student test pilot

khallups

Newbie
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May 11, 2010
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92
Location
Elk City, Okla.
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Luscumb, champ
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I have about 50hrs. in a Luscumb, and 40 hrs in a Champ, all tail draggers.
I thought the title would get someones attention.
Yes, I am a student pilot and trying to do my own test flights with a VW powered KB-2.

I was out on the runway practiceing balanceing on the mains. While balanced on the mains, I would push the stick left and the machine would yaw right. Pushing the stick right, makes the machine yaw left. It would only yaw slightly but to the opposite way the stick is pushed. I believe these are 20' Bensen blades blades with 2' bensen hub bar.

Yes, the blades are installed correct with the flat side down.
When the stick is pushed left the blades tilt left, when pushed right the blades tilt right.

I am not sure why it yaws opposite. Any thoughts?
 

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khallups

Newbie
Joined
May 11, 2010
Messages
92
Location
Elk City, Okla.
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Luscumb, champ
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I have about 50hrs. in a Luscumb, and 40 hrs in a Champ, all tail draggers.
I am getting training from Desmon.

I was hopeing to get some kind of explanation about why this happens.
thanks for the Encouragement Steve.
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,709
Location
Nipomo,California
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Givens Predator
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2200+ in rotorcraft
Ready to Solo your gyroplane?

Ready to Solo your gyroplane?

Hello Kelly,

All the gyroplanes I have flown control yaw with the rudder, not the cyclic.

In my experience a gyroplane does not have adverse yaw like your Luscomb or Champ.

I saw where you were going to get lessons from Desmon; how is that going?

Does Desmon feel you are ready to solo?

Many people have lifted off when their intention was to balance on the mains and discovered they were not ready to solo. It is often a very expensive mistake and can prove fatal.

I wish you success on your gyroplane adventure.

Thank you, Vance
 

khallups

Newbie
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May 11, 2010
Messages
92
Location
Elk City, Okla.
Aircraft
Luscumb, champ
Total Flight Time
I have about 50hrs. in a Luscumb, and 40 hrs in a Champ, all tail draggers.
thanks Vance for your reply.

I currently have 8 hrs with Desmon and plan on getting more. Desmon says I am ready to fly the runway at this time. He may feel that I am ready to make the pattern, but I want to take it slow and hopefully fly the runway for a while.

In Desmon's MTO and in my other gyro, Bensen, I have balanced on the mains down the runway and when I push right on the cyclic, the gyro drifts to the right,, and visa versa. I don't know why this KB-2 acts differently. I won't even attempt to fly this machine until I understand why this is happening. I double checked everything that I can think of. But I WILL figure this out first.
 

Vance

Gyroplane CFI
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Oct 30, 2003
Messages
15,709
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Nipomo,California
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Givens Predator
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Sounds Good Kelly.

Sounds Good Kelly.

I was not ready to fly the runway at 8 hours of dual in a gyroplane.

I am sorry I am not able to offer more information on why your aircraft is not responding as you expect.

To be clearer; it is my perception that the gyroplanes I have flown do not yaw at all with cyclic input including Desmon’s new MTO.

With The Predator when I give her full throttle she sometimes wanders left but I would not describe it as a yaw and I correct her path with cyclic.

I have an affection for the centerline even with the 150 foot wide 8,004 foot long runway at SMX.

For me in The Predator in wind it is sort of a guessing game to see if I have the combination of rudder and cyclic correct and the answer presents itself as soon as I lift off.

If I have failed she immediately yaws one way or the other.

When I have it right she climbs out straight ahead with no change in rudder or cyclic.

Thank you, Vance
 

bryancobb

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Owned Brantly B-2b/Fly Kitfox III/Mini-500b
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Your ONLY Question Asked

Your ONLY Question Asked

Kelly,

I'm sure I will get challenged on this since I have never even SAT in a gyro, but I have your answer.

If the pic you posted is the aircraft you are using, I can clearly see that if the nose is raised as if balancing on the mains, the geographical center of your teter-bolt or teter pin (which is the centroid of your rotor disc), is aft of a vertical line that is drawn from patch where the tire touches the runway.

Since lateral cyclic has a horizontal component of thrust, and since this lateral thrust is acting AT A POINT aft of the tire-to-runway contact point, it pushes the nose in the direction OPPOSITE the direction the disc tilts.

How's that? Sound plausible?
 
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Vance

Gyroplane CFI
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Nipomo,California
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Givens Predator
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Kelly,

I'm sure I will get challenged on this since I have never even SAT in a gyro, but I have your answer.

If the pic you posted is the aircraft you are using, I can clearly see that if the nose is raised as if balancing on the mains, the geographical center of your teter-bolt or teter pin (which is the centroid of your rotor disc), is aft of a vertical line that is drawn from patch where the tire touches the runway.

Since lateral cyclic has a horizontal component of thrust, and since this lateral thrust is acting AT A POINT aft of the tire-to-runway contact point, it pushes the nose in the direction OPPOSITE the direction the disc tilts.

