mixelflick wrote:Like the Tempest, I don't see this happening...
The amount of $ and expertise required is enormous, and countries such as Japan are much better off just buying up-rated F-35's from the US. Look... they had to stop making F-35's in Japan as it is. And that's more or less giving them all the tools to do it! That, and its a good bet defense budgets will be shrinking vs. growing in the next 10 years.
As well, Japan's needs in a fighter are strikingly different vs. say, what the US has planned for PCA. The don't need something with absurd range. They're not planning on flying over mainland China, just defending themselves against China/North Korea. Yes, they'll need good radars, long range weapons and sensors but the F-35 already has them covered.
Their "stealth fighter" will be to the F-35 what their F-2 was to the F-16: Likely a marginal improvement but at astronomical cost. I'm all for indigenous know how, etc. but sometimes you just have to look in the mirror and admit other nations do this better.
It's just way too simplified measuring everything with performance only. I would agree, that in most of the cases, someone who could buy F-35 is better off just buying the F-35 than trying something else but Japan doesn't fit into those "most of the cases". Those guys in UK and Japan are not some half-as*ed idiots that they've somehow magically ignored all the benefits of buying the F-35. The human resources created by FS-X program are slowly retiring without any replacement, just like what happened in Taiwan after F-CK-1. And no, you can't maintain that level of expertise by making ten other experimental aircraft because its a whole different ballpark to an actual fighter jet.
Also, the F-3 would have superior flight characteristics to the F-35, something they really wanted from the F-22. You see, Japan always wanted to buy the Raptor regardless of whether they can get the F-35 or not and that's for a reason. Now that they are making a decent engine they could probably achieve what they want as well. On top of that, unlike what you think, they need a fighter with quite a long range as well considering their main focus nowadays is defending their western isles, Senkaku among others. You're talking about them only defending the homeland but Japan's role as a strategic deterrent against China entering the Pacific is only getting bigger. Else they wouldn't be building aircraft carriers and ballistic missiles.
Most importantly, as a replacement for F-2 they need a fighter that could be equipped with their own ASM. F-2's primary role was a ship hunter after all, and there were no foreign armament integrated into F-35 apart from very few exceptions. UK is the only tier-1 partner and JSM is developed with heavy ties to Lockheed. ASM-3 has quite some advanced navigation technique built into it that the Japanese are developing a new MC to be able to use its full potential. Even integrating AAM-4 to F-15J needed J/ARG-1 to be developed. As if that's going to work with F-35.
In the end, what you expect as "marginally better" is just you're expectation and I suspect otherwise. It's going to be a fighter with quite a different character compared to F-35. F-35's probably going to have better SA and network capabilities though the F-3 wouldn't be far off. It's kinematic capabilities on the other hand would enable something else. I mean, Japan is still buying almost 150 F-35s, its not like they're spending all that money instead on making their own jet.
They've already spent around $ 2 billion developing the basic technology needed for their future fighter and it may well be that they came too far politically to stop as well. Talking about F-2, its well known that working under heavy American influence left quite a bitter taste for the Japanese folks, regardless of if the original FS-X development plan was realistic at all or not. I don't think they're gonna do it twice.