TAI and TUSAŞ Engine Industries (TEI) would lead the design, entry, and development processes of the fighter jet.

The studies would reveal the cost of the fighter, while investigating which mechanical and electronic systems would be employed and included, and a wider perspective of the opportunities and challenges in military aviation.

[20] In 2015, the TAI released three potential airframe configurations: Turkish Prime Minister Ahmet Davutoğlu announced on 8 January 2015, that the TF-X will be a twin-engined fighter.

[8] The Undersecretariat for Defence Industries published its 2016 Performance Report in March 2017, where it was revealed that the final decision was to continue with the twin engine FX-1 configuration.

[25] In the same period, Request for Proposal was published for the engine of the aircraft, and General Electric, Eurojet and Snecma companies returned to this file.

In February 2013, meetings were held with Saab AB upon the instruction of then-Prime Minister Recep Tayyip Erdoğan, and an agreement was signed between TAI and the Swedish firm Saab during the state visit of then-Turkish President Abdullah Gül to Sweden on 13 March 2013, according to which:[26] This plan was later abandoned and on January 8, 2015, then-Prime Minister Ahmet Davutoğlu announced that the TF-X program will be a completely independent domestic platform, not in partnership with Korea, Sweden, Brazil or Indonesia.

In December 2015, Turkey's Undersecretariat for Defence Industries (SSM) announced that it had chosen BAE Systems of the United Kingdom to assist with the design of the nation's next-generation air superiority fighter.

[29] On 20 January 2015, ASELSAN of Turkey announced that it had signed a memorandum of understanding with Eurojet, the manufacturer of the EJ200 engine used in the Eurofighter Typhoon.

On 8 November 2018, TRMotor signed a memorandum of understanding with the Presidency of Defence Industries to develop a jet engine for the TF-X project.

He emphasized the advantage of GE engines over its competitors stating that they have significant OEM support whereas the collaboration between other companies were yet to thrive.

"[42] His statement implied that the same dispute over intellectual properties of the engine which previously stalled the negotiation between Rolls-Royce and Turkey in 2019[43] remained unresolved.

[44][45] On 2 July 2022, the Defence Industry Agency published the invitation to tender for the domestic development of the engine to be used and İsmail Demir, undersecretary for Defence Industry Agency, stated that TRMotor, which is a subsidiary of TAI, has submitted its proposal and Turkish Air Engine Company (TAEC), consortium by Kale Group and Rolls-Royce, will submit its offer soon.

[49] TAI's Deputy General Manager responsible for TFX Dr. Uğur Zengin, stated on February 11, 2022, that 550 parts of TF-X were in production.

TAI shared a video showing a KAAN fighter jet taking off and then returning to Mürted Airfield Command in the north Ankara.

[58] In June 2021, the Turkish Air Force, in a presentation made to the press, announced its requirements for minimum capabilities of the TF-X:[1] Hüseyin Yağcı, TAI's chief engineer on the TF-X program, has stated that all three conceptual designs thus far feature a design optimized for low radar cross-sectional density, internal weapons bays, and the ability to supercruise, features associated with fifth-generation fighter jets.

The Turkish Defence Industry Agency has also issued a tender for the development of a new lighter carbon composite thermoplastic for the TF-X fuselage.