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benhongh

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Viewing 15 posts - 76 through 90 (of 146 total)
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  • in reply to: J-20 Black Eagle – Part 5 #2371043
    benhongh
    Participant

    Like this…. ???

    Ken

    I am baffled by the rather peculiar looking intake. Could anyone offer enlightenment?

    in reply to: Tornado GR 4 #2376980
    benhongh
    Participant

    617 Squadron at present in Afghanistan, last week, flew a staggering 1.000.000. flying hours, what an achievment, in the Tornado GR 4s.

    617 Squadron, makes you proud to be a BRIT. don’t it?.

    Jim.

    Lincoln .7

    The wording is a bit misleading. Surely it takes about 5900+ GR4s flying 24/7 to achieve 1000000 flying hours in a week…

    Nonetheless, a remarkable achievement. What a shame they are getting rid of the F3s and most of the GR4s, such a indispensable asset…

    in reply to: J-20 Black Eagle – Part 5 #2378555
    benhongh
    Participant

    I had watched that incident at Le Bourget. No lightning strikes, but a small bird seemed to be sucked into one engine. The few seconds of temporary thrust drop was enough to bring the MiG-29 out of control. Just too low in height for every recovery attempt by an outstanding test-pilot. http://en.wikipedia.org/wiki/Ramstein_airshow_disaster
    It had forced new safety regulations for air displays just in time. The MiG-29 display was parallel to the audiance north of the runway.

    Your claim about the G-limiter is nonsense. Neither the MiG-29 nor the Su-27 is an unstable design. The flight system of both. the former one analog and the later one a digital one to assist axis control. For the special displays some part of the axis control augementor has to be disabled temporary. Not allowed to ordinary frontline pilots for good reasons.

    This is inaccurate on so many levels. First of all, Ramstein?!! Really?!! You might want to read the link you provided.

    A bird strike that takes out an engine during a low pass is bound to make troubles. The MiG pilot tried to save the crowd by crashing the plane in an empty spot. If it was an F-22, I suspect the end result won’t be too different.

    And secondly, while the MiG-29 was marginally stable, the Su-27 was unstable in longitudinal mode. The MiG-29 has a mechanical control system with stability augmentation. The Su-27 had an analog FBW and digital ones since the 90s. Both has system built-in to limit aircraft in safe flight regime.

    in reply to: J-20 Black Eagle – Part 5 #2378561
    benhongh
    Participant

    Thx for the input i.e.
    Yes i stated earlier that ventral fins are helpful at keeping the aircraft stable at Directional Stability in high-speed mach too.

    Yaw demper. Isnt that part of the FCS?

    A modern FCS certainly manages yaw as well as other axes. Back in the 50s and 60s, when, you know, FCS really meant cables and pulleys and perhaps hydraulic boosts, yaw damper was altogether an independent (but not separate) system. Really it’s just there to improve lateral mode behavior (like damping off dutch roll), a kids play compare to what today’s FCS can do.

    in reply to: J-20 Black Eagle – Part 5 #2378973
    benhongh
    Participant

    Yes correct. That would be the term ‘relaxed stability’ or lack of it.
    That is not the same ‘stability’ we are talking about.
    If you like we can discuss the fact that Flanker design has a symetric airflow over the wings when engaged in crazy AoA with out any yaw and roll slide(no spinn), its in fact dead steady.
    Yet it is ‘Unstable’ to control without FCS, just like most other jet fighter.

    You might want to replace “stability” with “controllability” to save us from confusion. Stability really means the ability to return to equilibrium from uncommanded deviation.

    in reply to: Hot Dog's Ketchup Filled F-35 News Thread #2379533
    benhongh
    Participant

    No, it’s not just a buzzword. There is an ACTUAL difference between “Air Dominance” (aka “Air Supremecy”) and “Air Superiority”.

    But there’s no substantial difference between a air dominance FIGHTER and a air superiority FIGHTER.

