R22 Corner
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R22 Gyro
Hi
I had an introductory flight on an R22 a month or so ago but am stumped and dont want to go up again until i can get someone to explain what was happening mechanically with the machine.
I only have model experience (6 channel trex450) so im not sure exactly what was going on.
Before we lifted of i asked where the gyro was as he was showing me the motor etc. He said there was no gyro ? This is when i began to get confused.
We were heading SE at about 1500ft and 80 Knots. He instructed me to go full left and then full right yaw. I did so expecting the heading to change (model reaction) but all i felt was a funny vibration. He then showed me an instument and told me i had to keep it within 2 degrees of center to avoid the vibes, but no heading change.
To me i thought how does that happen with no gyro??
Ive looked and looked and ive found the R22 can come with or without a gyro so im just confused now.
I dont want to continue without being able to understand the mechanics of the machine.
If some one can explain why i didn't piro or change heading that would solve my misunderstanding of the machine.
If i did the same thing on my models in a head holding gyro i would just piro but maybe not with a rate gyro??
I someone can help i would really appreciate it. Thanks in advance, Andrew
I had an introductory flight on an R22 a month or so ago but am stumped and dont want to go up again until i can get someone to explain what was happening mechanically with the machine.
I only have model experience (6 channel trex450) so im not sure exactly what was going on.
Before we lifted of i asked where the gyro was as he was showing me the motor etc. He said there was no gyro ? This is when i began to get confused.
We were heading SE at about 1500ft and 80 Knots. He instructed me to go full left and then full right yaw. I did so expecting the heading to change (model reaction) but all i felt was a funny vibration. He then showed me an instument and told me i had to keep it within 2 degrees of center to avoid the vibes, but no heading change.
To me i thought how does that happen with no gyro??
Ive looked and looked and ive found the R22 can come with or without a gyro so im just confused now.
I dont want to continue without being able to understand the mechanics of the machine.
If some one can explain why i didn't piro or change heading that would solve my misunderstanding of the machine.
If i did the same thing on my models in a head holding gyro i would just piro but maybe not with a rate gyro??
I someone can help i would really appreciate it. Thanks in advance, Andrew
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There might be some confusion here as to what exactly you mean by 'gyro'. Most people on here fly full size helicopters rather than models, and the construction and kit is pretty different.
In forward cruise, the airflow from forward speed flowing over the vertical stabiliser (the vertical fin on the end of the tail boom) pretty much keeps the aircraft pointing forward. Putting in a boot full of yaw at lower airspeed may result in a pirouette.
Some of the instruments in the cockpit have gyroscopes in them, utilising a gyroscopes stability in space to provide a sort of reference datum; examples of this are the artificial horizon (or attitude indicator) and directional indicator (I've seen these called a gyro-compass). The gyroscope holds the instrument steady and the aircraft rotates around it.
Smaller helicopters are unstabilised. There is generally some adjustable control friction, and may be some form of electronic trim. Anything other than very small helicopters generally has some form of hydraulic system to allow the pilot to overcome control forces. As you go up in complexity, you start getting stabilisation (which may include some form of gyroscope), then various flavours of autopilot.
I'm not sure how much of this is helpful, as I'm not 100% sure what you're asking?
In forward cruise, the airflow from forward speed flowing over the vertical stabiliser (the vertical fin on the end of the tail boom) pretty much keeps the aircraft pointing forward. Putting in a boot full of yaw at lower airspeed may result in a pirouette.
Some of the instruments in the cockpit have gyroscopes in them, utilising a gyroscopes stability in space to provide a sort of reference datum; examples of this are the artificial horizon (or attitude indicator) and directional indicator (I've seen these called a gyro-compass). The gyroscope holds the instrument steady and the aircraft rotates around it.
Smaller helicopters are unstabilised. There is generally some adjustable control friction, and may be some form of electronic trim. Anything other than very small helicopters generally has some form of hydraulic system to allow the pilot to overcome control forces. As you go up in complexity, you start getting stabilisation (which may include some form of gyroscope), then various flavours of autopilot.
