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55

As noted in another answer, all helicopters can hover, but a so-called "high hover" (out of ground effect or especially at operational altitude) is a more difficult maneuver, requiring more power than a ground hover, and being harder to maintain (because reference points are much further away). Helicopters generate more lift for the same power when in ...


48

He's using the angle of his legs to control the attitude of the platform (and as a result, the direction he's flying in). So he can't take a relaxed pose, he's standing with his knees slightly bent the whole time.


41

This is what he said after the 1st attempt "When you fly with your body, even your hands affect the direction you want to go in. You feel the turbulence and the air through your fingers," Zapata told CNN. "It's like becoming a bird. But it's also very hard. I have to fight against the wind with my legs so there's pain too. It's not as peaceful as it ...


32

Yes all helicopters can hover, but it requires: More concentration to hover than to fly, because helicopters are unstable in the hover in pitch and roll. Forward airspeed provides stability and flying a helicopter with forward airspeed is comparable with flying a fixed wing plane, while hovering is comparable with standing on top of a large inflatable ball. ...


24

There is another bit of information worth mentioning in the CNN link in CrossRoads' answer The flyboard looks like a chunky skateboard and is powered by five small engines. It is fueled by kerosene, which Zapata carried 104 pounds [47 kg] of in his backpack. I believe that carrying a 50 kg backpack and balancing on a jet powered air skateboard ...


11

When navigating WX in a helicopter, it is often less workload to fly orbits. It gives additional perspective and permits easy lateral movement during the course of the orbit. It also reduces configuration changes, and possible power changes, as the aircraft can be kept in translational lift. IFR hold navigation for helicopters is essentially identical to ...


10

1) The 60 has a natural nose up, left wing down hover attitude. I want to say 3, and 1.5 degrees, but I'm going off memory. Given the angle of the shot, I would venture to say that it's more optical illusion of a excessive nose up angle than it actually is. 2) Given the nature of fastrope operations, and without opportunity to observe the video in entirety, ...


10

The key is that the Arca board only works in ground effect. Therefore, the pressure difference over the area of the board is the key for calculating its power needs. From the video I would estimate the size to be 0.6 x 1.2 m thanks to @mins more thorough research we know that the board measures 1.45 x 0.76 m for an area of 1.1 m². To lift both the occupant ...


9

No, it cannot, at least there is no reason for it to do so... A) The stick while in "hover mode" does not control the pitch/roll of the aircraft, but the forward/lateral position of the aircraft. This means that the aircraft can only shoot forward in a level attitude, it can't pitch up/down to hit a target. B) When in "hover" mode, the landing gear are ...


8

Up to a certain speed, which will be in the POH, the greatest power requirement is when hovering out of ground effect. Next is hovering in ground effect and power required in forward flight is the lowest, and decreases up until a point where the increase in parasitic drag starts to increase the power required. See a typical power required curve. From the ...


7

Because lift propellors need to provide static pressure to inflate the airbag and hover. This means more fan blades to stop backflow. The thrust propellors need to provide force which is a combination of static pressure and airflow but relies mostly on airflow. This means less fan blades to facilitate large airflow.


7

The cable is attached to the helicopter with a tensionometer. This can be used to vary the effective weight of the helicopter by varying the tension applied to the cable. The cable length can also be varied from 0 height, to hovering in ground effect and hovering out of ground effect. This test enables data to be gathered quickly for the helicopter ...


7

When a helicopter hovers, it's basically is sitting in its own wash. By pushing air down, it creates a low pressure region above itself, and a high pressure area below it. To stay hovering, it has to draw air from the low pressure area and push it into the high pressure are below it, which takes a lot of energy. If it instead flies forward, it encounters ...


6

Question 1: No, an S-76 can hover, but it's more energy intensive than economy cruise. It made more sense to circle and hold in an area as opposed to hovering. In addition, hovering at altitude can be hazardous in the event of an engine or tail rotor failure and having some forward airspeed can aid in making an autorotative landing, if needed. Question 2: ...


