Well what you say might be true on "ultra-light" H/C, basically underpowered, but not on "normal" H/C. I have been a H/C pilot in the French Army Aviation for 10 years, then I became an Experimental Test Pilot and, to be honest, regarding the fenestron I didn't see any problem with it. We operated about 300 Gazelles (1/3 SA341 and 2/3 SA342) in the ALAT without any crash due to a mechanical or design issue. The Gazelle was at the end the safest H/C we ever had and none of them ever encountered a LTE. I made my basic training on Alouette II and "combat training" on Gazelle. It was not a big deal, the Gazelle was just easier and more pleasant to fly compared to the Alouette and that's it. Never noticed that there was a "non linearized input" with a fenestron, it was the same. Moreover, we were not warned about any specific limitations or traps in relation with the fenestron. The only "limitation" was that the fenestron requires indeed more power (in hover) than a tail rotor, so that a Gazelle is a little less efficient in mountain flight than an Alouette III for example. Otherwise, no problem. Note that the Dauphin, which is also fitted with a fenestron, is still used by the US Coast Guard (MH65 Dolphin) and they are very happy with it. At cruise speed the fenestron brings even a huge advantage due to the design of the vertical stabilizer: it allows to survive a failure (breaking) of the transmission (Gazelle, EC120, EC130, AS365 Dauphin, EC135). With a conventional tail rotor ... you crash. Note that you can face a LTE with a conventional tail rotor either (R22 or Schweizer300) depending on the wind direction relative to the H/C while on Gazelle we trained to land with tail winds (tactical reasons) without any problem. In other words, depending on the H/C category you are reffering to, the arguments can be inverted. Final point: regarding the rotation direction of the rotor: you are not the first one who refers to "European helicopters". That's wrong. To make it short and simple: seen from above, French and Russian H/C (and only them) turn clockwise and the rest of the world anti-clockwise. Agusta-Westland, which is also European (Italian and British), have their H/C turning anti-clockwise (A109, A129, A139, WG13 Lynx, EH101). Even inside Airbus H/C (originally a merging of Aérospatiale-France with MBB-Germany) the H/C designed in France are turning clockwise (from the Ecureuil to the Super-Puma) while the H/C designed in Germany are turning anti-clockwise (Bö105, EC135, EC145). Regards

We need someone who can lipread...

Airplane guy, not a helicopter pilot ... lots of helicopter crashes caught on video show tail rotor hitting wire, trees, ground strike ... and the conventional tail rotor just breaks off leading to uncontrollable spin and crash. I feel having the Fenestron shrouded and providing significantly better protection to the tail rotor is one of the biggest safety benefits.

I'd prefer a fenestron for safety. A major part of a helicopter accident and crash is due to tail rotor strike. In a fenestron, the fan is protected by the frame around it. However they cannot make it as big as a regular tail rotor so designers have to limit it to 3ft or thereabouts, compared to around 5 to 6 ft for a conventional tail rotor. The difference in area is quite significant. Thus to compensate for loss of authority, the fenestron have to have more blades and spin about 50% faster. But overall a great design.

Why is there music overlay at 5:40 😕

I feel like this channel is turning into a sponsored ad for Hill Helicopters and their as of yet unseen concept. I just hope they aren't taking advantage of your channel to drum up investors to swindle.

Could you do a video on the NOTAR,always wondered how good they are,and there limitation? Thanks enjoy your videos 👍🏻👍🏻

I really love your videos, very informative and entertaining. What are your thoughts on the Notar system?

Love the website .. love the channel .. Maybe you can talk about NOTAR .. Im curious about performance differences. Keep up the good work.

Almost the entire audio of the liberalized ducted fan is missing and replaced with music! Can you fix this?

It might suck on the G2 but having flown and work for many years on the SA341- Gazelle when correctly designed and implemented it can be great !

Some designs are more forgiving than others. I once flew with the Enstrom test pilot in the company's then new F280c. In the hover, he rolled off m/r rpm to 90% but still had t/r authority.

Hey Yellow!!! On the topic of tail rotors, I was wondering if you could make a video about to Delta 3 Hinge.

What happened with the audio from 5:48 to 6:08:( When you are about to explain the difference between the new tail rotor?

Really interested to see how well the HX50 LDF works. So many advantages over traditional tail rotor.

Getting the Pilot Yellow Groove and beat at 5:41 lol...

