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Amiga500

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Viewing 15 posts - 256 through 270 (of 2,151 total)
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  • in reply to: US led coalition against IS #2226300
    Amiga500
    Participant

    Two engines is no guarantee

    In combat, nothing is guaranteed.

    But probability? Different story.

    in reply to: Taiwan plane crash #485172
    Amiga500
    Participant

    Yeah, on first glance looked like a straight-forward stall with not enough space for recovery.

    I wonder did both engines flame-out or was the pilot climbing aggressively?

    I feel for all the poor ******s on-board.

    in reply to: US led coalition against IS #2226332
    Amiga500
    Participant

    The F-16 had an engine failure. Can’t quote source, take it or not. Merry Xmas.

    I’ve got a great idea – lets make all attack aircraft… even better, lets make all attack and carrierborne aircraft in the future single engined.

    So any failure of parts or damage will result in an airframe loss and potentially pilot loss too.

    [/sarcasm]

    in reply to: The market for a larger turboprop… #485198
    Amiga500
    Participant

    The problem is selling the image to the public.

    The 747 changed all before it by introducing cheap air transport to the masses. I’m very wary of applying accepted social norms from the era before that and apply it to modern day – the majority of people using air transport then were fundamentally different from the majority of people using it now.

    For example; everyone hates Ryanair… yet they are the biggest airline in Europe (if not the world) in passengers carried.

    If the ticket price was 20% cheaper, would people really put image ahead of cost? If they did focus on image, why do the majority fly Ryanair or Easyjet ahead of the likes of BA?

    edit: I’m not saying you are wrong – certainly the perception that image is a problem for turboprops exist is widely held – is that perception correct? Is there any evidence in the modern day countering or supporting it? ATR and Bombardier have a decent backlog of turboprops – despite their small capacities inducing higher than possible seat-mile costs.

    [I also know that serious studies have been done by the Airbus/Boeing on the next generation of narrowbodies using prop-fans.]

    in reply to: Can fly by wire Airbus airplanes recover from a stall #2226806
    Amiga500
    Participant

    Thanks to everyone for their input. It just seems to me that when an Airbus get into storms they have a high rate of failure.

    It seems to me, with this and your subsequent post, you drew your conclusions before ever starting this thread and are hoping for posts that align with your preconception.

    Define high rate of failure please. When was the last fatal A330 crash before AF447? Or the last fatal A321 crash before QZ8501?

    in reply to: Movable tail planes #2228161
    Amiga500
    Participant

    What would that be good for?

    Lock sFoils in attack position!!

    http://38.media.tumblr.com/0251ad42e654ba61569d1451f7fcc248/tumblr_nfrcu2vfXb1sdfhwqo1_500.gif

    in reply to: Can fly by wire Airbus airplanes recover from a stall #2228178
    Amiga500
    Participant

    My question is can an Airbus be recovered from a stall?

    Yes… but the pilot has to recognise he is in a stall.

    Given this seems to be beyond some…

    A possible feedback fix would be, if the plane thinks its stalling* – shake the f__k out of the stick as well as audible warnings – and have the flight computer power down all other displays from the apart from artificial horizon, radar altimeter, compass and engine info. Then the folks in the driving seats will have no choice but to do what they should do. Focus on attitude and power in the immediate, then avoiding the ground, then course.

    After the plane senses recovery to a more stable environment, power back up the other instruments so the pilots can then determine what caused their stall. They can then also correct their speed, course and pressure altitude as necessary.

    *feedback from the loads on the wing control surfaces should be sufficient to tell if the flow above the wing is massively detached or not – also variation in the radar altimeter would help given the pilots should know what kind of terrain they are flying over.

    in reply to: Rise of the 6th Generation Fighter … #2228485
    Amiga500
    Participant

    It seems to me they would need an X plane to demonstrate a tailless delta.

    There is a solution that seemingly isn’t being considered.

    Vertically deployable tail for the higher AoA stuff when you need it – you already have suitable storage spaces alongside the engines and behind the rear wing spar. If your maneuvering hard, then your already discovered and signature isn’t critical. Furthermore, there is nothing to stop you deploying them above or below the airframe, depending on your maneuver, so that large actuation envelopes are not needed to exert considerable control authority.

