WHY MORE BLADES ARE SAFER 

Mast bumping is such mild word for a catastrophic event that slices the tail boom clean off then usually dismembers or decapitates the pilot.

Been flying commercially on helicopters for over 30 years. Love your passion and instruction brother. Fly safe. 👍🇿🇦

I have personally witnessed virtually EVERY LOH (OH6 Cayuse - multi-blade articulated rotor system) chop off its tail boom during autorotation flare/landing (two tours, Vietnam). Yes, underslung two-bladed systems can suffer mast bumping and sheer off - I've witnessed that as well - TWICE. ONE: When one of our Assault Helicopter Company UH-1H Pilots took off with a full load of Pax, cranked up to full speed (about 120K) across the Mekong Delta River - then did a cyclic climb. At the top, he committed the fatal error of pushing the cyclic forward to achieve level flight while simultaneously lowering the collective. That sheered off the rotor system with a nose dive straight down into the water. Wasn't bad enough he killed himself, he took three other crew members and eight servicemember Pax along for the eternity ride with his terminal stupidity. We never recovered the helo or any bodies. We had to go back to where they climbed aboard and work our way back to each command to find out WHO was on that helo. SECOND: An AH-1G Cobra pushed to high speed in his gun run firing everything he had. At the end, he too pulled up into an impressive cyclic climb with the same application of cyclic leveling and collective down as before. His gunship nosed over like a wounded badminton bird and zoomed straight down to meet the angels. How did I know this. I was monitoring our Guard Frequency and heard one voice shout, "This is it!" and another voice (the other gunner) screaming - for all of two seconds before silence reigned. His wingman answered my hail and described the entire event to me. I could go on all day with this - I wrote a book about it. Yes, accidents and SH*T happens - LISTEN to your IPs in school - LEARN proper safety procedures - PRACTICE safe and FULL recovery - and DON'T BE STUPID - that damned machine will end you in a heartbeat if you turn off your brain. John (two tours Vietnam, 1,955 Combat flight hours/helicopters).

So what you're saying is that my single blade helicopter design is just going to be just terrible?!?

Most 2 blade rotors are high inertia rotors; meaning if the engine quits you have more time to react before you lose rotor rpm. Three and four blade rotors are generally low inertia, bleeding off speed rapIdly when you lose power. I have done autos in both a Bell 206 (TH57) and a Bell 406 (OH58D), you have a little more time in the 206 to get the collective down and maintain rotor rpm vs its 4 bladed cousin.

There were lots of helicopters around my old home base (Langley). You knew when there was a Huey around. :-)

Thank you for the very thorough explanation that non pilots can understand, great channel !

Less blade, fewer points of failure but higher stress and loading. More blades, more possible points of failure as more moving parts but they are under less stress and load :)

Hands down best moment of the video was you saying "Wop wop wop wop" 🤣🤣🤣(all with love brother (from CALI))

You are the best Instructor very clear and concise instruction straight to the poit.

Very informative. I'm not too familiar with helicopters (I'm more on aeroplanes) but, as a aviation enthusiast, being told by someone who works with/pilots rotor crafts is such a treat! Thanks

I'm learning soooo much from you...truly grateful for the information you share. Thank you.

thank you very helpful you rock Mischa!!

I really enjoy your videos. Your presentations and positions are informative. I enjoy your teaching style!

Forgot the dampers, ground resenence, landing gear struts, droop stop pounding. - Extra blade adds drag in autorotation makes for a short steep 'glide' less places to land in a hostile area. - Look between your toes instead of out the windshield

I really enjoy your videos. Your around the world trip was wonderful.

Another great "con" against fully articulated multi-blade heads is Ground Resonance. Usually with the smaller birds and can be catastrophic. This doesn't happen with teetering heads.

Your videos are amazing! I love people who know what they're talking about and who know how to convey it visually. Very effective learning method:-)

Great explanations

Good Explanation,The flapping sound of two blades is very distinctive

On two blade helicopter the forces to roll the helicopter vary dramatically from when the blade is fore and aft position (low) to the port starboard position (maximum). For similar reasons wind turbines have standardized on the three blade design to reduce cyclic jaw forces.

