I flew this in Alabama when it was an MD demo aircraft.....like flying a high performance SUV!!! So smooth and stable....OGE pedal turns while in a vertical power pull was a non-event! Really gorgeous back cabin too!
Hey - I flew with Nick at MDHI - great IP! This was a great machine to fly and and the training areas off airport were stunning. Best AT of my career...
There are no such things as too many videos on NOTARs. This is my favorite helicopter. I’m sure there are those who don’t agree. Thing is, I do! Still a dream! Stay safe mates!😊👍🏻😷
If I'm understanding this correctly, the downwash from the main rotor is also aiding in anti-torque by the way the vortices affect the airflow over the starboard side of the tail boom? If so, that's pretty cool. I'd never have thought of that.
I remember seeing this system introduced on Beyond 2000 (or some other show of that type). I'm not a pilot but I've always wondered why this setup isn't more popular. The only other alternative implementation seems to Airbus models.
This invention ( change the tail rotor for a air deflector ) was created by the spanish company Aerotécnica in the fifties with the model AC-14. They were seeking for a more silence helicopter and safer for the ground crew. MD took the idea and improved it. Nice chopper.
It was actually invented by a french engineer named Jean Cantiniau in the 1950s for the SNCAN company in France, where he designed the first NOTAR helicopter, the N.1750 "Norelfe" prototype. Since the french air force wasn't interested in it he took his work to Spain and the Aerotécnica company and designed the AC-14 there. This helicopter wasn't successful again and so his system was forgotten until the 1970s the Hughes aircraft "resurrected" the idea and patented it as the"NOTAR" system in 1975.
Henri Coanda actually invented a rudimentary jet plane in the 20s. The principle worked, but the WOODEN structure burned up. He was a genius of fluid mechanics.
Interesting, but going a bit deeper would have been appreciated such as how much power is being consumed and as compared to a shrouded tail fan and verse a tail propeller.
@@vichy7661 I can't fill the pilot qualifications; one hand, but yes I could if that is what I wanted . Many times hiring is more efficient that owning.. as once owner of a hanger queen.
T Sclly - sorry for the late reply to you question. The NOTAR fan uses more engine horse power than a standard tail rotor. There is no tail rotor version of the MD 900/902 to compare, but on the 520N vs 530F aircraft (same main rotor systems) the NOTAR of the 520N uses approximately 16% more engine power. However, due to the placement of the 530F tail rotor, there is an interference between the tail rotor and main rotor that reduces the main rotor efficiency enough that it requires essentially that much extra horse power at a hover. Nick Page
So can you still spin if you lose fan effectiveness? Is it less likely than loss of tail rotor effectiveness. What are the emergency procedures for this scenario and is auto rotation similar or completely different concept with engine failure?
The notar makes such a distinct noise with the small turbine inside that i can call them out before i see them. They also add a very small amount of vertical lift and pitch when not being use for yaw control with the rear cone facing downward when centered. Unlike a tail rotor heli with majority of its energy wasted beyond countering the rotation of the main rotor at center.
Why, instead of a tail rotor, simply use a tail boom in the form of a wing with a variable angle of attack, slats and flaps, which will be blown by the main rotor, creating a lifting force on this wing that compensates for the rotational moment of the helicopter and carries out heading control? What is the difficulty?
I'm intrigued by this NOTAR. I fly RC helis and planes myself, but the physics of the NOTOR are not clicking with me, even after looking at the MD helicopter site. What I understand is that the slots allow for the coanda effect, allow flow from the rotors to 'stick' to the boom longer on the right side than the left side, as well as increasing airflow/ decreasing pressure. This creates an airfoil like a wing, in which the faster moving air losses pressure and the higher pressure air on the opposite side pushes against the the airfoil, allowing lift (This is the bernoulli effect, but this is not the only aspect to lift in an airfoil though). I am guessing the NOTAR relies more on this than a plane's wings. What doesn't make sense is that the rotors rotate CCW, and would cause the heli to yaw CCW without counter torque. Looking at the NOTAR, wouldn't the lower pressure air on the left side of the boom actually "push" the boom and join the torque from the rotors, rather than go against it?
