I am currently attempting to drop a flight packet. Apart from the military making everything harder, THANK YOU for making conceptualizing rotary aviation so effortless and easy. You have been so helpful, Mr. Jacob. Please continue to create and coach (also looking for a mentor if anyone is in the Bragg area, just FYSA).
Hey Jake, good job on all your videos. I am an old Army "Huey" pilot working on my civilian CFI license, (after 33ysr of no flying) and these videos have been very helpful. Keep up the good work and thanks. Good luck in your career
Again Jacob, another excellent video. I appreciate the way you breakdown the principles of helicopter aerodynamics into understandable blocks of information. Keep up the good work-looking for more video from you. Again BZ!
Your videos make everything so much easier!!!! We need more helicopter instructors and pilots on UA-cam. Once I get my cfi I plan on doing like you plus more. Thanks for all your help!
Dude, thank you! These videos are amazing. I'm currently working on my private pilot certification while I am preparing to cross-service train into WOFT and these videos have helped immensely.
Thank you so much for the easy-to-understand explanation. I have a request. Please tell us about aerodynamics of a tandem rotor type helicopter like CH-47.
Great content I have a question though. Aren't we compensating for dissymmetry of lift by blade flapping. Then why are we again taking it to consideration?
Blade flapping helps compensate but depending on airframe, you may still have to still compensate as a pilot. Blades and rotor systems can only flap so much until they reach a limit.
I knew of transitional (translational?)lift but did know know what it was or why. I remember learning left turning tendency, torque, p factor, gyroscopic procession, and other things similar only it was about the prop out front on fixed wing aircraft. Thank you and be safe
Hi Jacob. I really appreciate you for taking the time to produce this content. You are enabling me to learn all I can prior to Flight Training, which, in my civilian world is almost cost prohibitive. So I plan to learn everything possible in advance of going to the airport. Could you make a video for: "Aerodynamics of a (standard approach) Landing" ? I know it would be the reverse but, it would still be helpful. And, could you include the necessary changes required
As an engineer, not a helicopter pilot, I had imagined the rotors would increase angle of attack when moving downwind and reduce AoA moving upwind to balance lift in forward flight. Does that happen? Maybe when trimming for balanced controls once at steady speed?
@@helicopterlessonsin10minut10 ... thanks for taking your time to reply. I'm not a pilot but I find the helicopter physics endlessly fascinating. I have gone through a lot of your videos, very interssting! Well, I'm flying X-Plane helicopters...lol
awesome videos, all of them. but I think the rotor disk diagram on the right about ETL and DL together may be wrong?? It reads from LT - RT. ++. ++ SHOULD IT NOT BE +- ++. OR I B WRONG????? +- +- +- ++
Lucky Hoerner. The final diagram combines ETL, DL, and finally Gyroscopic Precession. The diagram in your comment doesn't include the 90 degree rotation in forces as a result of Gyroscopic Precession. Thanks for the question. I hope this helps.
Am I correct in assuming angle of incidence is the same as pitch angle? Since you change the angle of incidence by adjusting the collective "pitch", and they seem to have the same definition everywhere, angle between the chord line and the longitudinal line.
Are there any books I can buy to study to be a pilot?...My plans are to join the army in a year, I have the asvab book to study but I would also like to try to get some what ahead before I get into the Army.
Tracy Wilson. During landing the process is reversed. As the helicopter decelerates less than ETL and gets into the transition phase, the pitching up continues (due to Dissymmetry of Lift) but the right roll is introduced (due to Transverse Flow). As the helicopter comes to a stationary hover and loses all airspeed, the rotor is less efficient and more power is required.
Hello, I am using "DCS AH64 Apache" flight combat simulator. When I perform a vertical take off to hover (with 0 knots speed horizontaly), my heli moves turning to the right (thats is normal) an I counter with left pedal, but I have a roll left movemet (heli drifs to the right) so I have to put left ciclyc. I do not undestand it, because I am not moving forward in the transition phase. What is happening? Thanks.
12345fowler. Yes the vortices are affected by the ground effect. If you hover outside of ground effect the vortices are more pronounced than in ground effect.
