Thank you for such a detailed, yet easy to understand explanation. This content is the kind that makes me want to write a thank you above just the thumbs up. I didn't even know I wanted to know this information.
Hello planchetflaw, it is viewers like you(and your comment) that inspire me to continue putting these simple videos out there. My videos are quite simple and low budget, but carry concepts that I find to be interesting and sometimes helpful. That's not everyone's cup of tea, but that's ok. I'm more of a back-to-basics, classroom style kind of guy. Anyway, thank you very much for taking the time to write your nice comment. It is well received and really means a lot. PS: You have a cool screen name that a numismatist would like.
Hello P3DJumboJet, I agree! Every body should see my videos...😜! Nah, seriously now, I am glad you liked my video and thank you for taking the time to leave me a positive feedback. Take care.
Hello Sam Aj, I'm glad my simple videos are of value to someone. I enjoy making them since I enjoy the topic. I have a few ideas for some videos but if you have any questions or suggestions I'm all ears. Again, thank you for the positive encouragement and good luck in school.
Since entering service on the Boeing 747 aircraft in 1970, the JT9D engine has proven itself to be the workhorse for early 747, 767, A300, A310 and DC-10 aircraft models with more than 3,200 cumulative engines delivered.
Two things. FIRST I just realized that these 'locking rings' that hold the blades in the slots are transmitting 100%! of all thrust from the blades into the engine structure (and then to the engine mount/aircraft.) Talk about critical. SECOND I question your explanation early in the video that the clank sound happens from that guide vane hitting against the next blade. Wouldn't that create dangerous wear and create a stress point on the next blade? There is a significant clank when the single blade drops over - just coming from the socket movement itself. I've always believed that was the source of the noise. At any rate - THANKS for posting this. Very interesting.
Awesome spiffytown! I'm glad to hear that you found my simple video helpful. Thank you. I think that any day that you learn something new is a good day.
Interesting. Instead of trying to perfectly fastening each blade at a perfect 90 degree angle in relation to the axis of rotation, the blades are allowed a few degrees of freedom so that centrifugal force takes care of the problem. I assume that this solution was adopted because previous designs were cracking the blades and/or inducing vibrations
Hello enock elia, which clearance are you referring to? If it's the clearance between the hub and the blade root, that's done on purpose to allow for movement of the blades during changes in engine speed, to minimize vibration, etc.
Thank you F Grai737. That blade noise is not an issue on the GE Passport 20 engines. They made those blades out a solid disc so now they can't move independently. You can see it on one of my videos if you are interested.
Yes Sir! That's the aftermath of several generations of students parading through, purposely causing damage to the leading edge of the blades to then practice blending out the damage. This engine is retired and now serves as a teaching aid.
The blades on that first engine look heavily blended and previously damaged. I may be wrong but I doubt this is a Pratt & Whitney engine. Unless it is in for overhaul and repair.
Very good "Me", you have sharp eyes. These engines are retired and not airworthy. They are only teaching aids for A&P students at Broward College in Hollywood, Florida. Those blades are removed, damaged, blended again and reinstalled every semester and there's been many generations of students that have gone through there. That's why those blades look like that. Thanks for watching and taking the time to leave s comment.
@@planesimple8514 I work MRO and that was one of the first things i noticed was the blends and i was like my goodness what is the limits for blending on those blades! Thing looks like some one took a bucket of bearings and threw em in the inlet! Hahahaha
Hello Alexander Varga, there's nothing like a set of students armed with chisels and hammers to damage a set of blades. But it's ok, they get files and sand paper afterwards to blend the damage away. Obviously those blades will never see flight again. Thanks for watching and for your comment.
I presume the same clink sound happens when the blades pass the 6 O'clock (the bottom) position? I was going to ask but you answered my question about does that sound happen when the engine is running. No, you said. The blades find their "happy' place and don't flop back and forth. All I can say is good. :)
Hello J. Wolfe, great question! No, the blades don't make that noise, or at least nowhere near as loud as at 12 o'clock. The reason is that at the bottom the blade hangs like a pendulum and is free to slowly swing and change positions from one side to the other without a sudden stop. At the top, gravity holds the blade tilted back until the blade's center of mass goes past 12 o'clock, it is only then that the blade moves and quickly swings from one side to the other and produces the noise. I hope this makes sense. Thanks for that question.
