TR Air-Force TF-X KAAN Fighter Jet

[Sanchez]

Is it possible that there were two different aircraft in the video. If you look at the connection between the vertical control surfaces and the plane they are different and in some cutouts the back sensor (thing) between the engines is there and sometimes not

Either more than one test or more than one aircraft. Most possibly multiple tests.

See the vertical stab bases, more than one test, or more than one prototype.

View attachment 81777

 

[dBSPL]

View attachment 81810

Major modifications highlighted

The fact that the aircraft's external dimensions (length, wingspan, height) have been reduced by millimeters while its MTOW jumps to 34,750 kg is, in my opinion, one of the biggest pieces of evidence of the internal volume optimization.

Many things weren't functional on the PO (proof of concept) aircraft; the first functional prototype, P1, likely underwent significant optimizations, primarily in the internal weapons bay and fuel tanks. Presumably, to handle this enormous tonnage and make room for the internal weapons bays, the landing gear and its mounts were also completely re-optimized to occupy minimum space within the fuselage.

What caught my attention most in the geometry is the significantly sharper Chine Line in the front section. Also, the more rounded and plump nose structure of the P0 has been evolved in the P1 by a much flatter, pelican-beak-like shape with sharper edges. The geometric design of this line is one of the most challenging design parameters for the aircraft, especially in terms of scattering/non-direct reflecting radar signals. These sharp front lines are not only for stealth DNA; they also create controlled vortices around the nose of the aircraft at high angles of attack (AoA), allowing the aircraft to remain much more stable and agile in the air.

This also may have played a role in the reshaping of the aircraft's air intakes and the fuselage spine behind the canopy through a chain reaction. With the P1, the air intakes seem to have acquired a more integrated and aerodynamic angle to the fuselage, turning the vortices emanating from the sharper nose line to their advantage. Fifth-generation electro-optical sensor mounts such as IRST and EOTS, and internal weapon station hatches, which were structurally absent or non-functional in the P0, appear to be seamlessly embedded in this new optimized stealth body of the P1. In short; millimeter-scale reduction in the aircraft's external dimensions probably underpinned by a significant engineering re-optimization that maximizes the aircraft's internal volume and fuel capacity with more sharp stealth geometry.

 

[Fatman17]

Türkiye's homegrown Kaan fighter jet completes pre-flight taxi test

Türkiye's domestically developed fifth-generation fighter jet has successfully completed the pre-flight taxi test of its latest prototype, its...

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KAAN completes preflight taxi test

 

[Zafer]

The fact that the aircraft's external dimensions (length, wingspan, height) have been reduced by millimeters while its MTOW jumps to 34,750 kg is, in my opinion, one of the biggest pieces of evidence of the internal volume optimization.

Many things weren't functional on the PO (proof of concept) aircraft; the first functional prototype, P1, likely underwent significant optimizations, primarily in the internal weapons bay and fuel tanks. Presumably, to handle this enormous tonnage and make room for the internal weapons bays, the landing gear and its mounts were also completely re-optimized to occupy minimum space within the fuselage.

What caught my attention most in the geometry is the significantly sharper Chine Line in the front section. Also, the more rounded and plump nose structure of the P0 has been evolved in the P1 by a much flatter, pelican-beak-like shape with sharper edges. The geometric design of this line is one of the most challenging design parameters for the aircraft, especially in terms of scattering/non-direct reflecting radar signals. These sharp front lines are not only for stealth DNA; they also create controlled vortices around the nose of the aircraft at high angles of attack (AoA), allowing the aircraft to remain much more stable and agile in the air.

This also may have played a role in the reshaping of the aircraft's air intakes and the fuselage spine behind the canopy through a chain reaction. With the P1, the air intakes seem to have acquired a more integrated and aerodynamic angle to the fuselage, turning the vortices emanating from the sharper nose line to their advantage. Fifth-generation electro-optical sensor mounts such as IRST and EOTS, and internal weapon station hatches, which were structurally absent or non-functional in the P0, appear to be seamlessly embedded in this new optimized stealth body of the P1. In short; millimeter-scale reduction in the aircraft's external dimensions probably underpinned by a significant engineering re-optimization that maximizes the aircraft's internal volume and fuel capacity with more sharp stealth geometry.

I don't know how they can discern minute aerodynamic effects caused by minor geometry changes, maybe some guesswork is involved; educated guesses can come out right some of the time.

 

[Zafer]

Türkiye's homegrown Kaan fighter jet completes pre-flight taxi test

Türkiye's domestically developed fifth-generation fighter jet has successfully completed the pre-flight taxi test of its latest prototype, its...

share.google

KAAN completes preflight taxi test

Taxi tests are complete, then now what, maybe straight to flight, way sooner that people expected.

 

[Strong AI]

The fact that the aircraft's external dimensions (length, wingspan, height) have been reduced by millimeters while its MTOW jumps to 34,750 kg is, in my opinion, one of the biggest pieces of evidence of the internal volume optimization.

Many things weren't functional on the PO (proof of concept) aircraft; the first functional prototype, P1, likely underwent significant optimizations, primarily in the internal weapons bay and fuel tanks. Presumably, to handle this enormous tonnage and make room for the internal weapons bays, the landing gear and its mounts were also completely re-optimized to occupy minimum space within the fuselage.

What caught my attention most in the geometry is the significantly sharper Chine Line in the front section. Also, the more rounded and plump nose structure of the P0 has been evolved in the P1 by a much flatter, pelican-beak-like shape with sharper edges. The geometric design of this line is one of the most challenging design parameters for the aircraft, especially in terms of scattering/non-direct reflecting radar signals. These sharp front lines are not only for stealth DNA; they also create controlled vortices around the nose of the aircraft at high angles of attack (AoA), allowing the aircraft to remain much more stable and agile in the air.

This also may have played a role in the reshaping of the aircraft's air intakes and the fuselage spine behind the canopy through a chain reaction. With the P1, the air intakes seem to have acquired a more integrated and aerodynamic angle to the fuselage, turning the vortices emanating from the sharper nose line to their advantage. Fifth-generation electro-optical sensor mounts such as IRST and EOTS, and internal weapon station hatches, which were structurally absent or non-functional in the P0, appear to be seamlessly embedded in this new optimized stealth body of the P1. In short; millimeter-scale reduction in the aircraft's external dimensions probably underpinned by a significant engineering re-optimization that maximizes the aircraft's internal volume and fuel capacity with more sharp stealth geometry.

May i add

I want to add more information to this, because i find it interesting.

So let us start with what a vortex is.

Vortex - Wikipedia

en.wikipedia.org

Do fighter aircraft benefit from vortices?

Flow separation
View attachment 74790

To me it looks like that KAAN has chines.
View attachment 74786

Chine (aeronautics) - Wikipedia

en.wikipedia.org

Do vortices have negative effects? (F-18 as an example)

https://www.sciencedirect.com/science/article/abs/pii/S088997460200138X?via%3Dihub

https://www.sciencedirect.com/science/article/abs/pii/S0376042100000038

So basically, the vertical stabilizers of KAAN are mounted on top of the engines to minimize tail buffeting.
Here are some examples of tail buffeting. (Take a closer look at the vertical stabilizers)

F-22 (You have to watch this on YouTube)

 

[IC3M@N FX]

YF-22 ATF

TAI KAAN PT1

You can see just how much TAI KAAN was inspired by the YF-22 ATF. It bears a closer resemblance to this version of the Raptor.