So in going from a hover into forward flight you actually at times have dissymmetry of lift on the right and then the left side of the rotor disk? I imagine the reverse is true while landing.
Ken Quesenberry. You have Dissymmetry of Lift anytime there is any airflow across the rotor disk. That can be from movement (in any direction) or wind velocities. The difference in lift is relative to the speed of the airflow. In all cases, the advancing blade generates more lift than retreating blade. For more clarification, check out my Dissymmetry of Lift and Compensation for Dissymmetry of Lift videos in this video description. Thanks for the feedback!
I understand that there is always dissymmetry of lift, but it's compensated for through down flapping of the retreating blade and up flapping of the advancing blade. I would have thought that on a helicopter with a counter clockwise rotating rotor that the roll would be to the left along with a slight shutter during transverse flow while the blades are trying to figure out if they're at a hover or in ETL. I didn't take into account gyroscopic progression(Procession) acting on the component of lift, or the greater component of lift in this case. Does that make sense? I've got about 715 hours in simulations, and I've never noticed what you're describing; is that because the reaction is so slight it's difficult to notice or do I need a better simm? I notice the counter torque effects on lift off and the pitch up of the nose going into ETL, which tends to remain as long as I'm in ETL such that forward pressure on the cyclic must be maintained to keep the helicopter from going nose up; however, I don't think I'm getting any roll to the right at any point, if any roll is present it's a roll to the left during forward flight.
Ken Quesenberry. You're correct in that blade flapping helps offset some of Dissymmetry of Lift. But cyclic feathering is also required which is why you need to maintain forward cyclic inputs. I understand your thought on a left roll and I've heard that before. But logically speaking, the only way to have a left roll would be more lift on the right side of the rotor disk. For this effect to manifest here, the input would have to take place at the aft portion of the disk due to Gyroscopic Precession. This just isn't so. The aft portion of the disk is less efficient and creates less Lift due to more induced flow when compared to the front half of that disk. To address your last point, I'm not sure what type of simulator you use. But most people notice Transverse Flow the most as a drifting right of centerline when taking off and landing between 10-20 knots airspeed. Its even more pronounced in wheeled Helicopters during a rolling takeoff. I hope this helped clear things up.
Thanks for the input. Yes I do notice some drift to the right and a bit rearward, but always chalked it up to the wind. Actually what I described is what happens while lifting off into a hover, and is actually translating tendency caused by the tail rotor pushing the helicopter sideways. Anyway neither one seems to be much of a problem, so I'm good.
Not understanding why you would not have same lift on all blades at all same time no matter where they are rotating. Everything is moving at same speed as everything is attached at same places and sane size??
That’s the thing. Everything isn’t moving at the same speed. The advancing side of the the rotor gets more airflow than the retreating side. The front have has cleaner, flatter air than the back half which is more vertical. All of this affects 90 degrees off axis because of gyroscopic precession / phase lag. Check out my Dissymmetry of Lift, Transverse Flow, and Gyroscopic Precession videos for how each one affects the rotor differently.
Abhishek Harihar. Cyclic refers to the cyclic pitch control that tilts the main rotor disc by changing the pitch angle of the rotor blades in their cycle of rotation. The control is mounted in between the pilots knees and can pivot in all directions.
Where can I find the other lessons? I stopped watching this one as soon as you said I should watch the others first. I clicked the link above @t but that didn't give me the lessons, just "FARCE book".
Mike Owens. All of the links are in the description below the video. Also, the playlist titled “All videos in Order” should make it so everything is covered in the correct sequence.
You’re such a legend in explaining every concept so clearly and easier to understand
I am a retired US Army helicopter IP and I like your videos. Good Job!
I am currently attempting to drop a flight packet. Apart from the military making everything harder, THANK YOU for making conceptualizing rotary aviation so effortless and easy. You have been so helpful, Mr. Jacob. Please continue to create and coach (also looking for a mentor if anyone is in the Bragg area, just FYSA).
Cyclic & Collective, DCS or X-Plane and Flybarred RC helicopters will feed your brain and you will see these tendencies in action. Great video.
