Learjet 24

The Learjet 24 is an American six-to-eight-seat (two crew and four to six passengers) twin-engine, high-speed business jet, which was manufactured by Learjet as the successor to the Learjet 23.

Quick Facts General information, Type ...

Learjet 24
NASA Learjet 24
General information
Type	Business jet
Manufacturer	Learjet
Status	Active
Number built	259
History
Manufactured	1966–1977
Introduction date	November 9, 1966
First flight	January 24, 1966

Close

The Learjet 24 was designed as an improved version of the Learjet 23, which was limited to 12,500 pounds (5,700 kg) gross weight. Engineers designed the model 24 to accept up to the full 13,500 pounds (6,100 kg) gross weight permitted by FAR-25 standards.

Other improvements introduced in the Learjet 24 included:

• increased cabin pressurization, to allow a higher operating altitude
• the addition of one extra window on the right side of the cabin
• more powerful engines
• a new windshield
• auxiliary fuel in wing tip tanks
• a fire-extinguishing system for the engines

With these changes, the LJ24 became the first business jet to be certified under FAR-25.^[1]

The first flight of a Learjet 24 took place on January 24, 1966. From May 23 to 26, 1966, a Learjet 24 flew around the world in 50 hours and 20 minutes flying time as a demonstration of its capabilities.^[1] Different variants were the 24A, B, C, D, E and F, with changes of takeoff weight, in-fuselage fuel tank, range, cabin and engines.

Altogether 259 Model 24s were built, and in 2001, there were still 210 Learjet 24s in use. Thirty-nine LJ24s have been lost through accidents.

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 December 31, 2015. The Learjet 24 is listed explicitly in Federal Register 78 FR 39576. Any Learjet 24s 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 December 31, 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 December 31, 2015.

Mainly used by private individuals and corporations, one aircraft was used by NASA as the Learjet Observatory [de].

On January 6, 1977, Dolly Sinatra, the mother of Frank Sinatra, was one of four killed when Learjet 24 N12MK crashed into a mountain following a departure from Palm Springs Airport, United States.^[2][3][4]

• 055 – Learjet 24 on static display at the Tillamook Air Museum in Tillamook, Oregon.^[5][6][7]
• 24-131 – Learjet 24 on static display at Wings Over the Rockies Air and Space Museum in Denver, Colorado.^[8]
• 193 – Learjet 24B on display at the Dakota Territory Air Museum in Minot, North Dakota.^[9][10]
• 203 – Learjet 24B on static display at the Evergreen Aviation & Space Museum in McMinnville, Oregon.^[11][12]
• 281 – Learjet 24D on display at the Frontiers of Flight Museum in Dallas, Texas.^[13]
• Learjet 24D on display at ITE College Central
• 163 - Learjet 24F on display at Lewis University in Romeoville, Illinois. Formerly owned by Arnold Palmer from 1968-1976. Donated to Lewis By Waste Management in 1986 for use by maintenance students in their Aviation Department.

Data from Jane's All The World's Aircraft 1976–77^[14]

General characteristics

• Crew: Two (pilot & co-pilot)
• Capacity: 6 passengers
• Length: 43 ft 3 in (13.18 m)
• Wingspan: 35 ft 7 in (10.85 m) (over tip-tanks)
• Height: 12 ft 3 in (3.73 m)
• Wing area: 231.77 sq ft (21.532 m²)
• Aspect ratio: 5.01:1
• Airfoil: NACA 64A109
• Empty weight: 7,130 lb (3,234 kg)
• Max takeoff weight: 13,500 lb (6,123 kg)
• Fuel capacity: 840 US gal (700 imp gal; 3,200 L)
• Powerplant: 2 × General Electric CJ610-6 turbojets, 2,950 lbf (13.1 kN) thrust each

Performance

• Maximum speed: 545 mph (877 km/h, 474 kn) at 31,000 ft (9,400 m)
• Never exceed speed: Mach 0.86
• Cruise speed: 481 mph (774 km/h, 418 kn) at 45,000 ft (14,000 m) (econ cruise)
• Stall speed: 100 mph (160 km/h, 87 kn) (gear and flaps down) - IAS
• Range: 1,695 mi (2,728 km, 1,473 nmi) 4 passengers, max fuel, 45 min reserves
• Service ceiling: 45,000 ft (14,000 m)
• Rate of climb: 6,800 ft/min (35 m/s)
• Takeoff length to 35 ft (11 m): 2,800 ft (850 m)
• Landing distance from 50 ft (15 m): 2,450 ft (750 m)

• 1988 Mexico Learjet 24 crash^[15][16][17]
• 1999 South Dakota Learjet 35 crash

Related development

• Learjet 23
• Learjet 25

Aircraft of comparable role, configuration, and era

• North American Sabreliner