How's that? Sound plausible?
Hello Kelly,

In my opinion the rotor thrust vector is what is important and it is my observation that a gyroplane balances on the mains with the disk well back.

As I look at the picture; it appears to me that the rotor thrust vector passes well ahead of the mains with the disk back far enough to balance on the mains at low speeds.

In my experience cyclic input does not yaw a gyroplane.

I would check toe in of the mains. In my experience if gyroplane mains don’t have a little toe out the gyroplane will be less directionally stable.

Thank you, Vance
 

khallups

Newbie
Joined
May 11, 2010
Messages
92
Location
Elk City, Okla.
Aircraft
Luscumb, champ
Total Flight Time
I have about 50hrs. in a Luscumb, and 40 hrs in a Champ, all tail draggers.
I was not ready to fly the runway at 8 hours of dual in a gyroplane.

I am sorry I am not able to offer more information on why your aircraft is not responding as you expect.

To be clearer; it is my perception that the gyroplanes I have flown do not yaw at all with cyclic input including Desmon’s new MTO.[/COLOR]With The Predator when I give her full throttle she sometimes wanders left but I would not describe it as a yaw and I correct her path with cyclic.

I have an affection for the centerline even with the 150 foot wide 8,004 foot long runway at SMX.

For me in The Predator in wind it is sort of a guessing game to see if I have the combination of rudder and cyclic correct and the answer presents itself as soon as I lift off.

If I have failed she immediately yaws one way or the other.

When I have it right she climbs out straight ahead with no change in rudder or cyclic.

Thank you, Vance


Vance,
On my lesson with Desmon, we went over things to look and feel for in a test flight. One of the things Desmon had me do is balance his MTO on the mains and move the cyclic left and right while the mains were still on the ground. His machine did indead drift left and right with the cyclic alone and not moving the rudder.

bryancobb,
I really like your explanation. In fact, I changed the fuel tanks on the side and put on a seat tank. I also raised the seat to make it nearly center line thrust. I didn't do a hang test after these modifications like I should have. I will try to do one today or tomarrow and let you know what it comes out at.
 

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JRB549

J.R. Brown
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Please dont find this rude but rather questions...Why are you doing this manuver at this stage in your training? You are asking for a flip if your on the mains...if everyting is working right...streight down the runway at a given speed and you input the stick left or right, you are creating greater drag in that direction. Without rudder input to follow the stick input which way do you think it's going to go? Stick to the basics.
 

GordonT

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Feb 10, 2011
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Orlando Area
As someone that has not started flight training yet, and that has been reading the forums for a couple of years, the question I have is: Isn't this very type of issue the reason why it is always recommended that any pilot new to gyros never test their own gyro but get a trusted very experienced pilot in similar craft (hopefully their CFI if they offer this service) to test and tune in your craft?
 
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Vance

Gyroplane CFI
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Nipomo,California
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Givens Predator
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Drift as opposed to yaw.

Drift as opposed to yaw.

Vance,
On my lesson with Desmon, we went over things to look and feel for in a test flight. One of the things Desmon had me do is balance his MTO on the mains and move the cyclic left and right while the mains were still on the ground. His machine did indead drift left and right with the cyclic alone and not moving the rudder.
In my opinion drifting left and right is not the same thing as yaw.

In my opinion there have been several accidents in a gyroplane because the pilot imagined that he could steer a flying gyroplane with the rudder so I feel making the distinction between yaw and drift is important.

It is my observation that sometimes a fixed wing pilot imagines that the rudder steers the gyroplane once airborn.

In my opinion in flight a gyroplane rudder controls yaw and the cyclic controls position over the ground.

I feel this makes the difference between yaw and drift important.

I do not have the answer for why your gyroplane drifts opposite your cyclic input.

I feel this nontraditional response to cyclic input will make your gyroplane more difficult to fly until you are able to get her to respond in a more traditional way.

I can make The Predator drift one way or the other with either the cyclic or the rudder as long as the main wheels are on the ground.

As I mentioned earlier; for me the appropriate combination of cyclic and rudder input is always a guess as long as the wheels are on the ground. The quality of the guess reveals itself as soon as the wheels leave the runway.

Thank you, Vance
 

bryancobb

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Stick To The Subject

Stick To The Subject

It appears that Kelly is "White-N-21" as old people in the South used to say. He has an instructor. He, no doubt, knows the risk. I just answered the clear question he asked, and didn't go off on a tangent this time.

I have been accused of that before and some need to practice what they preach! :director:
 

bryancobb

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Reminder

Reminder

...it appears to me that the rotor thrust vector passes well ahead of the mains with the disk back far enough to balance on the mains at low speeds...
Vance,

May I remind you that all forces created by the rotor of a gyro or helicopter bear-on, and act at one and only POINT in the middle of the apparatus that attaches the rotor to the mast. In this case, that is the mid-point of the teter bolt or pin.