Vaterraman Id have to assume the torque caused by the internal "rotor" system would be counteracted by the mainrotor, and the design being small and almost entirely solid except for small blades would cause less torque
+Vaterraman No. When there is a low pressure vs high pressure scenario, the high pushes toward the low so the 'wing' makes lift. The longer chord-wise surface or surface where the air has to travel faster to cover the same distance is the low pressure side, as in the top of a wing. In this case, the low side is on the right where the slots are. That forces the tailboom to go right, which is equivalent to left T/R pedal input.
+ThePiperRC: One thing wrong with your statement is if you say the rotor goes CCW, then torque pushes against that & makes the fuselage want to go CW. You have to counter this by a CCW force on the fuselage, which is normally what a tailrotor does, in response to left pedal when adding power. What I don't get is where those Coanda slots are. He seemed to be saying they were inside the boom, so I don't know how that could cause a force against the boom. That would be like being on a sailboat and blowing on the sail to try to make the boat move.
@@KutWrite "What I don't get is where those Coanda slots are. He seemed to be saying they were inside the boom, so I don't know how that could cause a force against the boom." The slots aren't inside the boom, they're on the boom. They let air escape from inside the boom to the outside. The air coming out of the slots interacts with the rotor downwash, so it's more than just "blowing on your sail." Air is taken into the system from the top and then redirected into the boom. Some of it comes out the moveable vent at the rear of the boom, and some of it comes out on one side of the boom. Since the rotor wash splits nearly evenly around both sides of the boom but additional air is added only to one side, that's how a side force develops against the boom.
Why you DON´T use the exaustgases of the engine(s) for levelling/ equalling the torque? (I think you could save the necessary energy for the additional fan + gearbox ) ...
The helicopter's exhaust is much like the exhaust from a car's exhaust pipe---not powerful at all. In this regard, helicopter turboshaft engines are much different than turbojet engines.
Because in a helo the turbines energy is siphoned off and used to power the transmission and so after doing so the leftover air is not sufficient to do so and also it is far too hot to channel down the tail boom
That would require special engines that can handle the increased back pressure. Normally you want the exhaust to have the lowest possible speed, which doesn't produce thrust.
What I don't get is where those Coanda slots are. He seemed to say they were inside the boom, so I don't know how that could cause a force against the boom. That would be like being on a sailboat and blowing on the sail to try to make the boat move.
It keeps the flow attached to that side of the boom and raises the speed of the flow, which lowers the air pressure (higher speed lower pressure). Lower air pressure causes a force that torques the boom around the helicopter's center in the direction that the rotors rotate, and also causes a lateral thrust to the helicopter.
It would seem that the power expended to produce a lateral anti-torque force near the main body of the machine as opposed to out near the end of the tail boom is very inefficiently utilized...
This helicopter has lesser sound compared on the Bell 407, Bell 429, UH-1, and UH 60. The lesser noise is ideal for reconnaissance and combining with stealth technology that defeats enemy radar makes it more stealthier.
BOA TARDE AGORA EU TENHO CERTEZA QUE O FUTURO CHEGOU .MUITO ESPETACULAR ESSE NOVO SISTEMA. .GOSTARIA E MUITO DE RECEBER MAIS DETALHES SOBRE ESSA AERONAVE .PARABÉNS
Great machine all that criated per technology Howard HUGHES is fabolous, this project os tô much antique in Hughes develovment, I think did bê to decade 60 It. I seen images very long past about the idea
+Entoris19 Last I checked you don't need a tail-rotor to accomplish that. In fact, I think I remember something about autorotation being used in response to loss of tail rotor effectiveness Yes, I edited a 2 year old post.
