Is Turkey’s KAAN fighter genuinely a 5th-generation aircraft?

No, it’s not.

It only looks like a 5th-generation fighter.

Let’s break it down simply:

Take a look at the intake — see the red line and the gap between the intake and the fuselage?
That’s called a caret inlet.

Its purpose is to separate the slower-moving boundary layer air from entering the engine, which could otherwise cause engine surges.

Caret inlets were acceptable in earlier generations of fighter jets, but 5th-generation aircraft prioritize stealth.

In fact, the caret inlet contributes to approximately 89.8% of the F-22’s front radar cross section (RCS).
In other words, nearly 90% of what shows up on radar from the front of an F-22 comes from its air intake design.

The F-35, on the other hand, uses a more modern design: the diverterless supersonic inlet (DSI).
It’s simpler, lighter, and significantly reduces radar visibility.

The F-22 was designed before the necessary tools and knowledge to shape a DSI were fully available. Retrofitting one would require a complete redesign of the airframe — which is why the F-22 kept its original caret inlets.

However, DSI has become a defining feature for stealth-focused, 5th-generation fighters.

To give you a sense of the difference:

• The F-35's front RCS is estimated at 0.0015 m².

• The J-20's RCS ranges from 0.001 to 0.005 m² — up to 3 times larger than the F-35, but still within the stealth range. A difference within 10x is generally negligible.

Now let’s talk about KAAN.

• Estimated front RCS of KAAN ranges from 0.01 to 0.99 m².

• That’s 6.7 to 66 times larger than the F-35, which is stealthy — but not very stealthy.

• For comparison, the F-16’s RCS is around 0.1 to 1.5 m², and the Rafale's is about 0.06 ± 0.02 m².

So from a stealth and design standpoint, KAAN is — at best — a 4.5-generation fighter, not a true 5th-gen.

Additionally, there are questions about where Turkey will source the engines and avionics.
They’ve claimed plans to develop a domestic engine with 16 tons of thrust.
But considering their previous achievements only reached 4.5 tons, this goal seems highly ambitious — bordering on wishful thinking.