I'm not sure how much of this is helpful, as I'm not 100% sure what you're asking?
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GoneFusion
Your life will be simplest if you accept that your experience flying models is actually not helping you and will just get in the way. What you need to fly an unstabilised light helicopter is nothing like what you have used on your model. Forget gyro stabilisation - there isn't one on the R22 you flew. The only gyros are in the instruments. You (the pilot) are what keeps the ship steady. This works both ways - I tend to crash models because they don't react as I expect when I make control inputs!
In the R22 helicopter the tail (blade and rotor) acts to countract the yaw created by the single main rotor spinning one way (remember Einstein: every action has an equal and opposite reaction, so the body wants to spin oposite direction to the blades).
At low airspeed (like in a hover) the tail rotor provides the anti-torque. Your feet determine the pitch of the tail rotor blade and therefore the amount of thrust which is produced. Reduce the thrust (right foot forward in an R22) and there is not enough to counteract the torque operating on the cab in reaction to the blades turning and she begins to turn to the right. With little / no airflow over the helicopter this turn will continue until you arrest it by increasing the thrust from the tail rotor (left foot advanced a little). You can spin around all day until you apply left foot to balance the torque again. More left foot, and the thrust is now greater than the torque reaction and so you begin to spin to the left.
At high speeds the tail fin will do most of the anti-torque for you. With 80knt wind going over the tail fin, when you tried to put your foot in and twist the aircraft, the thrust of the tail rotor caused the tail to start to rotate (just like it would in a hover) but that put the tail fin at ever greater angle to the air stream thus increasing the pressure on the tail fin. At higher speeds there is insufficient thrust in the tail rotor to overcome the wind pressure on the tail, and at some angle of "twist" you achieve a balance between the thrust of the tail rotar and the back pressure of the tail fin in the 80knt wind. So you fly along in a crab-like way until you stop pratting about and adjust your feet to bring her straight again.
The direction in which you fly has a lot more to do with how the main disc is pointed. This is affected by the cyclic control, in your right hand.
For example; lifted into a hover and balanced with your feet, the helicopter stays over a single point on the ground. Now move the collective (right hand) slightly left and the helicopter will start to move left. Move the cyclic a little more to the left, and the rate of "flying left" increases. As you pick up speed to the left, the increasing wind hitting the left side of your tail will want to make you spin left (weathercocking the tail) and you will need to increase pressure with your right foot to prevent this. You can continue with sideways flight at increasing speed until you run out of right foot - then any increase in sideways flight speed takes the wind pressure on the left side of the tail fin beyond what the tail rotor can oppose, and the helicopter will weathercock into wind.
The effect of the tail fin is dependent on the size and shape of the fin as well as the speed of air moving over it. Helicopters like the R22 have less tail fin effect than (say) an EC120, which has a massive tail surface which is also shaped like an aeroplane wing on edge, so when she is flying along at speed you don't need any rotor effect to oppose the torque of the main rotor, the tail fin does it all.
Enjoy learning to fly helicopters - it is the greatest buzz!
Your life will be simplest if you accept that your experience flying models is actually not helping you and will just get in the way. What you need to fly an unstabilised light helicopter is nothing like what you have used on your model. Forget gyro stabilisation - there isn't one on the R22 you flew. The only gyros are in the instruments. You (the pilot) are what keeps the ship steady. This works both ways - I tend to crash models because they don't react as I expect when I make control inputs!
In the R22 helicopter the tail (blade and rotor) acts to countract the yaw created by the single main rotor spinning one way (remember Einstein: every action has an equal and opposite reaction, so the body wants to spin oposite direction to the blades).