Thank you for the video, great explanation. More of these informational take videos would be awesome. Thanks!

Thanks for this! Glad to thumbs up. As a humble request - having a photo pop up of the various helos you’re talking about would be awesome :)

Again, another great shot of information from my favorite helicopter personality. Thanks again

Thanks for the informative videos! 🤙🏼

Hi Mischa, love your videos! Thanks! I have a doubt, why there are not 2 blade rigid rotor systems?

Excellent tutorial. Please keep them coming

The storage issue at times is a vital point. True that building a separate shed probably cost less than a blade replacement, but space can be an issue and the folding kit would be, as a manufacturer, my top priority. I went to a school that only could “afford” space for a two bladed but preferred the three blades option If they knew where to park her

Great video. Keep them coming.

Love your content from here in Ireland Pilot yellow! Never even been in a helicopter but they’re so interesting. Your videos are really informative and interesting. Why the heck would anyone want to “hate on you” in the comments 🤷‍♂️ Keep up the great work and fly safe.

I'm an airplane guy but your videos are the best If I were learning I would be looking for you. Had a chance to fly helicopters in the Army but I was afraid of the night vision requirements in the early '80s

This is awesome. You're the man.

Mischa, in an earlier video you briefly mentioned the Enstrom brand helicopter and I believe there was something about either the company or helicopter itself that you did not like. Would you mind elaborating on that (Enstrom does use a 3 blade system). Thank you.

Very interesting and well explained! Would be awesome to see pictures of the models you mention while you talk bout them, that's much more video editting work however... Thank you!

I’ve ridden in a Bell Jet Ranger and a Schweitzer S269C. The Bell had two rotors and the Schweitzer had three. The Bell vibrated baby when turning to the left, (if I remember correctly), but the Schweitzer was smooth when turn either way. The Schweitzer was a fun little help to ride in. The pilot had a blast flying my brother and I around, chasing cattle that were grazing a few hundred yards from the airport, but when he tried to set it on the peak of the hanger roof he let off the throttle a little too much and it almost fell into the hanger. I don’t advise trying that!

Thanks for a great video

Thank you for teaching in simple English

I don’t fly helicopters but I’ve been around the EC135’s quite a bit with the air part of the ambulance company I work for! Interesting info thanks

Thank you for this explanation video, I had wondered about why designers went with the different rotor configurations. I have always loved the Hughes/MD/Boeing 367/ 500. Always loved the buzz it made as opposed to the Bell rotor slap. I loved the Hughes 500 AKA civilian model 367 from first time I saw one, and my admiration for it's designers have never faded. Thank you for your videos, one can always learn something if one has an open mind.

So good. Thanks.

Thanks I always like to learn

Love the song at the end

Excellent Explanation good service and information with education type

Well explained 👌🏻

With more blades, i.e. 5 blade, can you reduce the length of the blades vs. 2 blades? Does either rotate slower. Is there a simple trade off on drag vs lift on number of blades to consider?

Good brief. Thanks.

That was very informative, thank you. Greetings from Australia 🇦🇺

good review of multi rotor benefits. well done. DG

I've balanced 2 blade helicopters down to 0.05ips. The out of balance/out of track shakes have all been 1/rev vibrations. The same ship had a relatively low 2/rev with full tanks. However when the fuel level got down around 1/2 tank the 2/rev was noticeable. I've been told that 3 bladed helicopters do not have the 2/rev but instead have a 3/rev. Higher frequency can induce shorter fatigue lives?

No hate here! Thanks! Great info and subject.

Pilot Yellow, I have flown both two and three bladed systems. The three bladed system did seem smoother and more stable to me, but from a money point of view I guess the two bladed system is more practical. Anyway, thank you for your interesting topics and great videos. Stay safe and I hope you can fly soon.

Hey Mischa, very informative video. By the way, we'll never hate on you. 😁

I went from a 2 blade to a 4 blade mod. Now no one complains when I land at night. Watch out for loss of tail rotor authority though. I needed to install 18% more tail rotor thrust.