The lateral component of those forces BANK and TURN the aircraft, if in flight. If on the ground it tries to SLIDE the aircraft across the surface and if the tires stop it from doing that, it may roll over.

In this specific case, since the rear wheels are planted, and the nosewheel isn't, if the mid-point of the teter bolt is exactly vertical from where the main tires touch, it may rollover. If in front of the tire contact point, the aircraft will turn on the surface in the direction cyclic is applied. If aft of the tire contact point, the aircraft will turn on the surface opposite the direction cyclic is applied.

This is totally unrelated to the rudder force or yawing. Yes, the rudder will have the same effect but that was irrelevant to his original question.
 

BEN S

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Ok, ill do it......
Are you crazy??? You claim to have hours with an instructor whom you claim says your "ready"...Why don't youask HIM what he thinks??
Could it be you didn't want him know what your up to?
I believe in the "Big boy pants" theory of evoloution, but why on earth would you progress the way you make it seem like you are?
This forum has seen FAR to many experienced, well trained pilots die in preventable accidents to want to partake in seeing yet another blunder.
finish your training.have a pro look over your rig.understand what you are doing BEFORE doing it. Don't die learning.
Whiskey Two Sixer....OUT!
 

j bird

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Ben, absolutely right to call him out.
 

JRB549

J.R. Brown
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Just as a note to your statment.."The lateral component of those forces BANK and TURN the aircraft, if in flight." You are flying if your balancing on the mains...slow but flying none the less. And as others have said, if you havnt had your plane test flown yet....Stop. All info here is ment to HELP from everyone. You only get one chance to get it wrong. Lets do it right.
 

EI-GYRO

21st Century Crankhandler
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Why are you moving the stick left and right while wheel-balancing?

Wheel-balancing is essentially a pitch control learning tool.

Moving the stick left and right may easily turn you over.

No hang test after mods. Really? Not smart.

The signs indicate you are not approaching this properly.

We have had two fatalities in the past year with amateur test-pilots, whose ambitions
exceeded their skills.

I hope you wont be number three.

Combinations of instructor training and 'self' training seem to be particularly insidious.

At least tell me you are doing this stuff in flat calm conditions, cos if you are not, you
are very likely to screw it up.
 

Vance

Gyroplane CFI
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Location
Nipomo,California
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Givens Predator
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2200+ in rotorcraft
Please give it a rest Bryan.

Please give it a rest Bryan.

Vance,

May I remind you that all forces created by the rotor of a gyro or helicopter bear-on, and act at one and only POINT in the middle of the apparatus that attaches the rotor to the mast. In this case, that is the mid-point of the teter bolt or pin.

The lateral component of those forces BANK and TURN the aircraft, if in flight. If on the ground it tries to SLIDE the aircraft across the surface and if the tires stop it from doing that, it may roll over.

In this specific case, since the rear wheels are planted, and the nosewheel isn't, if the mid-point of the teter bolt is exactly vertical from where the main tires touch, it may rollover. If in front of the tire contact point, the aircraft will turn on the surface in the direction cyclic is applied. If aft of the tire contact point, the aircraft will turn on the surface opposite the direction cyclic is applied.

This is totally unrelated to the rudder force or yawing. Yes, the rudder will have the same effect but that was irrelevant to his original question.
You could remind me if it were true Bryan.

Perhaps someday you will understand how a gyroplane flies and what makes it lift the front wheel before it takes off.

I know better than to try to explain it to you.

In my opinion pretending something unrelated to how a gyroplane works is not the same thing as answering the question or staying on track Bryan.

Regards, Vance
 

bryancobb

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Vance,

I will stoop to your level and I don't know why. You don't understand $h1+ from shine-o-la about flying machines or physics or any science that applies to all flying machines. You have experience and you base your understanding only on your experiences. You may not read much and if you do you fail to absorb the material and understand it's presentation.

You lock onto one word or phrase that is said or written and get all disoriented and confused. You bring up your vivid prejudices to disbelieve what is fact. I'm sorry I even spent the time to type this but the vast majority of people on this forum know I have a very thorough understanding of physics.

My Ross-Perot style of presenting it gives you fits and I don't know why?

Any person who knows "bumpkus" about flying machines, knows that the drag of the spinning rotor disk, is applying a horizontal aft force at the mid point of the teter bolt. The propeller is applying a thrust force that is horizontal and forward. This force is BELOW the teter hinge. Those two forces create a MOMENT about the aircraft CG. That, my friend is what picks the front wheel up.

The pilot can control the magnitude of the horizontal drag force vector that is pulling rearward at the mid point of the teter bolt, by varying fore/aft cyclic.

The trick to not accidentally lifting off, is to have throttle set to less than required for Minimum Controllable Airspeed, and HOPE a gust of wind don't come into the disc from the front.

Can you understand or do your prejucices against ME slam the door to your understanding before you read my words. :)
 
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