Russian Su-57 Aircraft Thread (PAK-FA and IAF FGFA)

[Ultra]

Now, interesting thing is, LCA program seems to be integrating LEVCON into its design now.

As we can see in the earlier prototypes they did not have LEVCON:

I think LEVCON is a marvellous idea, both J-10 and J-20 could benefit greatly if this is integreated into the design. Especially the J-20's frontal arc radar reflectivity would significantly be reduced.

 

[Lethe]

The LEVCONs on LCA are specific to the Navy variant and undoubtedly relate to desired take-off and landing characteristics.

 

[Blitzo]

I think LEVCON is a marvellous idea, both J-10 and J-20 could benefit greatly if this is integreated into the design. Especially the J-20's frontal arc radar reflectivity would significantly be reduced.

I don't quite think that's quite how it works; canards and LEVCONs do similar things but I don't think one can simply replace one with the other and achieve the same performance.

One analogy I saw a few years ago that's stuck with me is that comparing canards and LEVCONs is like comparing all the traditional control surfaces of a plane with a plane only having thrust vectoring nozzles for maneuvre. I'm not quite sure if the difference is that large, and it also depends on how the rest of the aircraft's control surfaces are laid out.
But even with my limited knowledge of aerodynamics I think it is fair to say that LEVCONs are not simply closely cropped canards with the same aerodynamic properties, anymore than trailing edge flap of an aircraft's wing has the same aerodynamic properties of a proper tail.
In fact if I had to describe LEVCONs, I'd say they are an additional, more flexible leading edge slat rather than a true canard, but I'm sure there are different trains of thought to this and I've seen my fair share of long winded aerodynamics debates on this forum.

And of course canards are no more unstealthy than standard tailplanes especially given proper alignment and shaping, I'm not really sure where this myth started from.

 

[Air Force Brat]

I would add that these are very similar aero's to what we might expect initially from the close coupled or even distant coupled canards, as the angle of attack increases and the trailing edge flow detaches, the vortices off the levcon will continue to be tornadic and suck in low pressure air??? it may also server to keep the airflow on the wing up to a point and delay departure???? .

B787 and Blitzo, I would point out that I was commenting on the computer generated wind tunnel images showing airflow off the Levcon---- I stated for the record that "these are very SIMILAR aero's to what we might initially expect from the close coupled or even distant coupled canard, as the angle of attack increases" end quote

I would add that in no way do I believe Levcons would enhance the J-20s aeros, as that whole aircraft has been built around those distant coupled canards?

No doubt the Levcon is a different take on vortex creation and control, but the aerodynamics involved are very well studied science, if you read Aksha's well thought post following, illustrating the PAK-FA and the Naval version of the LCA which has incorporated a similar device. That is all???

 

[b787]

B787 and Blitzo, I would point out that I was commenting on the computer generated wind tunnel images showing airflow off the Levcon---- I stated for the record that "these are very SIMILAR aero's to what we might initially expect from the close coupled or even distant coupled canard, as the angle of attack increases" end quote

I would add that in no way do I believe Levcons would enhance the J-20s aeros, as that whole aircraft has been built around those distant coupled canards?

No doubt the Levcon is a different take on vortex creation and control, but the aerodynamics involved are very well studied science, if you read Aksha's well thought post following, illustrating the PAK-FA and the Naval version of the LCA which has incorporated a similar device. That is all???

LEVCON and LERX both are leading edge extension, both Le in Levcon and Lerx stand for the same.

Are their aerodynamics similar? sure like the canards of Kfir and Rafale are, but the levcon can be deflected up or down, in the same way Rafale foreplanes can, the LERX are on F-18s and Su-27s, but PAKFA has levcons or a moveable LERX, but for aerodynamic jargon they are LEVCONs and are not LERX

 

[Air Force Brat]

LEVCON and LERX both are leading edge extension, both Le in Levcon and Lerx stand for the same.

Are their aerodynamics similar? sure like the canards of Kfir and Rafale are, but the levcon can be deflected up or down, in the same way Rafale foreplanes can, the LERX are on F-18s and Su-27s, but PAKFA has levcons or a moveable LERX, but for aerodynamic jargon they are LEVCONs and are not LERX

no arguement here

 

[Air Force Brat]

no arguement here

7 days with no PAK-FA is too looong! come Sukhoi, crank them babies OUT!

