Is 'Airwolf' possible with our current technology? (Supersonic Helicopter)

[Dominic Santini]

Airwolf (from the T.V show Airwolf) is a Mach 1+ helicopter capable of reaching speeds up to Mach 2. For it's time, it's weapons system was pretty farfetched (had fourteen weapons systems overall, including chaffe and flares) at it's time.

I'm well aware of the limits of regular helicopters' speed limits, due to their blades being able to only take so much resistance before breaking off. Under normal circumstances, this would make a Mach 1+ helicopter like Airwolf laughable at best. HOWEVER, it is suggested that Airwolf actually TURNS OFF it's rotors before entering this 'turbo' mode. Given that the rotors don't immediately stop moving, would this help make Airwolf more feasible?

 

[CWatters]

I suppose if you could turn off the rotor, fold and stow the blades you might make something work. You would need to add wings, a horizontal tail and a source of forward thrust as their functions are all provided by the rotor on a helicopter.

Funny things happen when your aircraft goes supersonic, look at all the stability issues they had in the early days of supersonic flight. I suspect that by the time you have overcome all the problem the resulting airframe won't look much like a helicopter any more.

There have been numerous attempts to make aircraft that transition from vertical take off to horizontal flight and all have their own problems and solutions...

https://en.wikipedia.org/wiki/Tiltrotor
https://en.wikipedia.org/wiki/Tiltwing
https://en.wikipedia.org/wiki/Convertiplane
https://en.wikipedia.org/wiki/Tail-sitter
https://en.wikipedia.org/wiki/Ryan_XV-5_Vertifan

 

[Dominic Santini]

Well, the best we could possibly do for it would make it a rudimentary plane with very little surface control. It'd be functional; just wouldn't be as effective at dogfighting as planes would be. So, then the problem would be that we need to fill the time gap between folding the helicopter blades (it isn't going to be speedy-- the faster the rotors need to be, the bigger it also needs to get compensatingly so) with something to counter-act gravity with. I estimate that there may be three or four minutes of getting the rotors to cease rotation, and then another minute to fold it inwards. Perhaps less.

 

[Aaronvan]

I don't see the need for Mach 2 helicopter even if it were possible.

 

[Dominic Santini]

Hey, why not? It'd probably be able to outmaneuver, outfly and outgun most other things in the air. I imagine it'd be great for making speedy deliveries (for civilian use), and would be one step forward in the direction of 'future' transportation methods if it were made readily accessible to the everyday lowman.

 

[Baluncore]

I doubt the sonic transitions could be done in horizontal flight because of rotor disc balance and fuselage stability.

To go supersonic, gain sufficient height, reduce power, increase rotor pitch and tail down to stop rotation. Then start to fall, now nose first, back-flipped? As speed increases furl the rotors behind a raised heat shield. Use thrust motor plus free-fall to go supersonic. Avoid hitting the ground.

To recover from supersonic mode, enter a steep vertical loop without power. In a stall at the top, unfurl the rotor blades and return to helicopter mode through auto-rotation.

 

[OCR]

I'm well aware of the limits of regular helicopters' speed limits, due to their blades being able to only take so much resistance before breaking off.

The blades breaking off, is not really the problem...

Helicopter top speed is limited by retreating blade stall...

Retreating blade stall is the primary limiting factor of a helicopter's airspeed, and the reason even the fastest helicopters can only fly slightly faster than 200 knots (about 370 km/h).

Also, take a look at dissymmetry of lift...

http://avstop.com/ac/basichelicopterhandbook/ch2.html#15
http://avstop.com/ac/basichelicopterhandbook/index.html

 

[Dominic Santini]

Right. I suppose my dreams of flying a replica of Airwolf at mach 1+ is nothing but a pipedream. Thanks though! I learned a lot from this.

 

[the_punnisher]

With a $Billion and state of the art technology' we could build an Airwolf style heli. Carbon fiber with Kevlar to reduce weight and protect. The lifting body concept can be used. Ducted fan jets would reduce or eliminate a fall problem. An on-board supercomputer with A I could handle any instability problems. The Russian backward wing aircraft is proof of the concept. A supersonic lifting body has a proof of concept with stubby wings, better for control surfaces Add SMALL winglets on the tail rotor to go hypersonic. While the jets stabilize the aircraft, the rotors could be stowed before the jets make it a lifting body.. Creating and stowing munitions become the problem.

