V-280 & other current (non V-22) Tilt Rotor Aircraft

Discussion in 'World Armed Forces' started by TerraN_EmpirE, Mar 30, 2015.

  1. Jura
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    Jura Senior Member

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    wow

    Distance from Hawaii to Los Angeles is 3,997 kilometers. https://www.distancefromto.net/distance-from-hawaii-to-los-angeles-us
     
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  2. TerraN_EmpirE
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    TerraN_EmpirE Tyrant King

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    Okay First Hearing the Helo.
    The loudest part of a Helicopter is the Tail Rotor. This is because of the Way a conventional Helicopter flies. As the Main Rotor spins it generates Torque, The Helicopter naturally wants to spin with it. This however would cause the Helicopter to crash. So to counter this Igor Sikorsky added a second smaller blade that thrusts in the opposite direction of Spin. To get the thrust to counter the Spin while still retaining a small enough size to allow the Helicopter to land it needs to spin fast this results in problems however it robs the engine of power as It needs to drive the tail rotor this also increases drag. So the Tail Rotor goes almost supersonic that generates a lot of noise.
    The second Issue is Retreating blade Stall this is where the main Rotor well advancing creates a vacuum of air behind it. and as the retreating blade hits that vacuum it stalls
    The Quiet one.
    1_Wm1PdGlzi3cI_bN5YCoAuw.jpeg

    However as Far back as the Vietnam war the US was more than aware of this and working on countering it.The Quiet one was a Program back then to do just that they modified a Oh6 helicopter to infiltrate into North Vietnam some of the they most defended airspace in the world. To do this they widened the existing main rotor and doubled the then standard tail rotor number from 2 blades to 4 finally they added the most visible part of the Chopper. the Muffler to reduce the IR Signature. To give you an Idea how loud that that Chopper was they rated it to 77 decibels that is equal to the sound of a passing car at 65 mph at 25 ft. a Modern UH60 is about 108 DB. At 4000 ft. It's as quiet as a whisper, The Descendents of these modifications are seen on military choppers today. first is to add more blades If you look at the tail on the Stealth Blackhawk It has an additional blade ( 5 blades) when compared to a Stock Black hawk (4) This allows it to generate the same amount of thrust yet still have it's Stealthy hubcap. of course even more blades can be added.
    the-us-raid-in-syria-reminds-of-this-secret-stealth-black-hawk-helicopter.jpg
    this is what a Fenestron tail is a even larger number of Blades in a encased housing meant to reduce the effects of the Tail rotor sound. Or NOTAR where a fan system in the Tail generates thrust to counter torque. All result in quieter flight.
    RAH66.jpg

    But Jura Bell has an Advantage with the V280. Bell_V-280_Valor.jpg
    No Tail rotor. It's a Tiltrotor.

    Tiltrotors ( when in Vertical ) and Tandem Rotors both counter there own Torque by having 2 sets of blades operate in counter to each other. this means there is no need for a tail rotor.
    Even the Boeing Sikorsky team Defiant and Raider concepts counter there own Torque meaning that they do not need a Tail rotor ( they have instead a Pusher prop They also partially alleviate retreating blade stall in that the air being push by the Advancing blade of one set, feeds the retreating of the other)

    In vertical flight they would still generate retreating stall however. But here comes the Cheat in horizontal flight mode they would only generate as much noise as a turboprop as they are a Turboprop a normal turboprop is about 78 Decibels. basically unless they intend to land near that Machine gunner they will by flying on a quieter flight mode. Farther more FVL and JMR both want to operate at higher altitudes as options meaning that they don't need to fly over that gunner's position. So unless that gunner is the Target he won't know what passed him by, If he his the target...
    If that version comes in he's not going to have a nice day.

    Not necessarily, First Helicopters are generally always cheaper. Why? because they don't break the sound barrier. Once you start going super sonic the stresses start going up and special considerations come in. second they are made in far higher numbers to. So if costs started going that high it's game over. The cost of stealthiness though as been dropping because of drones though and most of what they are talking about I think is aimed as to a degree stealth as opposed to full. Some degree of stealth is even found in blackhawks and Apaches.

    No so with those goggles ( more likely a hud like on the F35 helmet) they can actually land or target weapons. It's still difficult to Fly a chopper or Tiltrotor at low altitudes and in mixed terrain like a city so they need every advantage they can get.
     
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  3. Jura
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    Jura Senior Member

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    wait here:
    Today at 7:16 AM I referred to "troops riding in the back":
    [​IMG]
    see?
    they could get a warm greeting on the ground
     
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  4. TerraN_EmpirE
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    TerraN_EmpirE Tyrant King

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    So the troops in back can see what is on the ground and even let the MG gunners give a greeting of their own.
     
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  5. Jura
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    Jura Senior Member

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    LOL OK

    have to go now, later I'm going to read what you wrote about helos' noise

    if you want, check the video gaming in
    Russian Military News, Reports, Data, etc. 31 minutes ago
     
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  6. TerraN_EmpirE
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    TerraN_EmpirE Tyrant King

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    The Prasing here was the key part actually From the West coast LA to Hawaii the listed estimate for a V280 on Bell's website is 3889 km the remaining 108 probably being first just the roundness of the estimate and the rotation of the earth with a jet stream.
     
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  7. Jura
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    Jura Senior Member

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    well I didn't mean to nitpick, simply didn't know helo's range might be so huge LOL

    I now googled
    Specifications http://www.bellhelicopter.com/military/bell-v-280
    saying
    Strategically Self-Deployable 2100+nm Range

    does "Strategically Self-Deployable" means "without refueling" in Pentagonese? LOL

    off top of my head, California - Hawaii is about 2200 nm
     
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  8. TerraN_EmpirE
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    TerraN_EmpirE Tyrant King

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    Basically the translation is accurate. But remember it's moving with the rotatrotation of the earth so as it travels the earth would move to.
     
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  9. Jura
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    Jura Senior Member

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    OK

    just not to forget, while saying Yesterday at 9:38 AM
    you converted
    2100 nm to kilometers?

    am asking because Yesterday at 8:07 PM
    Specifications http://www.bellhelicopter.com/military/bell-v-280
    saying
    Strategically Self-Deployable 2100+nm Range

    + highlighted
     
  10. TerraN_EmpirE
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    TerraN_EmpirE Tyrant King

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    Last I checked nm means nautical miles so yeah.
     
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