IMO, Turkey should develop aerospace cooperation(both civilian and militarily) with China. I also care about China's experience in the field of Aerospace and its enthusiasm for pioneering new generation technologies.
However, Technically, getting a ready-made fighter jet from China right now is almost a useless/extremely costly option. Billions of dollars of new infrastructure investment, a new and parallel logistics system. Tens of thousands of pages of documentation and evaluation training takes a minimum of 10 years to reach the operational level. Turkey is already aiming to reach the mass production phase in the MMU program by 2030s.
But there is an exception; Turkish naval force aviation. A fixed wing air force installation from scratch could develop with Chinese cooperation.
It is a concrete and correct example to determine the need, but Russia will never open this aircraft to Turkish avionics and weapon systems. So technically, it may be twice as expensive and painful as the F-35.
What if the USA refuses to send the B70/72 upgrade kits for the Turkish Block 40 F-16s?
Alternative plan is, OZGUR(freedom) modernization program. We have come to the end of the work that has been going on for about 10 years. A few more critical components need to complete the final test phase such ASELSAN's GaN-based F-16 AESA radar. Making a statement on this subject last month, Demir, GM of the Defense Industry President, stated that they can easily produce these B70 modernization kits, and indirectly mentioned that dialogue is important in order not to violate the existing license agreements of the USA.
Frankly, according to the information we received from the important journalists of the sector, it is said that the USA will not take a negative step in this regard. Already in the current conjuncture in the region, it is not suitable for the USA to completely exclude Turkey.
A more practical approach would be to channel your investments with regional tech powers like Sweden, Korea, Japan, Ukraine, Brazil, etc. These countries have robust aerospace industries, are open to industrial cooperation & do not attract much animosity globally. This would allow you guys to keep it low.
From what I have read, you Turks are going in the right direction, keeping your program limited to advanced, but less conspicuous partners such as the K2-Altay partnership or the TAI-Leonardo partnership for T-129 ATAK.
Addressing your immediate replacement needs, You could negotiate for a few Typhoon T3s with the British, who seem open to cooperating with you. France could have been an option but your bilateral ties are in the dumps due to the recent political duels between Macron and Erdogan.
War of politics. On one hand, Turkey with S400 is in shambles. On the other India enjoys the lavishes of the White House whilst petting several s400 units.
Please leave us out of this. We are not NATO members and do not enjoy its other perks. Turkey is, and it is between them and the Americans.