The T-50 (PAK-FA) Thread

[NoJoe]

More like in the neighborhood of >M1.7 :)

 

Whoa, that's faster than I'd thought. Source? :)

[GGTharos]

I don't recall my source, unfortunately I've seen too much stuff and spoken with too many people to finger something specific.

 

Basically MIL is too slow to get up to there, so you'd use AB, but MIL will sustain it. The thrust available to the F-22 in MIL only is the same as that of an F-15 in some stage of AB (but not max AB).

[NOLA]

Whoa, that's faster than I'd thought. Source? :)

The requirment was 1.6 if my memory doesn't fail me. 1.7 is commonly known number, and i believe an USAF paper refers to supercruise of F-22 as 1.7+.

 

As to "how old" F-22 is, i think it is best to compare oranges to oranges. "Real" F-22 didn't start with YF-22, but with first actual F-22 prototype that flew in 1997. T-50-1 is NOT on YF-22 stage. It is on F-22 prototype stage.

 

So, F-22 is 16.5 years old and T-50 is 4 years old at this point.

[Pilotasso]

As I said, many 4th Gen fighter engines are capable of supercruise without AB, however these are table test figures and are only slightly > M1.0.

 

Supercruise of a F-22 is in the neighbourhood of M1.4 at 35.000ft.

 

Since there's no similar engine in rest of the world one has to develop it and that's the main 2020 reason.

 

They achieved mach 1.7+ with the raptor. ;)

 

Edit: too slow ^^^^^

 

The requirment was 1.6 if my memory doesn't fail me. 1.7 is commonly known number, and i believe an USAF paper refers to supercruise of F-22 as 1.7+.

 

As to "how old" F-22 is, i think it is best to compare oranges to oranges. "Real" F-22 didn't start with YF-22, but with first actual F-22 prototype that flew in 1997. T-50-1 is NOT on YF-22 stage. It is on F-22 prototype stage.

 

So, F-22 is 16.5 years old and T-50 is 4 years old at this point.

 

its is irrelevant to compare age because both industries are at different levels of experience in the field and the tech level of equipment usually counts from IOC when the final equipment finds its place in the aircraft, and not from prototype stage (flight test gear only). The F-22 is really only less than 9 years old, as for PAk-FA, its not even out yet as its equipment is still being developed.

Edited January 27, 2014 by Pilotasso

[Vekkinho]

More like in the neighborhood of >M1.7 :)

 

Only way of reaching M1.7 is with use of AB.

 

Edit: I see now you already wrote that!

Edited January 27, 2014 by Vekkinho

[GGTharos]

I don't really know. It's a combination of technologies - an engine that can deliver enough thrust, intakes that can correctly shape the air flow, flying clean - ie. no external pylons or stores. If any one of those components were to go missing you'd have a drop in performance.

[Vekkinho]

Anyway, the biggest disappointment in seeing T-50 testbeds during last few years is with her engine wells. I mean we can talk radar absorbing materials used inside intakes but it sure doesn't look good so far from both sides...Stealth is not only being hidden from a radar, what's with IR signature? These nozzles provide no gain in IR reduction.

 

I've seen them fly at MAKS 2013, they smoke no less than average Flanker...

[GGTharos]

Do you need to hide the IR signature? There are a few questions to be answered with that respect. It seems that Sukhoi was not aiming at F-35 class stealth, if the reports are to be believed, but a 0.1m^2 frontal RCS is nothing to sneeze at.

[NOLA]

its is irrelevant to compare age because both industries are at different levels of experience in the field and the tech level of equipment usually counts from IOC when the final equipment finds its place in the aircraft, and not from prototype stage (flight test gear only). The F-22 is really only less than 9 years old, as for PAk-FA, its not even out yet as its equipment is still being developed.

 

No, it is not irrelevant. One can compare time from prototype to IOC. IOC for T-50 should be around 2017.

 

It seems that Sukhoi was not aiming at F-35 class stealth, if the reports are to be believed, but a 0.1m^2 frontal RCS is nothing to sneeze at.

 

Where did you get 0.1m^2 frontal from?

[Basher54321]

Where did you get 0.1m^2 frontal from?

 

 

Probably from the patent analysis

 

http://indrus.in/blogs/2014/01/16/patent_analysis_shows_how_pak-fa_differs_from_f-22_in_air_combat_philos_32309.html

 

 

 

There is a link to the patent on there - have transcribed it with google - but haven't located it myself yet.

[NOLA]

Ahem.

 

http://forums.eagle.ru/showpost.php?p=1978041&postcount=1928

[Basher54321]

Ahem.

 

http://forums.eagle.ru/showpost.php?p=1978041&postcount=1928

 

 

Haven't had time to read the whole thing yet :megalol:

 

 

In that case I assume you are asking for information on whether the quoted figure is specifically for the frontal aspect?

[NOLA]

Issue is that the patent doesn't talk about any particular position, so extracting 0.1 as frontal from it is nonsensical.

