The AIDC F-CK-1 Ching-kuo (經國號戰機), 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 preliminary search for a replacement for the Taiwan Air Force's F-5s and F-104s began with the XF-6 indigenous fighter project, later renamed Ying Yang, in the late 1970s. After the US established formal relations with the People's Republic of China and ended the Mutual Defense Treaty with Republic of China, President Chiang Ching-Kuo decided to expand the indigenous defense industry and on August 28, 1980, ordered AIDC to design an indigenous interceptor. Originally, the ROCAF listed the priority of the XF-6 behind the XA-3 Lei Ming attack aircraft, due to the believed high risks of the XF-6 project.
The signing of the 1982 US-PRC Joint Communiqué, limited arms sales to the Republic of China. The United States refused to sell the General Dynamics F-16 Fighting Falcon and the Northrop F-20 Tigershark (which had been developed largely to meet Taiwanese needs for a follow-on to its F-5s, therefore ensuring the continuation of the indigenous fighter project. Although US President Ronald Reagan reluctantly accepted his advisers' suggestion of building relations with the People's Republic of China to counter the USSR, Reagan decided to balance the 1982 US-PRC Communiqué with the "Six Assurances" to Taiwan. This opened the door for US technology transfer and assistance to Taiwan's defense industry, including the IDF project.
Pre-production F-CK-1A model.
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 (安翔):Safe Flight) and divided into four sections in 1983:
Ying-Yang (鷹揚): "Soaring Eagle". Development of the airframe. Cooperation with General Dynamics.
Yun-Han (雲漢): "Cloud Man". Development of the aircraft powerplant and propulsion. Cooperation with Garrett (Now Honeywell).
Tien-Lei (天雷): "Sky Thunder". Development of the avionics systems. Cooperation with Smiths Industries, with some components purchased directly from Lear Astronics (later BAE[clarification needed]), Litton (later Northrop Grumman[clarification needed]) and Martin-Baker.
Tien-Chien (天劍): "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[by whom?] 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[who?] 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.
 Ying Yang: Aerodynamic Design
Landing at Tainan
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.
 F-CK-1 A/B Ching-kuo
The first successful test flight by FSD A1 was made on May 28, 1989. The first two-seater (and the fourth prototype), FSD B1, conducted its first flight on July 10, 1990. The first successful firing of the Tien-Chien II (Sky Sword II) air to air missile took place in 1992, with the ROCAF establishing its first F-CK-1 squadron the following year with a batch of 10 pre-production aircraft.
The ROCAF's initial order for 256 aircraft was cut to 130 in 1991, following deals for the purchase of 150 F-16 Block 20 A/B and 60 Mirage 2000-5Ei/Di with the US and France. The last IDF A/B rolled off the production line in 1999.
 F-CK-1 C/D Hsiang Sheng
The ROC's Ministry of National Defense (MND) announced that beginning in 2001, the government would include a new budget allocation for the IDF upgrade plan (as included in the five MND proposals to help AIDC). The five proposals were:
Upgrades of the AT-3, IDF, and F-5 would be assigned to AIDC in the future.
The Army Utility Helicopter, the Navy's long range ASW aircraft, a helicopter for the Marines, and an Air Force medium transport will all be produced and assembled by qualifying domestic firms in conjunction with the foreign firms that originally designed them.
CSIST and AIDC will jointly assemble a team for the early planning of the ROCAF's next generation fighter, in order to assess procurement methods and suggest concepts.
AIDC's joint ventures with foreign firms or alliances with domestic firms will be given high priority in military aircraft service and maintenance.
In the future, the military will give responsibility for weapons system flight tests, electronic warfare exercises, air towing drones, avionics maintenance, and weapons procurement planning to AIDC, in situations where AIDC has the professional capacity that the military lack> This is part of the seven-year IDF C/D R&D plan (FY2001~FY2007), which allocates 10 million New Taiwanese Dollars (NTD) annually for a total of 70 million NTD for both CSIST and AIDC. Initial media reports indicated that the upgraded IDF would be called the "Joint Countermeasure Platform".
In a 2006 interview in Jane's Defence Weekly, former AIDC Chairman Sun Tao-Yu said that two new prototypes had been manufactured. The upgrade would allow the IDF to carry an additional 771 kg of fuel. In addition, it includes an improved avionics suite, retrofitted electronic warfare capabilities, and new weapons systems. The landing gear has been strengthened to accommodate the additional payload and fuel, but the plan for a dielectric radar-absorbing "stealth" fuselage was dropped due to concerns over weight. The project consists of three phases:
Increase the carrying capacity for the TC-2 Beyond-Visual Range Air-To-Air missile from two to four. Integrate the TC-2A anti-radiation missile and the Wan Chien cluster bomb. Plus 2 CFT (Conformal Fuel Tanks) also seen on the 2 newly built prototype aircraft.