 

[boneh3ad]

With a $Billion and state of the art technology' we could build an Airwolf style heli. Carbon fiber with Kevlar to reduce weight and protect. The lifting body concept can be used. Ducted fan jets would reduce or eliminate a fall problem. An on-board supercomputer with A I could handle any instability problems. The Russian backward wing aircraft is proof of the concept. A supersonic lifting body has a proof of concept with stubby wings, better for control surfaces Add SMALL winglets on the tail rotor to go hypersonic. While the jets stabilize the aircraft, the rotors could be stowed before the jets make it a lifting body.. Creating and stowing munitions become the problem.

No offense, but I am reasonably sure that you don't know anything about supersonic or hypersonic flight, helicopters, or the challenges involved in designing such vehicles.

 

[Bruce Murray]

Harrier

 

[gleem]

F-35?

 

[Bruce Murray]

Harrier isn't supersonic but close. I didn't mention F-35 as it is too controversial and may turn out to be a bag of worms.

 

[gleem]

I didn't mention F-35 as it is too controversial and may turn out to be a bag of worms.

It certainly looks like it is here to stay.worms and all.

 

[Bruce Murray]

After all the money they spent; no doubt. The Bomark Missile was useless and hung around for a while.

 

[Klystron]

Whether combining multi-role mission requirements into a single fuselage (F-22, F-35*) proves to be practical, the concept of supersonic helicopter is obviated by numerous VSTOL and related successful ducted fan, tilt-rotor, and related designs examined by @CWatters in post #2.

If the OP permits, the helicopter movie Blue Thunder uses at least two intriguing plot devices:

1. nearly silent "whisper mode" while hovering (despite the jet engines);
2. performing an inside loop at maximum forward speed.

Can a chopper loop?

 

[phinds]

No offense, but I am reasonably sure that you don't know anything about supersonic or hypersonic flight, helicopters, or the challenges involved in designing such vehicles.

 

[boneh3ad]

Harrier isn't supersonic but close. I didn't mention F-35 as it is too controversial and may turn out to be a bag of worms.

It has been a program with ballooning costs and beset by technical challenges, but the recent additional orders of the airframe by other countries who could buy anything else if they wanted to is a pretty strong indication that it has overcome most of the concerns.

 

[boneh3ad]

Can a chopper loop?

 

[trurle]

View attachment 188404​

Airwolf (from the T.V show Airwolf) is a Mach 1+ helicopter capable of reaching speeds up to Mach 2. For it's time, it's weapons system was pretty farfetched (had fourteen weapons systems overall, including chaffe and flares) at it's time.

I'm well aware of the limits of regular helicopters' speed limits, due to their blades being able to only take so much resistance before breaking off. Under normal circumstances, this would make a Mach 1+ helicopter like Airwolf laughable at best. HOWEVER, it is suggested that Airwolf actually TURNS OFF it's rotors before entering this 'turbo' mode. Given that the rotors don't immediately stop moving, would this help make Airwolf more feasible?

F-35B is de-facto supersonic helicopter with rotor built inside the fuselage.
F-35B has lifting rotor, but the rotor location and attitude control methods are all different from classical helicopter.
As Dominic Santini properly said, at supersonic speeds classical helicopter layout is a huge handicap, and real-world rotor-wielding yet high speed aircraft would not look helicopter-like.

Theoretically, retreating blade stall is not a fatal problem for counter-rotating dual rotors high-speed helicopters, but other problems (poor pitch stability, high drag and need for variable rotor geometry) of supersonic helicopters are still result in not very practical designs.

 

[jrmichler]

Conventional helicopters are speed limited because the advancing rotor blade tip approaches supersonic speed while the retreating blade stalls. One attempt toward solving this problem is to add a wing to the fuselage, then slowing the rotor. As speed increases, lift is transferred from the rotor to the wing. This was done by Jay Carter: http://www.cartercopters.com/. He has been working on the concept for over 20 years, and has flown some prototypes: https://en.wikipedia.org/wiki/CarterCopter. It has never been commercialized.

 

[Vanadium 50]

I don't see the need for Mach 2 helicopter even if it were possible.

You could hover at Mach 2.

 

[berkeman]

He has been working on the concept for over 20 years, and has flown some prototypes: https://en.wikipedia.org/wiki/CarterCopter. It has never been commercialized.

Wow, what are all those buttons for in the lower right of the instrument panel?

5th picture down here: https://newatlas.com/go/2504/#p4014

 

[Klystron]

Wow, what are all those buttons for in the lower right of the instrument panel?

5th picture down here: https://newatlas.com/go/2504/#p4014

View attachment 236978

Great pics! My guess are contact circuit breakers. Notice the wire bundle running under the control panel.

 

[boneh3ad]

F-35B is de-facto supersonic helicopter with rotor built inside the fuselage.

