Questions tagged [vtol]

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

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2
votes
2answers
120 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 ...
20
votes
2answers
20k views

Can you identify this fighter aircraft?

If someone can identify this aircraft, please tell me which aircraft this is?
2
votes
1answer
237 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?
0
votes
0answers
34 views

Is it more efficient to use inlet guide vanes or variable pitch blades

Again, its all in the question. two scenarios for a ducted prop in hover: inlet guide vanes close to the prop to control the angle of attack just a prop with a variable pitch mechanism. obviously, ...
-2
votes
1answer
154 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, ...
1
vote
1answer
88 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?
2
votes
3answers
222 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 ...
2
votes
2answers
183 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?
7
votes
4answers
548 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?
2
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1answer
100 views

How do I calculate the total cruise power from the propelers 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 ...
1
vote
1answer
103 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 ...
2
votes
0answers
76 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 ...
2
votes
1answer
359 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, ...
1
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0answers
106 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: ...
-2
votes
3answers
383 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 ...
5
votes
2answers
385 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 ...
1
vote
4answers
108 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. ...
18
votes
3answers
7k 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: ...
1
vote
1answer
113 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
1
vote
3answers
407 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 ...
3
votes
2answers
302 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 ...
1
vote
1answer
295 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 ...
1
vote
0answers
86 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 ...
2
votes
3answers
281 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 ...
5
votes
3answers
225 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 ...
5
votes
1answer
693 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, ...
-1
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3answers
331 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 ...
0
votes
2answers
174 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 ...
1
vote
4answers
363 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 ...
4
votes
3answers
1k 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?
3
votes
1answer
479 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 ...
4
votes
0answers
272 views

What is the typical procedure if an engine fails during a vertical takeoff?

My understanding of VTOL aircraft (correct me if I am mistaken) is that the plane accelerates vertically until it's a bit off the ground, at which point the thrust is slowly vectored horizontally, and ...
5
votes
3answers
1k views

Why didn't we see many VTOL aircraft in the history of aircraft development?

US aircraft carriers mostly use F/A-18 Hornet. French aircraft carriers mostly use Rafale-M. Indian aircraft carriers mostly use Mig-29K. Chinese use Shenyang J-15. ... None of them are VTOL aircraft....
9
votes
2answers
565 views

Can a VTOL jet such as the Harrier enter a Vortex Ring State?

I'm curious, because they obviously don't have those huge rotors pushing the air away, but they are still getting their upward thrust from somewhere. My gut says, yes, but it is more difficult. Is ...
2
votes
1answer
2k views

what are the advantages and disadvantages of tilt rotor vs ducted jet engine for a VTOL aircraft?

Please could someone summarize the main advantages and disadvantages of a tilt-rotor (the V22 Osprey) vs jet (F35) system for VTOL. I have been trying to look into this but found details very sparse ...
3
votes
1answer
699 views

Why does the V-22 Osprey have twin stabilizers?

I've noticed that the Bell Boeing V-22 Osprey has a twin vertical stabilizer, while the AugustaWestland AW609 has a T-Tail. Bell Boeing V-22 Osprey with twin stabilizers. Credit: Boeing AW 609 (T-...
87
votes
14answers
16k views

Are wings any more efficient at creating lift, versus orienting the engine's thrust downwards?

As I understood from this article, wings on an airplane basically create lift by pushing air down. Maintaining the lift force expends energy because air needs to be continually accelerated downwards. ...
2
votes
1answer
399 views

Do all the engines/propellers of a VTOL UAV need to be identical?

I would like to know if VTOL UAVs necessarily need $n$ identical propellers and motors. Have any design solutions considered the possibility of using non identical props? For instance 2 motors of type ...
-2
votes
2answers
2k views

How does the F-35 hover?

The picture shows the aircraft hovering; how does it do that?
2
votes
3answers
649 views

Why aren't tilting propellers used as an alternative for ailerons or elevators?

I was wondering what are the reasons for not using tilted propellers fixed to ailerons/elevators/elevons? Or even on wings with no control surfaces at all? Wouldn't the 2nd way of thrust vectoring ...
0
votes
1answer
182 views

Can I have two speeds on one motor? [closed]

I am designing an aircraft and it is my first that will use a combustion engine rather than electric, so I am curious, if I had a single engine in the fuselage and gear shafts to the wings that drove ...
4
votes
2answers
2k views

How do VTOL aircraft like the V-22 Osprey not tilt?

How do aircraft like the V-22 not tilt under an unbalanced load? if they are only supported by 2 forces on either side a large weight in the back should cause it to lean backward when stationary, ...
1
vote
2answers
2k views

What are the reasons why we do not have VTOL commercial airliners? [duplicate]

I understand that there are noise issues, and that there may be an economic case dependent on stage length, but other than that I'm not quite sure why they haven't happened. Is there something ...
0
votes
1answer
343 views

Can the lift fans used on a F-35 be driven by a turboshaft engine instead of the jet engine? If yes, which one? [closed]

This is for a sci-fi story I'm writing, so the answer doesn't have to be perfect, just close as possible. Can the lift fans on a F-35 be driven by a turboshaft instead of the jet engine If yes, which ...
1
vote
1answer
549 views

Has anyone successfully solo'd a helicopter with no actual flight experience?

Especially at low speed, such as during takeoff, while hovering, and while landing, helicopters are famously difficult (impossible) to control for someone with no experience. Is there a documented ...
1
vote
1answer
358 views

How is this rotor setup flying? [duplicate]

I've been researching about helicopter flight without a tail rotor and the closest I've found is intermeshing rotors or this: https://www.quora.com/Why-dont-helicopters-have-rotor-blades-at-the-bottom ...
18
votes
4answers
6k views

Can the V-22 autorotate?

Can tilt-rotors like the V-22 execute an autorotation landing? If so, are the conditions under which that would be possible (and survivable) different from a helicopter?
8
votes
2answers
1k views

Could a plane land vertically in a strong headwind?

I know there are VTOL craft meant to take off and land with a vertical trajectory. But, under the perfect wind conditions, could a normal airplane ever land (safely) with a vertical or nearly vertical ...
12
votes
3answers
3k views

Why do VTOL aircraft (F-35 or Harrier) have only one engine?

Why do VTOL aircraft (F-35 or Harrier) have only one engine? Is it because it is simpler and less expensive? Or what are the reasons?
7
votes
1answer
553 views

What is the current state of regulation regarding VTOL aircraft in the LSA category?

With quite a few concept designs in progress, I am curious what the current FAA regulations are regarding vertical takeoff and landing vehicles in the light sport aircraft category.