Very good. When I did my training, I was told in transition to expect rotor "flap-back" and "inflow roll". However, you explain why! Thanks. 🙂
Studying for the ARMY SIFT and trying to get into the WOFT program love the videos they are helping me more than anything
Hey Jake, good job on all your videos. I am an old Army "Huey" pilot working on my civilian CFI license, (after 33ysr of no flying) and these videos have been very helpful. Keep up the good work and thanks. Good luck in your career
Checkout Helicopter Online Ground School.
These videos are fantastic. So much easier to understand than my text book's description.
Perfect clarity among all YT instructional vids (haven't seen all, from what I've seen).
Thanks
As usual very clear, well explained and understandable. My hat off to you sir.
Again Jacob, another excellent video. I appreciate the way you breakdown the principles of helicopter aerodynamics into understandable blocks of information. Keep up the good work-looking for more video from you. Again BZ!
Your videos make everything so much easier!!!! We need more helicopter instructors and pilots on UA-cam. Once I get my cfi I plan on doing like you plus more. Thanks for all your help!
As always, fantastic job! I have NEVER seen this explained this way, I want to show this and the other couple ways now. Thank you!
Thanks man for the simple however wonderful videos.
From India with love.
Excellent descriptions. Thanks for posting.
Dude, thank you! These videos are amazing. I'm currently working on my private pilot certification while I am preparing to cross-service train into WOFT and these videos have helped immensely.
Thunder Domb. Glad you enjoy them so much. Best of luck to you!
Thus when hovering (IGE and OGE) with ground speed of zero, but with 16 knot headwind, the helicopter is in ETL regime.
Thank you so much for the easy-to-understand explanation. I have a request. Please tell us about aerodynamics of a tandem rotor type helicopter like CH-47.
Thanks for the video, clears up a lot of confusion.
Studying for the SIFT currently! Glad I found your channel!
Did you make it through selection ?
I was wondering the same thing...I'm studying myself right now
Marcus Wilkerson dope, good luck
@@Not-a-bot222 likewise
Good luck! I tried to go in, but im 32 now and "too old..." friends don't let friends re-enlist!!!!
Nice job...! Very clear and concise in explanation.....I look forward to seeing more of your presentations 🚁👀
Really interesting. Great illustration.
well summarized , keep this going
Thank you for these videos it's great plase colud you make a video to explain a Aerodynamic approach and landing
This what I want to learn in my life time all the time
I'd like to thank you on your videos! Your previous videos helped me do well on the SIFT!
Awesome explanation! Thank you
very well done. I really learned. keep up the good work
The BEST one!
This is perfect, thank you
Thank you for all your videos , it help so much 🙏🏻👏
You gawd damn Stud, you! Loved how you brought it all together and finally shit clicked for me. Many thanks.
Excellent video
Thank you sir, outstanding job!
Great content
I have a question though.
Aren't we compensating for dissymmetry of lift by blade flapping. Then why are we again taking it to consideration?
Blade flapping helps compensate but depending on airframe, you may still have to still compensate as a pilot. Blades and rotor systems can only flap so much until they reach a limit.
@@helicopterlessonsin10minut10 That helped a lot.
I knew of transitional (translational?)lift but did know know what it was or why. I remember learning left turning tendency, torque, p factor, gyroscopic procession, and other things similar only it was about the prop out front on fixed wing aircraft. Thank you and be safe
This is amazing content, I've been watching plenty of your videos to help me through my CPL(H)
Thank you so much 🙏🏼✨🌸
very nice vid! thanks so much!
This is good stuff. Thank you Watson
Good vídeo 👍🏾🚁
super helpful vids and how can you not love the intro? the music is a little tame though. i would prefer bone crusher never scared or so. 👊🏻
Hi Jacob. I really appreciate you for taking the time to produce this content. You are enabling me to learn all I can prior to Flight Training, which, in my civilian world is almost cost prohibitive. So I plan to learn everything possible in advance of going to the airport.
