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The Military News Science Technology

DARPA Moves Ahead With Radical Vertical Take-Off Aircraft (networkworld.com) 53

coondoggie writes: DARPA took one step further in building a radically different VTOL (Vertical Take-Off and Landing) aircraft that can fly fast and carry a big load. Specifically, DARPA awarded Aurora Flight Sciences the $89 million prime contract for Phase 2 of the agency's VTOL X-Plane program which looks to: achieve a top sustained flight speed of 300-400 kt, raise aircraft hover efficiency from 60% to at least 75%, present a more favorable cruise lift-to-drag ratio of at least 10, up from 5-6, and carry a useful load of at least 40% of the vehicle's projected gross weight of 10,000-12,000 lbs. DARPA said Aurora's Phase 2 design for the VTOL X-Plane envisions an unmanned aircraft with two large rear wings and two smaller front canards -- short winglets mounted near the nose of the aircraft. "A turboshaft engine -- one used in V-22 Osprey tiltrotor aircraft -- mounted in the fuselage would provide 3 megawatts (4,000 horsepower) of electrical power, the equivalent of an average commercial wind turbine. The engine would drive 24 ducted fans, nine integrated into each wing and three inside each canard. Both the wings and the canards would rotate to direct fan thrust as needed: rearward for forward flight, downward for hovering and at angles during transition between the two," DARPA stated.
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DARPA Moves Ahead With Radical Vertical Take-Off Aircraft

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  • by Janthkin ( 32289 ) on Friday March 04, 2016 @06:29PM (#51640049)

    From the blurb:
    "envisions an unmanned aircraft with two large rear wings and two smaller front canards -- one used in V-22 Osprey tiltrotor aircraft -- mounted in the fuselage would provide 3 megawatts"

    Huh?

    From TFA:
    "envisions an unmanned aircraft with two large rear wings and two smaller front canards—short winglets mounted near the nose of the aircraft. “A turboshaft engine—one used in V-22 Osprey tiltrotor aircraft—mounted in the fuselage would provide 3 megawatts (4,000 horsepower) of electrical power"

    Oh.

  • I don't even know what else I would say here.

  • Keep in mind (Score:2, Interesting)

    by Anonymous Coward

    DARPA does not exist to make sensible, practical things. They are there to throw spaghetti on the wall and see if it sticks. I think they actually get in trouble if too many of their projects succeed: it means they weren't pushing the envelope enough.

    Some fun numbers:
    DARPA has a budget of $3bn.
    NASA has a budget of $19bn.
    The 2012 elections cost about $7bn.
    The annual market for soft drinks in the USA is $98bn.

    • With the massive reverse dihedral... including, what the hell is up with those upside down winglets on the carnard???... the natural flying attitude of this abortion is upside down. Ducted fans are great right, so if we just multiply them, wow, zoom! But consider the cross sectional drag of all those ducts you can't see between the biplane style airfoils and those wings are really just massive air brakes. Because all the lift comes form the top surface of the foil, the bottom foils are doing nothing except

  • I'll save you $89 million: go buy some helicopters.
    • Sure. How much for a helicopter that can do 300-400 knots?

      • Also show me a helicopter with a 500 mile range.

        Helicopters are slow and limited range though useful for what they are.

        That is why the marines pushed the osprey so hard. A modern battle field can cover hundreds of miles in a day. An m1 Abrams can do 60 mph but even at 49 mph the front of a battle field can shift farther and faster a than helicopters can setup refueling depots.

        • by fnj ( 64210 )

          Also show me a helicopter with a 500 mile range.

          OK. I'll do a whole lot better than that. I'll show you one that set an unrefueled distance record of 1923.08 nautical miles [aerospaceweb.org] 50 years ago. And it was a small, very unimpressive looking helicopter with no edgy experimental or radical qualities, and only cost $19,860 [wikipedia.org] in 1966 dollars. The model is still being produced today, by the way.

          Granted, one has to differentiate between useful operating radius and max ferry range (possibly skimping on fuel reserves). But i

      • by fnj ( 64210 )

        Sure. How much for a helicopter that can do 300-400 knots?

        300 knots, no. But how about 255 knots [wikipedia.org] unofficial record? Other helicopters have reached or approached 250 knots.

  • by Anonymous Coward

    Good to see some people still remember the 14-bis. I thought everyone had forgotten about it by now.

