Engineering:Learjet 23

Short description: 1966 business jet aircraft

Learjet 23
Role	Business jet
Manufacturer	Learjet
Designer	William Powell Lear, based on a design by Dr.eng. Hans-Luzius Studer
First flight	7 October 1963
Introduction	13 October 1964
Status	Active
Produced	1964–1966
Number built	101

The Learjet 23 (originally Lear Jet 23) is an American six-to-eight-seat (two crew and four to six passengers) twinjet, high-speed business jet manufactured by Learjet. Introduced in 1964, it was Learjet's first model and created a new market for fast and efficient small business aircraft. Production ended in 1966 after 101 aircraft had been delivered.

Development

Recognizing the potential of the Swiss-designed single-engine ground-attack FFA P-16 fighter jet, William (Bill) Powell Lear, Sr. established Swiss American Aviation Corporation (SAAC) to produce a two-engined passenger version: the SAAC-23 Execujet. The company moved to Wichita, Kansas and was renamed Lear Jet Corporation. Production began on the first Model 23 Lear Jet on 7 February 1962. The first flight took place on 7 October 1963 with test pilots Hank Beaird and Bob Hagen. On 4 June 1964, the prototype crashed soon after takeoff, when the pilot inadvertently deployed the wing spoilers while demonstrating an engine failure on takeoff. Eventually determined to be pilot error, this mishap did not deter the Federal Aviation Agency (later the Federal Aviation Administration) from awarding the Lear Jet 23 its type certificate on 31 July 1964. On 13 October 1964, the first production aircraft was delivered.

Production ended in 1966 after one hundred and one aircraft had been delivered. In 1998, thirty nine Model 23s were estimated to remain in use. Twenty seven are known to have been lost or damaged beyond repair through accidents, the most recent being in 2008.

Noise compliance

In 2013, the FAA modified 14 CFR part 91 rules to prohibit the operation of jets weighing 75,000 pounds or less that are not stage 3 noise compliant after 31 December 2015. The Learjet 23 is listed explicitly in Federal Register 78 FR 39576. Any Learjet 23s that have not been modified by installing Stage 3 noise compliant engines or have not had "hushkits" installed for non-compliant engines will not be permitted to fly in the contiguous 48 states after 31 December 2015. 14 CFR § 91.883 Special flight authorizations for jet airplanes weighing 75,000 pounds or less – lists special flight authorizations that may be granted for operation after 31 December 2015.

Aircraft on display

NASA Learjet 23 chase aircraft

• N802L – Model 23 on static display at the Udvar-Hazy Center of the National Air and Space Museum in Chantilly, Virginia.
• N505PF – Model 23 on static display at the Kansas Aviation Museum in Wichita, Kansas.
• N20EP – on display outside White Industries, Bates City, Missouri.
• N23BY – Model 23 on display at the Arkansas Air & Military Museum in Fayetteville, Arkansas. This airframe was flown by Bobby Younkin in air shows.
• N154AG – Model 23 on static display at the Museum of Flight in Seattle, Washington.
• N73CE – Model 23 on display at the Yanks Air Museum in Chino, California.
• N824LJ – Model 23 on static display at the Air Zoo in Portage, Michigan.
• N88B – Model 23 on static display at the Pima Air and Space Museum in Tucson, Arizona.

Operators

United States

• NASA
• Executive Jet Aviation

Specifications

Data from Jane's All The World's Aircraft 1965–66

General characteristics

• Crew: Two pilots
• Capacity: 6 passengers
• Length: 43 ft 3 in (13.18 m)
• Wingspan: 35 ft 7 in (10.84 m)
• Height: 12 ft 7 in (3.84 m)
• Wing area: 231.2 sq ft (21.48 m²)
• Empty weight: 6,150 lb (2,790 kg)
• Max takeoff weight: 12,499 lb (5,669 kg)
• Powerplant: 2 × General Electric CJ610-4 turbojet engines, 2,850 lbf (12.7 kN) thrust each

Performance

• Maximum speed: 561 mph (903 km/h, 487 kn) at 24,000 ft (7,300 m)
• Maximum speed: Mach 0.82
• Cruise speed: 518 mph (834 km/h, 450 kn) at 40,000 ft (12,000 m)
• Stall speed: 104 mph (167 km/h, 90 kn) wheels and flaps down
• Range: 1,830 mi (2,950 km, 1,590 nmi) max fuel at 485 mph (781 km/h; 421 kn) and 40,000 ft (12,000 m)
• Service ceiling: 45,000 ft (14,000 m)
• Rate of climb: 6,900 ft/min (35 m/s)

See also

Related development

• Rogers P-51R, a custom-built racing aircraft with the wings and horizontal stabilizer of a Learjet 23

Related lists

• List of aircraft

External links

• A history of the Learjet 23-29 series on Airliners.net
• Lear Jet Prototype Nears October Flight Date – Aviation Week & Space Technology
• The William P. and Moya Olsen Lear Papers at The Museum of Flight (Seattle, Wash.)