only the future will tell .... yes example of single engine 5th generation F-35 is there, but i am considering scenarios realistically so far the design and development cost of F-35 crossed 1.5 Trillion Dollars. F-35 is the most expensive, and possibly the most error ridden, project in the history of the United States military but DOD has sunk so much money in it that it was not possible for them to pull back on the other hand our experience about jet engines incase of sino pak joint venture JF-17s .. is limited up to RD-93, J-31 is also using RD-93 but a pair of it, seems like pakistan will not go for a expensive engine because of our economy issues keeping in view the above, what engine options paksitan would have for project azam?