[6] 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.

The Aerospace Industrial Development Corporation (AIDC), based in Taichung, Taiwan, designed and built the IDF jet fighter.

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.

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.

[9] 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,[10] was named An-Hsiang (安翔, Safe Flight)[11] and divided into four sections in 1983: 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.

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.

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.

[citation needed] 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.

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.

[citation needed] The design is inherently unstable in pitch, so the IDF incorporated a modern triple-redundant full authority fly-by-wire control system.

[15] 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.

[citation needed] 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.

Modifications to the aircraft would have been required for it to obtain the desired 1,000 km range (especially without the centerline drop tank available) and were envisioned to include more efficient non-afterburning engines.

[18] In May 2014, the ROC Air Force made photos of the fighters with enhanced Wan Chien long-range missile capabilities public.

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: The development contract for the upgraded 32-bit IDF C/D flight control computer was awarded in 2002 to BAE Systems.

[39] The first test flight of the upgraded IDF was reportedly successfully completed a few days ahead of schedule in early October.

[40][41][42] 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.

[46] 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 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.