The tail rotor is always necessary, to control heading. Autorotation emergencies are for when you lose engine power. LTE's are a separate emergency; when you don't have sufficient tail rotor thrust to counteract main rotor (power on) torque, or enough to counteract a rapid (or heavy, or unfavorable wind environment) turning movement (to the right, in an MD helicopter.)
Man, sure would be nice to own/pilot something like that...... Whelp, That'll never happen LOL!!!. Instead, I'll stick to my 3D Helis that the Aviation world doesn't want me to have. They are a LOT of fun though and can do a lot of things these things can't. Vs carrying passengers..... Just more practical I don't want to be rich. It's amazing how helicopters fly. Take a 206 Ranger and look at the main shaft. A tiny little pole holding up all that weight and dynamics. Or watch an Align helicopter do a tictok on nothing but a 5mm main shaft. MD500 and how nimble it is on a small mainshaft. Or a Goblin, or Avante, or my fave of all time the Henseleit TDR (who just came out with the TDR2!!). Helicopters are cool :)
Now I heard of patents for NOTAR technology, but I think the low acceptance rate of NOTAR is due to its ugly and crude and inelegant look. Of course, it's anti-torque function has moved to inside the tail boom in order to "replace" the function of a tail rotor. Well, may be some day the designer will improve the "sexy" looks of many NOTAR helicopters.
I flew this in Alabama when it was an MD demo aircraft.....like flying a high performance SUV!!! So smooth and stable....OGE pedal turns while in a vertical power pull was a non-event! Really gorgeous back cabin too!
Love how quiet it is, and the explanation was perfect and easily understood, Thank you.
Hey - I flew with Nick at MDHI - great IP! This was a great machine to fly and and the training areas off airport were stunning. Best AT of my career...
Any body here from DCA's vid?
Digital Car Addict?
@@paolothorpe1461 yup
@@marttisydanmetsa1696 ye from the service rifle episode lmfaoo
There are no such things as too many videos on NOTARs. This is my favorite helicopter. I’m sure there are those who don’t agree. Thing is, I do! Still a dream! Stay safe mates!😊👍🏻😷
I listened to the video twice and I still don't understand 50% of what this video was about, but I loved it.
I didn't know about the slots in the boom to achieve the coanda effekt....now I do! Waahhhh!
Beautifully explained!
Thanks DCA
This is a great video! It really helped me understand how the NOTAR system works.
The best light twin in the world!
Thanks Nick!
NOTAR beautiful tail rotter technology with image, AMAZING 😇😇😇
This helicopter is a piece of art.✌👍😀
Thnx DCA
Nooooo, it was too short. i'm subscribing to see more!
If I'm understanding this correctly, the downwash from the main rotor is also aiding in anti-torque by the way the vortices affect the airflow over the starboard side of the tail boom? If so, that's pretty cool. I'd never have thought of that.
What an amazing system! Many thanks for the brief and detailed explanation. Liked and subbed.
I remember seeing this system introduced on Beyond 2000 (or some other show of that type). I'm not a pilot but I've always wondered why this setup isn't more popular. The only other alternative implementation seems to Airbus models.
I believe MD have the patent for it
This invention ( change the tail rotor for a air deflector ) was created by the spanish company Aerotécnica in the fifties with the model AC-14. They were seeking for a more silence helicopter and safer for the ground crew. MD took the idea and improved it. Nice chopper.
that's very unfortunate :P
It was actually invented by a french engineer named Jean Cantiniau in the 1950s for the SNCAN company in France, where he designed the first NOTAR helicopter, the N.1750 "Norelfe" prototype. Since the french air force wasn't interested in it he took his work to Spain and the Aerotécnica company and designed the AC-14 there. This helicopter wasn't successful again and so his system was forgotten until the 1970s the Hughes aircraft "resurrected" the idea and patented it as the"NOTAR" system in 1975.
Good
Antoine Garcia
Henri coanda in the 20s not some frenchd guy
Aap kahadiy he
That is a beautiful machine.
This should be made standard on all modern helicopters..this will put an end to the large number of deaths due to tail rotor failures
Henri Coanda actually invented a rudimentary jet plane in the 20s. The principle worked, but the WOODEN structure burned up. He was a genius of fluid mechanics.