  • Fuel and range are the real problems. VTOLs are the wrong idea to extend range and conserve fuel. Why not let a drone lift the jets straight up 500 feet or so and then lighting up the jet engine as it detaches from the drone? That same drone can carry fuel, weapons and even troops closer to the area of conflict as well as remove the injured.
    • Why not let a drone lift the jets straight up 500 feet or so and then lighting up the jet engine as it detaches from the drone?.

      Because no drone in existence can lift a jet even an inch? Plus there's that fun race to the ground while the jet attempted to gain enough airspeed to generate the lift required to stay airborne, while not burning more fuel than a VTOL would in the first place (not to mention what the drone would consume). They don't exactly have the same flight characteristics as a sailplane, you know...

    • The idea for V/STOL's was to be a troop-support (ground attack) craft that didn't need a runway or aircraft carrier. The troops go in, throw down the metal pads, and can quickly have nearby air support. Far smaller ships (amphibious assault crafts like the Wasp and America class LHD / LHA) that can go into smaller water ways than an aircraft carrier; in the US the Marine Corp is the main client; the Navy doesn't have any other ground assault aircraft. To utilize the "short" take off planes still need 1,500
  • http://www.wired.com/2015/03/n... [wired.com]

    Sounds like an interesting progression of the many-small-propellers concept.

  • Did anyone else picture "The Bus" from Agents of Shield after reading the summary?
    • by dbIII ( 701233 )
      Yes but it's just a big Harrier to me.
      Weird how we got that in 1967 and nothing better than it since.
  • What's with the negative dihedral on the wings? Are they trying to be unstable?
    • What's with the negative dihedral on the wings? Are they trying to be unstable?

      Yes, and that's not uncommon for fighter jets already.

    • What's with the negative dihedral on the wings? Are they trying to be unstable?

      No, they're trying to get funding purely on the strength of a cool CG render that has little to do with aeronautical engineering sanity. To hell with stability. The thumping base line is considerably more important in closing this deal, and maybe they threw in a hooker or two.

  • From TFA:

    Imagine electric aircraft that are more quiet, fuel-efficient and adaptable and are capable of runway-independent operations.

    Yep, I'm imagining it. And it won't be using ducted fans if it wants to be quiet. Anyone who's actually used ducted fans knows they are much, much louder than either turbines or turbo props. And due to their relatively small size they're not particularly efficient either.

    • From TFA:

      Imagine electric aircraft that are more quiet, fuel-efficient and adaptable and are capable of runway-independent operations.

      Yep, I'm imagining it. And it won't be using ducted fans if it wants to be quiet. Anyone who's actually used ducted fans knows they are much, much louder than either turbines or turbo props. And due to their relatively small size they're not particularly efficient either.

      From the experience of RC modellers, around half as efficient as a free propeller for the same power input. Higher foil loading due to the smaller diameter as you say, increased structural weight and increased drag from the additional wetted surface of the duct. Plus, a duct operates efficiently only at its design airspeed, so either static thrust (for hovering) or operating range at top speed must be sacrificed. Then there is the practical issue that, in order to gain the benefit of reduced fan blade tip l

  • Ducted fans, huh? That's not flying, that's just beating the air into submission.
  • The A-10 Warthog is thrilled to lose the title!

  • This was phase 1 and the results so bad they just quit testing it anymore; there are 3 more phases (including phase 2) it must go through before being accepted.

  • by Harold Halloway ( 1047486 ) on Saturday March 05, 2016 @08:27AM (#51643081)

    Well, that's the first prototype for the HKs sorted then.

  • It was shaking on takeoff in the video. Whoever designed this thing needs to have their head checked.

  • The picture is a crappy design. Inspired by box kite perhaps? Good at drag, not performance. This is misleading on the actual design.

    The power is from a conventional petroleum engine. It is hard to believe that is where they would want it to be: converting fuel into electricity at low efficiency and output.

    How about putting the Lockheed Martin "fusion that fits in a truck" inside there. That is the kind electrical power output and range you want for heavy and fast VTOL.

  • It seems pointless to have two tilting wings. tail sitters are kind of inconvenient when there are people on-board, in something like an Osprey but un-manned? probably a lot lighter to replace the wing tilting with landing legs like a SpaceX booster, a really long nose wheel that pushes the whole plane into a vertical position, a lot less moving parts, and the ones that move deal with a lot less strength and mass. Stick the camera in a bulb under the tail instead of the nose, and you can hover with it ju

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