Ching-Kuo Indigenous Defense Fighter (IDF)

After the severance of diplomatic relations between Washington and Taipei in January 1979, the future supply of military equipment for Taiwan's armed forces was in question. Thanks to the enactment of the the Taiwan Relations Act (TRA) in early 1979, Taiwan was able to purchase advanced weapons and military equipment from the US.

Taiwan built nearly 300 Northrop F-Ss under license from 1974 to 1986. From the early 1980's, Taiwan expressed an interest in purchasing US fighter aircraft to replace its obsolescent Northrop F-5 and Lockheed F-104 fighters. The United States, which was interested in improving relations with China, denied Taiwan's request to purchase the more capable F-16, and blocked a subsequnetly proposed $1 billion sale of 100F-20 Tigersharks in July 1982. The 1982 decision by the Reagan administration to bar export of new fighters to Taiwan left technical assistance unrestricted. Taiwan decided to go it alone to build the Indigenous Defense Fighter (IDF).

Taiwan produced the Ching-kuo Indigenous Defense Fighter with extensive assistance by American corporations, led by General Dynamics. The project consisted of four sub-projects. They were the Ying-yang project (in cooperation with General Dynamics Corporation) which made the air-frame; the Yun-han project (in cooperation with Hughes Corporation), which designed the engine; the Tian-lei project (in cooperation with Westinghouse Company), which took care of the avionics system; and the Tian-chien project, which developed the weapons system.

The twin-engine IDF is similar to the F-16 except that it is slightly smaller and has a slightly shorter range. The IDF is a hybrid as far as its external appearance is concerned. The nose of the fighter jet is a replica of the F-20A Tigershark, while ts body, wings, and vertical tail surface are apparently lifted from the F-16, and the shape of its cockpit hood and vertical tail wing and its girth near the engine inlets have a notable French flavor.

The IDF is superior to the F-5E in airborne performance. The IDF accelerates better than the F-104 and its turning radius is smaller than that of the F-5. The aircraft, equipped with four Sidewinder missiles, but without spare fuel tanks, has a combat endurance of three minutes on afterburner and a combat radius of between 70 and 90 nautical miles. With a combat radius of 600 nautical miles while carrying out armed reconnaissance and patrol missions, the IDF is capable of conducting preemptive raids and strikes at airports along the Chinese coast. It is mainly used in combat for air control and is capable of using "Hsiung Feng"-II missiles to attack targets at sea. Most of the IDFs are expected to be armed with the indigenously-produced, BVR Tien Chien-II (Sky Sword-II) ARAAM.

It is equipped with a GD-53 radar, which evolved from the APG-67 and is essentially similar to it in performance. The APG-67 radar uses pulse Doppler technology at X-band and has 15 operational modes in all, eight air-to-air and seven air-to-ground. It can also operate at three different pulse repetition frequencies [PRF]--high, medium, and low--depending on whether the plane is looking up, looking down, or involved in a dogfight in the air, respectively. In a look-down mode, the plane has an effective scanning range of 39 kilometers; looking up, 57 kilometers. The eight air-to-air modes are as follows: searching and range finding while looking down, searching and range finding while looking up, speed searching, tracking (10 targets) and scanning simultaneously, dogfight, tracking a single target, surveying the situation, and continuous-wave indicator interfacing. The seven air-to-ground modes are as follows: real wave velocity topography, Doppler wave velocity sharpening, air-to-ground range finding, moving surface target indicating, freezing, and searching for target at sea surface. In April 1997 Litton's Applied Technology division was awarded a production contract and options totaling $116.2 million by the Aerospace Industrial Development Corporation of Taiwan, ROC, for Improved Radar Warning Receivers (IRWR) to be installed aboard the Indigenous Defense Fighter.