model 18 Lodestar with new systems and interior fittings for eight to twelve passengers.

After Lear sold the licensing rights to the Learstar, he began to develop a small business jet aircraft around 1960. The first illustration published at the beginning of 1961 showed a low-wing aircraft with two engines attached to the stern and wing end tanks to maximize range. The price for a "bare" cell should be 250,000 US dollars and with a fully equipped cell at 325,000 US dollars for a delivery in 1963.


In order to be able to keep costs down, the cell should be manufactured in Europe, where at the time the labor costs were well below those in the USA. In the USA, the engines, instruments and interior equipment should then be retrofitted. As part of the project, Lear founded the parent company Swiss American Aviation Corp. in Delaware in April 1960 . (SAAC) with a subsidiary Aviation Development Corp. in St. Gallen. In Switzerland, the design was revised with the assistance of Gordon Israel, who had previously designed the Grumman F7F Tigercat and the Grumman F9F Panther before joining Lear to develop the Learstar. Further development work in Switzerland provided Hans-Luzius Studer , the combat aircraft FFA P-16 of the flight and Fahrzeugwerke Altenrhein had constructed largely the wings were taken from. The project was then named SAAC-23 . FFA was supposed to build the prototypes, but not be involved in series production because of the commissioning of the Mirage III production for the Swiss Air Force.


In 1962, the cost of series production had risen to such an extent that Lear abandoned the concept of international production and envisaged production in the USA alone. He founded the Lear Jet Corp in Wichita for this purpose . and there began the production of the prototypes with parts already produced in Europe. A few modifications were made before construction of the prototypes began, for example the rear fuselage was lengthened by 51 cm and the engines moved back by the same amount. The rudder areas have also been enlarged compared to the original design.

The first 30-minute flight of the Lear Jet 23 (the name was later written down as Learjet) of this revolutionary type took place on October 7, 1963 in Wichita. A second prototype began flight tests on March 5, 1964. Efforts to FAA - approved suffered a setback when on June 4, 1964, the first prototype at its 167th flight had to perform a belly landing and then burned. The two pilots survived. FAA approval was confirmed on July 31, 1964. The number "23" in the type designation was chosen because the draft should meet the requirements of the Federal Aviation Regulations (FAR) Part 23 published by the FAA . These specified an upper weight limit of 12,500 lb (5,669.9 kg).


On October 3, 1964, the third aircraft was the first to be delivered to a customer. By 1966, 104 series machines of the Learjet 23 model had been built before production was switched to the successor model Learjet 24 .

In 1998, 39 of the Learjet 23 were still in use. A total of 26 machines were lost in accidents.

With this aircraft, a completely new market for fast, high-performance business aircraft was opened up. It is considered a model for a number of similar aircraft and is still being built in this design today.


The Learjet is a low wing aircraft with two jet engines attached to the rear of the aircraft , the inlets of which are protected by the wings against the sucking in of foreign objects. In order to achieve the projected range of 2000 miles (3200 km), wing end tanks were provided from the start. The aircraft has a two-seat cockpit and a cabin for up to six passengers who are accommodated in the 1 + 1 seat arrangement. Typically, however, only seats for four passengers were installed.

Technical specifications

Parameter Data
crew Max. 6 passengers
length 10.84 m
span 13.18 m
height 3.73 m
Wing area 21.46 m²
Empty mass 2,790 kg
Takeoff mass 5,675 kg
drive 2 × General Electric CJ-610-4 with 12.7 kN each
Top speed 860 km / h
Cruising speed 817 km / h
Service ceiling 13,750 m
Range 2,660 km

See also


  • One thousand Learjets ... and a Longhorn or two! In: AIR International, May 1980, p. 215 ff.
  • John WR Taylor (Ed.): Jane's All The World's Aircraft - 1965–66. Sampson Low, Marston & Company Ltd., London 1965.

Web links

Commons : Learjet 23  - collection of images, videos and audio files

Individual evidence

  1. ^ John Fricker: Switzerland's P-16 - Father of the Learjet. AIR International, March 1991, pp. 139-146.