What's the Definition of...
- Thread starter Anne
- Start date
storm_pilot
Registered User
Casselton, ND
In simple terms it means that you are keeping the fuselage pointing "straight" into the relative wind by adding the correct amount of rudder to counteract the yawing tendencies of adverse yaw associated with turns and left turning tendencies of the engine's thrust and torque. By keeping the fuselage straight you reduce drag and also keep the wings perpendicular to the airflow which is important in a stall or one wing will stall before the other giving a spin entry.
Hope that's what you're looking for.
Hope that's what you're looking for.
Here's some interesting (paragraphs 6 and 8 ) on this at : http://www.friesian.com/flight.htmannestoy said:
taken from the 'Physics' section at: http://www.friesian.com/science.htm
Nancie
Steve Pierce
BENEFACTOR
Graham, TX
I visualize it as going around a banked race track without skidding the tires.
mvivion
SPONSOR
Bozeman,MT
Ah, but Steve, going around a banked race track at maximum speed would still involve some skidding. And a hey of a lot of outside G.
What more than the little ball in the center dost thou wish for, Ms. Anne?
There are many reasons to fly with the ball out of the center, but most of them are simply intentionally uncoordinated maneuvers.
MTV
What more than the little ball in the center dost thou wish for, Ms. Anne?
There are many reasons to fly with the ball out of the center, but most of them are simply intentionally uncoordinated maneuvers.
MTV
Steve Pierce
BENEFACTOR
Graham, TX
I realize you are still scrubbing tires due to geometry but I think it is a good mental picture to visualize what the aircraft is doing verses skidding around a corner.
Anne
Registered User
SE Michigan
My instructor asked me to define "coordinated flight," and I couldn't find a formal definition of it anywhere. Is it always when the ball is centered? Or can you have coordinated flight with crossed controls? I know that I'm coordinated when the ball is centered, but what makes it centered?
Storm_pilot's answer makes a lot of sense to me, keeping the fuselage straight into the relative wind with use of the rudders.
Anne.
Storm_pilot's answer makes a lot of sense to me, keeping the fuselage straight into the relative wind with use of the rudders.
Anne.
Erik
Registered User
Anne,
You want to know the physics behind what the turn coordinator ball is telling you. Coordinated flight happens when the ball is centered and it means that you are not in a skid (too much rudder) or a slip (too little or opposite rudder).
When you bank an airplane, a component of your lift acts towards the center of the turn. That is why you pull back (pitch up) a little more to support the weight of the airplane, if you want to maintain your same elevation (because some lift is used for banking and is unavailable to support the airplane). So, the plane rolls over (with aileron) and a component of lift acts straight up and a component acts straight towards the center of the turn radius. The rudder induces yaw and yaw creates side forces to pivot the plane about it's vertical axis. The yaw is used in a bank to counter (or exaggerat) side forces induced by a roll. So in the mix are forces related to weight, lift, bank, pitch, and yaw.
Coordinated (ball centered):
With the right amount of rudder, the forces are all balanced so that it feels as if the weight is acting through the vertical axis of the plane (which is not truely "vertical" at this time). Race car on track analogy with no feeling of side forces would be: side slope of the track just right for speed/radius = rudder input just right.
Uncoordinated - Slip (ball to the inside):
With the too little or opposite rudder, the forces are all balanced so that it feels as if the weight is acting through an axis angled to the inside of the turn. You and the little ball feel like you are being forced downward/inside of the turn. Race car on track analogy with inside/downward side forces: side slope of the track too steep for speed/radius = too little or opposite rudder input.
Uncoordinated - Skid (ball to the outside):
With too much rudder, the forces are all balanced so that it feels as if the weight is acting through an axis angled to the outside of the turn. You and the little ball feel like you are being forced upward/outside of the turn. Race car on track analogy with outside/upward side forces: side slope of the track too shallow for speed/radius = too much rudder input.
How did I do MTV?
Erik
You want to know the physics behind what the turn coordinator ball is telling you. Coordinated flight happens when the ball is centered and it means that you are not in a skid (too much rudder) or a slip (too little or opposite rudder).
When you bank an airplane, a component of your lift acts towards the center of the turn. That is why you pull back (pitch up) a little more to support the weight of the airplane, if you want to maintain your same elevation (because some lift is used for banking and is unavailable to support the airplane). So, the plane rolls over (with aileron) and a component of lift acts straight up and a component acts straight towards the center of the turn radius. The rudder induces yaw and yaw creates side forces to pivot the plane about it's vertical axis. The yaw is used in a bank to counter (or exaggerat) side forces induced by a roll. So in the mix are forces related to weight, lift, bank, pitch, and yaw.
Coordinated (ball centered):
With the right amount of rudder, the forces are all balanced so that it feels as if the weight is acting through the vertical axis of the plane (which is not truely "vertical" at this time). Race car on track analogy with no feeling of side forces would be: side slope of the track just right for speed/radius = rudder input just right.