Could you make a video for: "Aerodynamics of a (standard approach) Landing" ? I know it would be the reverse but, it would still be helpful. And, could you include the necessary changes required
0JustLook. I'm glad you're enjoying the videos. I'll see what I can do for the approach video. Right now I've got quite a lot of videos mapped out.
Please keep up the videos.
So so clear! Thank you.
Can you do a Aerodynamics during a VMC Approach? Thanks!
Nice video! Perhaps put the nice heli footage at the end.
As an engineer, not a helicopter pilot, I had imagined the rotors would increase angle of attack when moving downwind and reduce AoA moving upwind to balance lift in forward flight. Does that happen? Maybe when trimming for balanced controls once at steady speed?
Thank you so much, I was really having problems with understanding aerodynamics but after watching your videos I understand how it’s work
You have to coolest intros ever!!!😃
Solid.
real good！
Hope can see settling with power on your video!👀
Soo 😎. I like the music.
Brilliantly explained!
A question - is the cyclic set up so as to compensate for gp? Or does the pilot have to remember that and compensate manually?
Yes. Everything is generally rigged to have the 90 degree offset
@@helicopterlessonsin10minut10 ... thanks for taking your time to reply. I'm not a pilot but I find the helicopter physics endlessly fascinating. I have gone through a lot of your videos, very interssting! Well, I'm flying X-Plane helicopters...lol
awesome videos, all of them.
but I think the rotor disk diagram on the right about ETL and DL together may be wrong??
It reads from LT - RT. ++. ++ SHOULD IT NOT BE +- ++. OR I B WRONG?????
+- +- +- ++
Lucky Hoerner. The final diagram combines ETL, DL, and finally Gyroscopic Precession. The diagram in your comment doesn't include the 90 degree rotation in forces as a result of Gyroscopic Precession. Thanks for the question. I hope this helps.
Thank You
What you are saying is the airflow on blades
are at much different speeds advancing and retreating, is that I missed? --James
Yes. Check out my Dissymmetry of Lift video for further explanations.
Am I correct in assuming angle of incidence is the same as pitch angle? Since you change the angle of incidence by adjusting the collective "pitch", and they seem to have the same definition everywhere, angle between the chord line and the longitudinal line.
Somewhat. Angle of incidence is the mechanical pitch angle but not necessarily the aerodynamic pitch angle (Angle of Attack).
woul you please mind explaining the + and - inside the circular indicators for wind direction
good job ; )
At 5:55 when your combining the + & - shouldn’t the top left be + - not ++, thanks for making the videos.
Are there any books I can buy to study to be a pilot?...My plans are to join the army in a year, I have the asvab book to study but I would also like to try to get some what ahead before I get into the Army.
I took the ASVAB 1979, best advice then, go slow, use c'mon sense of your surroundings, all basic senses.
Good luck!
Please do Aerodynamics in landing (your short mention of it here was a bit confusing)
Tracy Wilson. During landing the process is reversed. As the helicopter decelerates less than ETL and gets into the transition phase, the pitching up continues (due to Dissymmetry of Lift) but the right roll is introduced (due to Transverse Flow). As the helicopter comes to a stationary hover and loses all airspeed, the rotor is less efficient and more power is required.
Its just opposite of ELT
OOPS. ETL
Hello, I am using "DCS AH64 Apache" flight combat simulator. When I perform a vertical take off to hover (with 0 knots speed horizontaly), my heli moves turning to the right (thats is normal) an I counter with left pedal, but I have a roll left movemet (heli drifs to the right) so I have to put left ciclyc. I do not undestand it, because I am not moving forward in the transition phase. What is happening? Thanks.
One question tough : are the vortex related to ground effect ? IF you hover far outside the ground effect you still have the vortex effect ?
12345fowler. Yes the vortices are affected by the ground effect. If you hover outside of ground effect the vortices are more pronounced than in ground effect.
@@helicopterlessonsin10minut10 Thanks
Is helicopter / rotor disc a gyro.?
muito bom
my heart betting fast when your marker touching the paper..haha..btw nice explaination bruh!