    In a hypothetical air war where a pack of F-22s engage another pack of F-22s of similar size, I doubt either side can achieve air dominance.

    in reply to: Hot Dog's Ketchup Filled F-35 News Thread #2379553
    benhongh
    Participant

    The F-22 is classified as an “Air Dominance” (aka Air Supremacy) fighter. It’s a step above “Air Superiority”.
    http://en.wikipedia.org/wiki/Air_supremacy

    A political buzzword invented to address the fall of cold war. You want air superiority when fighting the russians, but air dominance when fighting iraq.

    in reply to: Hot Dog's Ketchup Filled F-35 News Thread #2384207
    benhongh
    Participant

    Well, to stick my nose in again here , imo maybe one of the reason LM has such a poor performance in this programme is this …they have little, and even lost, the “knowledge ” to built a front line aircraft in substantial numbers , on time , on budget , and on specified performance (especially important in these times)

    It’s not really that, mack8. It’s almost a law that every generation of combat aircraft costs a whole lot more than the last. If you want stealth, agility, payload capacity, VTOL, advanced sensors, low maintenance, etc then you’d have to expect a giant price tag.

    Of course, for Lockheed, they had to propose a much lower purchase price initially, then stage it up as the program progresses. So you either cut the project and lose all your previous investments, or get milked and pay more to get things done.

    in reply to: Breakthrough in AF 447 search #474751
    benhongh
    Participant

    [QUOTE=nJayM;1759740]Any change of speed produces acceleration but in a civil aircraft in flight is minimal. e.g. compare the calculation for a car (0-100) and a civil airliner taking off and even then where the acceleration is highest, it is nothing compared to the car

    The plumb line will/may rock/sway side to side minimally if any as even in a stricken aircraft disengaged from auto pilot the crew would normally execute any change from level flight very gently.

    I’m not trying to sound sarcastic but you do realise that changing the DIRECTION of the velocity vector also count into the overall acceleration of the aircraft (and overshadowing the component from change in speed)? In a well balanced turn your plumb line should always point through the floor regardless of bank angle so that the aircraft does not go into a side slip.

    To push it to an extreme, if the pilot reduces engine output while pushes the york to execute a -1.5g nose down pitch while keeping airspeed constant, the plumb line should just point straight through the roof.

    in reply to: Der Pak-Fa Episode 17, return of the stealth #2311023
    benhongh
    Participant

    It is widly know why Sukhoi did the ‘Flankerish’ layout on the Pak-Fa,
    the tunnel underside between the engines, the long nose section, wide engine placment, wing/body blending, wing design bla bla..

    Is it just me or does anyone have a feeling that the F-22 is also quite similar to the F-15, in the same way the PAK FA is similar to the Flanker?

    I mean, look at them, compact side intakes, giant tapered wings, engine arrangement, tail booms that give support to horizontal tails way aft of engine nozzle…

    in reply to: Breakthrough in AF 447 search #476492
    benhongh
    Participant

    A civil aircraft in flight may accelerate in a nose down or decelerate in a nose up but usually so gently (even following a crisis) that the plumb line will move slightly but revert to pointing to the centre of earth very quickly.

    If you turn, you are accelerating. The whole reason of banking the airplane into the turn is to line up the lift vector with the desired acceleration vector so that the wing does most of the accelerating work.

    in reply to: F-35C Lightning II – 2011 #2312583
    benhongh
    Participant

    monica would have looked good if it had a more conventional f-16 like intake 🙂

    Let’s just say BOTH X-35 and 32 will look a lot better than they were if the marines hadn’t insisted on VTOL.

    in reply to: F-35C Lightning II – 2011 #2312705
    benhongh
    Participant

    What an ugly bird … 😮
    Then without its big engine , it is a brick .

    Luckily , it has some top of the line avionics .

    Cheers .

    Ugly? Hey that’s completely personal opinion. I’d say it’s a fine-looking bird all right.

    in reply to: Breakthrough in AF 447 search #477000
    benhongh
    Participant

    And here are 3 amateurish sketches – side view – level, nose down, nose up
    with plumb line always pointing to centre of earth.

    The plumb line always points in the same direction as the local acceleration, plus/minus the pendulum angle if it is not in equilibrium. So unless the airplane is flying absolutely straight and level in no wind condition, your plumb line solution isn’t particularly useful.

    in reply to: J-20 Black Eagle – Part 5 #2321440
    benhongh
    Participant

    Seeing as how we don’t know what the design goal was, it’s still an ambiguous statement. Even exceeding this unknown goal, still doesn’t tell us how it compares with the F-22, F-35, or T-50.

    No sh*t bro, I bet the person who sets the design goal knows not much better than we do on how stealthy those American and Russian designs are.

Viewing 15 posts - 76 through 90 (of 146 total)