Story ID: 347 AIDC AT-5
Taiwan’s Brave Eagle Leaves the Nest
By: Jon Lake
Caption: Based on the design of the F-CK-1 fighter, the T-5 is now in the early days of its service with the Republic of China Air Force.
Word Count: 777
Taiwan’s Aerospace Industrial Development Corporation (AIDC) T-5 Yung Yin (Brave Eagle) has entered service with the Republic of China Air Force (ROCAF). The second of two production Brave Eagle advanced jet trainers arrived at Taitung Air Base in Taiwan on December 22 last year, where it joined the first low-rate initial production (LRIP) aircraft, delivered on November 28. For the ceremonial delivery, the first prototype (with AIDC chairman Hu Kaihong in the back seat) accompanied the new aircraft, and the first LRIP aircraft escorted the pair to Taitung, flying a neat Vic formation over the base before landing.
The first cadre of T-5 instructors successfully completed the first phase of training on November 12. The six pilots came from the Air Force Academy, the 1st Fighter Wing, the 3rd Fighter Wing, and the 7th Fighter Training Wing, and received training from two instructors from the Aviation Development Center. 
The ROCAG will use the two aircraft for further operational test and evaluation and for developing the training syllabus. Further aircraft that roll off the production line later this year will augment them. AIDC plans to begin high-rate mass production of the T-5 in March 2023 and deliver the 66 aircraft on order between 2026 and 2028.
The first T-5 Brave Eagle squadron will be based at Taitung Air Base, home of the 7th Flight Training Wing and the Tactical Training and Development Center. The T-5 will replace the F-5E/F there and operate in the lead-in fighter training role. The aircraft will also be based at Kangshan Air Base, home to the Air Force Academy, where it will replace the AT-3s of the Fighter Training Group in the basic training role. Meanwhile, the two prototypes delivered earlier in 2021 will continue development testing to further improve and develop this homegrown Taiwanese advanced trainer and light fighter aircraft.
The T-5 is a dedicated trainer derivative of the F-CK-1 Ching Kuo Indigenous Defense Fighter (IDF). AIDC developed it in collaboration with the National Chung-Shan Institute of Science and Technology (NCIST) to meet the ROCAF’s Advanced Jet Trainer (AJT) requirement and provide a replacement for the indigenous AIDC AT-3 basic trainer and the Northrop F-5s used as advanced and fighter lead-in trainers. The ROCAF plans to retire both types during the early 2020s.
Initially, plans called for the fulfillment of the AJT requirement by a foreign aircraft, perhaps to be assembled locally, and Taiwan evaluated the KAI T-50 and the Italian Finmeccanica/Aermacchi (now Leonardo) M346 Master. Taiwan initially chose the M-346, but after Tsai Ing-wen was elected President of the Republic of China (Taiwan) in 2016, attention switched to indigenous options.
President Tsai’s Democratic Progressive Party has pursued a policy of developing indigenous defense industries, though budgetary constraints meant that an existing aircraft type would form the basis for the new AJT design. The three aircraft proposed were the M346, the AT-3 MAX—a modernized version of the existing AT-3 with a lightweight composite airframe, updated avionics, a glass cockpit, increased thrust, and an integrated training system—and an evolution of the AIDC F-CK-1 Ching Kuo fighter initially designated as the XAT-5. Leonardo-Finmeccanica reportedly reduced the cost of its M346 offer by around 25 percent, but Taiwan rejected the new offer, leaving the XAT-5 and the modernized AT-3 MAX.
Taiwan surprised many by officially selecting the XAT-5 (unproven as a trainer) in 2017 as the basis of the TWD68.6 billion (US$2.2 billion) program. While AIDC had marketed simplified versions of the two-seat F-CK-1C/D IDF for Lead-In Fighter Training (LIFT) for some 20 years, the T-5 represents a fresh take on this approach.
Although based on the F-CK-1 Ching-Kuo airframe design, the T-5 has 80 percent new components and makes greater use of composites in the fuselage to reduce all-up weight and improve strength. The wing has undergone a redesign, with a “fatter” aerofoil section to increase stability at low speeds and low altitudes, as well as provide increased internal fuel capacity. The manufacturer claims the new aircraft has lower drag and better high angle-of-attack handling than the F-CK-1.
The Brave Eagle is powered by a pair of non-afterburning Honeywell/ITEC F124-200TW engines. Essentially a non-afterburning version of the Ching Kuo’s F125 engine, the Honeywell/ITEC engines will limit the aircraft to subsonic/transonic speeds in level flight. The design omits the internal cannon of the Ching Kuo, but includes a provision for armament (including an external gun pod). NCIST has developed an airborne AESA radar for the T-5 using gallium-nitride technology.