Hi, so just a question.. whats the reason for most people using the Huey for fire fighting then? I was under the impression that a Huey created more lift due to the large blade area from leading to trailing edge?

Learnt a lot !

A good breakdown but I believe you over stressed mast bumping and down played ground resonance, also the notion that with more moving parts there is that many more things to go wrong

I really would appreciate an video of you, talking / discussing with a experienced MD 500, MD-Explorer & especially with a lot of hours on the NOTAR Technology-Helicopters. Hearing about comparing a lot of topics like this here or stability, aerodynamic , etc., etc, ... This would be so interesting!. With kindest regards from Germany ✌🏼

I love this channel man I've always loved helicopters and I've always wanted to fly one I've come to realize I'm a poor mother hucker and I'm never going to be able to afford that never but at least I got a channel I can come to and learn all about them and fly ride along with you when you go thanks for that bro thank you very much keep up the good work 👍🙄🇱🇷🇱🇷🇱🇷🇱🇷🇱🇷

Thank you sir

Would like some technical study and information on Blade folding and what G.A. types are available and cost...?

Hello, Just Curious, is autorotation more efficient/safer with more blades? I have never flown a helicopter, but wish to in the future. Really enjoy your videos! Thanks

Can you talk about what "fully articulated"is all about. Also, what has changed in rotor system design from the Enstrom 3 bladed system to a more modern system like on the Cabri?

Mischa, great content, you should have mentioned MI-26 with 8 bladed rotor system.

I really enjoy this series. What is the typical lifespan of a set blades?

Love the Bell 2 blade thong slap ;)

Another very well presented video on some very interesting rotocraft related stuff.....very well explained too. Why anyone would want to make indignant comments towards your opinions about the various rotor systems and your thoughts for future progress in that area, is beyond me. Your videos are EXTREMELY informative. I always look forward to each one!

"3 bladed rotor system always has a blade in each QUADrant" ......... spot on bud.... spot on. glad the next generation of pilots are being trained by you. . . . .

whar is going on with the military ka50 where there are opposite direction spinning blades ?

So does this mean when you have a helicopter in whisper mode so it is making no sound from the blade is that because of having more blades?

Ok, you talk about Mass Bumping on a two bladed system but you did not mention Ground Resonance on a fully articulated system? I'm a bell guy and I like my 2 Blades, nice auto's and the Heli does not disintegrate on the pad from an unbalanced rotor system.

The greatest benefit of a 2-bladed helicopter is, it is MUCH better than a single bladed helicopter. 😁 But, in all seriousness ... great vid Mischa. Thanks for the info.👍🍻

Greetings from Chile , what about ground resonance ?

Just discovered your channel. Excellent! A question: 50 years ago, rearming my “C” model Huey on the tarmac in Dong Tam, South Vietnam, an Air Cav Cobra shut down nearby. First one this Huey gunship driver had ever seen up close. After suppressing my envy, noticed the Cobra’s 2-bladed system was completely void of the fly bar (or “stabilizer bar”) with all the accompanying parts & bits seen on my rotor head. From my vantage point, all I saw were 2 pushrods going directly from the swash plate to pitch change links on each blade. How does this “new” (back in ‘69) system work?

👍 like motorcycle cc's any number is fine as long as it flies and does what I want!

Went from zero knowledge on "why" to a point of understanding. Thanks!

definitely stability. a two blade sysyem gives you that "rocking horse' hover that you have to compensate for. Three blade is rock solid, touch the skid down on a dime

Do you foresee Cabri offering a folding package for the G2 just to make it more convenient for tight storage in a more narrow hanger?

Loved your simple explanation. However you didn't mention ground resonance of multi-bladed rotors.

Can we redesign the R22 blades to fully articulated but still maintain 2 blades But no mask bumping issue?

Crikey, I was not aware that rotor blades were so expensive! Thanks so much for a great video.

What do you think about notar copters?

No mention of ground resonance with the fully articulated system. How come?

