It is currently Sun Nov 24, 2024 12:12 am



Reply to topic  [ 56 posts ]  Go to page 1, 2, 3  Next
 Yaw and Torque Roll in a gyro 
Author Message
Are not yaw and torque roll in a gyro not inextricably linked in the practice of flying? I'm trying to understand the claims that in a machine like a Dom there is zero yaw or torque roll tendency with the cruciform tail centered in the middle of the prop.
Is it true as some seem to claim, that in a Dom if you fly hands off and feet off, and you retard and advance the throttle, there is zero tendency to roll or yaw? and the Dom will fly completely straight with only pitch changes no matter how aggressively you advance or retard the throttle. Or even the Aviomania design for that matter? I understand how a tail can modify the effect of the corkscrew slipstream of the prop, but I do not understand how the tail can counteract the torque effect of the engine accelerating or decelerating on the frame (Newtons 3rd law). Seems to me that torque roll cannot be dynamically balanced without rudder input by the pilot, does a Dom not require any rudder input when accelerating or decelerating in flight?
In trying to understand the dangerous torque roll in a gyro it seems to me the various forces are cumulative. Ignoring for a minute the tendency to yaw on the ground on take off and landing, lets just talk about in flight with aggressive pitch and throttle changes.
Lets use the MTO example because it fits my experience. With aggressive throttle changes, there is a twisting force on the frame. I get how the prop wash may be better balanced in a Dom, but not the torque roll effect on the Dom vs the MTO. So lets say it's uncorrected in either a Dom or an MTO, will not both tend to roll and change to some extent their attitude towards the oncoming wind . This will create increased pressure on one side or other of the aircraft with increasing yaw and roll effect. I understand roll and yaw are different, but I see them as linked in this process, as one will tend to accentuate the other as the process progresses.. In any Eurotub or machine with some type of cowling this will be greater than a completely open machine due to the increased area facing the oncoming airflow. If uncorrected dynamically by rudder control will this not result in a progressive roll of any machine into an inverted position?
I get where tail design can improve this tendency, but I don't understand how tail design alone can eliminate dynamic control input from the pilot with aggressive throttle input.


Last edited by loftus on Sun Feb 07, 2016 11:38 am, edited 1 time in total.



Sun Feb 07, 2016 11:25 am
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
If that claim were true (I am not knocking Chuck Beaty!!!) you wouldn't need the tab on the tall tail.
Just because you put a 4 way divider into the middle of the vortex flow it will not stop the torque of it.
It will however evenly distribute it on all 4 sections causing the even amount of lift on the airfoils.
But the slip stream being cone shaped it is the matter of distance from the prop that can render a tail more or less effective considering what part of the airflow is hitting it.
Just my very uneducated humble point of view.

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 11:37 am
Profile
Gabor wrote:
If that claim were true (I am not knocking Chuck Beaty!!!) you wouldn't need the tab on the tall tail.
Just because you put a 4 way divider into the middle of the vortex flow it will not stop the torque of it.
It will however evenly distribute it on all 4 sections causing the even amount of lift on the airfoils.
But the slip stream being cone shaped it is the matter of distance from the prop that can render a tail more or less effective considering what part of the airflow is hitting it.
Just my very uneducated humble point of view.

OK I agree, and understand. I guess only having been in a Dom a couple of times early on in my training with Davie, can one fly a Dom with zero rudder input when accelerating or decelerating?


Sun Feb 07, 2016 11:41 am
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
No that's a myth. I have seen plenty of Aircommands and Butterflies having the same characteristics. Greg Spicola has a great picture of him no feet or hands flying the Red Rocket.
Watched videos of him flying and never once a yaw or roll while changing throttle position!!!
This whole torque roll is such a freaking marketing myth.
Ask Jukka about it if you want a real educated and scientific answer.
Yeah.....Magni! There is your answer.

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 11:52 am
Profile
Gabor wrote:
No that's a myth. I have seen plenty of Aircommands and Butterflies having the same characteristics. Greg Spicola has a great picture of him no feet or hands flying the Red Rocket.
Watched videos of him flying and never once a yaw or roll while changing throttle position!!!
This whole torque roll is such a freaking marketing myth.
Ask Jukka about it if you want a real educated and scientific answer.
Yeah.....Magni! There is your answer.

So you are saying that a Dom requires no rudder input with throttle changes as in Greg's Dom?
Are you also saying that there is no roll effect on any airframe when the engine is accelerated or decelerated?
Is the video of Greg changing throttle position with hands and feet off?


