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WinterStars

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Viewing 15 posts - 286 through 300 (of 349 total)
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  • in reply to: Su-34 Black-out curtains ?? #2342282
    WinterStars
    Participant

    It almost looks as though the whole cockpit can be curtained off – sides and front 😮

    😮
    I guess providing toilet is not all, they added curtains for sleeping as well. :confused:

    Excellent photos.

    in reply to: Su-34 Black-out curtains ?? #2342326
    WinterStars
    Participant

    The white dielectric cap at the end of the tail sting should house the antenna of the L-175 Khibiny jammer.

    Thanks Martinez. Does the 34 use braking chutes then?

    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342331
    WinterStars
    Participant

    Try dx*SUM([function values]).

    I have been trying to figure out…:o But We have standard filter/summer/shifter/integrator etc blocks with our Engineering SW @Work which is making me retarded these days. You would know Simulink, Copy and paste Blocks …

    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342409
    WinterStars
    Participant
    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342473
    WinterStars
    Participant

    Full book found here. Interesting…

    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342483
    WinterStars
    Participant

    For most aircraft a G-load to be pulled briefly is limited by flying-weight, speed and time. All have a 1,5 factor safety margin most of the time. A F-4 with 7,5 G certification at NTOW can pull close to 12 G in an emergency without break-up. All that was done but every fighter is out of order for some time for safety reasons. After a thorough inspection it will be freed for a new lease of life, but it will be reduced by a noticeable number of flight hours. In loaded condition all fighters are limited close to 6 Gs and even clean ones were seldom operated behind that value in peace-time. All the claimed 9 G fighters have life-time restrictions when opereated with that value too often. At ~9 G nearly every pilots suffers from “grey-out” or will “black-out” in short notice even with the support of the most advanced G-suit. In short every pilot with some senses will avoid that flight situation whenever possible. At ~9 G your SA is gone and you are in some trouble by that. The USAF learned it the hard way with the F-16s which allowed more than a briefly peak-load of Gs and “killed” a number of pilots doing so in peace-time before some restrictions were forced about that. Today it is common sense to stay well below 9 G for good reasons and every FBW can adapted to a peace-time mode.
    The nominal 8,5 G limited for the JF-17 is with two wing-tip AAMs and half internal fuel at subsonic speed. The practical one is that pulled by the pilot till the fighter breaks-up whatever it is in the end we will not learn it for obvious reasons. 😉

    Not denying this, but what I am trying to say is relation between Airframe strength, Speed and Transient/Sustained G limits. With increased speed the G limits also becomes smaller and with more mass means more strain on the airframe.

    See here Naval Test Pilot School Flight Test Manual, Fixed Wing Performance, Theory and Flight Test Techniques
    It mention something about the speed at which max G can be sustained for a specific aircraft. Also some mention of the G sustainability variation with Alitude. Lots of calculation, I cannot do Calculus with Excel

    WinterStars
    Participant

    True, the plan as it stands now is pretty sound, but a lot of time and money was wasted along the extraordinarily convoluted way which led there. Some projects which should not have survived are still around and most of the others were delayed more than necessary.

    Indeed, the consolidation of various OKBs should be a step in the right direction I feel, since money is not unlimited to support multiple OKBs developing overlapping product lines. KTRV, UAC, ODK, Almaz Antey etc needs to compete on the international market besides RuMOD orders. I would say UAC and Almaz Antey are doing OK for the time being.

