Negative Gs at the top of loops
08-14-2014, 05:11 PM
#26
The reversal thing is not aileron reversal in the aerodynamic sense. What I was trying to convey altering of flight path do to non-level wings and how that reverses when inverted.
Scenario--
I think that sums up the issue.
I think the cure is --
I know someone said to avoid rudder correction but I would think that rudder correction would be what's needed here to compensate for wind. If the winds blowing straight at the pilot and the pilot applies a tad of left rudder through the entire loop (loop entered left-to-right), wouldn't that compensate for the wing and help keep the plane on a straight heading?
-l2t aka Ken
PS
Please drop aerodynamic control reversal from this thread. There is no need to debate how wing twisting or supersonic compressibility might or might not cause it as it is 100% not germane to this thread.
Scenario--
- Plane is flying straight and level left to right.
- Pilot applies up elevator at center of box to begin loop.
- The wind is toward the pilot so pilot uses ailerons to roll plane left, left wing down, right wing (nearest pilot) up.in an attempt to keep the plane on a straight path.
- At top of loop, since the right wing was toward the inside of the loop during the beginning of the loop it is still toward the inside and therefore now down.
- If the plane slows at the top of the loop, the wing will begin to lift while inverted (negative Gs).
- With the wing lifting inverted and the wing toward the pilot now down, instead of preventing the plane for altering course toward the pilot, the wing has the opposite effect, adds to the displacement do to the wing and actually alters the path further toward the pilot.
- Since the plane is slow and now out of a line, the loop is not completely on time. That lengthen's the top segment even more extending the time inverted and exacerbating the problem until the plane is out of path to the point of heading almost toward the pilot.
I think that sums up the issue.
I think the cure is --
- Go into the loop slower.
- Apply throttle from the 4 to 1 o'clock phase (flying the loop counter clockwise, to avoid neg Gs at the top).
- Make the loop big but not so big that there is an extended neg G segment at the top. (If you want to do the math, I don't care how fast the plane is flying or how much power it is, there is a loop radius at which it will pull negative Gs at the top.0
- Be more subtle about adjusting course in the loop.
I know someone said to avoid rudder correction but I would think that rudder correction would be what's needed here to compensate for wind. If the winds blowing straight at the pilot and the pilot applies a tad of left rudder through the entire loop (loop entered left-to-right), wouldn't that compensate for the wing and help keep the plane on a straight heading?
-l2t aka Ken
PS
Please drop aerodynamic control reversal from this thread. There is no need to debate how wing twisting or supersonic compressibility might or might not cause it as it is 100% not germane to this thread.
5. For the wing to provide lift, it has to have angle of attack, that's why there is positive incidence on the wing. When the plane is inverted there is still positive incidence on the wing which will naturally try to make the plane drop. That's the positive incidence providing lift on the model which is now inverted. If you release the elevator to neutral just before the top of the loop, the plane will continue on the arc of the loop, which is positive G. Slow speed will not change positive G's to negative G's. You would need to push down elevator to get a negative G condition in an inside loop.
6. In level upright flight the lift of the wing is acting upward. When the plane is inverted, the lift is still acting the same way on the model, which is now trying to pull the plane down. The right wing needs to be down at the top of the loop to prevent the plane from coming in. If the right wing is lifted so it is up at the top, then the plane will come in towards the pilot.
7. Flying slow does not make the top segment longer. It will take longer to travel that segment, but the distance is still the same. Inverted flight isn't the cause of the lost heading. Incorrect plane attitude and control inputs are.
1. All models behave different at the same speed. You need to work out what speed best suits your model. As a rule of thumb, trim for level flight at 1/2 throttle and adjust until it suits your plane.
2. You need to start gradually increasing throttle at or before center to maintain the momentum. Adding alot of power at the 4 o clock position will most likely cause the plane to veer off (Really??).
3.The size of the maneuver will depend on the size and power of your particular plane. Negative g's at the top? That's a negative.
4. Yep, small gentle corrections is what's needed.
I did say it's best to avoid using rudder and I still say that. Rudder is used for wind correction, but the less you use it the better, especially while performing loops. A slight aileron roll to keep the model on track will be easier to manage and less noticeable.