It's no surprise. That is a retired engine that has been a teaching aid at the school for several generations of students, each taking their turn at blending out damages to the blades. The result is what you see.
They are indeed damaged, they ALL are! This is a non airworthy, partially dismantled and retired engine that is used as a teaching aid in school. All the blades have seen many generations be of students learning to blend dents on the blades and by now are all out of limits. You have a sharp eye though. Thanks for watching and commenting.
Thank you for such a detailed, yet easy to understand explanation. This content is the kind that makes me want to write a thank you above just the thumbs up. I didn't even know I wanted to know this information.
Hello planchetflaw, it is viewers like you(and your comment) that inspire me to continue putting these simple videos out there. My videos are quite simple and low budget, but carry concepts that I find to be interesting and sometimes helpful. That's not everyone's cup of tea, but that's ok. I'm more of a back-to-basics, classroom style kind of guy.
Anyway, thank you very much for taking the time to write your nice comment. It is well received and really means a lot.
PS: You have a cool screen name that a numismatist would like.
All ATPL EASA students should see this video, thank you so much!
Hello P3DJumboJet, I agree! Every body should see my videos...😜! Nah, seriously now, I am glad you liked my video and thank you for taking the time to leave me a positive feedback. Take care.
@@planesimple8514 You are very welcome sir!
I am actually an AME student 147 basic these videos are literally gold mines to me so plz keep making them 🔥
Hello Sam Aj, I'm glad my simple videos are of value to someone. I enjoy making them since I enjoy the topic. I have a few ideas for some videos but if you have any questions or suggestions I'm all ears.
Again, thank you for the positive encouragement and good luck in school.
That's a good suggestion. I will. Thank you.
And by the way, thank you dude for recommending my videos, it means a lot! Thank you.
Thank you
Cheers for making my ATPL studies more interactive, very well visualised! 👍
Thank you Alexander. I'm glad you liked it.
Good luck with your ATPL
I'm an ATPL student, and I just wanna say a big THANK YOU!!!!
Since entering service on the Boeing 747 aircraft in 1970, the JT9D engine has proven itself to be the workhorse for early 747, 767, A300, A310 and DC-10 aircraft models with more than 3,200 cumulative engines delivered.
Jt9d beast
Best teacher in the world 🙂 you deserve more subs ❤️ I love how you just keep the explanation neat and simple keep going
Wow! Thank you very much for your kind words man.
@mohammed nawab your welcome I am glad you found something worth your time 😊
Wow, very nice explanation. I'll really appreciate your help. thanks, bro.👏
Thank you very much Mahdi Hossein gholi nejad. I'm happy to hear you liked my video.
Welcome to Plane Simple.
Wow the leading edges of those blades have seen alot of action
Yep. Many generations of students have put their hands on them.
Great explanation .....Gracias Bernardo ..I understood why the noise..clear and easy 😁
Muchas gracias Bernardo.
I appreciate it.
Two things. FIRST I just realized that these 'locking rings' that hold the blades in the slots are transmitting 100%! of all thrust from the blades into the engine structure (and then to the engine mount/aircraft.) Talk about critical. SECOND I question your explanation early in the video that the clank sound happens from that guide vane hitting against the next blade. Wouldn't that create dangerous wear and create a stress point on the next blade? There is a significant clank when the single blade drops over - just coming from the socket movement itself. I've always believed that was the source of the noise. At any rate - THANKS for posting this. Very interesting.
Cool! Just last week I was near a Gulfstream making noises like this, I thought they should be silent when healthy. Learn every day!
Awesome spiffytown! I'm glad to hear that you found my simple video helpful.
Thank you.
I think that any day that you learn something new is a good day.
Very lovingly explained.
Thank you Christophe L.
Interesting. Instead of trying to perfectly fastening each blade at a perfect 90 degree angle in relation to the axis of rotation, the blades are allowed a few degrees of freedom so that centrifugal force takes care of the problem.
I assume that this solution was adopted because previous designs were cracking the blades and/or inducing vibrations
Exactly.
Great explanation!
helped me with AGK exams :) thank you!
Hello pilot dinos, I'm happy to hear that.
Thank you for the feedback.
What is the reason behind that big clearence sir?
Hello enock elia, which clearance are you referring to? If it's the clearance between the hub and the blade root, that's done on purpose to allow for movement of the blades during changes in engine speed, to minimize vibration, etc.