Uncoordinated - Slip (ball to the inside):
With the too little or opposite rudder, the forces are all balanced so that it feels as if the weight is acting through an axis angled to the inside of the turn. You and the little ball feel like you are being forced downward/inside of the turn. Race car on track analogy with inside/downward side forces: side slope of the track too steep for speed/radius = too little or opposite rudder input.
Uncoordinated - Skid (ball to the outside):
With too much rudder, the forces are all balanced so that it feels as if the weight is acting through an axis angled to the outside of the turn. You and the little ball feel like you are being forced upward/outside of the turn. Race car on track analogy with outside/upward side forces: side slope of the track too shallow for speed/radius = too much rudder input.
How did I do MTV?
Erik
Taledrger
SPONSOR
SW Michigan
Anne,
A simple explaination of coordinated flight is "when the fuselage is parallel to the RELATIVE wind". Any time it is not you are uncoordinated.
Air mass movement across the earths surface has nothing to do with coordinated flight. The aircraft does not know it is in an air mass. It only knows it's relationship to the relative wind. As long as the ball is centered you are coordinated.
Bob
A simple explaination of coordinated flight is "when the fuselage is parallel to the RELATIVE wind". Any time it is not you are uncoordinated.
Air mass movement across the earths surface has nothing to do with coordinated flight. The aircraft does not know it is in an air mass. It only knows it's relationship to the relative wind. As long as the ball is centered you are coordinated.
Bob
Cajun Joe
GONE WEST
LS86 or Hammond, LA
You know I really have no business commenting on this but it appears that the guys with the knowledge are sitting back laughing themselves crazy.
With my very limited knowledge and even more limited intelligence I have to submit that you are confusing crabbing with slipping or skidding in efforts of comparison.
OK, so as not to confuse those from other ethnic backgrounds I'm speaking from a South Louisiana point of understanding. Crabbing is a term that can openly describe the aircraft's movement relative to a course made good. Seen from above the plane with a crosswind from the right would assume a position that (while coordinated and a centered ball) was pointing with its nose 5, 10, 20 degrees to the right of this course made good over the land. BUT the plane would be flying directly into the relative wind or the actual air flowing across the aircraft surface. This is crabbing just as a boat crossing a river would head into the current and crab across the river to make good a 90 degree course. That a crabbing airplane is heading directly into the relative wind is evident by the absence of wind blowing away your sunglasses.
On the other hand both slipping and skidding would be an attack on the relative wind with the front right or left quarter of the airplane and this wind would definitely be felt inside a cub with an open window.
Both terms of coordination come into play when a left crosswind landing is properly executed as the airplane crabs along the extended centerline heading into the wind perhaps 10 or 15 degrees off the runway heading then, before touchdown, the airplane is maneuvered into a slip to achieve runway heading and being uncoordinated lands with the ailerons left and the rudder right, left wing low and left wheel touching but the plane flying straight down the center and the relative wind now moving left of the nose.
I thank Joe for lending me his computer to compose this thesis.
Ruidoso Ron
With my very limited knowledge and even more limited intelligence I have to submit that you are confusing crabbing with slipping or skidding in efforts of comparison.
OK, so as not to confuse those from other ethnic backgrounds I'm speaking from a South Louisiana point of understanding. Crabbing is a term that can openly describe the aircraft's movement relative to a course made good. Seen from above the plane with a crosswind from the right would assume a position that (while coordinated and a centered ball) was pointing with its nose 5, 10, 20 degrees to the right of this course made good over the land. BUT the plane would be flying directly into the relative wind or the actual air flowing across the aircraft surface. This is crabbing just as a boat crossing a river would head into the current and crab across the river to make good a 90 degree course. That a crabbing airplane is heading directly into the relative wind is evident by the absence of wind blowing away your sunglasses.
On the other hand both slipping and skidding would be an attack on the relative wind with the front right or left quarter of the airplane and this wind would definitely be felt inside a cub with an open window.
Both terms of coordination come into play when a left crosswind landing is properly executed as the airplane crabs along the extended centerline heading into the wind perhaps 10 or 15 degrees off the runway heading then, before touchdown, the airplane is maneuvered into a slip to achieve runway heading and being uncoordinated lands with the ailerons left and the rudder right, left wing low and left wheel touching but the plane flying straight down the center and the relative wind now moving left of the nose.
I thank Joe for lending me his computer to compose this thesis.
Ruidoso Ron
Ruidoso Ron
Registered User
Alto, NM
Cajun Joe said:
Enough said.
storm_pilot
Registered User
Casselton, ND
Well it's nice to know that $50,000 degree is good for something. :-?
storm_pilot
Registered User
Casselton, ND
Hey Ron,
"Jets are for kids"
My grandpa used to tell me that when he was still with us.
"Jets are for kids"
My grandpa used to tell me that when he was still with us.
Ruidoso Ron
Registered User
Alto, NM
It's a fact! Anybody can light off a jet; just throw a match at it and stand back. But to pickle a 4360 without a backfire, using only the cockpit instruments, with 3 others already running..................Now that's art!
