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  • in reply to: Blackbird vulnerability #2615185
    firebar
    Participant

    you are sying that with those huge cone symetric shape intakes (even painted with ferropaint) that stuff would have only 1m2 RCS????….comon….

    i guess that most people whe see the strange shape of the sr71 they say “its stealth”, but actually the shape and the later changes were for supersonic performance

    You are right. Many people would like Blackbird to be stealth design because of unusual shape, but that is not true.

    Designers had so much trouble designing Mach 3 airframe and solving stability and all other problems at such speeds that even thinking of stealth makes no sense.

    Blackbird is designed with only speed in mind.

    Regarding Blackbird fins, it is a matter of stability and aerodynamics.
    The fins are canted 15 degrees inboard to reduce very strong rolling moment due to sideslip.
    With upward fins, rolling moment due to sideslip would be to high at high speeds.

    This is good example how people make up things.

    in reply to: Mig-31 versus F-22 #2616279
    firebar
    Participant

    Very high AoA is achievable only at low speed! Most dogfiths recorded up to now (in jet era) took place between 0.6-1.2 M. At these speeds, you can’t perform cobras, bells, kulbits, etc.

    At low and medium speeds actually.
    In air combat simulations, almost every air battle, which starts at higher speeds, deteriorates to lower speeds.

    That is the reason why, controllability at lower speeds is very important.

    Also, that is why every modern fighter is better, in that respect, that fighter which it replaced.

    But, Thrust to Weight ratio is very impotrant, to enable the fighter to accelerate fast to higher speeds again.

    in reply to: Blackbird vulnerability #2616992
    firebar
    Participant

    After the incident on 30. oct.1967, when A-12 was slightly damaged with SAM-2, it is understandable that Americans have not been willing to risk flights over known SAM-2 sites.

    Not to speak of SAM-5 with 250 km efective range, or MiG-25 interceptors.

    Problem of Blackbird pilots was that its aircraft has been extremely limited in maneuverability, so that its flight path had been very predictable.

    This is, of course, true, more or less, for all Mach 3 aircraft, but Blackbird is especialy bad in that respect, because of its engines and stability constraints.

    in reply to: Blackbird vulnerability #2617014
    firebar
    Participant

    Kelly Johnson said that Blackbird was stealth aircraft with one of the lowest RCS in inventory, yet he said also that there had been a thousand of SAM launches against it.

    That statements contradict each other.

    If it has so low RCS, how it is so visible on radars, to provoke launch of so many radar guided missiles ?

    It seems that Johnson”s statements are not entirely sincere and true.

    He said about a thousand missiles, but keep in mind that he was designer of Blackbird.

    in reply to: Mig-31 versus F-22 #2617021
    firebar
    Participant

    Very high AoA capability is needed in fighter aircraft because it means that pilot will control the fighter in any maneuver, without fear of departure.

    For example, when avoiding missile during high g transient maneuvering, or when pointing its weapons to high g maneuvering targets, etc, etc.

    The pilot confidence that its own fighter is free of departure in any maneuver is of utmost importance.

    in reply to: Mig-31 versus F-22 #2617526
    firebar
    Participant

    Firebar, the F 22 can suatain 60 deg; it can too execute a 360 deg rotation. What I considered incorrect formulated was this:

    I have a numerous literature about its behaveour at high AoA, but I did not find that it could do even 70 degrees.

    The 360 degrees rotation about its lateral axis means that there is no limit in AoA. It is a full turn. Did you see SU-37 demonstration ?

    From a flight control system standpoint, it is extraordinary.

    in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2618200
    firebar
    Participant

    So, firebar, where’s that “radome melting” info?

    It is mentioned in one of many AIAA papers about YF-12 system testings.
    I have many such documents, and after reading such sources you can get more accurate picture about Blackbird.

    It was undeveloped aircraft.The radome is only one issue.

    So, it makes no sense comparing it with highly reliable and numerous MiG-25.

    in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2618208
    firebar
    Participant

    How can you keep being ignorant of the fact that the aircraft was an interceptor designed to protect the US against bombers? Even with an 80-mile turn radius or so, it had a faster re-attack time than the F-106. The fact that it wouldn’t be able to outmaneuver an F-4 had nothing to do with it’s performance as an interceptor.

    Nobody said that it had to maneuver as F-4, but with two hours alert time it was totaly insuitable as interceptor, and could not has possibly entered service.
    Only its preheating of hydraulic oil takes 2 hours average. Not to speak of other systems preparation.

    in reply to: Mig-31 versus F-22 #2618217
    firebar
    Participant

    Wow! Another Russian aviation first!

    Why are you surprised? From Polikarpov I-16 Russians are first in fighter technology, first cantilever monoplane with retractable undercarriage, first armed with air to air rockets etc, etc. But that is another matter.

