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June 11, 2005 at 1:27 pm in reply to: Mig-31 versus F-22 #2633390

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Both GE and Pratt have flown with 3D round nozzles so it’s not like the US doesn’t know how to make them work.

They have flown them but they did not perfected them. That is the big difference.

SU-30MKI is the only in service fighter with 3D nozzle. It entered Indian Air Force service. The Russians achieved to perfect them.
The F-22 has 2D nozzle but it has not yet entered service.

The fighter with 3D nozzle has a big advantage because it has TVC authority in yaw, not only in pitch.

But, it is very hard to solve technical problems with 3D nozzle. Not easy at all.

The 3D nozzle is truly a revolution in flight control field. Note also that SU-30 MKI has Integrated Fllight/Engine Control.
Another first which is barely noticed.

June 11, 2005 at 1:06 pm in reply to: Mig-31 versus F-22 #2633400

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The wingspan increased by a foot and a half. Barely noteworthy. The fuselage has slimmed down considerably (reducing drag) and the engines are more powerful than those the YF-22 flew with. It’s been reported several times by reputable sources that the F-22A can exceed Mach 1.7 without afterburners.

A foot and a half has a great influence on drag at high speed. The engines are the same 35.000 lb thrust class.
The aspect ratio and wing sweep have also big influence.
That is aerodynamic law.
We can not help the F-22 to be faster than it is by talking.

When you have no aerodynamic and flight mechanics knowledge, you are prone to believe whatever you want.
For example, that F-15 or F-111 have Mach 2,5 max speed or that SR-71 has 100.000 ft ceiling, etc,etc.

June 11, 2005 at 12:54 pm in reply to: Mig-31 versus F-22 #2633404

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The question was about speed related to other elements like ratio’s and weight. The max speed due not suffer from that as F* claims for the F-22 versus YF-22 and the MiG-31 example shows. Drag-thrust-ratio is the decessive factor and how long an aircraft can sustain that heat-stress, before forced to throttle down to avoid thermal damage by that.

You forgot that F-22 and YF-22 have the same engines.
The Mig-25 and Mig-31 have entirely different engines.

You can not compare these things.

Also, always remember that engine thrust at sea level static conditions have nothing to do with thrust at height and high speed. The differences in thrust between various engine types at high speed are very big.

June 10, 2005 at 8:20 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634041

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And firebar, where’s this information on YF-12A radome melting?

Do not worry, I will present this to you. Do not doubt that.

June 10, 2005 at 8:12 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634044

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Compare that with F-15 which can attain only Mach 1,78 with 4 small underwing missiles at max thrust.

June 10, 2005 at 8:05 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634047

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Not really a mystery at all. It’s called lower performance and less range. A Mig-25 couldn’t sustain Mach 3.2 at 85,000 feet for 2000 miles in it’s wildest dreams.

Nobody says that it can.
But with its 4 long range missiles it has more than enough speed and ceiling to destroy any Mach 3 intruder. It is designed for that kind of mission. Never forget that.
It has Mach 2,83 max cruise with 4 missiles and it has zoom climb with 4 missiles to height more than 30 km.
Nothing can escape that kind of performance.

June 10, 2005 at 7:57 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634052

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“They said, so what ? Who can confirm that ?
Anybody can say anything.”

But Sferrin, we are talking of Indian Air Force site, regarding MiG-25. They had experiences with it.
It is not some private site where anybody can say anything.

June 10, 2005 at 7:53 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634056

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Not confirmed by R. A. Belyakov and infos for the less educated Indian public like ****!

Note that the book MIG is not writen by Belyakov but by some French author. What of that is exactly said by Balyakov is not entirely known.

June 10, 2005 at 7:48 am in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2634061

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I think you both are missing the real point. The real problems were costs.. No matter who of you is right, one has to wonder how the MiG-25 managed to achieve absolutely hilarious performances at the costs of YF-12 vertical tailplanes plus cockpit section..

Given the same budget, Lockheed team would hardly manage to get beyond artist concepts.. It is unimportant whether YF-12 beat the Foxbat by some fractions of Mach number or not, the effectivity of its design is ridiculously low compared to the rude Russkie and was mirrored by small numbers of airframes built and operated.. The Foxbat effectively reduced SR-71 (or Y-12 or A-12 or whateveryacallit) missions over Russia, that was its primary goal (not the Valkyrie), it surely has its place on aviation sun..

You are absolutely right. From technical aspect, it is far better if you succeed to build an aircraft with similar performance but with a fraction of price. That is something that american aircraft designers have never understood.

Even in John Barrons book MIG Pilot, it is stated that american engineers were stunned with russian designers ability to use non strategic materials for such a high performance aircraft.
They thought it was impossible. And that is , from engineering point, one of the most important thing.

May 30, 2005 at 2:43 pm in reply to: Mig-31 versus F-22 #2639463

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I said earlier.
Comparing with prototype, the production F-22 has much greater wing span, smaller wing sweep angle, higher aspect ratio wing and has higher weight.

All of this reduce speed.

May 30, 2005 at 2:36 pm in reply to: Mig-31 versus F-22 #2639471

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The YF-22 sustained 70 degrees AOA in flight tests.

Are you sure ?

May 30, 2005 at 2:32 pm in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2639475

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Anybody can write anything!! All three YF-12s had their radomes melt off when they went into flat spins because they didn’t have any directional stability!!

Do not doubt it at all.

The YF-12 was, like XB-70, undeveloped aircraft when program has been teminated. Both had many technically unsolved problems.

So, comparing the experimental YF-12 with highly developed, reliable and numerous Mig-25 is not serious.

The Mig-25 and Mig-31 are the only combat aircraft in the world which are capable of breaking a thermal barrier.
And that with underwing stores.

That is , from technical aspect, incredible achievement.
Anybody with technical and aeronautical knowledge have to appreciate that.

May 30, 2005 at 2:14 pm in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2639481

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We have to believe facts about Mig-25 in Indian Air Force site.
They have much experience with it.

If they say max speed is Mach 3,2 and ceiling 24.000m, I do not know why not to believe them.

May 29, 2005 at 12:27 pm in reply to: Mig-31 versus F-22 #2639988

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Lets back to Mig-31 versus F-22.

The Mig-31 with 700 km radius of action at 2,35 Mach cruise speed, normal cruise ceiling above 20.000m and with long range electronically agile radar, 120 km range R-33 missiles (300 Km demonstrated with R-37), long range FLIR and ability to dash at 2,8 Mach, I can see that F-22 would be in a deep trouble.

True, F-22 has less radar cross section, but Mig-31 compensates with greater radar range and far more missile range.

The cruise speed and cruise altitude are Migs great advantages regarding shooting distance. It will shoot at F-22 from far more greater altitudes.

Also with 3000 km/h dash, it represent a very tough target for any missile.

May 29, 2005 at 12:08 pm in reply to: Mig-31 versus F-22 #2640005

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http://www.globalsecurity.org

F-119 engine, page 1:

“The F-22 can attain Mach 1,4+ in military power.”

I said earlier: The production F-22 has a far more drag than prototype.
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