On most models, applying rudder will affect elevator and aileron control. Holding a constant amount of rudder while adjusting throttle, elevator and aileron is not as easy as it sounds.
The main things that will help are; 1. Trim the model as best you can, 2. Ensure the wings are level, 3. Good throttle control, 4. Fly at a speed that suits your model.
08-15-2014, 07:33 AM
#27
My Feedback: (28)
Here's the manuver description and suggested downgrades from the Sportsman Sequence .pdf on the NSRCA website:
Two Inside Loops (U): Model pulls up and executes two (2) consecutive loops. All loops shall be round and superimposed.
Downgrades:
• Loops not round
• Loops not superimposed
• Wings not level during loops
• Changes in heading (track) during loops
• Exit not at same altitude and heading (track) as entry
Two Inside Loops (U): Model pulls up and executes two (2) consecutive loops. All loops shall be round and superimposed.
Downgrades:
• Loops not round
• Loops not superimposed
• Wings not level during loops
• Changes in heading (track) during loops
• Exit not at same altitude and heading (track) as entry
08-15-2014, 07:39 AM
#28
The two loops in Sportsman are probably my most inconsistent move. Sometimes I get it pretty good and sometime my plane wanders at the top deviating from the line almost to the point where it's pointing across the box.
I started to think about what goes on in the physics of a round loop. Compare to what I call a roller-coaster loop, i.e., pull back on the stick hard and the radius decreases at the top of the loop and gradual increases again come out of it. With a loop like that, the plane pulls positive Gs all the way through. Now compare that to a round loop where you ease up on the elevator over the top. During the top, I'm thinking could the plane be pulling negative for a bit, so the inverted wing is providing up lift? Now if the plane is actually flying inverted for a bit, ailerons are going to turn the opposite direction. So if I'm trying to correct the plane to move it a bit further away from me but it goes inverted and then the plane flies toward me instead of away.
I'm trying to figure out what to do to correct this issue if it occurs. I could correct with rudder. Or maybe the answer is speed management so I fly after at the top and don't really go much into negative Gs.
Thoughts?
I started to think about what goes on in the physics of a round loop. Compare to what I call a roller-coaster loop, i.e., pull back on the stick hard and the radius decreases at the top of the loop and gradual increases again come out of it. With a loop like that, the plane pulls positive Gs all the way through. Now compare that to a round loop where you ease up on the elevator over the top. During the top, I'm thinking could the plane be pulling negative for a bit, so the inverted wing is providing up lift? Now if the plane is actually flying inverted for a bit, ailerons are going to turn the opposite direction. So if I'm trying to correct the plane to move it a bit further away from me but it goes inverted and then the plane flies toward me instead of away.
I'm trying to figure out what to do to correct this issue if it occurs. I could correct with rudder. Or maybe the answer is speed management so I fly after at the top and don't really go much into negative Gs.
Thoughts?
Learn2turn, i find the following article very helpful and may help with this and other similar questions you have like tips on rolling and practicing rolls, etc.
http://www.ckaero.net/blog/2014/01/3...ts-of-success/
08-16-2014, 10:24 AM
#29
As I remember, a body in motion tends to go in a straight line unless a force is applied to force it off the straight line. For the body to trace a perfect circle it continuously needs a force applied pointing at the center of the circle.
Did I remember right?
Jim O
Did I remember right?
Jim O
08-16-2014, 03:11 PM
#31
There is a lot of 'stuff' in this thread. I think the best thing to do is to keep it simple - trim your plane well, watch wings level, and use power appropriately.
The stuff about gravitational forces and changes in direction may contain a few myths, to put it nicely. G forces have no impact on wings or airfoils generating lift. Momentum will always force the airplane in a straight line in the direction of it's current travel. If your inside wing is down, you will loop inward. If you keep the plane in that attitude (meaning inside wing is now high over top of loop) it will continue on an inward path as long as you are on the elevator. As you're flying over the top with the inside wing still 'down' relative to the airplane (up in your frame of reference), it will still fly in due to the relationship of the wing (positive angle) to the forward motion of the airplane, and obviously more so if you are on the elevator.