Fenestrons work just fine, the problem is pilots that transition from standard tail rotor helicopters without adequate training or knowledge. Eurocopter put out a paper on this that is very well explained. The TLDR is that they are rigged differently in EC products ( now airbus ) so that more pedal throw is used to get the same amount of thrust. It feels weird at first, like going from power steering to manual, but not precisely that. Once adapted to it you will find that you have a finer control feel and can keep the helicopter more accurately trimmed/pointed at all times. I've flown the EC120, 130, and 135 for decades and never had a problem, hot and high or sea level, even parking 130s with some regularity with strong tail winds. I'd wager a round of drinks that if you total up accidents at ANY regulatory authority around the world that have been attributed to LTE or the like, that the majority of these will be in standard tail rotor helicopters and not fenestron aircraft. This may be related to the much higher speed, blade count, and thus much lower angles of attack of the fenestron. Much harder to stall. Also probably to many early Bell and a few MD helicopters that had tail rotors too small for the MGTOW of the aircraft. If you're heavily overpitched and the rotor systems are decaying, well, you're going to have a bad day regardless.

Hey ! What do you think about no tail rotor at all? Like in a MD520N NO TAR. Can you please make a video on that one?

Im thinking its ok! Its power band is high where as a tailrotor can fly at slower speeds depending on a low power situation as the fenestron requires full power band which works great on like a EC 155 which manages itself efficiently.

Sounds like Fenestrons would really benefit from going electric. Besides a CG change, the weight difference between driveshaft to gearbox and wire to motor The battery increase shouldn’t add much weight. You wouldn’t need more than a minute or two of augmented power from the battery. So Generator size/weight shouldn’t be that much bigger.

The picture quality of your videos is the best I have seen.

Great video,thanks

I prefer a fenestron. Two different, methods of flying. With a conventional tail rotor you can make power changes and then apply pedal. A fenestron, slightly different. You have to anticipate pedal needed when using the collective and get the pedal moving early. Example, people criticise an EC120 for lacking power. At sea level anyway can make a steep approach, fully loaded, flare and as you get to raising the lever your right foot is ahead of you and already putting power to the tail. Fly it like a conventional tail rotor and react to power changes second, you will spike it, possibly run out of power and have an accident.

Love the safety feature of the fenestron in regards to visibility. As someone new to helicopters, infrequently flying HEMS missions, the big disc around the blades on the H135 and H145 is always clearly visible. If they could do the same for the main rotor system, I’d feel safer in regards to entering the disc with it running ;). Don’t think I’ll ever get used to moving in and out under the disc with engines running! 🙈😰

Good point , thx for explaining ,,why isnt fun ? Im so used to lose my head with TR ,,however I just fit it back in place like Terminator

That was a very well explained video as all of your videos are so basically a regular tail rotor is like driving a Corvette and a Fanta Strachan tell rotor is like driving a 63 impala was sloppy ball joints he just have to get used to oversteer and very cool explanation no and I’m looking forward to booking to an introductory flight with you guys as I live in Abbotsford and see you flying all the time have a great day

Hi~! Nice to meet you and i saw impressed your videos~! And I have a question Why fenestron tail rotor system have fixed rotor?? I know fenestron tail copters tail pitch rotor can make yawing But why have cant move and fixed rotor additional??

I’m thinking of electric tail rotors, like Bell’s EDAT (Electrically Distributed Ant-Torque). Could this significantly reduce the problems you have outlined?

So I don’t fly helicopters but would it not be possible to have a seperate motor maybe electric for the tail. Would this not then remove LTE?

Just curious. Do you believe that this fenestron issue really only affects the smaller trainers, or is it also an issue on the larger helecopters such as an EC-135, 145, and the Dauphins? Fyi, I always wanted to fly helos ever since I was a child, I'm 50 now, at 45 I started my training on an R22, with 53 separate flights, 22 hours, 3 solos, and ran out of money. I plan on getting back into it once I retire and your videos have been great to watch to keep somewhat fresh and into it. Thanks.

Conventional, Fenestron, or NOTAR which one do you prefer?

That extra input was a bit disconcerting when I first flew the EC 120.

You are a very good teacher.

Great video - Personally I'm a great fan (pardon the pun) of the Comanche off-set fenestron to reduce the rotor noise and give 'some' extra protection. The Comanche - like the F-35, was probably a bit too far ahead of its' time but there is way too much invested in the F-35 for it to fail now and tbh it's pretty damn effective. The Comanche would have been a game changer - sneaking in low & fairly quiet and able to pass real time target locations to other assets. It was a mistake to cancel it but Boeing had a lot of feature updates to contend with. The Army should have accepted a basic model & upgraded it as technology progressed. Personally I think that now either stealth tilt rotors or push-dual rotors are the way ahead - but I think the Comanche was a real missed opperitunity! It just needed more oversight!

