firebarIf this is the case really, please explain, why that record was not taken by the SU.
Why the record was not taken by the SU ? Look at that:
-27.01.1971 absolute speed record for turboprop aircraft was taken by Lockheed P-3 Orion. It attained 806 km/h.
-In april 1960, Tupolev TU-114 took world speed records in closed circuits of 871 km/h in 1000 km circle and 877 km/h in 5000 km circle.
It never attempted speed record in streight line, but , obviously, it could have taken it easily. Why they did not taken it, it is a mystery.
So, we have a currious situation:
Current world speed record for turboprops still hold P-3 !!!
The same situation applies for several other aircraft: Be-10, Be-12, AN-22, AN-124 etc. They all hold speed records in closed circuits in their class, but never attempted speed records in streight line. Currious but true.
firebarD-21 were launched operationaly by B-52s.
After only 4 operational flights over China by D-21, program was terminated and overflights were continued from time to time by other drones like AQM-156.
That is sure proof that D-21 could not penetrate safely Chinese airspace. Otherwise , program would have continued.
By the way, AQM-156 had RAM skin.
firebarMig-25 achieved 3,2 Mach on 26.03.1971.
It is interesting that at that time absolute world record was 3,13 Mach held by YF-12.
firebarWhen PRC exploded its first nuclear weapon, an SR-71 was overhead at 120,000 feet.
The Western AF’s paniced when Gary Powers was shot down in his U-2. USAF bombers could not use altitude to penetrate Soviet air space, BS! Powers had a flameout and his U-2 was down to 60,000 feet when the SAM’s near miss damaged the plane to the point that Powers had to bail out.
SR-71 can not fly over 85.000 ft because of stability and engine power limitations. Above that its directional and longitudinal stability is unacceptable.
Regarding Powers flight, he said that he had been in maksimum height when hit.
firebarScramjet engines are something else. In it, airflow mix passes through combustion chamber at supersonic speed. That is something different.
Secret of R-15 engine is in its transonic compressor blades and impulse type turbine which gives a very high exhaust velocity but at expense of low efficiency at subsonic flight speeds.
firebar`
I only know of one D-21 wreck in China, which was attributed to a systems malfunction in the drone. The other mission loss was because of the USAF first failing to pick-up, and then accidentally destroying the D-21s mission package.
Why do you think that it had systems malfunction and that was not shot down?
As you know, D-21 oprations were conducted from late 60s to 1972. There were 4 operational flights. 2 were lost.
1972 flights over China were abrupty ceased with D-21, but were continued with other drones.
If D-21s had been lost because of systems malfunction, there would have been other flights after that. But D-21s have been put to storage.
Chinese defence proved to be too strong.
firebarThe MiG-25/31 is designed for a constant cruise of Mach 2,35 and not Mach 3+. So heat limitations were/are not so severe.
The “agility” given does not include very high heights (60+) and speeds (2,35+). There the max. G goes down to 2.0 and at the corner of envelope to 1.2 .
2,35 Mach cruise is true for Mig-25R. It had about 10 min max thrust limit.
About 1972 entered RB version. It had 40 min maks engine thrust capability.
Mig-25 is designed to endure more than 300 degr. C skin temperature. This is pretty much like SR-71.
Agility is not only G number. It is ,also, ability of an airplane to rotate fast about its 3 axes without going into departure. This is very important feature of any fighter.
There are reports of military journalists, who fly in Mig-25, that it behaves at 25 km height with such agility as if it has Reaction Control System. A remarkable feature.
firebarRegarding overflights by SR-71, note that China have displayed remains of 2 D-21 drones that have been shot down.
There were 4 operational flights of D-21, all over China in early 70’s and half of them were shot down.
Think of it.
And SR-71 is much slower and much larger target than D-21.
firebar> firebar
> J-58 engines of SR-71 is not so technologicaly advanced. Secret
> behind SR-71 speed is propulsion system, not engines.
The Pratt & Whittney J-58 (JT11D-20A) engines were very advanced for their time (still are). A combination turbo jet/ramjet engine, who else has desinged an engine that operates efficiently at Mach 3.0+ for many hours and does not require significant engine work upon landing. The SR-71 can fly a 7,000+ mile mission and the only segnments of which are flown subsonically are the take-off, refuelings and, the landing.> Did the Russians ever come close to shooting SR-71 Blackbird
In some respects you could say yes but, these were recon profile flights that were in international airspace with SR-71 flying at lower speeds and altitudes. When the USAF did not want to be “touched” (like when the SR-71 flew over ground zero for the PRC’s first nuclear explosion at Mach 3.0+ at an altitude of 120,000+ feet plus) the SR-71 was and still is untouchable.
Adrian, there is difference between engines and propulsion system.
SR-71 propulsion system is advanced, that is true, but engine, J-58 is odinary high thrust engine. Airflow velocity must slow down to 0,5 Mach before entering compressor, just like in ordinary jet engine. That is why it is so bulky.
Mig-25, on the other hand, have transonic compressor, which allows much higher airflow velocity to enter compressor face. There is no equvalent in the west. It allows much lighter and smaller propulsion system for the same thrust.
Also, R-15 engine is not so constrained regarding airflow disturbances.