Very interesting 👌

Thanks for this information. This answered many questions. Are you the ceo of bc helicopters?

Hi just a question is a two bladed rotor safer or easier to autorotate since the blades have more mass and might fly a bit more distance and last longer in the air? Thanks

Things I learned during this video: pilots are horrible engineers (but not the other way around). 2 blade helicopters have less rotor wash interference and are actually more efficient. The main reason for adding more rotors is because 1: You can only make them so long 2: Extra blades to absorb extra power 3: less vibration. That’s pretty much it.

U.S. NAVY have a two engines and four blades UH -1 helicopters. Originaly they had one engine and two blades, they made a big improvement on those helicopters.

@Misca thank you so much for the invitation to hate! I wish more Tubers offered that up to viewers! Have you flown 4 blade helicopters and if you could do it over again would you learn on a 4 blade system instead of the squirrelly Robinson platform.

Hello, When you mention that the root of the blades can strike the Tower of the heli is it also a boom strike or is that different? In another video can you explain a RIGID HEAD such as on the BO105 that allows it to do aerobatics without the fear of a boom strike.

Great info and great video. Idea for a new video if you take them. How climates affect the lift. Example: High altitude mountain and cold air compared to sea level and dense humid hot air. Also answer climate questions like: is lighter better for higher altitude; do blades matter in the climate; and does the rotor rmp matter?

I like bell 430. But i heard that its bad helicopter to fly... Is that true? Can you explain that in any other video?

But i like to hear two bladed helicopter's noise it gives me a kind of joy

Are helicopters safer then airplains? I'm a truck driver that's invested. I've though about learning to fly and in curious

top marks bro

I have a 6 rotor. It's great.

Will Hill HC50 come with blade folding kit ?

From my time in the Navy, I assumed all helicopters had folding blades. I guess you learn something new all the time.

Great channel ive subscribed I no longer fly full size helicopters anymore its a life style change.. but I fly my huge rc 105 helicopter I guess we never leave them ..

is it possible to design a rigid 2 blade system ?

There is no "better" about either designs, its just different. 1- Strictly from lift perspective, 2-bladed systems are not inherently worse performers, they just need larger disk area to perform as good.. If physical dimensions are not the issue, 2-blade designs are actually the most aerodynamically efficient, followed closely by 3, and adding more blades subtact from efficiency. This is why there are 2 and 3-blade wind turbines, but we don't really see a 5-6-10-20 bladed wind turbines. Because so long as they are safely away from the ground, there isn't any dimensional contraints and its always better to have longer blades and have a larger disk area, than to add more blades. 2- Closely related to #1, storage advantage goes both ways.. A 2-bladed helicopter of same weight will have greater rotor diameter to retain aerodynamic efficiency. Since tail length is also proportional to rotor diameter, a 2-bladed helicopter of same weight will inherently be longer. A folding multi-blade helicopter will be comperable in width, but smaller in length to a folding 2-blade helicopter. 3- 2-blade will have unique mast bump risk, 3-blade will have ground resonance. Mast bump is pilot-induced 99% of the time, ground resonance is both pilot induced and maintenance-related. 4- A 3 blade rotor will be easier on the pilot and more stable to fly, 2 blade will be much more responsive to controls. 5- Misalignment on 2 blade is easier to notice, but that "advantage" argument goes both ways.. Is it not better to notice a problem early without symptoms getting worse? For example, if one blade has damper issues and drags just a little bit more, its not really noticable with minimal cyclic inputs, like when hovering, but it can have lethal consequences. 6- Misalignment on 2 blades is more noticable, but misalignment plane is (mostly) on a single axis on semi-rigid rotors, so easier to diagnose. On a fully-articulated system there are 3 misalignment planes. 7- Adding more rotor blades to SOME designs work, because they are done so with other constraints. Some are specifically designed for a certain rotor diameter, or started with a puny engine and upgraded along the way to a much stronger engines. Both points apply to AH-1G to AH-1J to AH-1W to AH-1Z evolution: AH-1G with 2-blade (