Questions tagged [vtol]

For questions about vehicles capable of vertical take-off and landing.

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What is the decrease in power when a drone is in descent?

For a quad-copter, or a fixed-wing drone with quad-rotor formation, how much would the power of the motor decrease when a constant speed descent is needed to bring the drone back to the ground? Does ...
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0 votes
1 answer
103 views

If I put two ductfans behind one another, would I got the sum of the rated thrust or other thrust values?

I am trying to design a VTOL system for a drone and I don't want to have extending motor arms that make it look like a quadcopter. I want to use duct fans and thrust vectoring nozzles. However, the ...
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3 votes
3 answers
250 views

How does the Urbanaero flying car move forward?

From the pictures of UrbanAero flying car: https://www.urbanaero.com/cityhawk, I can see that can achieve VTOL using the two propeller in front of and in the back of the passenger compartments. ...
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5 votes
1 answer
358 views

How a takeoff decision point(TDP) for vertical takeoff vehicle is defined?

For a vertical takeoff vehicle like a helicopter, how the takeoff decision point is defined or computed? Look at the snapshot below, seems the height of TDP is related to the rejected takeoff distance?...
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2 votes
3 answers
213 views

Can you have a Hybrid Turboprop-Jet engine?

To start things off I am writing this to gain information for vehicles in a story, so I am more so looking for theoretical possibilities, unless there are real world examples. The background and my ...
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3 votes
2 answers
313 views

Why does Harrier have split hot exhaust nozzles?

This is a repost after the original questions were deemed too complicated. Hawker Sea Hawk shot by Smudge 9000 under CC-SA 2.0 licence. Harriers seem to inherit elements from Sea Hawk, that the ...
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1 vote
1 answer
144 views

I need some help to understand the rationales behind some STOVL jet designs, especially the Pegasus-Harrier configuration [closed]

In the question:Why do VTOL aircraft (F-35 or Harrier) have only one engine? Aeroailas answered why mature STOVL fighter designs only use one main engine, but did not answer why there are no mature ...
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1 vote
1 answer
76 views

Can a normally poorly handling airframe with high moments of inertia actually have superior flight dynamics under autonomous control? [closed]

I’m not a pilot but know a thing or two about flight dynamics. As you know there are currently quite a few aircraft under development designed for low-and-slow and (eventually) autonomous flight. ...
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1 vote
1 answer
645 views

What would be the Sref i.e. Reference Wing Area for Drag Build Up Calculation in case of a box wing design?

Would Sref be sum of areas of both, the front and the back wing? or just one wing? Assuming both the wings have equal areas (image below) Details - So, I am calculating drag using the component drag ...
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2 votes
0 answers
82 views

The cost of maintaining VTOL devices

Which device for VTOL flight costs the most to maintain for a given number of flight hours? A tiltwing mechanism? A 2D thrust-vectoring nozzle (vectoring only between VTOL position and cruise ...
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  • 315
-4 votes
3 answers
214 views

Would this quadrilateral-shaped airfoil produce lift with a zero angle of attack?

I have been recently studying the shapes and characteristics of different high-lift airfoils that have been used for VTOL aircrafts. While studying these different designs today, a particular ...
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13 votes
2 answers
2k views

How much thrust is lost through a curved exhaust nozzle?

In modern VTOL aircraft energy is usually directed through nozzles to achieve vertical lift. How much energy is lost when changing the direction of flow in static thrust conditions?
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0 votes
1 answer
97 views

How to use a set of Pressure Transducer to mimic pitot static tube for VTOL vertical airspeed indicator?

May i know if i have 3 pressure transducer, 1 facing upwards and the other downwards to measure the vertical velocity of a VTOL (Vertical Takeoff and Landing aircraft) and another 1 on the nose of the ...
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11 votes
2 answers
641 views

Why is the F-35B's elevator not in neutral position when in vertical flight mode?

I was watching videos of F-35B taking off and landing vertically on ships when I realized that when transitioning from horizontal to vertical flight mode (I don't know the exact vocabulary to describe ...
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3 votes
3 answers
2k views

What are the disadvantages of a Tail providing lift? (tandem-wings included)

Most aircraft feature the tailplane configuration, which requires the main wing to provide higher lift than the weight of the plane itself, what seems counterproductive. Few aircraft have featured ...
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  • 45
1 vote
4 answers
1k views

How do STOVL and V/STOL aircraft differ?