If you still have trouble with the direction the airplane wants to travel in this situation, practice your knife edge and rolls, and try some point rolls if you can with only elevator inputs. You will get a feel for all of this. Up elevator is always toward the canopy, down always toward the gear. The wings basically follow the path of the nose (for all intents and purposes of this discussion).
Edited: I should listen to my own advice and keep it simple! Had a mistake about lift at top of loop.
The stuff about gravitational forces and changes in direction may contain a few myths, to put it nicely. G forces have no impact on wings or airfoils generating lift. Momentum will always force the airplane in a straight line in the direction of it's current travel. If your inside wing is down, you will loop inward. If you keep the plane in that attitude (meaning inside wing is now high over top of loop) it will continue on an inward path as long as you are on the elevator. As you're flying over the top with the inside wing still 'down' relative to the airplane (up in your frame of reference), it will still fly in due to the relationship of the wing (positive angle) to the forward motion of the airplane, and obviously more so if you are on the elevator.
If you still have trouble with the direction the airplane wants to travel in this situation, practice your knife edge and rolls, and try some point rolls if you can with only elevator inputs. You will get a feel for all of this. Up elevator is always toward the canopy, down always toward the gear. The wings basically follow the path of the nose (for all intents and purposes of this discussion).
Edited: I should listen to my own advice and keep it simple! Had a mistake about lift at top of loop.
Last edited by Jetdesign; 08-16-2014 at 05:59 PM. Reason: mistake about lift at top of circle - corrected.
08-16-2014, 03:45 PM
#32
There is a lot of 'stuff' in this thread. I think the best thing to do is to keep it simple - trim your plane well, watch wings level, and use power appropriately.
The stuff about gravitational forces and changes in direction may contain a few myths, to put it nicely. G forces have no impact on wings or airfoils generating lift. Momentum will always force the airplane in a straight line in the direction of it's current travel. If your inside wing is down, you will loop inward. If you keep the plane in that attitude (meaning inside wing is now high over top of loop) it will continue on an inward path as long as you are on the elevator. As you're flying over the top with the inside wing still 'down' relative to the airplane (up in your frame of reference), it will still fly in, if you are on the elevator. If you stop driving the plane with elevator and let the wings generate 'lift' (negative lift in this case, toward the bottom of the airplane, or up in your frame of reference), it will force the airplane to start flying out, because the inboard wing is aimed toward the sky, therefore the bottom of the airplane is aimed 'out' and lift toward the bottom of the airplane is therefore 'out'. As soon as you get back on the elevator the plane starts flying back in again because the canopy is aimed toward you.
If you still have trouble with the direction the airplane wants to travel in this situation, practice your knife edge and rolls, and try some point rolls if you can with only elevator inputs. You will get a feel for all of this. Up elevator is always toward the canopy, down always toward the gear. The wings basically follow the path of the nose (for all intents and purposes of this discussion).
If you do get off the elevator just before the top of the loop and start on a slight climb while inverted, yes, you will generate negative G's on the airplane. But that is a result of the change in direction (away from the center of the loop), not a cause.
The stuff about gravitational forces and changes in direction may contain a few myths, to put it nicely. G forces have no impact on wings or airfoils generating lift. Momentum will always force the airplane in a straight line in the direction of it's current travel. If your inside wing is down, you will loop inward. If you keep the plane in that attitude (meaning inside wing is now high over top of loop) it will continue on an inward path as long as you are on the elevator. As you're flying over the top with the inside wing still 'down' relative to the airplane (up in your frame of reference), it will still fly in, if you are on the elevator. If you stop driving the plane with elevator and let the wings generate 'lift' (negative lift in this case, toward the bottom of the airplane, or up in your frame of reference), it will force the airplane to start flying out, because the inboard wing is aimed toward the sky, therefore the bottom of the airplane is aimed 'out' and lift toward the bottom of the airplane is therefore 'out'. As soon as you get back on the elevator the plane starts flying back in again because the canopy is aimed toward you.