At low airspeed (like in a hover) the tail rotor provides the anti-torque. Your feet determine the pitch of the tail rotor blade and therefore the amount of thrust which is produced. Reduce the thrust (right foot forward in an R22) and there is not enough to counteract the torque operating on the cab in reaction to the blades turning and she begins to turn to the right. With little / no airflow over the helicopter this turn will continue until you arrest it by increasing the thrust from the tail rotor (left foot advanced a little). You can spin around all day until you apply left foot to balance the torque again. More left foot, and the thrust is now greater than the torque reaction and so you begin to spin to the left.
At high speeds the tail fin will do most of the anti-torque for you. With 80knt wind going over the tail fin, when you tried to put your foot in and twist the aircraft, the thrust of the tail rotor caused the tail to start to rotate (just like it would in a hover) but that put the tail fin at ever greater angle to the air stream thus increasing the pressure on the tail fin. At higher speeds there is insufficient thrust in the tail rotor to overcome the wind pressure on the tail, and at some angle of "twist" you achieve a balance between the thrust of the tail rotar and the back pressure of the tail fin in the 80knt wind. So you fly along in a crab-like way until you stop pratting about and adjust your feet to bring her straight again.
The direction in which you fly has a lot more to do with how the main disc is pointed. This is affected by the cyclic control, in your right hand.
For example; lifted into a hover and balanced with your feet, the helicopter stays over a single point on the ground. Now move the collective (right hand) slightly left and the helicopter will start to move left. Move the cyclic a little more to the left, and the rate of "flying left" increases. As you pick up speed to the left, the increasing wind hitting the left side of your tail will want to make you spin left (weathercocking the tail) and you will need to increase pressure with your right foot to prevent this. You can continue with sideways flight at increasing speed until you run out of right foot - then any increase in sideways flight speed takes the wind pressure on the left side of the tail fin beyond what the tail rotor can oppose, and the helicopter will weathercock into wind.
The effect of the tail fin is dependent on the size and shape of the fin as well as the speed of air moving over it. Helicopters like the R22 have less tail fin effect than (say) an EC120, which has a massive tail surface which is also shaped like an aeroplane wing on edge, so when she is flying along at speed you don't need any rotor effect to oppose the torque of the main rotor, the tail fin does it all.
Enjoy learning to fly helicopters - it is the greatest buzz!
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remember Einstein: every action has an equal and opposite reaction
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Hi Andrew
I gained my PPL(H) in an R22 a few years back having been flying model helicopters for 20 years. The poster who suggested completely putting model helicopters out of your mind has hit the nail on the head. The thing to remember is that a model's power to weight ration is way better than any full size helicopter, and you are also dealing with far higher head speeds etc which change lots of aerodynamic characteristics. I'd also go as far as to say that the technology of models is way more advanced, which makes them a lot easier to fly. It's certainly way more advanced than an R22.
The issue you mention is due to weather cocking of the tail. Modern models are generally designed for 3D flying, and are pretty much balanced in terms of weather cocking moments, so that you can maneouver the tail as you like at any point. That's one of the reasons why the fin on your Trex has cut outs in it. The gyro is also of very significant help when flying a model. Try turning your gyro to its 'rate' setting and turn the gain right down; see what happens. Actually I don't really recommend it unless you are a 'very' experienced model pilot.
I'll tell you the biggest problem I had with learning to fly the R22 with the model experience and 10 years of commercial airline flying behind me. By far the biggest challenge was keeping my feet moving in the hover, and keeping the cyclic relatively still. The effectiveness of the tail rotor is continuously changing even in slight gusts or general helicopter orientation changes with respect to a constant breeze. I found the first recognised motion due to this change was body roll. This is due to the fact that the sideways tail thrust is now leaning the body over to a greater or lesser extent. My first reaction would always be to use cyclic control to stop the roll as you would in a model, but it was actually the feet that needed to be adjusted. This problem was compounded for me, due to an inherent instinct to avoid ground contact of an engine pod on a commercial airliner when close to the ground. Once I managed to condition myself against these instincts, the rest was easy, but it did take me quite a while. I think I'd have learned a lot quicker had I not had the model or airline experience, and also had I done a course over a couple of weeks rather than the space of a year. Irt hunk my instructor would definitely agree that I could easily have knocked 10 or 15 hours off my training had I not had this instinctive behaviour in the hover. Saying that, my ATPL(A) would obviously have helped in other areas so I guess it all balances out.