    What do you mean? The Raptor can sustain a 60 deg AoA. The MKI can execute a full rotation at very low speed, but I don’t know for sure what is the max. AoA that it can sustain. Certainly is not 360 deg. Because 360 deg AoA means, in fact 0 deg

    !

    Are you aware that F-22 did not demonstrate AoA above 60 degrees, transient or sustained whatever. I still wait to see whether it could do a 90 degree AoA, which MiG-29 do without TVC. I did not see this yet.

    Full 360 degrees turn means full turn around lateral axis. And that is, from flight mechanics point, a remarkable achievement.

    in reply to: Mig-31 versus F-22 #2618295
    firebar
    Participant

    Firebar i have resisted to this so far but now i feel that i have to call names..U come here making all sort of claims that things are in a particular way when everyon else sees them diffrently and then dont have the backup necc. to substantiate your claims..u have absolutely no eveidence to verify that the highers TRANSIENT (not sustained) AOA for the raptor is 60 degrees..and also that its max pitch rate is 40 degrees..almost everything u have presented has been swiftly rebutted by myself and a whole lot of other respectful members of this forum.

    The F-22 is not in the same class as SU-27/30 in close combat.

    For close combat, besides high T/W ratio, fighter must have excellent high AoA behaviour, low wing loading and high pitch rate to change flight path quickly.

    Max pitch rates (degrees per sec.), and max AoA degrees:
    -SU-27: 70, 120

    -F-16: 20, 26

    Source for above data: Aviaton week and space technology, 14.avg,1989, page 55

    The F-22: “Max AoA up to 60 degrees”. -Globalsecurity.org

    “The F-22 attained max AoA of 60 degrees and pitch rate greater than 40 degrees per second.”- http://www.defense-i.com (The F-22 pilot perspective).

    The F-22 close combat capabilities are overrated for propaganda purposes.

    Do not tell that above mentioned sources are not respectful.

    And, remember that transient AoA is much greater than sustained one in any airplane.
    So, tell me, if 60 degrees is sustained AoA of F-22, than what is its max transient AoA? It should be much greater. But there is no such data at all.

    Can!t you understand that.

    in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2630245
    firebar
    Participant

    One more reason in the big list why the YF-12 could not enter service.

    Its engines could not tolerate anything but a very slow descent. The pilot had to fly it in a strictly prescribed procedure while descending or ascending.
    It is unthinkable for a fighter aircraft.
    Note,also, that its engines could tolerate only 8 degrees angle of attack, which render it totaly unsuitable for anything but a very mild maneuvers.

    in reply to: Mig-31 versus F-22 #2630261
    firebar
    Participant

    Compare these two flight control technologies, both with Thrust Vector Control:

    -F-22 with 60 degrees angle of attack capability, and
    -SU-30MKI with 360 degrees, unlimited angle of attack.

    This represents two entirely different classes.

    in reply to: Mig-31 versus F-22 #2630266
    firebar
    Participant

    India has TEN Su-30MKI

    http://www.globalsecurity.org/military/world/india/su-30.htm

    The US has over FORTY F-22s in operation.

    The SU-30 MKI has entered service in 2004, and will be remembered as first in service fighter with TVC. The F-22 is not yet in service.
    It will enter inventory at the end of this year, if no further delays occur.

    in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2633379
    firebar
    Participant

    The SR-71 and A-12 were very effective when they were in service. It’s not fair to blame the rising costs of operating the aircraft entirely on the design or Lockheed; had McNamara not ordered all tooling destroyed, spares would be easier to come by. Had there been more than just 50 aircraft, more effective logistical support, etc. would probably have came about.

    The A-12 was a failure. It was in service only 1 year, and was retired when one pilot has lost control and died in 1968 returning from recce flight.
    It has a very serious problems with intake control at high speeds and longitudinal stability.
    It was unstable and had a very rude Stability Augmentation System.
    Later, a better SAS was introduced in SR-71.

    The McNamara was correct. It would be waste of tax payers money. Just like XB-70 or B-58. ( The B-58 was also a failure in spite of beign “only” Mach 2 aircraft.)

    in reply to: YF-12/A-12/SR-71/MIG 25/MiG 31 thread #2633382
    firebar
    Participant

    None can save “someone” to make himself an idiot !!!!!

    The author is R.A. Belyakov and the writer or coauthor is Jacques Marmain of DOCAVIA. All the data came from OKB MiG and its members.

    To name Jacques Marmain “some French author” shows an exceptional level of ignorance.

    Sens, why do you insult me? I think that I have been correct to you.

    I said “some French author” only because I have not had a book at hand at that moment.

Viewing 15 posts - 406 through 420 (of 644 total)