Japan's FS-X (Fighter Support-Experimental) Program

[F-2]

Why did Japan go with an Agile Falcon derivative and not an F-16XL derivative? The F-16XL appears to be a much better fit for the requirements and would have likely saved cost over the eventual F-2.

It probably was the next best viper choice. JASDF officials did see it fly in person

One of the biggest, little chance for work share but in need of a lot of money and development to make a viable combat aircraft.

Probably couldn’t meet the air to air requirements. The F-1 and F-4 were not considered adequate to deal with new generation Soviet aircraft entering service in the 80s. Supposedly the F-16XL struggled against older Red Eagle jets and wouldn’t be a major improvement in this area.

 

[Maro.Kyo]

Why did Japan go with an Agile Falcon derivative and not an F-16XL derivative? The F-16XL appears to be a much better fit for the requirements and would have likely saved cost over the eventual F-2.

You should understand that the FS-X was a political/diplomatic tug of war between US and Japan, as well as between MoFA and MoF, and MoD and MITI. In short, the US, MoF and MoFA wanted as much commonality between FS-X and pre-existing F-16 models.

 

[Desertfox]

You should understand that the FS-X was a political/diplomatic tug of war between US and Japan, as well as between MoFA and MoF, and MoD and MITI. In short, the US, MoF and MoFA wanted as much commonality between FS-X and pre-existing F-16 models.

Which they ended up not having at all.