What do you think of that 4 electric tail rotor system that Bell is developing?

Hey another question, i find an RC heli takes more power to hover than fly forward at reasonable speed, i believe the turbulace of propwash causing a well the heli is fighting, not a problem moving forward in clean air?

So all the pluses (harder to hit the tail on something, tail strikes, chop head off) are avoided just like you said "if your a good pilot" lol.

Since talking about this subject, is there a downside to the NOTAR system?

Why the music towards the end? I would have liked what you had to say about the ducted fan. Be safe.

Almost spilled the beans there 🤣🤣

"LTE" is due because there is a flow of wind blowing in the direction of & into the tail rotor, therefore resulting in its ability to do its job effectively to compinsate for the torque of the main rotor

I've been a helicopter AME for 30+ years. The best and safest fenestron or tail rotor is NO FENESTRON OR TAIL ROTOR. I'm sold on coaxel main rotor systems or tandem main rotors. Bee safe everyone.

very well explained

What happened at 5:41 ? Then suddenly at 6:07 "So the reason that's so important..." 😂

Very cool, what’s your take on the NOTAR helicopters that use either bypass from the engine or pressure instead of a tail rotor

Is this why no fenestron on heavy/cargo helicopters?

Since i only have experience flying RC helis, can u do a video on flying RC difficulty level and the increadible stunts done by pro RC pilots

I miss just the flying videos with the students!!

hi mischa....why does the R66 seem to have a 30 degree angle on the tail boom?

The controller at Essendon (in Australia) called me a gumball the other day in the G2 😂😂

Interesting detail, thank you for explaining! I always thought fenestron is superior just because it looks better and more modern while the common tail rotor design is a more conventional and old and therefore maybe outdated, but looks can mislead and it´s vice versa.

Very informative video. Just out of curiosity why the name "pilot Yellow" is Yellow your name?

first question. Why is the fenestron non linear for pedal inputs? second question, are you talking about modifying the conada effect used in the MD Series helicopters?

Just a thought ,why aren't tail rotors painted in high visibility or fluorescent colours for greater safety?

Why isnt the relationship between pedal input and tail rotor thrust in fenestrons not linear? Isnt there a direct relationship between pedal inout and angle of attack / lift of the fenestron blades?

I did most of my private/instrument/commercial in the Cabri and I agree that the Fenestron is a non-issue as long as you're prepared to move your feet far enough to produce sufficient anti-torque thrust. Coming from fixed-wing aircraft it's not really a big deal, in fact it's just about the same amount control movement as landing a taildragger in a crosswind. I am curious, however, about the statement that a Fenestron loses thrust more quickly with decreasing RPM, due to its higher gear ratio compared to a traditional tail rotor. I heard this same factoid in my training and dutifully nodded my head, but from a physics standpoint it's never made sense to me. Can anyone walk me through an explanation for why this would be?

Hi, why did you play music over where you were explaining the Hill HX50 tail rotor. It is top secret still?

So it hasn't got enough bite under extreme circumstances.

How can auto rotation work with the drag of a dead or damaged engine?

i wanted to know about the linierized ducted fan why did you put music over it?

A fensetron allows the tail rotor to be equipped with fixed stator blades. The stator blades will cancel out rotational turbulence from the main rotor and prevent loss of tail rotor effectiveness. For even more lateral stability use a stack of multiple tail rotors and stators, essentially forming an open frame compressor turbine. Though alas the rotor and stator blades closely sweeping past each other will generate lots of noise.

My experience has been just about the opposite of what is presented in this video with regard to the helicopters I have flown. I flew three versions of the 206 LongRanger, one with the standard bell TR blades, one with the Van Horn blades and one with the Bell high altitude blades (basically a 407 TR) and only the original 206 blades were linear. The Van Horn would generate more thrust off of neutral making it more "responsive" initially then drop off with additional pedal application. It was much easier to overtorque with the Van Horn. As for the Fenestron, the Airbus EC135 and H145D3 version (can't speak for others like the skinny one in the video) is really excellent with plenty of authority in all conditions I have flown in with it. It has a few small quirks such as lip stall that makes for a wiggly situation but control is always maintained. The other advantage to the fenestron is a failure (broken off at the root) of a blade crates a vibration but the aircraft still flies with no catastrophic failure. I was skeptical about flying a Airbus Fenestron but quickly became a fan of the design.

