US Military Going Beyond Helicopters

19 thoughts on “US Military Going Beyond Helicopters”

1. Well there was DARPA LightningStrike, but that got cancelled before the full up prototype got built out. They did make the 1MW generator that was to be matched with the honeywell turboshaft engine though, and distributed propulsion using boxfans is mostly understood via the subscale prototype…

2. Coaxial rotors neutralize the tendency of a single-rotor craft to spin its airframe in the opposite direction of the rotor above. (This is why many “simple” helis have that little whizzing tail-rotor: mostly to counteract body spin, but also to allow yaw (intentional spin around center-of-gravity axis). 

   THe tree-strike potential of the pusher propeller is overplayed. It is a propeller, contained in the overall frontal envelope of the craft. Its fine. 

   Tilt-rotor craft are wickedly noisy. There is essentially no stealth that they’re capable of. The smaller (total) rotor area requires thrusting the smaller columns of air to higher velocities to achieve the same static lift. Higher velocities equal higher turbulence, equal higher propwash pressures, equal higher modal noise. Counter-rotating the pair of props helps a lot in vectoring the craft without “Corialis” effects and anisotropic (asymmetric) speed-vs-lift issues. 

   GoatGuy

3. ScaryJello says it, and there is another answer too. 
   Naturally… 

   A helicopter ‘works’ by accelerating a column of air “down”, so as to produce lift. When that air column isn’t directly “down”, but is tilted, then the copter also gets a transverse thrust. Forward, backward, sideways.  

   The reason why conventional copters only have one big rotor is because of the word “one”. One of anything is almost always less complicated than “two or more” of those things. Except when it isn’t. Airplanes have TWO wings, because, well, one would be a disaster. The tail “fin-thing” usually has 2 or more winglets. For the same reason: should one be damaged, the whole aircraft doesn’t need to fall out of the sky like a damaged bumblebee. 

   Given the very real complexity of the “contraption at the top” of a helicopter, which actually slightly twists the individual rotor blades as they spin about their radial axis (giving offset or non-homogeneous lift), having to make one tough, competent, armored “thing” is a heck of a lot cheaper (and easy to control by the pilot) than 2 or more. 

   Quadracopters (and higher order) helis abstract the complexity of controlling them all interdependently by using fast real-time sensor-and-computation algorithms. This abstraction lets “ordinary mortals” fly the things with simple joysticks and other finger controls. Such real-time computation wasn’t thought desirable or defensible when helis were evolving in the 1950s-thru–80s. 

   GoatGuy

4. Double LOL

5. LOL

6. “if we can imagine it, it must be eventually possible, right?”

   Rule 34 doesn’t quite go like that. Close, but not quite.

7. Because real helicopters use 5,000 hp gas turbines and gear boxes to turn the rotor(s) and not rinky dink cordless drill motors powered by batteries.

8. Yes the Osprey can have problems landing.

   For my money’s worth I would reconfigure Ospreys to be mini AC-130 gunships for close fire support for troops. It can loiter longer due to wings.

9. And the tilt rotor doesn’t have the ability to do precision helicopter like landings well. Apples and Oranges unfortunately. Range & speed vs putting special operators where they are supposed to go.

10. V-280 and Defiant are already winners- the problem is that they are winners at different things.

    Defiant is clearly going to dominate at low speeds with excellent maneuverability because it is a helicopter. V-280 will carry more and be faster.

    Question is what does the Army need more?

11. Actually, why are all the tiny drones quad or hexa copters, while large helicopters usually have just one or two large rotors? Presumably which is better depends on scale, but why?

12. I think the tilt rotor is less efficient in the hover and its downwash can be damaging. Not good for rescue or stealthy insertion. We really need both.

13. The question lis why coaxial rotors. Yes they allow you to go faster…however it a maintenance nightmare. And the pusher prop is a treestrike waiting to happen. This restricts NOE operations. The 280 however in helicopter mode can get in the trees and rivers…low level…then pop up…tilt the rotors in seconds…and be gone at 300+…carries more weight…longer range… Better fuel consumption…critical on deep insertions. Capability of quick change out to an AH version. Coming from the spec op world…I know where I’d put my money. Wish we had the 280s down south in the 80s

14. Deleting your feed from Google due to the massive ads coverage

15. So tilt rotor has twice the range of other one. That is a huge advantage right there plus should be faster too..

16. Don’t be such a sceptic in the new year.

17. before the years out it will be sitting in a BONEYARD JUNK

18. It’s right here: https://en.wikipedia.org/wiki/Bell_Boeing_Quad_TiltRotor

    That V-280 is already the winner. This is like SLS vs SpaceX… just cancel that ugly thing already.

19. [irony]Where’s my Quadracopters? Or hexacopter? How about those flying battleships, ever so popular on PowerDude SciFi films?  I mean … if we can imagine it, it must be eventually possible, right? [/irony] Happy new year.GoatGuy

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