That's a misleading statement in the context of this thread (which is admittedly silly). The F-35 can "hover" for short periods, particularly for a vertical landing. It is not designed to hover long-term while maintaining maneuverability, as is a helicopter. It's about as close as you can reasonably expect to get to a supersonic helicopter. It can "hover" and it can fly supersonic. It certainly won't be filling any traditional helicopter roles, though, no matter what Live Free or Die Hard says.

 

[Bill an engineer]

Retreating blade stall can be overcomed by the dual rotos design(Sikorsky calls it "Advancing Blade Concept"). Essentially it's two rotors on the same axis and rotate in opposite direction, so each side of the chop has one rotor advancing and one retreating. I don't know how fast this design can go, but it potentially has the capability to send a chopper to at least mach 0.5-0.8, if a few rocket propellers are used (like the idea of Airwolf).

There are many advantage of a chopper over the VTOL/STOL planes. It can definitely lift more stuffs, and is much more fuel efficient. If there's a chopper that can fly close to mach 1, it would be really useful.

 

[boneh3ad]

On one thing I think we all agree: a helicopter unconstrained by physics would be neat.

 

[Nik_2213]

"Harrier isn't supersonic but close."
It could have been: I used to know the guy who led the team that solved the supersonic Pegasus' problems.
Just in time for the entire project to be canceled on political grounds...
FWIW, even decades later, the details were still NDA...

IIRC, the fastest helicopter remains a jet-assisted experimental Bell design, dating back to the 1960s.
The fastest current design appears to be the Airbus X-3.
YMMV.

 

[NCIS1996]

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View attachment 188404​

Airwolf (from the T.V show Airwolf) is a Mach 1+ helicopter capable of reaching speeds up to Mach 2. For it's time, it's weapons system was pretty farfetched (had fourteen weapons systems overall, including chaffe and flares) at it's time.

I'm well aware of the limits of regular helicopters' speed limits, due to their blades being able to only take so much resistance before breaking off. Under normal circumstances, this would make a Mach 1+ helicopter like Airwolf laughable at best. HOWEVER, it is suggested that Airwolf actually TURNS OFF it's rotors before entering this 'turbo' mode. Given that the rotors don't immediately stop moving, would this help make Airwolf more feasible?

Technically we already have a supersonic helicopter (and airwolf) it's called The Bell 360 invictus... was made after the rah-66 Comanche. Here is some real airwolfs. Its not in the field yet but they exspect it to be by 2024.

 

[boneh3ad]

Technically we already have a supersonic helicopter (and airwolf) it's called The Bell 360 invictus... was made after the rah-66 Comanche. Here is some real airwolfs. Its not in the field yet but they exspect it to be by 2024.

330 km/h is a far cry from supersonic.

 

[phinds]

330 km/h is a far cry from supersonic.

@NCIS1996 this is a science forum. It's a good idea to have your facts straight before posting, 'cause folks WILL notice when you don't.

 

[berkeman]

330 km/h is a far cry from supersonic.

Well, in fairness, that's its listed cruise speed. Maybe it's got, like, afterburners or something to go lots faster?

 

[phinds]

Well, in fairness, that's its listed cruise speed. Maybe it's got, like, afterburners or something to go lots faster?

https://verticalmag.com/news/bell-360-invictus-to-use-429-engine-as-supplemental-power-unit/

The aircraft is designed for speed, with the Army calling for a cruise speed of 180 knots, and a maximum of 205 knots.

205 knots is under 400mph.

 

[Rive]

I don't see the need for Mach 2 helicopter even if it were possible.

Kind of reminds me of some tussle about A10 still having too high attack speed

 

[phinds]

I don't see the need for Mach 2 helicopter even if it were possible.

Seriously? You don't think the military would LOVE to have almost instantaneous transport to a drop zone or a pickup zone (or even "just" Mach 2 if it were possible)? I don't think you've thought that through.

They would LOVE to have a Mach 2 helicopter (but sadly it isn't possible). Convertibles like the Harrier just aren't the same since they have down-pointing jets during hover and that would make it a little tough to drop troops by rope or hoist up a litter.

 

[Zeddlar]

Well, the best we could possibly do for it would make it a rudimentary plane with very little surface control. It'd be functional; just wouldn't be as effective at dogfighting as planes would be. So, then the problem would be that we need to fill the time gap between folding the helicopter blades (it isn't going to be speedy-- the faster the rotors need to be, the bigger it also needs to get compensatingly so) with something to counter-act gravity with. I estimate that there may be three or four minutes of getting the rotors to cease rotation, and then another minute to fold it inwards. Perhaps less.