    Probably quicker, cheaper and better aerodynamic fix than all the control hoops that they’ll need for a tailless solution – albeit with a slight weight and maintenance penalty. But the vertical tail would not be high-g rated items – so its not quite like the swing-wing complexities of MiG-23, Tornado or F-14.

    in reply to: Rise of the 6th Generation Fighter … #2228500
    Amiga500
    Participant

    It is “almost a given that directed energy weapons will be in play for these future platforms,” says McCormick. He anticipates a power offtake requirement for at least 1 megawatt. “We are trying to define the design space.

    The 787 has 2x 250 kVA generators per engine (which is about 2x 180 kW on the 787). That is a 280 kN engine (yes not apples for apples with fighters, but the combustor power and turbine draw relate). [360/280 = 1.29 W/N]

    The F-22 has by contrast has 2x 116 kN engines (no reheat) and generates 130 kW through 2 generators. [1.12 W/N]
    The F-35 has 1x 125 kN engine giving 160 kW through the generator. [1.28 W/N]

    So… to get 1MW (assuming 2 engines), and assuming the engine non reheat thrust jumps to 2x 150 kN, the W/N coefficient has to more than double to 3.3. In a fighter?

    Aye. Good luck with that.

    in reply to: USAF picks Boeing 747-8 as next Air Force One platform #2228553
    Amiga500
    Participant

    This is real surprise. One would have thought that with the GAU/8 it would have been the A-10.

    No indeed.

    With its superb 8th gen mix of stealth, super(high-altitude)cruise, endurance, edge-of-space flight, advanced electronics and systems allowing for communication and information gathering at all times the Lockheed Martin U-2 is the superior solution.

    in reply to: Rise of the 6th Generation Fighter … #2228637
    Amiga500
    Participant

    DEW power requirements will be balanced out by using super-capacitors to hold energy for discharge.

    Of course, number of shots and recharge time then becomes dependent on capacitor size and generator capacity.

    Furthermore, laser shielding will come with a weight penalty of its own. Even if such shielding is not available or viable at this time, a significant weight budget should be reserved for such materials existing nearer the time of build.

    Amiga500
    Participant

    Carbon nano tube material =much lighter weight ( 20-30% lighter) + effective again wide range of frequency

    I think those numbers are cherry picked.

    Its a while since I’ve been involved with CNF infused resins, but from what I remember:
    – the weight difference is marginal (its only a small percentage of the overall resin weight that is changing).
    – the material strength improves a reasonable amount (better transfer of load from resin to fibre and visa-versa.
    – the material thermal expansion coefficients drop to a more isotropic behaviour pattern (CNF has low CTE and is not aligned to one axis)
    – the crack propagation properties improve immensely (CNF bridging cracks and spreading load to fibre).

    in reply to: F-35 News, Multimedia & Discussion thread (2015) #2231575
    Amiga500
    Participant

    It also only called for 35k pounds of thrust, the F135 puts out 43k

    Did the wing area change?

    in reply to: Lessons from Textron Scorpion… #2231973
    Amiga500
    Participant

    Over the past 36 years, I have seen government oversight get worse, not better.

    The rule of thumb is it takes 2 contractor personnel to generate documents to keep each government beancounter happy.

    The problem is – bureaucrats believe paperwork is the best way to pass information….

    So that entails report upon report, each having significant time overhead.

    An email at the end of each week from someone working on the project but “on your side” with a few bullet points would do the job better instead. No bogging down in info, easier for any one person to accumulate multiple opinions and actually process them – and the info is not being massaged by managers intent on papering over cracks.

    in reply to: Lessons from Textron Scorpion… #2232203
    Amiga500
    Participant

    “Oversight” as is conventionally used is a load of balls.

    They needed to have air force engineers embedded in the design teams working on the thing. Who were also reporting up the chain of command. Then they’d have quickly become aware of the real problems in the program – before they were filtered via project managers MBA bullsh!t bingo and Lockheed executive PowerPoint Pish.

Viewing 15 posts - 256 through 270 (of 2,151 total)