The AIDC F-CK-1 Ching-kuo, commonly known as the Indigenous Defence Fighter (IDF), is an air superiority jet fighter with multirole capability named after Chiang Ching-kuo, the late President of the Republic of China. The aircraft made its first flight in 1989.
The IDF program was initiated when the United States of America refused to sell F-20 Tigershark and F-16 Fighting Falcon fighters to the Republic of China (Taiwan) following pressure on the United States from the People's Republic of China (PRC). The Republic of China therefore decided to develop an indigenous fighter. The IDF jet fighter project was designed and built by the Aerospace Industrial Development Corporation (AIDC) based in Taichung, Taiwan, with assistance from American defense corporations.
It entered active service with the Republic of China Air Force in 1994, and 130 production aircraft had been manufactured by 1999.
The AIDC officially began the IDF development project in May 1982 following the ROCAF's failure to purchase new fighters from the United States as a result of the PRC's diplomatic pressure. The project was named An Hsiang:Safe Flight) and divided into four sections in 1983:
- Yin-Yang: "Soaring Eagle". Development of the airframe. Cooperation with General Dynamics.
- Yun-Han: "Cloud Man". Development of the aircraft powerplant and propulsion. Cooperation with Garrett (Now Honeywell).
- Tien-Lei: "Sky Thunder". Development of the avionics systems. Cooperation with Smiths Industries, with some components purchased directly from Lear Astronics (later BAE), Litton (later Northrop Grumman) and Martin-Baker.
- Tien-Chien: "Sky Sword". Development of air-to-air missiles.
The greatest difficulties were encountered by the propulsion group in attempting to develop or acquire suitable advanced jet engines. There is also speculation that the use of less powerful engines was due to political rather than technical reasons, namely that the US did not want to see the Republic of China provoke the People's Republic of China and thus mandated the IDF to have a "range no greater than the F-5E" and "ground attack capability no greater than the F-16". Regardless of the reason, many people consider the original 1980s prototype F-CK-1 to be somewhat underpowered due to its original engines.
In April 1997 American company Litton's Applied Technology division was awarded a production contract and options totaling $116.2 million by the Aerospace Industrial Development Corporation for Improved Radar Warning Receivers (IRWR) to be installed aboard.
Yun Han: engine research
Exports of advanced engines such as the General Electric F404 or the Pratt & Whitney F100 were not available to the Republic of China. Both the General Electric J85 and General Electric J79 were considered unsuitable in their performance, and most European and American engine companies declined to cooperate with the Republic of China. Joint investment with Garrett became the only practical solution.
In 1978, following the success of the TFE731 engine, U.S. engine company Garrett announced joint research of the TFE1042 afterburner with the Swedish company Volvo Flygmotor. The TFE731 Model 1042 was touted as a low bypass ratio "military derivative of the proven commercial TFE731 engine" and that it would provide "efficient, reliable, cost effective propulsion for the next generation of light strike and advanced trainer aircraft", with a thrust of 4260 lbf (18.9 kN) dry and 6790 lbf (30.2 kN) with afterburner. After the initial negotiation, the investment was going to be divided between Garrett, Volvo, AIDC, and the Italian company Piaggio. The development would consist of the non-afterburning TFE1042-6 for light attack aircraft and advanced trainers, and the TFE1042-7 for the AMX or the F-5 upgrade. AIDC also suggested upgrading the TFE1042-7 to 8,000 lbf (36 kN) thrust in a twin-engine installation, in order to compete with the GE F404. However, the JAS 39 Gripen project decided to continue with a single F404, and Piaggio asked to participate at a later date due to financial concerns.
ITEC completely redesigned the TFE1042-7 into the TFE1042-70 - for example, the bypass ratio was changed from 0.84 to 0.4 -, and the investment had increased from USD 180 million to about USD 320 million. However, to avoid pressures from the PRC, the United States government had asked all the US companies cooperating with the Republic of China on the IDF project to remain low-key. Therefore, the perception that "the TFE1042 is merely the civilian engine TFE731 with an afterburner" was never completely dispelled.
In 1985, the preliminary review of the IDF's design revealed some performance requirement shortfalls, and it was determined that an upgrade of engine thrust by 10% was the simplest solution. Due to American export license restrictions, ITEC used FADEC to artificially limit the thrust below a certain altitude (the restriction was not removed until 1990). Although the upgrade essentially used the TFE1088-11 configuration, to reduce political interference ITEC renamed the original, lower-thrust version as the TFE1042-X70 and retained the TFE1042-70 designation for the upgraded version.
In 1988, ITEC decided to invest in the 12,000 lbf (53 kN) thrust TFE1088-12, which was re-designated as the TFE1042-70A for political reason as well. Preliminary studies had shown that the IDF could supercruise with the new engine. At the same time, General Electric Aviation decided to enter the market with the J101/SF, a smaller version of the F404. However, after the IDF order was cut in half due to budget concerns, the TFE1088-12 engine upgrade plan ended as well.