Wooden jet 💀
That's funny, just got my Rotorcraft Pro mag for this month and this is the same 902 that's on the cover. Awesome video. Can't wait to read the mag.
Great explanation
I have just understood this technology thanks to my studies (aerospace engineering) and this video - awesome system!
Thanks for explaining! I was wondering cause alot of german police helicopters have NOTAR here...
That's freaking brilliant, I can see this entirely changing the ball game
@TheTimeTraveler2025 I must have been living under a rock, I never knew that was even out, it does look promising tho
Thanx for the update
Aight DCA understood 👍
Great explanation, thanks!
Great video; thanks for posting!
Beautiful bird
Interesting, but going a bit deeper would have been appreciated such as how much power is being consumed and as compared to a shrouded tail fan and verse a tail propeller.
As peered to a Rolls Royce owner, if you need to ask the question, then you probably can't afford one,,,,when talking efficiency
@@vichy7661 I can't fill the pilot qualifications; one hand, but yes I could if that is what I wanted . Many times hiring is more efficient that owning.. as once owner of a hanger queen.
T Sclly - sorry for the late reply to you question. The NOTAR fan uses more engine horse power than a standard tail rotor. There is no tail rotor version of the MD 900/902 to compare, but on the 520N vs 530F aircraft (same main rotor systems) the NOTAR of the 520N uses approximately 16% more engine power. However, due to the placement of the 530F tail rotor, there is an interference between the tail rotor and main rotor that reduces the main rotor efficiency enough that it requires essentially that much extra horse power at a hover. Nick Page
Love that sound 👍😃😎🎵
This helicopter has a good sound where is it
What about the variable vertical stabilizer? Can you explain how that works too?
So can you still spin if you lose fan effectiveness? Is it less likely than loss of tail rotor effectiveness.
What are the emergency procedures for this scenario and is auto rotation similar or completely different concept with engine failure?
I imagine if the fan goes out and you don't have enough airspeed you would spin. 60 knots + and you could fly with limited heading control.
The main rotor is connected to the fan, it is the same as with any other.
Cool channel! I doubt I'll ever get beyond a Robbie or a Hughs 269/300 but this is a cool ship!
The notar makes such a distinct noise with the small turbine inside that i can call them out before i see them. They also add a very small amount of vertical lift and pitch when not being use for yaw control with the rear cone facing downward when centered. Unlike a tail rotor heli with majority of its energy wasted beyond countering the rotation of the main rotor at center.
Some close ups of the slots would've been nice to see.
How do you have directional control during a dual engine failure? Is it completely lost at a certain airspeed?
Why, instead of a tail rotor, simply use a tail boom in the form of a wing with a variable angle of attack, slats and flaps, which will be blown by the main rotor, creating a lifting force on this wing that compensates for the rotational moment of the helicopter and carries out heading control? What is the difficulty?
I'm intrigued by this NOTAR. I fly RC helis and planes myself, but the physics of the NOTOR are not clicking with me, even after looking at the MD helicopter site. What I understand is that the slots allow for the coanda effect, allow flow from the rotors to 'stick' to the boom longer on the right side than the left side, as well as increasing airflow/ decreasing pressure. This creates an airfoil like a wing, in which the faster moving air losses pressure and the higher pressure air on the opposite side pushes against the the airfoil, allowing lift (This is the bernoulli effect, but this is not the only aspect to lift in an airfoil though). I am guessing the NOTAR relies more on this than a plane's wings. What doesn't make sense is that the rotors rotate CCW, and would cause the heli to yaw CCW without counter torque. Looking at the NOTAR, wouldn't the lower pressure air on the left side of the boom actually "push" the boom and join the torque from the rotors, rather than go against it?