Wikipedia's page for STOVL begins with A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically ...
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3 votes
1 answer
403 views

Which prop location creates more lift? Leading edge or blown flap?

Which prop creates more lift? Leading edge or blown flap? In distributed propulsion there seem to be 3 prop locations: leading edge (NASA X57, blackfly), blown flap (Lillium), and pusher prop (...
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  • 889
2 votes
2 answers
195 views

XFY-1 Vertical take-off mechanics

Hi I saw this video the other day of an XFY-1 doing a vertical take-off and landing and moving left to right while hovering. See the video Here. After watching this I had a few questions on how ...
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-1 votes
1 answer
100 views

Questions regarding VTOL and VMU inhibits [closed]

I have been working on a game which has futuristic VTOL-capable air and aerospace crafts. A player recently wrote that the stall warning (tone and aural) and AoA (tone and visual) were distracting/...
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2 votes
2 answers
239 views

Is a chambered fan more efficient than a ducted fan?

A chambered fan is not exposed to the oncoming airflow in forward flight. I am working on a VTOL design that uses a chambered fan. There will be a wing attached to top of the thrust arms. Could it ...
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20 votes
2 answers
20k views

Can you identify this fighter aircraft?

If someone can identify this aircraft, please tell me which aircraft this is?
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3 votes
1 answer
433 views

Why does the US Marine Corps fly the Harrier, a VTOL or operationally STOVL aircraft?

The UK flies the Harrier because they have STOBAR carriers, but why does the United States Marine Corps fly the Harrier?
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-2 votes
1 answer
434 views

What are the commercial benefits of VTOL? [closed]

there are a lot of companies doing R&D on VTOL aircraft. I understand their necessity for the military, but for civilian aviation, there are a very few application that requires it( medevac, ...
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  • 411
1 vote
1 answer
129 views

About F-35 hover/ roll posts responsiveness [closed]

how responsive is the f35 in hover. especially in the roll axis. What do think of the roll posts? is it a good concept?
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  • 411
2 votes
3 answers
260 views

Could wing tilting be a mechanism for VTOL and high angle of attack for jetliners? [closed]

My question is about turbofan airliners, could an airplane tilt its wings 90 degrees so that the fuselage horizontal axis is perpendicular to the longitudinal axis of the turbo fan. This way an ...
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3 votes
2 answers
296 views

Are there planes that can fly without wings? How would a plane be able to fly without wings? [duplicate]

Are there any planes that can fly without wings? How do they produce lift? How do they control the attitude?
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7 votes
4 answers
733 views

During VTOL landings, do Harrier pilots cut power before touching the ground?

When vertically landing, do Harrier pilots cut power before they touch the ground?
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2 votes
1 answer
200 views

How do I calculate the total cruise power from the propellers accounting for the losses?

Let's say I have an aircraft with four propellers (see diagram below) and I am supposed to calculate the cruise power required to drive the aircraft forward. The wing creates the lift and propellers ...
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  • 427
1 vote
1 answer
123 views

What's the smallest 3-blade propeller for this motor? [closed]

I've got a 15470 brushless 35kw motor from China How do I find the smallest 3-blade propeller I can use for this motor? Here are it's specs, Max Power: 35KW Max Amp: 400A Max RPM: 8500 Max Volt: 120v ...
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2 votes
0 answers
83 views

How are rotorcraft and/or VTOL aircraft handled once they get to an airport? [duplicate]

I am asking this from an ATC perspective ... my experience as a pilot is that they would make helicopters fly the same approach but once they got the airport environment in site where do they go? Taxi ...
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2 votes
1 answer
839 views

How fast do four Tire-Propellers have to rotate to lift 2000 lbs? [closed]

I just saw this come out, Goodyear's Tire-Propeller Concept – a combination tire that can also act as propeller (well, more like a ducted fan I guess). There's a neat video that goes with it, ...
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1 vote
0 answers
170 views

What are the effective span and lifting properties of a circular wing?

Today I read an article on FlightGlobal about the Bell air taxi demonstrator. It includes some paraphrased quotes from the Bell VP of innovation, Scott Drennan, among which the following stood out: ...
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-1 votes
3 answers
744 views

Would this hybrid impeller design create enough thrust for a VTOL aircraft?

I am wondering if combining a centrifugal blower impeller with an Archimedes screw impeller would create a hybrid impeller that would create enough thrust to lift up a VTOL aircraft. Please reference ...
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5 votes
2 answers
1k views

How to calculate the power required during transition from VTOL to fixed wing?