6

From a conservation of energy perspective, the rotor is transferring energy to the air, which then moves down and is deflected by the ground. A soft or drag-inducing surface will absorb more of that energy, whereas a smooth hard surface will deflect it. Think of it like running: If you run on a hard surface, your down force creates an equal force up. If you ...


6

Your expectation is correct. A tilt-wing has a lower drag penalty in hover (but that's not the full picture). The XV-15 had a penalty of 635–680 kg, while a tilt-wing would have 23 kg, for the reason you mention. The sentence on Wikipedia unfortunately lacks the context of the reference (Flight), which is down for maintenance, but the web archive version is ...


6

It's the difference between jet engines and propellers. It is a lot more efficient to accelerate more air to a low velocity, than it is to accelerate less air to a higher velocity. For fixed wings, the only reason to use jets is if propellers hit their speed limit, when the tips break the speed of sound. Hovering flight is particularly demanding on fuel ...


5

The rotor size helicopter (or a tiltrotor, in this case) is determined by its aerodynamic requirements, most importantly, its hover characteristics. The main constraint is the weight that has to be lifted by the helicopter at a give a altitude. In this context, it can be seen that the blades of V-22 are actually smaller. For example, V22 has a Max. TOW(Take-...


4

There are two parts to this: number of blades and squared off tips. 1. Number of blades. A propeller blade is actually just a wing. This is true regardless of weather you are talking about a piston engine airplane, a jet engine, a table fan or the propeller of a cargo ship. A wing is most efficient if the air coming onto the wing is undisturbed. While it ...


4

Not all can hover indefinitely. A fully loaded Soviet era MI-24 Hind attack helicopter could only hover for 15-20 seconds, before the engines are damaged from the overload. US intelligence agencies wondered why the Hinds always seemed to make a running takeoff rather than pull up in a hover to take off, until they got their hands on one and found that out....


3

As many of the other commenters here mentioned, it is much easier and lower work load for the pilot to fly forward than hover. It also takes more power from the engine to hover than it does to fly forward, and this largely has to do with the effects mentioned above about having to pull air from above the rotor to below. That also saves me quite a bit of gas. ...


3

First, let's compare apples to apples, and compare the Flyboard to the Mosquito XET, the gas turbine powered version. The Mosquito XET with it's 90hp Solar turboshaft engine consumes around 8.5 gph, while the Flyboard with six small turbojets is more like 38-40gph. Aside from the greater efficiency of propellers over pure jet exhaust, also consider that the ...


3

The yaw would be accomplished by angling one rotor a little forward, and the other a little backwards. The shifting move to the side is accomplished by generating more thrust on one side. Either by increasing the rotor AOA (collective pitch) or increasing RPM. You increase the lift, until you have your desired roll angle, then you equalize the lift so you ...


2

Does the ARCA hoverboard violate known limits on small-diameter electric fans? 1) The max theoretical static thrust that can be obtained with an Electric Ducted Fan characterized by: Diameter = 120 mm and Power = 272 hp / 36 = 5.63 kW is: (1.2 kg/m^3 x (5.63 kW)^2 x pi x (120 mm)^2/2)^(1/3) = 9.7 kgf (I used the formula that gives the max possible static ...


2

Yes - it can work. Colin Furze (UK inventor & TV personality) built an essentially similar device. Skip to about 1:40 to see some of the problems he had.


1

The difficulty in hovering a helicopter lies in the fact that hover is unstable. Any tiny divergence will increase over time, so you have to keep adjusting the controls all the time. And this does not differ between single rotor with anti-torque and dual-rotor.


1

All helicopters can hover. That's the key advantage of that type of aircraft over the autogyro. Almost all rotating-wing aircraft are today helicopters, with only a relatively small number of autogyros still around. The most advanced autogyros of the 30s, before helicopters existed, were capable of vertical take-off and landing, but could not hover.


1

I think it's based mostly on perception of altitude above ground level. If you're hovering over trees, or over a rough sea, what you care about first and foremost is your clearance from the tops of the trees and waves. And if the surface of the vegetation is dense, like tall crops, trees or bushes, that's what your eyes will focus on, so you perceive that as ...


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