    WinterStars
    Participant
    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342666
    WinterStars
    Participant

    A very strange claim. The top-speed of every fighter is limited by the propulsion system at first. It can accellerate as long as surplus thrust is not even out by drag. At supersonic speeds most of the trust is not generated by the engine but by the inlet- and outlet-system at first. The inlet-system is the limiting thrust factor for every fighter and by that the top speed. To install a higher thrust engine will change nothing about that.
    The JF-17 is an excellent example about that. The original unregulated inlet gave a design top speed of Mach 1,6. The modification of that inlet by DSI rose that design top-speed to Mach 1,8.
    Every fighter with an unregulated inlet-system has a design top-speed given from the inlet design. That value allows some divergations from that due to atmospheric conditions. Related to that every fighter can be a bit slower or faster on every day not showing the “standard day” conditions. But that divergations go not behind +/- 10% in general. Just test pilots are looking for that to explore the maximum and minimum flight envelope of a clean fighter, when front-line pilots will never come close to that with some military equipment fitted. All claims of test pilots about speed are useless without all details of that very flight. The “redline” is no absolute limit just the limit of the flight-envelope freed for daily use and a safety margin as well.

    That is what I meant :). The redline is a self imposed limit that you don’t keep crossing all the time thereby putting unnecessary fatigue on the airframe. an airframe designed for M1.5 cannot be flown at M2.5 and pulling the same Gs even if you have surplus engine thrust. e.g. Even if you can pull big Gs on a light transport it is not done because some day structures fail for no reason. Add the loadout to that and structural failures are bound to happen. e.g. The SR 71 has a G Limit of 1.5G/-0.1G @ M3. It has better G ratings @subsonic (Flying the SR-71 Blackbird: In the Cockpit on a Secret Operational Mission By Richard H. Graham. P 69). Strengthening the structures increase weight and affects TWR.

    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2342879
    WinterStars
    Participant

    The JF-17 is redlined at M1.8 and 8G which means its lightness can partly be attributed to a lightly reinforced structure. Gripen is redlined at M2 and 9G. Even small G and/or Mach increments require a lot of strengthening of the airframe which adds up weight especially if you don’t have access to high strength alloys/composites/titanium etc. But by limiting the flight envelope you can have pretty good TWR figures on paper. And then there are sustained G limits as well to consider not just transient G limits.

    in reply to: Somalia pirates: EU approves attacks on land bases #2023914
    WinterStars
    Participant

    Striking land bases might involve lots of collateral damage as these pirates are not exactly Al Qaeda. The remedy lies in overhauling their economy but it is an ugly job and no one wants to get involved. 🙁 . But when they cross the line someone has to act. It is ugly in any case.

    in reply to: Pak-Fa news thread part 20 #2342965
    WinterStars
    Participant

    http://www.fotosik.pl/u/hobbymodel/album/1031215

    Nice model of PAK-FA, hell of a payload :).

    For that load out, better use an Su-35. No need to to take out your ferrari.:D . Your VW is enough.

    in reply to: Su-34 Black-out curtains ?? #2344155
    WinterStars
    Participant

    Or maybe to hide from Maverick when he tries to give the birdie … :p Russians knew Maverick would be back…
    Or to avoid sun burn.

    But won’t they have other problems besides the super brilliant flash in case of nuke detonation. They would need different paint and stuff for the 34 itself. Most likely the 34 will carry only tactical nukes. Strategic nukes will most likely be ALCMs.

    in reply to: Small Air Forces Thread #14 #2345332
    WinterStars
    Participant

    Has anyone posted these…

    http://1.1.1.4/bmi/4.bp.blogspot.com/-nDhKUiPAdoo/ToXkT9ClpFI/AAAAAAAAIkk/gWVToWzBaEU/s1600/seaplanes_Iran.jpg

    No disrespect… just curious…
    Not mine. Lifted from here http://www.informationdissemination.net/2011/09/next-phase-of-iranian-naval-expansion.html

    in reply to: AVIC JF-17 Thunder versus SAAB JAS-39 Gripen #2345337
    WinterStars
    Participant

    I am signing off from this thread. Nothing is wrong with the topic but Its tooooo
    http://1.1.1.2/bmi/thediscipleproject.net/wp-content/uploads/2011/12/cartman_lame-1046.jpg

Viewing 15 posts - 286 through 300 (of 349 total)