 

Patent clearly speaks of average. It can be average in terms of position only (fixed frequency) or average compared to frequency (position fixed, lets say direct side only). Or of course both at same time.

 

For example, if we take first example, and i am just inventing numbers here. Frequency is fixed at X-band but position vs radar is changing.

 

RCS direct front: 0.001

RCS direct side: 0.5

RCS from directly behind: 2

RCS from directly under: 1

 

Average for those numbers is 0.875 m^2. If i had just 0.875 i wouldn't be able to know RCS from direct front. And that is the situation with 0.1-1 number.

[Weta43]

But then by your own admission, the T-50 will be a max of 4 years old in 2020.

 

Now you're just using logic to confuse people - stop it !!! :(

 

:)

[Namenlos Ein]

 

 

 

 

 

[Vekkinho]

But then by your own admission, the T-50 will be a max of 4 years old in 2020.

 

In the end that's really irrelevant cause comparing these two aircraft is impossible...

 

P&W - F119 engine or PW5000 as it was called back in the day already powered YF-22 when YF-22 tests started in late 80s. This engine was "finetuned" and adopted for use with F-22 and her main roles during tests and was finally installed on first (and current) Raptors produced for use with USAF.

 

So entire F-22 envelope (radar, weapons, flight performance) and ways of her practice was based on an existing platform unlike T-50 which will be in active service with RuAF for 3 or 4 years before they upgrade their main component - which is an engine.

 

You'll have to reorganize entire "flight manual" and weapon delivery tactics that can not be definite as long as there's temporary solution.

 

That's like buying a gun that you can only use as a club as long as there are no suitable bullets...

Edited January 29, 2014 by Vekkinho

[Basher54321]

Issue is that the patent doesn't talk about any particular position, so extracting 0.1 as frontal from it is nonsensical.

 

Patent clearly speaks of average. It can be average in terms of position only (fixed frequency) or average compared to frequency (position fixed, lets say direct side only). Or of course both at same time.

 

Yes - its potentially an average taken from multiple angles considered from the entire sphere.

 

Comparisons on forums are normally argued over frontal aspect speculation only - easy to see the confusion.

[Vekkinho]

^^^^

However frontal aspect (business end of the 5th gen fighter) is probably the most important one. I hardly believe you'll live long enough to see Raptor overshooting you or hauling ass back out of the fight...

[Vekkinho]

Do you need to hide the IR signature?

 

Yes, why do you think it wouldn't be important? Hiding a IR signature from IRST devices is just as important as painting a camo pattern to hide it from a Mk1 eyeball.

 

T-50 has a nice camo pattern...but this is tragic:

 

She's idling in that picture.

 

It's supposed to be stealth or lo observable in all three aspects: visual, thermical and radar.

Edited January 29, 2014 by Vekkinho

[GGTharos]

My point is that this their choice, and they may have reasons to not worry about it so to speak.

 

Everything is a choice/compromise. Head-on, the heat signature is already significantly reduced. Do they need additional measures? Or more to the point, do they want/need them? Maybe they're assuming delivery of weapons beyond IR detection/tracking range on average.

 

Yes, why do you think it wouldn't be important? Hiding a IR signature from IRST devices is just as important as painting a camo pattern to hide it from a Mk1 eyeball.

 

T-50 has a camo pattern...

 

It's supposed to be stealth or lo observable in all three aspects: visual, thermical and radar.

[NOLA]

I hardly believe you'll live long enough to see Raptor overshooting you or hauling ass back out of the fight...

 

I wasnt aware that raptor could fly backwards. Is this Iranian technology?

[Basher54321]

^^^^

However frontal aspect (business end of the 5th gen fighter) is probably the most important one. I hardly believe you'll live long enough to see Raptor overshooting you or hauling ass back out of the fight...

 

 

Well - probably more true for limited A-A type scenarios over friendly lines. Flying the other side of the line you have no control where the multiple Fire control radars come from - unless you fly NOE (but probably no point having a low RCS if you have to do that).

[Weta43]

Yes, why do you think it wouldn't be important? Hiding a IR signature from IRST devices is just as important as painting a camo pattern to hide it from a Mk1 eyeball.

 

T-50 has a nice camo pattern...but this is tragic:

 

She's idling in that picture.

 

It's supposed to be stealth or lo observable in all three aspects: visual, thermical and radar.

 

I'm not seeing how it's so much worse than this : (especially given the difference in the ambient temperatures the photo's were taken in)

 

 

 

While I think the T-50 even looks like it's still waiting for its final engines, WRT IR signatures, maybe the Russians just thought that of all the stealth technologies, hiding the IR signature of the engines looked like it returned the least bang for buck :

 

[aaron886]

The Raptor's design cuts the visible area of the immediate exhaust by ~30-40% from directly aft, and by a huge amount when viewed from a small off-angle. That could be a significant difference in rear-hemisphere detection. I could imagine IR acquisition denial or delay as well, which could mean the difference between death or a fighting chance when talking about a high HCA/AOT IR missile shot.

 

Great selection of pictures, though, Weta43.

[Namenlos Ein]