Learning to fly the R22 is great fun but it is a totally different skill to flying models. You wouldn't compare it to driving a car, similarly; put models completely out of your mind - they have the same basic controls, but the way they behave and therefore what you need to do with those controls is honestly completely different.
Enjoy.
I gained my PPL(H) in an R22 a few years back having been flying model helicopters for 20 years. The poster who suggested completely putting model helicopters out of your mind has hit the nail on the head. The thing to remember is that a model's power to weight ration is way better than any full size helicopter, and you are also dealing with far higher head speeds etc which change lots of aerodynamic characteristics. I'd also go as far as to say that the technology of models is way more advanced, which makes them a lot easier to fly. It's certainly way more advanced than an R22.
The issue you mention is due to weather cocking of the tail. Modern models are generally designed for 3D flying, and are pretty much balanced in terms of weather cocking moments, so that you can maneouver the tail as you like at any point. That's one of the reasons why the fin on your Trex has cut outs in it. The gyro is also of very significant help when flying a model. Try turning your gyro to its 'rate' setting and turn the gain right down; see what happens. Actually I don't really recommend it unless you are a 'very' experienced model pilot.
I'll tell you the biggest problem I had with learning to fly the R22 with the model experience and 10 years of commercial airline flying behind me. By far the biggest challenge was keeping my feet moving in the hover, and keeping the cyclic relatively still. The effectiveness of the tail rotor is continuously changing even in slight gusts or general helicopter orientation changes with respect to a constant breeze. I found the first recognised motion due to this change was body roll. This is due to the fact that the sideways tail thrust is now leaning the body over to a greater or lesser extent. My first reaction would always be to use cyclic control to stop the roll as you would in a model, but it was actually the feet that needed to be adjusted. This problem was compounded for me, due to an inherent instinct to avoid ground contact of an engine pod on a commercial airliner when close to the ground. Once I managed to condition myself against these instincts, the rest was easy, but it did take me quite a while. I think I'd have learned a lot quicker had I not had the model or airline experience, and also had I done a course over a couple of weeks rather than the space of a year. Irt hunk my instructor would definitely agree that I could easily have knocked 10 or 15 hours off my training had I not had this instinctive behaviour in the hover. Saying that, my ATPL(A) would obviously have helped in other areas so I guess it all balances out.
Learning to fly the R22 is great fun but it is a totally different skill to flying models. You wouldn't compare it to driving a car, similarly; put models completely out of your mind - they have the same basic controls, but the way they behave and therefore what you need to do with those controls is honestly completely different.
Enjoy.
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Thankyou for the replies. I have a better understanding of what is going on now.
Yes i can see how the model flying will confuse me a touch!
A 3D trex is obviously a completely different animal.
I have alot to learn but am not afraid to expand my memory banks !!!
I think im going to ask my instructor Alot more questions next time.
I didn't want to come across like a smarty pants or what not
I think the 3D model will help me in a way but from what i understand of the mechanics of a real heli it will now just become even more fun as I could/can do what i think would rip a real on to bits....
Thankyou so much for taking the time to explain. More reading needed.
Yes i can see how the model flying will confuse me a touch!
A 3D trex is obviously a completely different animal.
I have alot to learn but am not afraid to expand my memory banks !!!
I think im going to ask my instructor Alot more questions next time.
I didn't want to come across like a smarty pants or what not
I think the 3D model will help me in a way but from what i understand of the mechanics of a real heli it will now just become even more fun as I could/can do what i think would rip a real on to bits....