Vaterraman Id have to assume the torque caused by the internal "rotor" system would be counteracted by the mainrotor, and the design being small and almost entirely solid except for small blades would cause less torque
+Vaterraman No. When there is a low pressure vs high pressure scenario, the high pushes toward the low so the 'wing' makes lift. The longer chord-wise surface or surface where the air has to travel faster to cover the same distance is the low pressure side, as in the top of a wing. In this case, the low side is on the right where the slots are. That forces the tailboom to go right, which is equivalent to left T/R pedal input.
Benjie Seal i could get used to this easily it would be something to get used to though, ...
+ThePiperRC: One thing wrong with your statement is if you say the rotor goes CCW, then torque pushes against that & makes the fuselage want to go CW. You have to counter this by a CCW force on the fuselage, which is normally what a tailrotor does, in response to left pedal when adding power.
What I don't get is where those Coanda slots are. He seemed to be saying they were inside the boom, so I don't know how that could cause a force against the boom. That would be like being on a sailboat and blowing on the sail to try to make the boat move.
@@KutWrite "What I don't get is where those Coanda slots are. He seemed to be saying they were inside the boom, so I don't know how that could cause a force against the boom."
The slots aren't inside the boom, they're on the boom. They let air escape from inside the boom to the outside. The air coming out of the slots interacts with the rotor downwash, so it's more than just "blowing on your sail." Air is taken into the system from the top and then redirected into the boom. Some of it comes out the moveable vent at the rear of the boom, and some of it comes out on one side of the boom. Since the rotor wash splits nearly evenly around both sides of the boom but additional air is added only to one side, that's how a side force develops against the boom.
waiting for my MD902 to download for xplane11, thought i look at some in action
Why you DON´T use the exaustgases of the engine(s) for levelling/ equalling the torque?
(I think you could save the necessary energy for the additional fan + gearbox ) ...
The helicopter's exhaust is much like the exhaust from a car's exhaust pipe---not powerful at all. In this regard, helicopter turboshaft engines are much different than turbojet engines.
Because in a helo the turbines energy is siphoned off and used to power the transmission and so after doing so the leftover air is not sufficient to do so and also it is far too hot to channel down the tail boom
That would require special engines that can handle the increased back pressure. Normally you want the exhaust to have the lowest possible speed, which doesn't produce thrust.
Great bird
Nice and secure method!
Is the MD 902 still built in 2020 ?
جد جميل مروحية أداءها ثابت
This helecopter is my local air ambulance
Same!
London?
@@markmnorcal Yes, this type often operated into Ruskin Park for King’s College Hospital
I kinda like that no tail rotor blades
What is the boom extension for?
Very helpful sir
I would love to fly
What I don't get is where those Coanda slots are. He seemed to say they were inside the boom, so I don't know how that could cause a force against the boom. That would be like being on a sailboat and blowing on the sail to try to make the boat move.
It keeps the flow attached to that side of the boom and raises the speed of the flow, which lowers the air pressure (higher speed lower pressure). Lower air pressure causes a force that torques the boom around the helicopter's center in the direction that the rotors rotate, and also causes a lateral thrust to the helicopter.
Excellent tutorial.
Its a genius idea
Awesome!
How Much??
I really like how it looks without a tailrotor but why do they never make a duoprop helicopter or a helicopter with counter-rotating weights inside?
It would seem that the power expended to produce a lateral anti-torque force near the main body of the machine as opposed to out near the end of the tail boom is very inefficiently utilized...
Will NOTAR helicopter experience LTE
So where is your flight school?
Love this helicopter.
Mesa AZ, at MD Helicopter's factory. (Note: Nick is a fantastic instructor; very personable, and an outstanding pilot.)
This helicopter has lesser sound compared on the Bell 407, Bell 429, UH-1, and UH 60. The lesser noise is ideal for reconnaissance and combining with stealth technology that defeats enemy radar makes it more stealthier.