Finally, someone that understands aerodynamics and has relatively the same thought as me. The real problem will be those wings though. That's why nothing up to the osprey has succeeded. And the lift and forward flight engines are the same and mounted on the wings that rotate with them. If you put a real even small sized set of wings under a rotor, it either nullifies or destabilizes the lift from that rotor. As for the folding and storing of the rotors, the jet engines could provide the forward thrust while that took place, provided that while thing didn't destabilizes the flight characteristics of the aircraft. There is a crap ton of hurdles to get over to even begin building something that complicated.

 

[airwolflover]

No offense, but I am reasonably sure that you don't know anything about supersonic or hypersonic flight, helicopters, or the challenges involved in designing such vehicles.

I think no one also did reasurch on mach angles created by the main fuselage and how blades would fit inside that angle/cone and as most of the blades stick past the fuselage they would be expost to even greater forces

 

[airwolflover]

I think no one also did reasurch on mach angles created by the main fuselage and how blades would fit inside that angle/cone and as most of the blades stick past the fuselage they would be expost to even greater forces

So how fast can we get this helicopter to on its rotors until the wings will create enough lift to support the transition, how big would they need to be without interfering with normal hover mode then their is how is everything going to fit in a certain mach angle

 

[airwolflover]

If you would take the hull of the comanche alone (reshape the nose and without rotors ) it would go like a misile over mach 1

 

[airwolflover]

Well, the best we could possibly do for it would make it a rudimentary plane with very little surface control. It'd be functional; just wouldn't be as effective at dogfighting as planes would be. So, then the problem would be that we need to fill the time gap between folding the helicopter blades (it isn't going to be speedy-- the faster the rotors need to be, the bigger it also needs to get compensatingly so) with something to counter-act gravity with. I estimate that there may be three or four minutes of getting the rotors to cease rotation, and then another minute to fold it inwards. Perhaps less.

Then there is the question how big can we make the wings how much speed need to create enough lift.
Can we gain enough elefation to do maybe a nose dive transition to gain speed and time for the transition?

 

[berkeman]

So how fast can we get this helicopter to on its rotors

Probably about negative one miles per hour...

 

[airwolflover]

Next to all this, the question is what are helicopters designed for what role do they need to fill.
Supersonische flight ? No we have jets to do that.
So what then?
The function that i read about in the comments that i would think would be best is the wispher or silent mode.
Does it need to faster than any helicopter on the battlefield? It sure does!
Does it need to go supersonic?
Nope!

 

[Nugatory]

Does it need to faster than any helicopter on the battlefield? It sure does!

This is why the V-22 Osprey.

 

[phinds]

Supersonische flight ? No we have jets to do that.

You're missing the point. Jets require long runways. The Harrier is what you're looking for, or as @Nugatory pointed out the Osprey.

 

[phinds]

If you would take the hull of the comanche alone (reshape the nose and without rotors ) it would go like a misile over mach 1

What on Earth is your point with that statement? LOTS of airframes would go over mach 1 if reshaped and with no rotors, just jets engines.

Hell, if you reshaped me (it would take some work) and put a jet engine on me, I could probably go over mach 1.

 

[jrmichler]

The CarterCopter referenced in Post #21 is the closest anybody has come to a stopped rotor helicopter yet. After over 20 years of development, they have not yet hovered more than 5 seconds, or got the rotor speed stopped. Their top speed is slower than current fast helicopters. The Wikipedia link in that post is still good, and does a good job of discussing the tradeoffs in slowed/stopped rotor fixed wing flying machines. More info, and the photo below, at the Carter Aviation website: https://carteraero.com/home2/. Note that their best L/D is 11, which is not conducive to high speed.

But it has actually flown, so is not vaporware. It just has, at this time, no real world advantages over existing technology.

 

[glappkaeft]

The Rotary Rocket orbital class rocket would have been a (very) supersonic helicopter by some definition of helicopter. However they (and all the other private rocket companies around at the time) lost funding in the early 2000s financial crisis so they only did four test flights of the concept, none of them supersonic.

https://en.wikipedia.org/wiki/Rotary_Rocket

 

[boneh3ad]

What on Earth is your point with that statement? LOTS of airframes would go over mach 1 if reshaped and with no rotors, just jets engines.

Hell, if you reshaped me (it would take some work) and put a jet engine on me, I could probably go over mach 1.

No reshaping required. Anything of any shape can go supersonic with enough thrust.

 

[phinds]

No reshaping required. Anything of any shape can go supersonic with enough thrust.

Yes, but it would also fall apart rather quickly if it were not aerodynamic.

 

[Bystander]

No reshaping required. Anything of any shape can go supersonic with enough thrust.

https://www.physicsforums.com/searc...ter+++Red+Flag&c[users]=Bystander&o=relevance