Because of that , Mig-25 is very maneuverable at high altitudes. It can do loops, rolls, immelmans and other fighter maneuvers with ease. See russian advertisement for civilian flights in Mig-25.
SR-71 is, because of its mixed compression propulsion system, restricted to only small maneuvers or otherwise, inlet unstart will occur with great power loss.
That is why it never attempted a max altitude record. It would certainly have crashed.
SR-71 is basicaly streight line flying fuel tank. A very inflexible machine.
And its max altitude is 85.000 ft.
There are many myths about its max ceiling. Do not be missinformed.
firebarIn SR-71, at high speed, most airflow passes by compressor. It is mixed compression propulsion and, so, it has a great vices.
firebarAugmentor thrust
The engine system was geared to providing near-ideal conditions of temperature, pressure and oxygenation at the augementor. In fact, the main function of the core was to further compress and heat the air, making the augementor more efficient; at high speed, its contribution to the thrust was small. Virtually all the thrust at high speed was generated by the expansion through the convergent-divergent nozzle, driven by the combustion of massive quantities of fuel in the augmentor.
This type of powerplant has been called a ‘turboramjet’, or a ‘supercharged ramjet’ and the term is accurate to a degree. While the components of the propulsion system are the same as those of any supersonic turbojet, most of the compression is done in the inlet and most of the thrust is generated at the final nozzle, just as happens in a pure ramjet. Perhaps ‘turboramjet’ is appropriate, since the other type of powerplant to carry the name – in which the jet is switched out of the cycle at high speed – has never been flown.
Just how much sheer thrust this sort of engine can produce at high speed is best illustrated by example. The F-15, judged a high-speed fighter, weighs just over half as much as the MiG design, when both are carrying missiles and half internal fuel, but the MiG has only 12 per cent more static thrust, and moreover its missiles are far larger and less efficiently carried. Yet the Soviet type is 60 per cent faster, mainly because it has a completly different type of powerplant. This is no discredit to the F-15, which was designed with entirely different missions in mind, but points out the unique thrust-producing characteristics of the turboramjet engine.
The engine and the augmentor were installed for early flight tests in a test-bed aircraft derived from the MiG tailed-delta design. Designated Ye-166, it flew in 1961 and set a series of speed and altitude records in the following year. It tested the engine up to the design Mach 2,8 maximum speed.
Meanwhile work on the Ye-26 continued. The aircraft systems were mostly conventional: thanks to the limited supersonic endurance, the aerodynamic heat from the skin, would not soak through every part of the aircraft, as it did on the contemporary A-12. Apart from a new high-temperature synthetic hydraulic fluid, and a special cooling system for the engine accesories – a single-pass methanol/water system was used to cool the generators, the hydraulic pumps, and the avionics, the hot liquid being dumped into the inlets – the systems could have been taken of any contemporary Soviet aircraft, with two hydraulic circuits for the flight controls and pneumatics for the brakes.
…..Please read carefully, before blaming a famous author.
I still in hope you will understand the design of the MiG-25 some day. 😉
I know this source. It is from MIGS- Fact File series. I am saying again, it is an old source and it is not correct.
R-15 engine is not turboramjet. All flow goes through compressor. Also, there is no methanol/ water injection.
These are old informations. So, this author is not very useful as data source.
Only turboramjet has SR-71.
firebarThey didn’t find new Ti sources after the mig-25s were built. And the large subs I was thinking off were Sierra and Mike classes.
I can not tell about titanium sources but keep in mind that Sierra and Mike are designed in 80’s. 20 years after Mig-25.
firebarF-111 can not attain 2,5 Mach.
That was requirement but have not been achieved in practice.
Ask any F-111 pilot. They say that there is not one pilot who attained 2,5 Mach speed from specs.
It is a commom case with many other fighters. One thing is stated in specifications and, in fact, the true speed is something else.
Do not be missinformed by some authors.
At sea level, limiting factor is dynamic pressure, at high altitudes it is compressor temperature limit. It depends of engine design and internal thermodynamics.
By the way, there is no known fighter in service which could surpass 1,15 Mach at sea level in level flight.
You can read about 1470 or 1500 km/h at sea level for some. That is all incorrect. F-4 still holds the record with 1,17 Mach for service fighters.
firebarThe reality is they made it with steel because they could. It is much cheaper and much easier to both work and maintain. If they wanted to make 1200 titanium planes they certainly could have. They made 9,000 ton submarines out of the stuff and they are a major exporter of Ti. The simple fact is they wanted a cheaper simpler plane. They could have used gold mesh around the engines instead of silver mesh to improve cooling that would have been more effective but also more expensive. They also chose the cheaper option there too.
Titanium subs of ALPHA class were built in late 70’s, much later than Mig-25.
And they were 2500 t class.
firebarNickel steel is very good for high temperatures. In fact it better withstands high temperatures than titanium, but have somewhat lower yield/ weight ratio.
R-15 engines are entirely different that than RR Viper.
Both have similar pressure ratio, 4,8:1 but these two engines are totaly different. Viper can not exceed 1 Mach even in afterburner.
It is matter of internal thermodynamics, shape of compressor and turbine blades etc.
Bill Swetman is not very good source of this data.
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