Learjet 35

The Learjet Model 35 and Model 36 are a series of American multi-role business jets and military transport aircraft manufactured by Learjet between 1973 and 1993. When used by the United States Air Force, they carry the designation C-21A. Learjet was acquired by Bombardier Aviation in 1990 and is now a subsidiary, so the aircraft is also known as the Bombardier Learjet 35.

When first released in 1973, the Learjet 35 was among the fastest medium haul jets of its era. As of 2020, more Learjet 35s have been sold than any other Learjet aircraft, with many still in service after 50 years.

The aircraft are powered by two Garrett TFE731-2 turbofan engines. Its cabin can be arranged for six to eight passengers. The longer-range Model 36 has a shortened passenger area to provide more space in the aft fuselage for fuel tanks.

The engines are mounted in nacelles on the sides of the aft fuselage. The wings are equipped with single-slotted flaps. The wingtip fuel tanks distinguish the design from other aircraft having similar functions.

Development
The concept which became the LJ35 began as the Learjet 25BGF (with GF referring to "Garrett Fan"), a Learjet 25 with a then-new TFE731 turbofan engine mounted on the left side in place of the 25's General Electric CJ610 turbojet engine. This testbed aircraft first flew in May, 1971. As a result of the increased power and reduced noise of the new engine, Learjet further improved the design, and instead of being simply a variant of the 25, it became its own model, the 35.

By 2018, 1980s Learjet 35As start at $500,000.

Operational history
When released in 1973, Learjet's marketing claimed that the Learjet 35 was among the fastest business jets in its class. In 1976 American professional golfer Arnold Palmer used a Learjet 36 to establish a new round-the-world class record of 22,894 miles (36990 km) completed in 57 hours 25 minutes 42 seconds.

Because of its speed and long range, leaders of many nations bought the aircraft as their primary or secondary jet. Countries who did this include: Brazil, Chile, Finland, Switzerland and Saudi Arabia among others.

During the Cold War, the Finnish Air Force has used the Learjet 35/36 as a shorter range AWACS aircraft, for monitoring Soviet bombers and fighter jets coming over the Baltic Sea and over the Arctic. Learjet 35s made the bulk of Argentina's Escuadrón Fénix flights during the 1982 Falklands War mainly on diversion and reconnaissance flights.

Production on the 35/36 series ceased in 1994. There are still well over 500 Learjet 35s in service around the world, despite the model being almost 50 years old.

, the U.S. National Transportation Safety Board database lists 25 fatal accidents for the 35/35A, and two for the 36/36A.

Learjet 35
The original Model 35 was powered by two TFE731-2-2A engines and was 13 inches longer than its predecessor, the Model 25. First flight of the prototype Model 35 was on 22 August 1973, and the aircraft was FAA certified in July, 1974. It could carry up to eight passengers. There were 64 base-model 35s built.

Learjet 35A
The Model 35A is an upgraded Model 35 with TFE731-2-2B engines and a range of 2,789 miles, with a fuel capacity of 931 US gallons (3,524 L) with refueling accomplished at ground level through each wingtip tank. It was introduced in 1976, replacing the 35. Over 600 35As were built, with a production line that ended with serial number 677, in 1993.

On February 12, 1996, a Learjet 35A, N10BD, owned by Cable Television Founder Bill Daniels and piloted by Mark E. Calkins, Charles Conrad, Jr., Paul Thayer, and D. Miller completed an around-the-world flight in a record 49 hrs, 21 min, and 8 sec. The record remains standing. This aircraft is now on display in Terminal C of Denver International Airport.
 * Learjet 36
 * The Model 36 is essentially identical to the 35, except that it has a larger fuselage fuel tank, giving it 500 miles longer range, but reducing the passenger area's length by 18 inches (0.46 m). It was certified, along with the 35, in July, 1974.


 * Learjet 36A
 * Like the 35A, the Model 36A has upgraded engines and a higher maximum gross weight. It was introduced in 1976, replacing the 36.

Military variants

 * C-21A
 * The C-21A is a United States military designation for an "off the shelf" variant of the Learjet 35A for the United States Air Force, with room for eight passengers and 42 ft3 (1.26 m3) of cargo. In addition to its normal role, the aircraft is capable of transporting litters during medical evacuations. Delivery of the C-21A fleet began in April 1984 and was completed in October 1985.