If you still have trouble with the direction the airplane wants to travel in this situation, practice your knife edge and rolls, and try some point rolls if you can with only elevator inputs. You will get a feel for all of this. Up elevator is always toward the canopy, down always toward the gear. The wings basically follow the path of the nose (for all intents and purposes of this discussion).
If you do get off the elevator just before the top of the loop and start on a slight climb while inverted, yes, you will generate negative G's on the airplane. But that is a result of the change in direction (away from the center of the loop), not a cause.
Lift doesn't make the plane climb, angle of attack on the wing does. The plane needs positive incidence to climb. Letting the elevator off at the top while inverted, will not make the plane fly out as the positive incidence is still making the plane pull towards the canopy, which because it's inverted, will make the plane continue on the arc of the loop (down in your reference). For the plane to fly outwards the incidence of the wing would have to change to negative.
Lift doesn't change from positive to negative (in relation to the model) just because the plane is inverted. The positive incidence is still acting the same relative to the model.
08-16-2014, 05:27 PM
#33
Edit: yeah I had a mistake in there - wings always have positive (toward canopy) angle relative to the axis of the airplane, so if it's moving forward it's being forced canopy side.
Incidence angle (AOA) is needed for a (symmetric) wing to generate lift, but lift is responsible for flight or climbing. Too much AOA and you stall and lose lift, and fall.
Incidence angle (AOA) is needed for a (symmetric) wing to generate lift, but lift is responsible for flight or climbing. Too much AOA and you stall and lose lift, and fall.
Last edited by Jetdesign; 08-16-2014 at 05:56 PM. Reason: mistake
08-16-2014, 08:51 PM
#34
Edit: yeah I had a mistake in there - wings always have positive (toward canopy) angle relative to the axis of the airplane, so if it's moving forward it's being forced canopy side.
Incidence angle (AOA) is needed for a (symmetric) wing to generate lift, but lift is responsible for flight or climbing. Too much AOA and you stall and lose lift, and fall.
Incidence angle (AOA) is needed for a (symmetric) wing to generate lift, but lift is responsible for flight or climbing. Too much AOA and you stall and lose lift, and fall.
The wing airfoil creates lift. In the case of a flat bottom or semi symmetrical wing, the air speed is faster over the top which creates a low pressure area compared to higher pressure underneath, which creates lift underneath the wing. I suppose if the amount of lift generated is greater than the weight of the model, then it would climb, but generally AOA is what makes the plane climb.
With a fully symmetrical wing, air pressure above and below is the same, so to climb or descend requires the AOA to change. Even with a fully symmetrical wing, AOA is set as positive incidence, which enables the model to fly level without descending. But of course speed also affects the climb rate at a given AOA and or incidence.
Exceed the critical angle of attack and it will stall and fall.
Make sense Joe?
08-17-2014, 04:49 AM
#35
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No true. Read post #10 on this thread. If the radius of the loop is large enough with respect to airspeed, to make loop round the wing has to provide lift up away from the center of the loop through the top of the loop. That's because gravity is providing a greater force that the centrifugal acceleration and in the opposite direction.
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08-17-2014, 05:38 AM
#36
No true. 1. Read post #10 on this thread. 2. If the radius of the loop is large enough with respect to airspeed, to make loop round the wing has to provide lift up away from the center of the loop through the top of the loop. That's because gravity is providing a greater force that the centrifugal acceleration and in the opposite direction.
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2. The size of the loop has nothing to do with it. Of course if the model gets too slow you will need to push down elevator to try to keep the loop round, but by that time it's too late and all you can do is add power and try to salvage as much of the maneuver as you can, but it won't be round. This is nothing more than pilot error. To perform an inside loop well, everything has to be right.
The size of the loop has to be such as to match the size and power of the model. The speed of the model has to be right and elevator inputs have to be made at the right time and correct amount to keep the loop round. That's why it's called, precision aerobatics. Get all these things right and the model will always be in a positive G condition.
There are full size aircraft that are rated for positive G maneuvers only and are able to do inside loops. If an inside loop required negative G's these aircraft would not be able to do them.
I've been flying pattern for 14 years and the only time I have had to push down elevator at the top of a loop, is if I have not made the loop round and had to make a correction to get back on track.
I currently fly F3A class but hey, what do I know.