Sun Feb 07, 2016 12:03 pm
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
I am saying that the Dominators I have flown (Ron's, Davie's, Greg's and the 150HP Yamminator) did not required any correction with the change of throttle position.
You could just take your feet off the pedals and nothing would happen yaw or nose up/down ways as you change the thrust.
In the videos obviously he is flying normally his Aircommand but with all the drastic throttle changes you can't see any movement that needed input to be corrected.
So I was just eluding to the fact that Dominators are not the only well balanced and stable machines out there although the magic tall tail is not present on those machines!

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 12:14 pm
Profile
Jake should weigh in on this. I think he has a handle on it from all angles and my sense from his builds and advise and commentary is it's a trade off in terms of
how custom each machine is and who it's built to fit.

My feeling on Doms is they fly like a dart, precise and accurate with thrust and not as much without but very stable nonetheless.

MTO's, etc the same with somewhat less rudder authority but much the same at higher AirSpeeds for the same maneuvers. not as precise as Doms when cranking and banking and somewhat more stable in disturbed air due to more mass. :twopennies


Sun Feb 07, 2016 12:16 pm
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
Yeah....when Jake starts building tall tail gyros I'll re-examine this whole tall tail is the only way to go myth.
:wol

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 12:26 pm
Profile
On the MTO I am required to apply compensatory rudder, generally right pedal when accelerating, particularly on takeoff, and left pedal with significant backing off on the throttle like when turning to base on descent, in order to keep the nose straight.
So two questions with simple yes or no answers.
1. Are you able to accelerate, full throttle, on take of - on the ground and climb out with zero right pedal input on a Dom?
2. When cutting back the throttle from 5300 rpm (rotax) to 3500 rpm is there zero right turn of the nose requiring compensatory left pedal


Sun Feb 07, 2016 12:36 pm
loftus wrote:
On the MTO I am required to apply compensatory rudder, generally right pedal when accelerating, particularly on takeoff, and left pedal with significant backing off on the throttle like when turning to base on descent, in order to keep the nose straight.
So two questions with simple yes or no answers.
1. Are you able to accelerate, full throttle, on take of - on the ground and climb out with zero right pedal input on a Dom?

YES (Greg trained me that way specifically-use the rotor he would say)

2. When cutting back the throttle from 5300 rpm (rotax) to 3500 rpm is there zero right turn of the nose requiring compensatory left pedal
No


Sun Feb 07, 2016 12:43 pm
Flying Wolverine wrote:
loftus wrote:
On the MTO I am required to apply compensatory rudder, generally right pedal when accelerating, particularly on takeoff, and left pedal with significant backing off on the throttle like when turning to base on descent, in order to keep the nose straight.
So two questions with simple yes or no answers.
1. Are you able to accelerate, full throttle, on take of - on the ground and climb out with zero right pedal input on a Dom?

YES (Greg trained me that way specifically-use the rotor he would say)

2. When cutting back the throttle from 5300 rpm (rotax) to 3500 rpm is there zero right turn of the nose requiring compensatory left pedal
No


Okay so as I understand it on take off in a Dom you control any nose yaw tendency with the stick (rotor). No pedal input needed.
And on cutting back throttle in a Dom when coming in to land for example, there is zero tendency of the nose to yaw to the right. (No pedal input needed)
Pedal input on a Dom is therefore 100% to turn the aircraft in the direction you want and not required at all to make compensatory changes with throttle input. I guess I need to go fly one to check it out.


Sun Feb 07, 2016 12:50 pm
That's pretty much my experience. Greg always corrected me when I would try to use the rudder to turn or compensate directional control under throttle on or off.
It was about rotor management. the rudder was necessary in windy conditions for compensation but the emphasis was to use the rotor to control speed, directional
control and rudder to back it up. He had a habit of shutting down the throttle and making me glide it in and pick the spot....rotor management.


Sun Feb 07, 2016 1:01 pm
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
A take off roll is a whole different animal from a flight throttle position change.
And yes you need to compensate.

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 1:21 pm
Profile
Gabor wrote:
A take off roll is a whole different animal from a flight throttle position change.
And yes you need to compensate.
In wind or side gusts ...in the absence of these conditions it was the rotor i managed to balance transition from ground roll to flight


Sun Feb 07, 2016 1:36 pm
Gabor wrote:
A take off roll is a whole different animal from a flight throttle position change.
And yes you need to compensate.

I guess I should clarify a little. In the MTO, the rudder is generally held straight, pedals equal, to control nose direction during takeoff roll with full throttle, and controls the nose of the aircraft down the runway both while the nose wheel is on the ground and while the landing gear is still in contact with the asphalt. Stick will be used to control for drift left or right due to crosswinds. However once the aircraft no longer has contact with the runway the nose will yaw to the left and right pedal is needed. So effectively what I meant was takeoff, but immediately upon becoming airborne. So in this respect it is the same animal as in flight throttle position change. The two most important critical times being on takeoff when transitioning from ground to airborne, and on landing when turning, descending and cutting throttle significantly.
Flying the MTO requires these pedal compensations, I want to experience how this is different in a Dom.