Thankyou so much for taking the time to explain. More reading needed.
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Hi GoneFusion,
RC-helos where only a slight help, back when there where NO gyros on RC-models!! Mechanics, Aerodynamics, etc. are pretty much the same.
Only todays RC-helos are so overpowered, they can do things that would rip the 1:1 apart (not even talking about the pilot/pax).
If you ever tried a "classic" model - 25 years back, you where pretty close to real world helo flying (no gyros for RC back then)
Today I can buy a 45.-$ model the size of a quart of oil in any shopping mall, and the sales girl flying the thing "like a pro" - you just input what you want, and the little helo does it. Let go of everything and it stops in mid-air and holds the position by itself!
Not much of challenge anymore, if these things are loaded with 4+ gyros, autohover, save-land, etc....
Question: How do you fly your collective on the RC model?
Stick forward for pitch increase or Stick back for pitch increase?
As was mentioned before, try to put aside everything you know about FLYING RC-helos! The aerodynamics do apply though!
(A helo is a helo is a helo is a helo - any size)
Another tip, DON'T go at it 1hr per week!
Try to get the first 30-40 hrs in one go - everyday an hour at least!
Cheers,
3top
RC-helos where only a slight help, back when there where NO gyros on RC-models!! Mechanics, Aerodynamics, etc. are pretty much the same.
Only todays RC-helos are so overpowered, they can do things that would rip the 1:1 apart (not even talking about the pilot/pax).
If you ever tried a "classic" model - 25 years back, you where pretty close to real world helo flying (no gyros for RC back then)
Today I can buy a 45.-$ model the size of a quart of oil in any shopping mall, and the sales girl flying the thing "like a pro" - you just input what you want, and the little helo does it. Let go of everything and it stops in mid-air and holds the position by itself!
Not much of challenge anymore, if these things are loaded with 4+ gyros, autohover, save-land, etc....
Question: How do you fly your collective on the RC model?
Stick forward for pitch increase or Stick back for pitch increase?
As was mentioned before, try to put aside everything you know about FLYING RC-helos! The aerodynamics do apply though!
(A helo is a helo is a helo is a helo - any size)
Another tip, DON'T go at it 1hr per week!
Try to get the first 30-40 hrs in one go - everyday an hour at least!
Cheers,
3top
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Thanks 3top
Yes i can see intensive training would help alot. My mother is selling her house (to many stairs) and she has promised to lend me enough to at least get my student licence done (20 hours im told). Fingers crossed she will be able to lend it to me....
I fly mode 2, stick up for pitch with TR on the same left stick. Right is cyclic so i guess its somewhat close but i think you may be right to reverse the pitch and throttle to what is 'real'.
Now im itching to go again.....
Yes i can see intensive training would help alot. My mother is selling her house (to many stairs) and she has promised to lend me enough to at least get my student licence done (20 hours im told). Fingers crossed she will be able to lend it to me....
I fly mode 2, stick up for pitch with TR on the same left stick. Right is cyclic so i guess its somewhat close but i think you may be right to reverse the pitch and throttle to what is 'real'.
Now im itching to go again.....
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20 hrs I'm told
GF
I'm not sure who told you you can get a PPL(H) in 20 hrs (if that's what you mean by a student license) but the minimum is 45 hours. The average is probably well over that figure though.
Good luck and enjoy.
I'm not sure who told you you can get a PPL(H) in 20 hrs (if that's what you mean by a student license) but the minimum is 45 hours. The average is probably well over that figure though.
Good luck and enjoy.
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Pandalet exposes my inadequacies! 
Failure to accurately recall the glitterarti of Physics..... my fraudulent nature is rightly exposed!
After all, I did much of my training at no cost thanks to Eurocopter. Splendid chaps very thoughfully provided this:
Virtools Generated Page
I particularly enjoyed the SAR mission, in case I was ever asked to SAR someone as part of PPL(H) training.
