A sensible national strategy would then have evaluated the cost and value of meeting Marine requirements, which would first have meant defining them.

That is the crux of the problem right there.

Do the marines need a (relatively) delicate, supersonic, VLO striker that operates off a LHD? Do they f**k (in my opinion).

A rugged, conservative, mongrel of an aircraft is what they need. When the going gets tough, it keeps going.

One could even argue that the USMC would be better served from LHDs by either a high speed helicopter based off the S-97 or a tiltroter – a gunship-esque V-22 like the Huey gunship back in the day (obviously, it would be a smaller airframe) than by a VLO supersonic striker as the aircraft cannot land on the beach, whereas the choppers can.

[I suppose we can assume UAVs for CAS is out the window.]

Easy now…

Currently the 117S has ca 8800kg of force in max dry thrust, will it be able to let the Pak FA supercruise @mach 2?
The F22 has 11’500 kg of dry thrust and the fuselage weight is just marginally (<10%) heavier than Pak FA.

Do we have any official sources?

I have this one for starters: http://npo-saturn.ru/?sat=64&slang=1

Erm, am I very confused or does the 117S not power the Su-35?

Which is not the same engine as the PAK-FA…?

Currently the 117S has ca 8800kg of force in max dry thrust, will it be able to let the Pak FA supercruise @mach 2?
The F22 has 11’500 kg of dry thrust and the fuselage weight is just marginally (<10%) heavier than Pak FA.

Lift dependent drag is essentially a negligible part of the overall drag polar at Mach 2.

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Taking the F-15 as an example, decreasing aircraft weight by 10% reduces drag by ~0.005% at Mach 2.

Public statements are most likely disinformation just like that press release was about rcs from India side.

Given the timeframe (Dec 2004 if I am right on which statement everyone is referring to), the statement may have been made in good faith – but 6 years of design work later – what has come out of that design process is not something that adheres to good design rules for a ≤ Mach 2.0 aircraft.

Considering the Russian obsession with agility in their fighters, I simply cannot reconcile the concessions they would have given up for nothing.

It is a Mach ~2.5 airframe. Perhaps they don’t want to publicise it, I dunno. More likely is a requirement change to be a possible MiG-31 replacement too. But it (PAK-FA) is what it is and some things cannot be hidden.

Additionally, the reason given was Vstab/Hstab weight. Well, all moving elevators have been de-rigeur for years now, all moving Vstabs less so.

Therefore, we must assume the problem was the Vstabs – the use of TVC as a primary control device has reduced their size quite a bit and Vstab loading is widely known to be at its most problematic in high alpha due to the buffet from the longitudinal vortices emerging off the forebody, not high speed supersonics.

Given a questionable reason and given even more questionable design compromises I have to conclude that the Mach 2.0 either no longer applies, or never did apply to this concept of PAK-FA.

Says former VVS Fuhrer. 🙂 We have been through this, look it up.

All I can find is a website stating a 2004 requirement change to Mach 2 on the back of (I assume) Yefim Gordon.

Which I will emphasis doesn’t match up to the aerodynamic design of the aircraft.

Given a choice between what the aircraft aerodynamics have been designed to do (along with the compromises those characteristics entail – its quite important to consider that), or mere words…. I go with physics every time and trust that the aerodynamicists designing the thing knew what they were doing. Words can quite quickly be changed and adapted to any intention. Physics is significantly less amenable to whatever impression the speaker wishes to convey…

[Of course, there are cases where the engineers have to work within a box not of their own making, such as the wingspan of the Shorts Stirling.]

Hehe. better not bring up the F-22’s supercruise ability then had we…. LOL

Is that about our discussion over its supersonic range?

Besides being rude you have no proof the PAK-FA has better Aerodynamics than a F-22 or even the F-35 for that matter.

No, no proof that would be deemed acceptable by some folks (kids) on here.

Besides getting the datasets I don’t know what would convince some… even then, they probably wouldn’t accept reality.

The rudeness is a straightforward response to the all too common xenophobic position of “ours is best, regardless of what physics might think”.

Yet, I would at least speculate that Lockheed Martin and the US has the advantage with its decades of experience in advance stealthy fighter. Which, have a “proven record” in high performance. (Super Cruise for example). In addition unless something has changed I don’t believe the PAK-FA prototypes have been flown anywhere near the extreme of there flight envelopes. Let alone on a operational production fighter.

All that means squat when you compare the two aircraft using the parameters that describe their aerodynamic characteristics and the features within (or not within) the design that aid aerodynamic performance.

All of that is not to say the PAK-FA couldn’t match or even beat the F-22 in say Super Cruise or another aspect of its Flight Performance. Yet, we’re or at least I am talking about the combination of the two. (i.e. Stealth & High Speed) So, while it’s possible the former could match the F-22 in pure performance. It would likely have to pay a high price in Stealth! So, my contention the F-22 has the best odds with what little information is available.

Did you read the explaining post to MSphere’s question?

Compared to the F-22, Suhkoi have compromised the PAK-FAs VLO characteristics – so you shouldn’t be surprised that they have a better aerodynamic platform.