Sun Feb 07, 2016 1:40 pm
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
Got it! You'll find that it is not at all that different from the Dominator. MTO has a little slower response that's all. Doms do react faster but the mechanics of the correction will be pretty much the same. The amount and the speed will vary. At least that is how I felt.

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Sun Feb 07, 2016 1:50 pm
Profile
Online
Site Admin
User avatar

Joined: Tue Sep 02, 2014 7:45 am
Posts: 10129
Location: Poona, Qld, OZZY
Has thanked: 21874 times
Been thanked: 6221 times
You cant have zero or NO torque roll in a gyro.... you can only have more or less torque roll....

The motor is turning the prop and the rotors are doing their thing too... so that is in effect 2 gyroscopes acting against each other (or both trying to do their own thing)

A tall tail can only reduce the torque roll, not eliminate it completely.... the only thing that could reduce the torque roll to almost zero would be contra-rotating props.... but you would still have the various other gyroscopic effects .... so rudder inputs will need to be made in a Dom, as well as an MTO or any other gyro, even one with a single engine and contra props... just some will require bigger inputs than others, for different reasons :like :laughing :yoda2 :Wolvie

:Confederate

_________________
I do all of my own stunts..... most of them are even planned! Ok, Ok.... some of them are planned..

If electricity comes from ELECTRONS, then surely morality comes from MORONS??


Sun Feb 07, 2016 7:24 pm
Profile
MadMuz wrote:
You cant have zero or NO torque roll in a gyro.... you can only have more or less torque roll....

The motor is turning the prop and the rotors are doing their thing too... so that is in effect 2 gyroscopes acting against each other (or both trying to do their own thing)

A tall tail can only reduce the torque roll, not eliminate it completely.... the only thing that could reduce the torque roll to almost zero would be contra-rotating props.... but you would still have the various other gyroscopic effects .... so rudder inputs will need to be made in a Dom, as well as an MTO or any other gyro, even one with a single engine and contra props... just some will require bigger inputs than others, for different reasons :like :laughing :yoda2 :Wolvie

:Confederate

What is it about the Aviomania tail that is so special?
In all of these accidents like the WAG accident, torque roll seems to be way too simplistic an explanation for everything as Birdy alludes to.
Forgetting about the helmet coming off part. In my gyro it seems the potential dangerous situation I can get into is when cutting throttle etc on turning in say from base to final and not controlling the yaw of the nose with compensatory left pedal, and then the oncoming airflow creates an unbalanced increased lateral and rotatory force on the the aircraft. I could imagine combining all this with rotor unloading etc could all together contribute to flipping the aircraft. Seems to me not controlling yaw in a Eurotub with a larger surface area body and getting sideways into the airflow, is more of an issue than a torquing or twisting effect related to the motor and prop. It would be interesting to compare the flight characteristics of the standard MTO with the naked MTO. I suspect the naked MTO would be much less susceptible to flipping over than the standard MTO just because of the lack of body surface area.


Mon Feb 08, 2016 12:11 pm
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
Is this about the accident? Oh my...I can only imagine the usual suspects making the sales pitch again against Eurotubs.
I give up.
FUCKUM!!!!!!!!!!!!!!!!!!!!
WOLVERINES!!!!!!!!!!!!!!
:fuckum

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Mon Feb 08, 2016 12:38 pm
Profile
Site Admin
User avatar

Joined: Sat Nov 02, 2013 2:18 pm
Posts: 11382
Has thanked: 16461 times
Been thanked: 10056 times
By the way Stan can tell you about Aviomanias tail design more since he has built one.
Nothing special there.
The only special thing would be if it automatically adjusted for the ever changing "toque roll" effect.
A fix incidence correction only works in certain conditions.
Conditions are never constant.
End of myth!
GO ahead prove me wrong all ya'll scientists!
:punch

_________________
Image
A walk in the woods helps me relax and release tension. The fact that I am dragging a body should be entirely irrelevant!
A simple thank you would have been enough for the morning coffee without all that "how did you get in here" nonsense.


Mon Feb 08, 2016 12:41 pm
Profile
Reply to topic   [ 56 posts ]  Go to page 1, 2, 3  Next

Who is online

Users browsing this forum: Freebird, Henry Bowman, skyguynca and 811 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software.
Americanized by Maël Soucaze.