Upgrade the mission computers, the electronic counter-countermeasures, the electronic warfare systems, the Active Identification Friend or Foe (AIFF) system and the terrain-following radar.
Ground and air testing. If the program is approved, service entry is projected to occur in 2010.
The development contract for the upgraded IDF C/D flight control computer was awarded in 2002 to BAE Systems. The computer has a 32-bit PowerPC-based processor with faster processing/computing, higher reliability, and better integration with avionics. AIDC said that the improvements of the flight computer will result in "a safer, higher-performing aircraft".
AIDC originally planned to launch the IDF C/D prototype on National Day, October 10, 2006. However, the first test flight of the upgraded IDF was reportedly successfully completed a few days ahead of schedule in early October.
A decision on production of the aircraft has not yet been announced. However, some media have already begun to speculate about project Hsiang Sheng’s demise, due to ROCAF’s recent interests in procuring Block 50/52 F-16s and some ROCAF officials' lack of confidence in the IDF upgrade project.
During the visit to AIDC's Taichung Shalu factory on March 27, 2007, President Chen Shui-Bian witnessed a test flight of F-CK-1D, and announced that the upgraded IDF will be named Hsiung Ying (Brave Hawk), which signifies that the new fighter would protect the homeland just like the Crested Goshawk.
As of 12/2009, 71 F-CK-1 A/B will be allocated for upgrade to F-CK-1 C/D over 4 years span for over 500 million USD, according to AIDC CEO, under Project Hsiang Chang (翔展), as AIDC and ROCAF had signed contract for the expected upgrade program.
 IDF Lead-in Fighter Trainer
F-CK-1C/D cockpit view.
According to the media, the AIDC IDF trainer concept apparently involved the removal of the fire control radar and combat systems with the retention of rear-seat flight controls, so that the IDF could be used as a lead-in fighter trainer (LIFT). The ROCAF seemed to have reservations with the concept, however, as it would mean the IDF LIFT would not be usable in wartime. A MND letter said, "Regarding the newspaper report of AIDC's desire to use the IDF fighter as a basis for supersonic trainer development, it is only that company's operational planning concept. The Ministry of National Defense and the Air Force currently do not have such a plan". The letter then said that due to a tight budget allocation the ROCAF would instead ask AIDC to extend the life of the AT-3 and continue to use the F-5 in the LIFT role.
In 2003, the former AIDC Chairman Huang Jung-Te said that AIDC still hoped the ROCAF would consider using a simplified version of the IDF for LIFT, and that such a concept could have a cost as low as USD 16 million per unit, compared to the T-50's USD 19 million. However, the F-CK-1 LIFT modifications or new production concepts never received government funding or approval.
In May 2006, Lt. General Cheng Shih-Yu testified that the MND indeed plans to retire the F-5E/F by 2010 and allow the in-service IDFs to take over training missions. It is unclear what modifications (if any) will be made to IDFs after they become trainers.
All ROCAF pilots selected and sent to US and France to receive training on F-16 block 20 and Mirage 2000-5 fighters had to have flown with IDF/F-CK-1 for at least 6 months, which makes IDF a LIFT except in name.
 Advanced Defense Fighter
There were some initial concepts for further developments of the IDF project. After the IDF basic variant was finalized, the next step would have involved an upgrade with systems improvement, new technologies, and adjustments of material and weight. Then the next advanced version of the IDF would have configuration modifications, performance improvement, advanced technologies, new materials and applications of advanced weapons. Finally, the next generation design would have taken place.
Republic of China
Taiwan Air Force - 130 aircraft, including 10 pre-production aircraft.
 Specifications (F-CK-1)
The F-CK-1D prototype ("Brave Hawk"), with the accompanying F-CK-1C single-seater prototype in the background, at their public unveiling.
Data from GlobalSecurity.org, Milavia, TaiwanAirPower.org
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
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)
Guns: 1× 20 mm (0.787 in) M61A1 6-barreled gatling cannon
4× Sky Sword I
4× Sky Sword II
Wan Chien GPS-guided cluster bomb
Radar: 1× GD-53 X-band pulse doppler
Effective scanning range:
Look up: 57 kilometres (35 mi)
Look down: 39 km (24 mi)