 * There are 38 Air Force active duty aircraft, and 18 Air National Guard aircraft in the C-21A fleet. On 1 April 1997, all continental U.S.-based C-21As were realigned under Air Mobility Command, with the 375th Airlift Wing at Scott Air Force Base, Illinois, as the lead command. C-21As stationed outside the continental United States are assigned to the theater commanders.


 * U-36A
 * A Japanese military designation (not a U.S. military designation). Utility transport, training version of the Learjet 36A. Equipped with a missile seeker simulator in addition to a radar, avionics, firing training assessment devices, an ejector pylon, a special communications system, a target towing system and a jammer system. Six were built for the Japan Maritime Self-Defense Force.

Success and popularity
When first released in 1973, the Learjet 35 was among the fastest medium haul jets of its era. As of 2020, more Learjet 35s have been sold than any other Learjet aircraft.

As a private jet the Learjet 35 was popular because of its good range (it can fly 2,056 miles nonstop), takeoff and landing performance (its Honeywell engines provide 3,500 pounds of thrust and can land on short runways at regional airports), fast cruise capabilities (it can cruise at speeds as high as 451 knots true airspeed (KTAS), or 424 KTAS with four passengers), good handling characteristics, a low fuel burn, and comfortable cabins. Together with the Learjet 25, the Learjet 35 was a favorite among celebrities.

The Learjet 35 is one of Bombardiers most successful light jets and remains one of the fastest in its category on the private jet charter market.

The Learjet 35 has been used to film aerial sequences for movies. A camera-equipped Learjet 35 was used to film some of the aerial sequences for the 1980 film The Final Countdown.

The Learjet 35 also appeared in the movies Between the Lines (Ep. 3.05, 1994), A Wing and a Prayer (1998 TV Movie), Free Fall (1999), Prison Break (season 4) (Ep. 4.18, 2008), The Bourne Legacy, Fast & Furious 6 (2013), and many others.

A 2018 survey by Corporate Jet Investor found 14.9% of Americans recognized the Learjet brand compared with 12.5% for Boeing.