 

[kwaigonegin]

LEVCON and LERX both are leading edge extension, both Le in Levcon and Lerx stand for the same.

Are their aerodynamics similar? sure like the canards of Kfir and Rafale are, but the levcon can be deflected up or down, in the same way Rafale foreplanes can, the LERX are on F-18s and Su-27s, but PAKFA has levcons or a moveable LERX, but for aerodynamic jargon they are LEVCONs and are not LERX

Of course.. I hope everyone here knows lerx and levcon are not the same. A levcon can and do act as a lerx in certain flight regime but not the other way around because as we all know lerx are just an 'extension' of the wing root as the name aptly suggest.

Freking industry people should've just called levcon MoLERX or something instead of trying to be fancy!.

 

[Deino]

First of all one good news: '055' will indeed be rebuild (by canibalising T-50-6) and more not really good news:

Here's an interesting overview of the so far achieved flight hours + flights for the individual T50s (via Berkut / Key-Forum again via

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) !

T-50-1 - is being revised in OKB "Sukhoi", operating time 219 hours 197 landings.
T-50-2 - located in Zhukovsky, operating time of 123 hours, 141 landings.
T-50-3 - in LIiDB Akhtubinsk, operating time of 181 hours, 92 landings.
T-50-4 - in LIiDB Akhtubinsk, operating time of 74 hours, 49 landings.
T-50-5R - is in the final assembly shop KnAAZ. 5P - a project to restore the machine T-50-5 with elements of T-50-6, stopped in production.

...

Finally, so good clarity in future T-50's designations;
- T-50-5 became T-50-5R, will cannibalize T-50-6.
- T-50-6 is what we referred to as T-50-6-1 as before; IE a flying frame of "phase 1".
- T-50-6-1 is in fact a static frame of "phase 2", now known as T-50-7.
- T-50-6-2 is flying phase 2 frame, so we always had that right.
And for future frames;

...

50-6 was stopped, as it was decided to proceed with the construction of "2nd phase" aircraft. T50-6-1 - is a static testing frame, which turned into a T50-7 and now its fuselage [the most basic translation] is in Zhukovsky, wings (basically) and stabilizers are still here [at KnAAZ]. T50-6-2 - transitioning frame to the 2nd phase, has its fuselage now docket and handed over to the final assembly shop. Also this year will be put T50-8 (now there is a dock fuselage) and T50-9 (year-end). T-50-9 promise with the new engines [Izd 30 or whatever they are now testing on "710"?]. In 2016, the planned are 50-10, 50-11 and static testing frame 50-12.

Deino

 

[Jeff Head]

First of all one good news: '055' will indeed be rebuild (by cannibalizing T-50-6) and more not really good news:

Here's an interesting overview of the so far achieved flight hours + flights for the individual T50s (via Berkut / Key-Forum again via

Please, Log in or Register to view URLs content!

) !

Deino

Thanks Deino!

So, if I have it right, all of that translates into:

T-50-1 - Is a flying prototype is being revised/refurbished.
T-50-2 - Is a flying prototype located in Zhukovsky.
T-50-3 - Is a flying prototype located in Akhtubinsk.
T-50-4 - Is a flying prototype located in Akhtubinsk.
T-50-5R - Was the damaged prototype T-50-5 now being repaired using T-50-6
T-50-6 Is now a flying prototype which had been called T-50-6-1
T-50-6-2 Is a flying phase 2 prototype
T-50-7 Is a static phase 2 prototype which had been called T-50-6-1

But there is one discrepancy/issue/misunderstanding. On one hand it mentions T-50-6-1 now being called simply T-50-6...but then later, says that T-50-6-1 was a static prototype that is now being called T-50-7.

I wonder, which is it?

Later in 2015:
T-50-8 Will be a flying phase 2 prototype
T-50-9 Will be a flying phase 2 prototype with new engines

In 2016:
T-50-10 Will be a flying prototype
T-50-11 Will be a flying prototype
T-50-12 Will be a static prototype

Correct?