08-17-2014, 01:00 PM
#37
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1. You're assuming what is said in post #10 is correct and you know what they say about theory versus what actually happens in practise.
2. The size of the loop has nothing to do with it. Of course if the model gets too slow you will need to push down elevator to try to keep the loop round, but by that time it's too late and all you can do is add power and try to salvage as much of the maneuver as you can, but it won't be round. This is nothing more than pilot error. To perform an inside loop well, everything has to be right.
The size of the loop has to be such as to match the size and power of the model. The speed of the model has to be right and elevator inputs have to be made at the right time and correct amount to keep the loop round. That's why it's called, precision aerobatics. Get all these things right and the model will always be in a positive G condition.
2. The size of the loop has nothing to do with it. Of course if the model gets too slow you will need to push down elevator to try to keep the loop round, but by that time it's too late and all you can do is add power and try to salvage as much of the maneuver as you can, but it won't be round. This is nothing more than pilot error. To perform an inside loop well, everything has to be right.
The size of the loop has to be such as to match the size and power of the model. The speed of the model has to be right and elevator inputs have to be made at the right time and correct amount to keep the loop round. That's why it's called, precision aerobatics. Get all these things right and the model will always be in a positive G condition.
So take this comment "if the model gets too slow you will need to push down elevator". and change it do "if the model gets too slow in relationship to the size of the loop you will need to push down elevator" and all the physicists will be happy.
Now being that I don't know all that much, okay pretty much nothing, about the capabilities of a 2m plane, maybe a loop that big would be 1100' high and you couldn't even see the plane to fly it in that loop. So maybe indeed it is mostly theory and doesn't apply for practical flying.
In any case, your comments are well taken and I will take heed. I do believe the issue I have is related to airspeed going into the top segment of the loop and that's something I intend to work on.
(Hey, this thread is now in the top 15 so I guess I didn't start that sucky a thread.)
-l2t aka Ken
08-23-2014, 10:27 AM
#38
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I found this handy calculator -- http://www.calctool.org/CALC/phys/newtonian/centrifugal
Setting it to feet and mph. If flying 30mph, a loop with r > 62' and you'll have less the 1g of centrifugal force at the top so you would be in negative Gs, perhaps for a fraction of a second. At 40mph, you could get r up to around 105'. At 50mph, around r = 170'.
Hop in your F15 at a peppy 500mph you'll need R around 17000 to pull negative Gs at the top of the loop.
Setting it to feet and mph. If flying 30mph, a loop with r > 62' and you'll have less the 1g of centrifugal force at the top so you would be in negative Gs, perhaps for a fraction of a second. At 40mph, you could get r up to around 105'. At 50mph, around r = 170'.
Hop in your F15 at a peppy 500mph you'll need R around 17000 to pull negative Gs at the top of the loop.
08-23-2014, 12:45 PM
#39
I found this handy calculator -- http://www.calctool.org/CALC/phys/newtonian/centrifugal
Setting it to feet and mph. If flying 30mph, a loop with r > 62' and you'll have less the 1g of centrifugal force at the top so you would be in negative Gs, perhaps for a fraction of a second. At 40mph, you could get r up to around 105'. At 50mph, around r = 170'.
Hop in your F15 at a peppy 500mph you'll need R around 17000 to pull negative Gs at the top of the loop.
Setting it to feet and mph. If flying 30mph, a loop with r > 62' and you'll have less the 1g of centrifugal force at the top so you would be in negative Gs, perhaps for a fraction of a second. At 40mph, you could get r up to around 105'. At 50mph, around r = 170'.
Hop in your F15 at a peppy 500mph you'll need R around 17000 to pull negative Gs at the top of the loop.
Less than 1 G is still positive. Negative is below 0.
Centrifugal force is trying to force the model away from the centre of the loop, so requires an opposite force to keep it on track which is positive G's.
As already said, if the loop is performed correctly as a pattern maneuvre, the model will always be in positive G's.
If all you want to know is when, where and how the model is in positive or negative G's, then you are in the wrong forum.