BOA TARDE AGORA EU TENHO CERTEZA QUE O FUTURO CHEGOU .MUITO ESPETACULAR ESSE NOVO SISTEMA. .GOSTARIA E MUITO DE RECEBER MAIS DETALHES SOBRE ESSA AERONAVE .PARABÉNS
why exhaust fumes are not moved directly to tail always a little more energy
Anyone know the version of what I assume is Clocks by Coldplay in the video?
Pretty cool. This proves my theory that pretty soon we won’t need a main rotor either.
This helicopter reminds me of the helicopter from the movie the 6th day
Nic can belch louder than any human I have ever known
McDonnell/Douglas made the F4 & F15..= Any questions.
50% less noise and just a little more fuel consumption.
Why NOTAR is not much popular???
Very few helicopters use this system.
That's one sexy helicopter.
I am guessing here but snow and ice would make this not do so well? I would say arctic weather is not for this bird?
Why I can’t see anything that would make it more vulnerable to freezing then any other bird
kinda looks like the ec135 with an amputated tail rotor
Out performs the ec 135 by a large margin...
I can see a couple steps a bit further than notar a few years out with NO moving parts, physics are rapidly enhancing reality.
He failed to mention the spoiler running along the oppsitite side to spoil lift from the downwash.
Shit im not the only watching cause the new GTA update
Great machine all that criated per technology Howard HUGHES is fabolous, this project os tô much antique in Hughes develovment, I think did bê to decade 60 It. I seen images very long past about the idea
What about Autorotation ?
+Entoris19 Last I checked you don't need a tail-rotor to accomplish that. In fact, I think I remember something about autorotation being used in response to loss of tail rotor effectiveness
Yes, I edited a 2 year old post.
The tail rotor is always necessary, to control heading. Autorotation emergencies are for when you lose engine power. LTE's are a separate emergency; when you don't have sufficient tail rotor thrust to counteract main rotor (power on) torque, or enough to counteract a rapid (or heavy, or unfavorable wind environment) turning movement (to the right, in an MD helicopter.)
This video was very informative to bad the cameraman was any good
Why are not popular???
MD isn't such a big company like Bell or Airbus etc.
👍
WERE AND HOW I CAN TRAIN ON THAT FLAYING ANGEL
+Rafa FAW Have your license in hand and book yourself a week at MD. You might also want to bring a check for $20,000.00 with you as well.
@@BobABooey. 😂😂😂
Who is here because of the new GTA Online update?
Interesting idea, but their are ways to make a helicopter with no tail rotor that does not use a fan of any kind.
Coaxial or tandem rotors don't need a tail rotor. They main rotors counter act each other. The Notar is a great concept.
Man, sure would be nice to own/pilot something like that...... Whelp, That'll never happen LOL!!!. Instead, I'll stick to my 3D Helis that the Aviation world doesn't want me to have. They are a LOT of fun though and can do a lot of things these things can't. Vs carrying passengers..... Just more practical I don't want to be rich. It's amazing how helicopters fly. Take a 206 Ranger and look at the main shaft. A tiny little pole holding up all that weight and dynamics. Or watch an Align helicopter do a tictok on nothing but a 5mm main shaft. MD500 and how nimble it is on a small mainshaft. Or a Goblin, or Avante, or my fave of all time the Henseleit TDR (who just came out with the TDR2!!). Helicopters are cool :)
I had a dream I was flying in a small helicopter. I have never flown in a small helicopter.
My dad flys AStars
London
Exactly!
I would like mine in dark eggplant please.
NOTAR heli's looks like a amputated heli
It is cool
The worcking is the same at a normal tail rotor helicopter
Waiting for no main rotor invention ...
Notar helis look like amputees
They should make NOTAR cigarettes.
Looks like a complicated solution to a problem that didn't exist.
Now I heard of patents for NOTAR technology, but I think the low acceptance rate of NOTAR is due to its ugly and crude and inelegant look. Of course, it's anti-torque function has moved to inside the tail boom in order to "replace" the function of a tail rotor.
Well, may be some day the designer will improve the "sexy" looks of many NOTAR helicopters.
Gta5
I don't see air slot along tail he talked about, poor camera skills.