firebarWhat hole did you pull this little “fact” from? :rolleyes:
Have you ever heard or read that Mig-25 suffered from engine unstarts?
Of course not. Its engines are not mixed compression type.
On the other hand, it is well known and documented that the XB-70’s engines suffered from this nasty habit badly, which is not surprise.
firebarIndian Air Force knows nothing about supposed engines damages at 3.2 Mach.
Mig-25 at Pune Air Force Academy.
firebarThat stories about its engines is often quoted hoax. Its source is a book “Mig pilot” by John Barron, which say that the Mig-25 has max action radius of 300 km!!! and that its max range is 1200 km !!!
Obviously the book is full of lies.
He also said that: “Every time after 3.2 Mach speed it ruined its engines.”
That statement is pure nonsence. Everyone familiar with aircraft design and flight mechanics knows that there is no Mach 3 aircraft which can land deadstick.
Without engines working it would crash for sure.
Even F-4 , with medium speed aerodynamics, can not land without engines working.
Pay attention that John Barron statement confirmes that the Mig-25 flew at 3.2 Mach many times. (“Every time when it flies 3.2 Mach…. )
Anyhow, the statement of OKB MIG chief designer, Belyakov, that there is no any damage when it flies at more that 3 Mach, and that there is even no need for inspection, has much higher value than that of John Barron’s.
No inspection and overhaul is necessary, acording to Belyakov and many pilots.
firebarThe engine in the Foxbat is more like a J-93 in concept than a J-58.
They look similar only at the first sight. In fact is they are not.
The J-93 suffered badly from unstarts. This vice has never been overcomed in XB-70.
On the other hand, the Mig-25 never experiences unstarts. That is because it has no mixed compression engines.
A truly big advantage in combat conditions, which is often overlooked.
firebarContrary to the J-58, the time at max speed is limited to the amount of coolant for PCB.
The Mig-25 Manual says nothing about PCB. Nor OKB MIG chief designer says anything about that.
See also Yefim Gordon-Mig-25. No trace of PCB.
The fact is that the Mig-25 has no any precompressor cooling.
Its engines use technology, which I mentioned earlier, that is not familiar in the west.
firebarTechnically it’s not a “turboramjet” as all of the air goes through the turbine. It’s just a low pressure engine with compression due to the intakes. That doesn’t make it a “turboramjet”.
True. Only Blackbirds have mixed compression turboramjets.
The R15BD-300 has much better solution for high speed flight, avoiding nasty inlet unstarts, which make any normal maneuvering impossible.
The R15 uses very low compression ratio compressor, but it is not enough for Mach 3 flight. The Viper engines or Atars also have low compression.
The key for R15’s such enormous performance at high speed and altitudes is in its thin compressor and turbine blades, which have no western equivalent.
In its transsonic compressor there are no great waste of energy and, because of that fact, much higher speeds are allowed before compressor.
Also its impulse type turbine is much more optimised for high speed flight than normal impulse-reaction type, in ordinary engines.
It allows much higher exhaust velocity.
That is the key of Mig-25 great combat performance.
With turboramjets, it would be inflexible and totaly unuseful for combat and maneuvering.
firebarAll the MiG-25s did stick to the R-15B-300 variants.
Not true. Check this better.
Only first versions, which entered 1970, had this engine.
From 1972 and later, the standard engine was R15BD-300.
It had better fuel consumption, higher dry thrust and the max thrust allowed for 40 minutes instead of 15 min.
firebarWhat about the fact that while capable of M3.2, this destroys the engines as they’re exceeding their redline, and M2.8 is the realistic top speed while clean. I don’t see a Mig 25 with combat load cruising over M2 for 1800+ KM.
That stories about its engines is often quoted hoax. Its source is a book “Mig pilot” by John Barron, which say that the Mig-25 has max action radius of 300 km!!! and that its max range is 1200 km !!!
What stupidity.
He also said that: “Every time after 3.2 Mach speed it ruined its engines.”
That statement is pure nonsence. Everyone familiar with aircraft design and flight mechanics knows that there is no Mach 3 aircraft which can land deadstick,without engines.
Such aircraft are optimised for high speeds.
It is interested that John Barron statement confirmes that the Mig-25 flew at 3.2 Mach many times.
Anyhow, the statement of OKB MIG chief designer, Belyakov, that there is no any damage when it flies at more that 3 Mach, and that there is even no need for inspection, has much higher value than that of John Barron’s.
firebarThese are ranges and radiuses for the Mig-25 which entered 1970. That is for the first version.