08-23-2014, 02:30 PM
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Seeing as gravity is providing us with a convenient source of 1G of the top of the loop, it's pretty clear that of the loop is large and the speed is low and you need less than 1G over the top of the loop then your wings will be producing lift towards the wheels to cancel out some of that 1G.
So yes, it's quite possible for your wings to be producing lift towards the canopy all the time in a small fast loop, but also transition from producing lift towards the canopy to producing lift towards the wheels if you loop is big and slow enough. Depending on how big and slow you're flying depends if you need to hold in a bit of down elevator or not to. I've never had to with my pattern ships, but a nose heavy, underpowered sport thing huffing and puffing it's way over a loop just might need some.
So yes, it's quite possible for your wings to be producing lift towards the canopy all the time in a small fast loop, but also transition from producing lift towards the canopy to producing lift towards the wheels if you loop is big and slow enough. Depending on how big and slow you're flying depends if you need to hold in a bit of down elevator or not to. I've never had to with my pattern ships, but a nose heavy, underpowered sport thing huffing and puffing it's way over a loop just might need some.
08-23-2014, 03:17 PM
#41
Seeing as gravity is providing us with a convenient source of 1G of the top of the loop, it's pretty clear that of the loop is large and the speed is low and you need less than 1G over the top of the loop then your wings will be producing lift towards the wheels to cancel out some of that 1G.
So yes, it's quite possible for your wings to be producing lift towards the canopy all the time in a small fast loop, but also transition from producing lift towards the canopy to producing lift towards the wheels if you loop is big and slow enough. Depending on how big and slow you're flying depends if you need to hold in a bit of down elevator or not to. I've never had to with my pattern ships, but a nose heavy, underpowered sport thing huffing and puffing it's way over a loop just might need some.
So yes, it's quite possible for your wings to be producing lift towards the canopy all the time in a small fast loop, but also transition from producing lift towards the canopy to producing lift towards the wheels if you loop is big and slow enough. Depending on how big and slow you're flying depends if you need to hold in a bit of down elevator or not to. I've never had to with my pattern ships, but a nose heavy, underpowered sport thing huffing and puffing it's way over a loop just might need some.
Regardless of the model, if you get everything right, ie. Speed, elevator input and the size of the loop in relation to the size and performance of the model, there will not be negative G's at the top.
I never have to with my pattern ships, but I don't have to with my sports models either. That's why it's called "precision aerobatics".
Like I said, if it's only about negative V positive G's, then this is in the wrong forum.
08-24-2014, 02:17 PM
#42
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I think the gist of this thread is that it's better to make the speed of plane such that the plane does not pull negative Gs in the top segment. At least that's what I learned from it. It's academic that it can happen at any speed if the loop is large enough.
08-24-2014, 04:12 PM
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I think you blokes need to stop arguing and accept the fact that reverse control coupling is the problem induced by supersonic flow over the wings causing the wing to twist
hehehe.
hehehe.
08-24-2014, 06:17 PM
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But if the loop is big enough in relationship to the speed of the plane and round, then down elevator will needed and the plane will pull the negative Gs in the top of the loop.
I think the gist of this thread is that it's better to make the speed of plane such that the plane does not pull negative Gs in the top segment. At least that's what I learned from it. It's academic that it can happen at any speed if the loop is large enough.
I think the gist of this thread is that it's better to make the speed of plane such that the plane does not pull negative Gs in the top segment. At least that's what I learned from it. It's academic that it can happen at any speed if the loop is large enough.
Let me put it another way ... fly smaller if you don't have the necessary power. Control, especially in crosswinds, requires that you keep the plane G-loaded, and that means no zero or negative G's in an inside loop.
Regards,
Dean Pappas
08-24-2014, 08:19 PM
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I agree the simple solution to flying a rounder loop is to fly faster and smaller.
However, maneuvers where you're forced to loop back into the wind (ie, Cuban eight) are where you'd expect sombody struggling with power and size to have to open up their loop by either completely releasing the elevator letting the plane fall over the top of the loop or even hold in a bit of down to hold it up a bit (but still maintain an arc) as they try to penetrate upwind. But as soon as that holding it up a bit becomes a clear segment then it's a point off
so do it smoothly....