@@planesimple8514 i refer the clearence btn hub and blade, thanks i've understand.
I had no idea the fit was so loose! I guess once it's running the centripetal force pulls them into alignment but still!
Very easy and well explained
Thank you F Grai737.
That blade noise is not an issue on the GE Passport 20 engines. They made those blades out a solid disc so now they can't move independently. You can see it on one of my videos if you are interested.
Verygood explanation...
Thank you Vinu kp, I appreciate it.
thanks you for explanation appreciate the time and effort
Thanks for taking the time to write in your positive feedback.
Is there a way to lock the engine so it doesn't windmill? Or does it not really affect the blades enough to matter?
It doesn't affect them at all
I had no idea this happened.
Those blades have taken a beating looks like.
Yes Sir! That's the aftermath of several generations of students parading through, purposely causing damage to the leading edge of the blades to then practice blending out the damage. This engine is retired and now serves as a teaching aid.
@@planesimple8514 That's great. Do they still do such repairs and "blending" on these newer engines with the composite blades with the titanium edge?
Ive never heard that around fedex planes when they were parked and windmilling.
Thanks man!
The blades on that first engine look heavily blended and previously damaged. I may be wrong but I doubt this is a Pratt & Whitney engine. Unless it is in for overhaul and repair.
Very good "Me", you have sharp eyes. These engines are retired and not airworthy. They are only teaching aids for A&P students at Broward College in Hollywood, Florida. Those blades are removed, damaged, blended again and reinstalled every semester and there's been many generations of students that have gone through there. That's why those blades look like that.
Thanks for watching and taking the time to leave s comment.
@@planesimple8514 I work MRO and that was one of the first things i noticed was the blends and i was like my goodness what is the limits for blending on those blades! Thing looks like some one took a bucket of bearings and threw em in the inlet! Hahahaha
Hello Alexander Varga, there's nothing like a set of students armed with chisels and hammers to damage a set of blades.
But it's ok, they get files and sand paper afterwards to blend the damage away. Obviously those blades will never see flight again.
Thanks for watching and for your comment.
@@planesimple8514 not every day you get an opportunity to tear up thousands of dollars of parts in the name of training 😅
Amazing video keep making more videos 😍💖
Thank you man. I appreciate the encouragement.
Thank you! Obvious explanation. Everything is clear.
What about these engines? Why are blades so worn? Will these engines fly? Or are they retired?
These are retired engines that are now a school's teaching aid and practice tool
Pw jt9d is my favourite engine
You see them on 747-200 and 747-100
Excelente gracias
Yeap it was👏🤝
Thanks Yunior.
Is that a pw jt9d
Correct! Well done Nixon Z3 ses.
Good 😉
Thank you César.
4:53, 5:13 Thank you!
You're welcome
Thanks a lot!
My pleasure Billy Pilgrim.
I presume the same clink sound happens when the blades pass the 6 O'clock (the bottom) position?
I was going to ask but you answered my question about does that sound happen when the engine is running. No, you said. The blades find their "happy' place and don't flop back and forth. All I can say is good. :)
Hello J. Wolfe, great question!
No, the blades don't make that noise, or at least nowhere near as loud as at 12 o'clock.
The reason is that at the bottom the blade hangs like a pendulum and is free to slowly swing and change positions from one side to the other without a sudden stop.
At the top, gravity holds the blade tilted back until the blade's center of mass goes past 12 o'clock, it is only then that the blade moves and quickly swings from one side to the other and produces the noise.
I hope this makes sense.
Thanks for that question.
Hmm look at all that damage on all the blades! WTF
It's no surprise. That is a retired engine that has been a teaching aid at the school for several generations of students, each taking their turn at blending out damages to the blades. The result is what you see.
Blaid #5#6 seem dameged
They are indeed damaged, they ALL are! This is a non airworthy, partially dismantled and retired engine that is used as a teaching aid in school. All the blades have seen many generations be of students learning to blend dents on the blades and by now are all out of limits.
You have a sharp eye though.
Thanks for watching and commenting.
1st view
Ding ding! You claimed the tittle! Lol...
Jt9d
Correct! Good eye!
B 747-100 have Jt9d
Boeing 747-100 and 200 have jt9d engines but 747-200 also has rolls royes engines
I love jt9d
That engine was a BIG step into the modern, high bypass engines.
PLEASE get a monopod