AIDC F-CK-1 Ching-kuo


The AIDC F-CK-1 Ching-Kuo, commonly known as the Indigenous Defense Fighter, is a multirole combat aircraft named after Chiang Ching-kuo, the late president of the Republic of China. The aircraft made its first flight in 1989. It entered service with Republic of China Air Force in 1992. All 130 production aircraft were manufactured by 1999.
Taiwan initiated the IDF program when the United States refused to sell them F-20 Tigershark and F-16 Fighting Falcon jet fighters following diplomatic pressure from China. Taiwan therefore decided to develop an advanced indigenous jet fighter. The Aerospace Industrial Development Corporation, based in Taichung, Taiwan, designed and built the IDF jet fighter.

Development

Background

The preliminary search for a replacement for the ROCAF'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 China and ended the Mutual Defense Treaty with Taiwan, 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 single seat attack aircraft, due to the believed high risks of the XF-6 project.
The signing of the 1982 US-China Joint Communiqué limited arms sales to Taiwan. The United States refused to sell the General Dynamics F-16 Fighting Falcon and the Northrop F-20 Tigershark thereby ensuring the continuation of the indigenous fighter project. Although US President Ronald Reagan reluctantly accepted his advisers' suggestion of building relations with 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.

Design phase

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 Chinese diplomatic pressure. The project, led by Hsi-Chun Mike Hua, later known as the father of the Indigenous Defense Fighter, was named An-Hsiang and divided into four sections in 1983:
  • Ying-Yang : "Soaring Eagle". Development of the airframe. Some cooperation with General Dynamics.
  • Yun-Han : "Galaxy". Development of the aircraft powerplant and propulsion. Cooperation with Garrett.
  • Tien-Lei : "Thunder". Development of the avionics systems. Some cooperation with Smiths Industries, with some components purchased directly from Lear Astronics, Litton and Martin-Baker.
  • Tien-Chien : "Sky Sword". Development of air-to-air missiles.
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 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 Taiwan and 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 project. 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 dry and 6790 lbf 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 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 US$180 million to about US$320 million. However, to avoid pressures from China, the US government had asked all American companies cooperating with the Taiwan 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. 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 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

The cooperation between AIDC and General Dynamics was divided into four phases:
  • GD analyzed the ROCAF's aircraft performance and force requirements.
  • Taiwan assessed GD's reports and chose 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. After the General Electric J79 was officially abandoned as the potential engine solution in 1983, three configurations emerged from AIDC.
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 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

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 a 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: missiles

The CSIST's Tien Chien 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 is a short range infrared-seeking missile with an external configuration similar to that of the AIM-9 Sidewinder, while the Tien Chien 2 is an active radar homing Beyond Visual Range missile.
The first test firing of the TC-1 missile was performed by an 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 1995–96 Taiwan Strait Missile Crisis. Over 200 production TC-2s were originally planned.

Upgrades

During the F-CK-1's development, it was tapped as the secondary delivery vehicle for the Taiwanese nuclear weapons then in development. The primary delivery method was to be the Sky Horse missile. Weapons designers at CSIST were instructed to design the nuclear weapon to fit within the dimensions of the F-CK-1's centerline drop tank. Modifications to the aircraft would have been required for it to obtain the desired 1,000 km range and were envisioned to include more efficient non-afterburning engines. The F-CK-1 would not have been able to fulfill the nuclear strike mission until mid-1989 at the very earliest. Early designs called for an unpowered gravity bomb. The nuclear weapons program was shut down under US pressure before the F-CK-1 entered service and the dedicated nuclear strike variant was never produced.
The first stage of upgrades to the fleet was originally planned to be completed by 2013, and was planned to include improved avionics, radar, electronics, weapons capabilities and lifespan extensions. In May 2014, the ROC Air Force made photos of the fighters with enhanced Wan Chien long-range missile capabilities public. The upgrade program was finally completed in 2018.