Surce: Manual, which states that these data refer to a/c which entered in 1970.
-Action radius 920 km with belly tank, at 2.35 Mach cruise speed.
-Action radius 680 km without belly tank, at 2.35 Mach cruise speed.
-Action radius 770 km without belly tank, at 0.9 Mach speed at 10.000 m.
-Action radius 560 km without belly tank, at 2.35 Mach cruise speed with 4x 500 kg bombs.
These data refer to oldest version, as Manual say. The newer versions have improved engines and lower fuel consumption.
Nevertheless, even this action radius is remarkable, bearing in mind that it has only 14.5 tonnes of int fuel. (The SR-71 has 38 tonnes).
firebarThe thing you have to remember about Firebar and the Mig-25 is he’s convinced all top performance figures can occur at the same time. So the Mig-25 can fly to 123,000 feet at Mach 3.2 with four huge missiles hanging under it, stay there for 2000km, and pull 11 Gs along the way if it needs to. :diablo:
Of course not.
The 123.000 ft altitude is achieved in zoom climb. It is not operational ceiling, but it shows us tremendous performance capability compared to other fighters.
I said earlier that Mig-25’s 11 G demonstrated is ultimate G, not cleared for service. But it anyway shows us great structure strengts.
Just as reports of F-4, pulling 11g in some combat situations, and staying in one piece although suffering some damage, show us great strength of F-4.
firebar<15 minutes. Or did you miss that?
You think that McNamara miss that too ?
Refuelling of nitrogen filled tanks and heating of hydraulic oil takes 2 hours, sometimes more. It is all well known.
Even pilots need one hour of breathing pure oxygene before flight.
All this totaly excludes Blackbird family as usable combat a/c, and render them useful only as strategic reccon a/c for well known, fixed targets.
firebarhttp://en.wikipedia.org/wiki/Viktor_Belenko
The flight distance was ~800 km with full fuel. 😉
That is from the book “Mig pilot” by John Barron, not Belenko.
What Belenko told him realy is a matter for a debate.
For example, John Barron says that the Mig-25 has 300 km radius at best and max range of 1200 km !!!!
That is a pure lie.
According to manual it has action radius of 920 km with belly tank at criuse speed of 2.35 Mach, and 680 km without belly tank.
At subsonic 0.9 Mach it has 770 km radius of action at 10.000 m altitude.
So much so of the often quoted John Barron’s book “MIG pilot”
firebarIt’s an interceptor, not a fighter, and as such did not require the ability to maneuver to any greater degree. Even with a massive turn radius at Mach 3, the reattack time against an incoming bomber formation was shorter than that of the F-106. I guess the F-106 was also unsuitable as an interceptor then, right?
The F-106 was very maneuverable interceptor, like it should be. And it had a good reaction time.
Imagine the long range radars detect Russian bombers, then this information passed to supposed F-12 squadron, and with its 2 hours reaction time, what would happen ?
That is where YF-12 failed. It was unacceptable.
firebarJust hilarious:
“The aircraft displays handling characteristics of an aeroplane at lower altitudes and that of a spacecraft at higher altitude.”So the MiG-25 can shoot down the space shuttle?
Who remembers the film with Clint Eastwood and the Soviet superfighter? I lost the title.
The inscription before Indian Mig-25 say that it has
handling
characteristics like airplanes designed for lower altitudes, and like spacecraft at higher altitudes, where is no enough air density.
Obviously it has very effective flying controls.
To design Mach 3 airplane which combines these two contradicting requirements is truly outstanding, from engineering point.
According to Manual the Mig-25 is cleared to any fighter maneuver: loops, slow rolls, zoom climbs, high G pull outs, etc.
That is a remarkable achievement compared to Blackbird family, which are in essence streightline, unmaneuverable flying fuel tanks with flimsy airframes.
firebarThe thrust drag ratio of the F-14 will be much better still. More thrust impresses the layman, but as I said above there are more important criteria and the MiG-23 looses in most against all F-Teens.
What? The F-14 has enormous drag coeficient compared to Mig-23.
The Thrust/drag ratio is very important for rate of climb.
And you probably know that the F-14A had a patheticaly low rate of climb.
As for what it takes to make a good close combat fighter, read “‘Figher tactics and maneuvering”- Robert Shaw, TOP GUN instructor.
-“Because of its low T/W ratio, the F-14 was in fact underpowered aerial truck.”
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