It never did happen, and I was so, so disappointed!
John
Failure to accurately recall the glitterarti of Physics..... my fraudulent nature is rightly exposed!
After all, I did much of my training at no cost thanks to Eurocopter. Splendid chaps very thoughfully provided this:
Virtools Generated Page
I particularly enjoyed the SAR mission, in case I was ever asked to SAR someone as part of PPL(H) training.
It never did happen, and I was so, so disappointed!John
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I cant quite remember so im most likely wrong. I know i have to do 105 hrs minimum to get Commercial, 50 something private.
I think they let me go solo after 20.
I will have to check it again !
Geez you guys are so helpful. Very refreshing. Thanks to all very much.
I think they let me go solo after 20.
I will have to check it again !
Geez you guys are so helpful. Very refreshing. Thanks to all very much.
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Don't mind me, I just like to get some use out of my physics degree. Turns out, aside from being a research physicist, it's only really useful for being pedantic. The rest of your post covered things nicely
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No worries, mate. I'm actually quite difficult to upset (not an invitation to try, though)
My post - attempted humour. Clearly failed. Sorry, will never happen again.
Oh, aside from the free training package. I suspect that during unexpected entry into IMC, in the last 90 seconds of life a PPL(H) will find that link to have been as much use as the "instrument training" I was (we still are?) forced to undertake.
Have a great 2012. Keep out of cloud: clouds are EVIL!
My post - attempted humour. Clearly failed. Sorry, will never happen again.
Oh, aside from the free training package. I suspect that during unexpected entry into IMC, in the last 90 seconds of life a PPL(H) will find that link to have been as much use as the "instrument training" I was (we still are?) forced to undertake.
Have a great 2012. Keep out of cloud: clouds are EVIL!
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GF not sure where you did your first lesson / trial flight, but I would imagine that a decent ground briefing should have addressed some of those issues for you, before you got in the air.
Good luck and if you are not understanding your instructor well, then ask for another. It's your money. If needed I have met students who actually changed schools, but this is extreme.
Good luck and if you are not understanding your instructor well, then ask for another. It's your money. If needed I have met students who actually changed schools, but this is extreme.
GF - Ask away.
As an instructor I like nothing more than a student who asks questions. It proves you're interested, listening and willing to learn.
"The only stupid question is the one that doesn't get asked".
HC
As an instructor I like nothing more than a student who asks questions. It proves you're interested, listening and willing to learn.
"The only stupid question is the one that doesn't get asked".
HC
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HC
To be fair to the guy, it was at 2pm and he had already been working since early and once he heard 'model' his eyes seemed to glaze over.
Next time i am going to ask if i can go up with one of the older guys as i think i was a touch more mature than the instructor ! It was amazing to do it anyway and was only supposed to be shown basic stuff but he let me fly nearly the whole way to the training area, (he took back control to do an auto) out to the bay and then back along the beach (he didn't say much except 'dont fly over the top of those houses, fly out 100-200 meters over the water', he then only took back control to land) I was happy and got a good feel for what im in for !
Now just need $$$ to continue.
Thanks heaps guys. I will surely be back to ask more
To be fair to the guy, it was at 2pm and he had already been working since early and once he heard 'model' his eyes seemed to glaze over.
Next time i am going to ask if i can go up with one of the older guys as i think i was a touch more mature than the instructor ! It was amazing to do it anyway and was only supposed to be shown basic stuff but he let me fly nearly the whole way to the training area, (he took back control to do an auto) out to the bay and then back along the beach (he didn't say much except 'dont fly over the top of those houses, fly out 100-200 meters over the water', he then only took back control to land) I was happy and got a good feel for what im in for !
Now just need $$$ to continue.
Thanks heaps guys. I will surely be back to ask more
I think im going to ask my instructor Alot more questions next time.
I didn't want to come across like a smarty pants or what not
I didn't want to come across like a smarty pants or what not
HC