However, maneuvers where you're forced to loop back into the wind (ie, Cuban eight) are where you'd expect sombody struggling with power and size to have to open up their loop by either completely releasing the elevator letting the plane fall over the top of the loop or even hold in a bit of down to hold it up a bit (but still maintain an arc) as they try to penetrate upwind. But as soon as that holding it up a bit becomes a clear segment then it's a point off
so do it smoothly....
Last edited by bjr_93tz; 08-24-2014 at 08:22 PM.
08-24-2014, 09:32 PM
#47
I agree the simple solution to flying a rounder loop is to fly faster and smaller.
However, maneuvers where you're forced to loop back into the wind (ie, Cuban eight) are where you'd expect sombody struggling with power and size to have to open up their loop by either completely releasing the elevator letting the plane fall over the top of the loop or even hold in a bit of down to hold it up a bit (but still maintain an arc) as they try to penetrate upwind. But as soon as that holding it up a bit becomes a clear segment then it's a point off so do it smoothly....
However, maneuvers where you're forced to loop back into the wind (ie, Cuban eight) are where you'd expect sombody struggling with power and size to have to open up their loop by either completely releasing the elevator letting the plane fall over the top of the loop or even hold in a bit of down to hold it up a bit (but still maintain an arc) as they try to penetrate upwind. But as soon as that holding it up a bit becomes a clear segment then it's a point off
so do it smoothly....1 point down grade for a segment and 1 point down grade for each segment.
08-25-2014, 03:16 PM
#48
Flying faster is not necessarily the answer, if you need to push on inverted it is due to lack of power, period, fly smaller then and manage the power;I do not understand why there is a discussion about negative G, it is impossible to have a round loop with negative G's, one thing is to hold the flight path, but if there is any negative G's the airplane at that moment is not maintaining the circumference but making a line,
There has to be enough power to make a big round loop, all these commands reversing etc, meaning more flight time is needed, just that, but with no power, there will be no explanation which can fix the loop. And try to not use the rudder on the first loops, it will make it easier, if someone can not make a round loop, will hardly be able to control rudder to maintain flight path.
Again, just make it smaller, relax elevator on top (NOT pushing!!) and upon power reduction let the airplane make the arc down, then just follow that arc with elevator.
Regards
There has to be enough power to make a big round loop, all these commands reversing etc, meaning more flight time is needed, just that, but with no power, there will be no explanation which can fix the loop. And try to not use the rudder on the first loops, it will make it easier, if someone can not make a round loop, will hardly be able to control rudder to maintain flight path.
Again, just make it smaller, relax elevator on top (NOT pushing!!) and upon power reduction let the airplane make the arc down, then just follow that arc with elevator.
Regards
08-25-2014, 04:28 PM
#49
Flying faster is not necessarily the answer, if you need to push on inverted it is due to lack of power, period, fly smaller then and manage the power;I do not understand why there is a discussion about negative G, it is impossible to have a round loop with negative G's, one thing is to hold the flight path, but if there is any negative G's the airplane at that moment is not maintaining the circumference but making a line,
There has to be enough power to make a big round loop, all these commands reversing etc, meaning more flight time is needed, just that, but with no power, there will be no explanation which can fix the loop. And try to not use the rudder on the first loops, it will make it easier, if someone can not make a round loop, will hardly be able to control rudder to maintain flight path.
Again, just make it smaller, relax elevator on top (NOT pushing!!) and upon power reduction let the airplane make the arc down, then just follow that arc with elevator.
Regards
There has to be enough power to make a big round loop, all these commands reversing etc, meaning more flight time is needed, just that, but with no power, there will be no explanation which can fix the loop. And try to not use the rudder on the first loops, it will make it easier, if someone can not make a round loop, will hardly be able to control rudder to maintain flight path.
Again, just make it smaller, relax elevator on top (NOT pushing!!) and upon power reduction let the airplane make the arc down, then just follow that arc with elevator.
Regards
On a side note Alejandro, my Camodel carbon spinners turned up, but I haven't had a chance to try them yet. I also have some Phileppe Marquette carbon spinners that are specifically designed for use with YS's and weigh 42 grams.