Yin Yang: Aerodynamic Design
The cooperation between AIDC and General Dynamics (GD) was divided into four phases:
- GD analyzed the ROCAF's aircraft performance and force requirements.
- Taiwan assessed GD's reports and choose between AIDC's original design and GD's new design.
- AIDC sent personnel to GD for the preliminary design phase.
- GD sent personnel to Taiwan to complete the project.
GD's assistance was restricted by the US State Department's arms export control, which limited GD's work to initial design consulting but not further development, production, or marketing.
Many different airframe design concepts were explored (e.g. the 2D Thrust-Vectoring nozzle of XX-201, the double delta wings/twin tailed 401). After the General Electric J79 was officially abandoned as the potential engine solution in 1983, three configurations emerged from AIDC.
- Configuration A was similar to the F-5E.
- Configuration B was similar to the Eurofighter Typhoon and Saab Gripen.
- Configuration C was similar to the F-15.
At the same time, GD worked on the G configuration in parallel. Eventually the G-4 was selected, but with many features of the C-2 integrated. During this time, the project was named the "Light Weight Defense Fighter". In 1985, the configuration conceptual design had evolved into the SE-1 preliminary design. By the end of 1985, AIDC decided to skip the prototype stage and go into Full Scale Development (FSD) directly, in order to reduce time and save money. The project was again renamed into the "Indigenous Defense Fighter". Four FSD aircraft were made, with three single-seaters and one double-seater.
Tien Lei: Avionics Integration
The IDF is equipped with a GD-53 Golden Dragon multi-mode monopulse Pulse-Doppler radar, which is based on the General Electric AN/APG-67 X band radar developed for the F-20 while sharing some components and technologies of the AN/APG-66 radar of the F-16A, and using a larger antenna than used by the F-20. and this adaptation resulted in the look-down and shoot-down capability of GD-53 being greatly enhanced in comparison to that of the original AN/APG-67, reaching that of the AN/APG-66. The radar can simultaneously track 10 targets and engage two of the 10 targets tracked with TC-2 active radar seeker BVRAAMs.
The design is inherently unstable in pitch, so the IDF incorporated a modern triple-redundant full authority fly-by-wire control system. The avionics suite was based on modular architecture with dual redundant MIL-STD-1553B digital databuses. The Honeywell H423 Inertial navigation system, the TWS-95 RHAWS, and the Bendix-King Head-up display were selected. Some capabilities may have been delayed or dropped in order to meet the performance requirement, since the engine limitation has resulted in the necessity of strict weight control.
Tien Chien: Missile R&D
The CSIST's Tien Chien (Sky Sword) project was slightly more independent, since it was considered to be a development for all the ROCAF's aircraft rather than only the IDF. The Tien Chien 1 (TC-1) is a short range infrared-seeking missile with an external configuration similar to that of the AIM-9 Sidewinder, while the Tien Chien 2 (TC-2) is an active radar homing Beyond Visual Range missile that is claimed to be in the same class as the AIM-120 AMRAAM.
The first test firing of the TC-1 missile was performed by a F-5E in April 1986, with the Beech target drone successfully destroyed. Initial production of the TC-1 began in 1989, and it entered service in 1991. Both the AIM-9 and the TC-1 have been seen in use on operational IDFs.
CSIST is believed to have cooperated with Motorola and Raytheon on the TC-2's active seeker, which is believed to be based on their seeker design which was proposed for the AIM-120. 40 pre-production TC-2 missiles were produced before 1995, and were the only BVR AAMs that the ROCAF had in its inventory during the 1995-1996 Taiwan Strait Missile Crisis. Over 200 production TC-2s were originally planned.
General characteristics
- Crew: 1-2
- Length: 14.21 m (46 ft 7 in)
- Wingspan: 9.46 m (31 ft 0 in)
- Height: 4.42 m (14 ft 6 in)
- Wing area: 24.2 m² (260 ft²)
- Empty weight: 6,500 kg (14,300 lb)
- Loaded weight: 9,072 kg (20,000 lb)
- Max takeoff weight: 12,000 kg (27,000 lb)
- Powerplant: 2 × Honeywell F125-70
- Dry thrust: 27 kN (6,000 lbf) each
- Thrust with afterburner: 42 kN (9,500 lbf) each
Performance
- Maximum speed: Mach 1.8
- Range: 1,100 km (600 nmi, 680 mi)
- Service ceiling: 16,800 m (55,000 ft)
- Rate of climb: m/s (ft/min)
Armament
- Guns: 1× 20 mm (0.787 in) M61A1 6-barreled gatling cannon
- Missiles:
- 4× Sky Sword I
- 4× Sky Sword II
- Bombs:
- Wan Chien GPS-guided cluster bomb
Avionics
- Radar: 1× GD-53 X-band pulse doppler
- Effective scanning range:
- Look up: 57 kilometres (35 mi)
- Look down: 39 km (24 mi)