In a VTOL, I have calculated the power required for take off and cruise which was not difficult at all. Between take off and cruise, there is a phase where the VTOL has to transition by tilting the ...
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  • 427
1 vote
4 answers
207 views

Would a propeller extracting air from a cylinder with holes in it be an ideal lift apparatus for a VTOL aircraft?

I am wondering if enough lift can be created for a VTOL aircraft using a propeller that is extracting air from a cylinder which is closed at one end and has holes in the top half of the cylinder. ...
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21 votes
5 answers
9k views

How does the F-35B not flip over during transition?

As the engine nozzle rotates, the lift-fan cannot. Wouldn't this imbalance of moments around the center of gravity result in the F-35 pitching up onto its back? As can be seen at 5:14 in this video: ...
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1 vote
1 answer
177 views

Can ailerons be used to control yaw and pitch [closed]

Is it possible for an aileron to be used to control the roll, pitch and yaw of a vtol drone
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1 vote
3 answers
1k views

Disadvantages of using thrust vectoring only in an aircraft with variable rotation nacelles such as the X-19

Take a quad tilt rotor aircraft such as the curtiss-wright X-19 or even a bi-tilt aircraft such as the V-22. What would be the advantages or disadvantages of using thrust vectoring only for control ...
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  • 11
2 votes
3 answers
537 views

Did any VTOL aircraft implement an airfoil with engine-blown exhaust?

Did any VTOL aircraft implement an airfoil with engine-blown exhaust?
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  • 2,252
3 votes
2 answers
459 views

Does the Lilium VTOL wings produces lift during takeoff?

I just had a look on some of the recent development in the personal VTOL electrical aircrafts. I am wondering if the Lilium VTOL wings produces lift during takeoff? I would expect a quit high wind ...
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  • 131
2 votes
1 answer
472 views

Why are smaller wings in the front with these VTOL aircraft?

I would think it would be better to put the larger wings under the front or middle closer the the payload/center and have the smaller wings in the tail? Why would these designs do the opposite? With ...
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1 vote
0 answers
128 views

How much lift can be generated by the intake lip of a duct?

How to calculate the extra lift gained by the intake lip of a duct? Aside from improving efficiency by preventing tip vortices, if a duct has a bell-shaped intake, this lip around the edge creates ...
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  • 149
4 votes
3 answers
568 views

Carrier VTOL takeoff or not?

In this picture, shown in a recent news article, a "shooter" seems to be giving a "go forward" command to what I believe is a Lockheed-Martin F-35 aircraft already prepped in a VTOL configuration. But ...
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5 votes
3 answers
949 views

How to calculate lift and drag coeffecients for VTOL aircraft in the takeoff stage?

How would I calculate CL and CD for a VTOL aircraft while it is in it's takeoff/landing stage? The particular aircraft is a fixed wing/quadcopter hybrid so I know that I can treat this as a thin ...
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6 votes
1 answer
2k views

How can a VTOL aircraft control yaw while hovering? [duplicate]

I watched this video of a F-35B performing a flight-hover-flight transition and was pretty impressed by the fact that it was able not only to control pitch and roll (which could be, I suppose, ...
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-1 votes
3 answers
523 views

Can a Stewart Platform be used instead of a swash-plate assembly in a helicopter? What are the pros and cons? [closed]

https://en.wikipedia.org/wiki/Stewart_platform Also, are there any helicopters in service that use this mechanism? I was thinking along the lines of using it instead of the part of the swashplate ...
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0 votes
2 answers
190 views

Why do we not have autonomous helicopters? [closed]

We see a lot of fixed wing autonomous UAVs. What is preventing this in the case of helicopters? I know the helicopter flight dynamics are complicated. But what exactly is the complication in this ...
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1 vote
4 answers
530 views

How bad is the efficiency of jet engines under low loads?

VTOL operations need 4-5 times more thrust than a conventional take-off of an aircraft. If you don't want to install additional lift-engines into a hypothetical aircraft and use thrust vectoring to ...
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4 votes
3 answers
4k views

What is the difference in VTOL technology between British Aerospace Harrier II and F-35B?

F-35B safer and looks more stable in terms of VTOL capability. What is the basic difference between Harrier II and F-35B's VTOL technology?
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3 votes
1 answer
1k views

How does the V22 Osprey manage such high rotor speeds without shock waves?

I read somewhere that the engineers presented an ingenious solution to the rotor tip shockwave problem, except the article didn't actually explicitly mention it. So, does anybody actually know if ...
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