It's a shame the main rotor system in the G2 is so low. The added safety of the fenestron is diminished by such a low hanging main rotor.

You need to do a video on Notar's.

I used to get low and look up if i got at on tail rotor side as the heli took off.it would be prolly be quick.lol

They look like helicopters designed by Dyson, the vacuum cleaner people.

Hi! Why did you cut out some of the words and put music? Did you say something wrong? I like your channel, thank you for being there! I'm from Russia and really want to learn how to fly a helicopter) P.S. Sorry for the English if I wrote something wrong)

What about NOTAR??

Some music started playing, I could'nt understand, what you were saying in the video. What???

Thirty-eight years fast jet and helicopter including Gazelle. I agree heartily with the comment below. Not only is the safety factor of supreme importance but the Fin surrounding the tail rotor is of a lifting section, thus relieving the power requires by the anti-torque penalty in forward flight. The t/rotor drain drain being much reduced. Further more due to the higher RPM of the Fenestron, the torque on the T/rotor drive shaft and gearboxes is lighter and so in less stress compared with the conventional drives. Also, in forward flight the Fenestron rotor is working in relatively less disturbed air and requires no flapping hinges. The conventional tail rotor is flapping back in forward flight and it's thrust vector is consequently tilted aft. The loss of authority outlined in this article is, in my experience, the result of cavalier, cowboy handling. It is true that a bootful of rudder initiating a hover turn will cause overtorqueing and possible loss of t/r authority but flown sensitively the Fenestron is to be recommended. Having flown five different types in my time, the Gazelle was indeed the prince of helicopters and a delight to fly in all aspects of rotary operation..

How about the NOTAR from Bell Helicopter?

What's with the beatbox at 5:44? Or is the ducted tail rotor system secret?

What do you mean by Authority in relation to what you were talking about?

why is there a song drowning out your words ? time stamp 5:42 to 6:09

what on earth happened at 5:41? I really want to hear what you've got to say, but the audio is replaced with music!

Linear ducted fan. Cut to the music 🎶🎵🎶. What was that?

Its sound like it might be pilot error to "overpitch" Perhaps flying outside of the design characteristic?

What happened to NOTAR?

I totally agree that getting my head lopped off by a tail rotor would be "no fun at all." 😇

He mentions a change to Jason's design, then starts to talk about it. That is when the music starts, so it seemed to me Mischa was trying to cover up proprietary information he might be going over. Maybe to be funny, instead of deleting it?

Fascinating; though the random music cutting out the ducted fan explanation was. Jarring. And not great? Would have preferred to hear that,but...

What about the notar system

What about NOTAR helicopters?

VERY INTERESTING!!! You're the second person I've heard said "Fenestrons Suck." Based on what you're saying, the fenestron appears to have an exponential response. Personally I believe the design is a good concept, it just was not implemented properly. The fenestron is obviously overdue for a design upgrade. That 1:10 main to tail rotor ratio is too much.

Your discussion about the ducted fan got overdubbed by a techno dance song?

Why don’t you use the benefits of the the two and do a ducted version of a normal tail rotor or something? Have an air inlet scoop that directs the air to the rotor more efficiently etc... Edit: I wrote this before the end.

Interesting interlude

As always your explanations are very interesting and very clear. thank you. Can you explain us why modern helicopters don't use the stabilization bar any more.

Why did you put music over the bit that Jason said? That was disappointing?

If it has a Fenestron tail rotor it does not look like a Helicopter - it looks like a machine with spinny things on top and in the rear. Notice: I am talking about appearance and nothing else. Not talking about safety, reliability, technology... apearance only.

Do a vid on tail rotors fatality

what happen to 5:42 suddenly change to music

How about NOTAR?

Thank you very much Misha for detailing the HX-50 tail rotor design!

Okay...I think you sold me. Now I have some investment goals to track so I can get a Hill helo...thanks...wife will not like you now, but I'll get over it. :-)

Isn't it trivial to linearize a control system in 2021? Why is this not something one cam or lookup table could do?

Because no one can figure out that the vaporware peddlers have yet to patent some sort of cam-profile so their design feels linear...🙄 Yup, thats a trade secret.

Did you cut out what you were saying so as not to give away trade secrets?

Why did you overdub the technical explanation? Were you wrong?

What's happening with the music at 5.41?