Notable accidents and incidents

 * On 7 June 1982, during the Falklands War, a Learjet 35 of Argentina's Escuadrón Fénix was shot down by HMS Exeter. The aircraft had been participating in a reconnaissance mission when it was hit by a Sea Dart surface-to-air missile launched by the destroyer. All five crew were killed.
 * On 13 February 1983, a Learjet 35A carrying Sri Lankan business tycoon Upali Wijewardene disappeared over the Straits of Malacca (Malaysia). The wreckage has never been found, nor any trace of Wijewardene, his top executives, or crew.
 * On 17 September 1994, a Learjet 35A owned by Golden Eagle Aviation was accidentally shot down by the Republic of China Navy while being used as a target tug. All four crew on board were killed.
 * On 17 April 1995, a C-21 crashed into a wooded area near Alexander City, Alabama killing the two pilots and six passengers, including Clark G. Fiester, assistant secretary of the Air Force for acquisition, and Major General Glenn A Profitt II.
 * The 1996 New Hampshire Learjet 35A crash on Christmas Eve, 24 December, led to the longest missing aircraft search in that state's history, lasting almost three years, and eventually resulted in Congressional legislation mandating improved emergency locator transmitters (ELTs) be installed in U.S.-registered business jets.
 * On 29 August 1999, a U.S.-registered Learjet 35A owned by Corporate Jets, Inc., was shot down near Adwa, Ethiopia, while flying from Luxor, Egypt, to Nairobi, Kenya, with the loss of three persons.
 * On 25 October 1999, professional golfer Payne Stewart and five others were killed in the crash of a Learjet 35. The plane apparently suffered a loss of cabin pressure at some point early in the flight. All on board are thought to have died of hypoxia, lack of oxygen. The plane, apparently still on autopilot, continued flying until one engine flamed out, most likely from fuel starvation. It crashed near Aberdeen, South Dakota after an uncontrolled descent. The exact cause of the pressurization failure and the reason behind the crew's failure or inability to respond to it have not been definitively determined.
 * On 24 October 2004, A Learjet 35A, N30DK,, departed Brown Field's runway 08 at 00:23 after dropping a medical patient off, and was returning to Albuquerque. It climbed straight ahead and the SoCAL TRACON controller instructed the pilots to turn to a heading of 020 degrees, maintain VFR (visual flight rules), and expect their IFR clearance above 5,000 feet. The aircraft then entered a broken-to-overcast layer of clouds and crashed into the Otay Mountain at an altitude of 2300 feet, killing all 5 occupants.
 * On 9 March 2006, Argentine Air Force Learjet 35A serial T-21 struck terrain and broke up shortly after takeoff from El Alto International Airport in La Paz, Bolivia killing all 6 on board. The Learjet was sent to Bolivia to deliver humanitarian aid.
 * On 4 November 2007, a Learjet 35A crashed in São Paulo, Brazil, after a failed takeoff attempt. It destroyed a house in a residential area near the Campo de Marte Airport, killing the pilot, co-pilot and 6 family members who were in the house.
 * On 24 June 2014, a Learjet 35A of the Gesellschaft für Flugzieldarstellung (GFD) was involved in a mid-air collision with a Eurofighter Typhoon of the German Air Force and crashed at Olsberg, Germany.
 * On 9 November 2014, a private Learjet 36 crashed in Freeport, Grand Bahamas, Bahamas. The jet struck a shipping crane at the Grand Bahama Ship Yard, exploding on impact and crashing into the ground near a junkyard area. The plane was en route from the Lynden Pindling International Airport with nine people on board heading to Grand Bahama International Airport. All nine persons perished, including Myles Munroe, a Bahamian pastor.
 * On 15 May 2017, Learjet 35A aircraft N452DA was on a repositioning flight from Philadelphia to Teterboro Airport in New Jersey, near New York City. The two pilots were killed after the aircraft stalled and crashed into a warehouse while circling to land. The NTSB investigation cited pilot error in continuing an unstable approach.
 * On 27 December 2021, Learjet 35 aircraft N880Z was en route to Gillespie Field (KSEE) in El Cajon, California, near San Diego when it crashed onto a nearby street, killing all four occupants.
 * On July 1, 2022, a medical flight Learjet 35A, registration LV-BPA suffered an accident at the Río Grande Gob. Ramón Trejo Noel airport, in the Province of Tierra del Fuego, Antarctica and South Atlantic Islands, Argentina, killing all four occupants.
 * On, November 1, 2023, A Learjet35A operating as an air ambulance, overran runway 20 at Cuernavaca Airport in Morelos and went into step sided ravine, bursting into flames. The 2 pilots along with a passenger and a patient were killed.

Civilian operators
The Learjet 35 is operated by private, corporate and air taxi operators.

Military operators

 * Argentine Air Force - operates a single Learjet 35.
 * Bolivian Air Force
 * Brazilian Air Force - six in service.
 * Chilean Air Force - two in service.
 * Finnish Air Force - three in service.
 * Japan Maritime Self Defense Force - four Learjet 36 in service.
 * Mexican Air Force
 * Namibian Air Force
 * Peruvian Air Force - one Learjet 36 in service.
 * Royal Saudi Air Force
 * 🇨🇭 Switzerland
 * Swiss Air Force
 * United Arab Emirates Navy
 * United States Air Force - 19 C-21A in service.
 * United States Navy - Two Learjet 35/36s.
 * Uruguayan Air Force - Operated one L-35A from 1981 to 1988.
 * Royal Thai Air Force
 * Peruvian Air Force - one Learjet 36 in service.
 * Royal Saudi Air Force
 * 🇨🇭 Switzerland
 * Swiss Air Force
 * United Arab Emirates Navy
 * United States Air Force - 19 C-21A in service.
 * United States Navy - Two Learjet 35/36s.
 * Uruguayan Air Force - Operated one L-35A from 1981 to 1988.
 * Royal Thai Air Force
 * United States Navy - Two Learjet 35/36s.
 * Uruguayan Air Force - Operated one L-35A from 1981 to 1988.
 * Royal Thai Air Force
 * Royal Thai Air Force
 * Royal Thai Air Force