The last diagram is a bit confusing. It doesn't quite add up. Please advise
So in going from a hover into forward flight you actually at times have dissymmetry of lift on the right and then the left side of the rotor disk? I imagine the reverse is true while landing.
Ken Quesenberry. You have Dissymmetry of Lift anytime there is any airflow across the rotor disk. That can be from movement (in any direction) or wind velocities. The difference in lift is relative to the speed of the airflow. In all cases, the advancing blade generates more lift than retreating blade. For more clarification, check out my Dissymmetry of Lift and Compensation for Dissymmetry of Lift videos in this video description. Thanks for the feedback!
I understand that there is always dissymmetry of lift, but it's compensated for through down flapping of the retreating blade and up flapping of the advancing blade.
I would have thought that on a helicopter with a counter clockwise rotating rotor that the roll would be to the left along with a slight shutter during transverse flow while the blades are trying to figure out if they're at a hover or in ETL. I didn't take into account gyroscopic progression(Procession) acting on the component of lift, or the greater component of lift in this case. Does that make sense?
I've got about 715 hours in simulations, and I've never noticed what you're describing; is that because the reaction is so slight it's difficult to notice or do I need a better simm? I notice the counter torque effects on lift off and the pitch up of the nose going into ETL, which tends to remain as long as I'm in ETL such that forward pressure on the cyclic must be maintained to keep the helicopter from going nose up; however, I don't think I'm getting any roll to the right at any point, if any roll is present it's a roll to the left during forward flight.
Ken Quesenberry. You're correct in that blade flapping helps offset some of Dissymmetry of Lift. But cyclic feathering is also required which is why you need to maintain forward cyclic inputs. I understand your thought on a left roll and I've heard that before. But logically speaking, the only way to have a left roll would be more lift on the right side of the rotor disk. For this effect to manifest here, the input would have to take place at the aft portion of the disk due to Gyroscopic Precession. This just isn't so. The aft portion of the disk is less efficient and creates less Lift due to more induced flow when compared to the front half of that disk. To address your last point, I'm not sure what type of simulator you use. But most people notice Transverse Flow the most as a drifting right of centerline when taking off and landing between 10-20 knots airspeed. Its even more pronounced in wheeled Helicopters during a rolling takeoff. I hope this helped clear things up.
Thanks for the input. Yes I do notice some drift to the right and a bit rearward, but always chalked it up to the wind.
Actually what I described is what happens while lifting off into a hover, and is actually translating tendency caused by the tail rotor pushing the helicopter sideways. Anyway neither one seems to be much of a problem, so I'm good.
Thanks, and great job on all the vids, lectures. I think I'm getting this. ;)
Now it makes sense why when I pull back to slow down, it's so difficult to transition to an actual hover! I'm not compensating for the tf. Thank you 😂
Not understanding why you would not have same lift on all blades at all same time no matter where they are rotating.
Everything is moving at same speed as everything is attached at same places and sane size??
That’s the thing. Everything isn’t moving at the same speed. The advancing side of the the rotor gets more airflow than the retreating side. The front have has cleaner, flatter air than the back half which is more vertical. All of this affects 90 degrees off axis because of gyroscopic precession / phase lag. Check out my Dissymmetry of Lift, Transverse Flow, and Gyroscopic Precession videos for how each one affects the rotor differently.
R they exact opposite +variables
In a Huey you could really feel her trying to roll over with you at higher speeds.
What is forward cyclic??
Abhishek Harihar. Cyclic refers to the cyclic pitch control that tilts the main rotor disc by changing the pitch angle of the rotor blades in their cycle of rotation. The control is mounted in between the pilots knees and can pivot in all directions.
Where can I find the other lessons? I stopped watching this one as soon as you said I should watch the others first. I clicked the link above @t but that didn't give me the lessons, just "FARCE book".
Mike Owens. All of the links are in the description below the video. Also, the playlist titled “All videos in Order” should make it so everything is covered in the correct sequence.
When your job is to identify as a meme.
You said “ass half” 🤣
What is...less than a 10 min...aaram se samjha na
Great Apache footage at the starts....you must really enjoy your job!!
Haha! Yep, I really do.