Aircraft Technical - Balance Ball - I just don't get it
Pompey till I die
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Aircraft Technical - Balance Ball - I just don't get it
27) You are turning left, and the balance ball is out to the right. What does this indicate?
A You have applied insufficient left rudder
B You are slipping into the turn
C You are skidding out of the turn
D A malfunction of the balance ball assembly
You chose B, but the correct answer was C.
Balance ball moves in the opposite direction to the turn - I thought. I turn left, balance ball is out to the right, must mean I'm slipping into the turn, i.e. yawing left too. Nope, you are skidding out of the term.
Why ? I get these questions wrong EVERY time.
A You have applied insufficient left rudder
B You are slipping into the turn
C You are skidding out of the turn
D A malfunction of the balance ball assembly
You chose B, but the correct answer was C.
Balance ball moves in the opposite direction to the turn - I thought. I turn left, balance ball is out to the right, must mean I'm slipping into the turn, i.e. yawing left too. Nope, you are skidding out of the term.
Why ? I get these questions wrong EVERY time.
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Remember: Always step on the ball. If the ball is out to the right, it means you need to step on right rudder. In other words, you need to loosen up on the left rudder.
If you have too much left rudder selected, the aircrafts nose is too far left for the (left) turn you're trying to achieve. You're skidding out of the turn. Just like a car, in a turn, where the front wheels have lost grip.
Works for me.
If you have too much left rudder selected, the aircrafts nose is too far left for the (left) turn you're trying to achieve. You're skidding out of the turn. Just like a car, in a turn, where the front wheels have lost grip.
Works for me.
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One of these 2 thoughts might help:
Step on the ball
The the ball is not in the centre you should increase pressure on the rudder pedal on the same side as the ball is (or reduce pressure on the opposite side - depending on what your feet are doing at the time.
Starting with this we get:
The slip ball can be looked at like a pendulum.
It's so much easier to explain with a couple of diagrams
Does this help at all?
OC619
Step on the ball
The the ball is not in the centre you should increase pressure on the rudder pedal on the same side as the ball is (or reduce pressure on the opposite side - depending on what your feet are doing at the time.
Starting with this we get:
- You are turning left
- You need more right rudder / less left rudder
The slip ball can be looked at like a pendulum.
- If you have too much pro-turn rudder it will move out of the turn (towards the top wing) - you are skidding.
- If you don't have enough pro-turn rudder it will move towards the inside of the turn (towards the lower wing) - you will be slipping into the turn.
It's so much easier to explain with a couple of diagrams
Does this help at all?
OC619
Pompey till I die
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I'm obviously a complete dunce
Turning left, ball is right.
I remember the "stand on the ball" rule.
Therefore I need to stand on the right rudder.
The right rudder brings me out to the right, I'm turning left.
Therefore before hand I was slipping INTO the turn (i.e. turning more left) ?
Obviously not for some reason....
I remember the "stand on the ball" rule.
Therefore I need to stand on the right rudder.
The right rudder brings me out to the right, I'm turning left.
Therefore before hand I was slipping INTO the turn (i.e. turning more left) ?
Obviously not for some reason....
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It's also a matter of definition.
In a correctly executed turn, in balance, the tail flies through the exact same piece of air as the nose.
If (in a left turn) you have too much left rudder (balance ball is right), the nose is too much inwards and the nose follows a trajectory with a shorter radius than the tail. The aircraft moves sideways, to the right, through the air. This is called skidding out of the turn.
If (in a left turn) you have not enough left rudder (balance ball is left), the nose is too much outwards and the nose follows a trajectory with a larger radius than the tail. The aircraft moves sideways, to the left, through the air. This is called slipping into the turn.
In a correctly executed turn, in balance, the tail flies through the exact same piece of air as the nose.
If (in a left turn) you have too much left rudder (balance ball is right), the nose is too much inwards and the nose follows a trajectory with a shorter radius than the tail. The aircraft moves sideways, to the right, through the air. This is called skidding out of the turn.
If (in a left turn) you have not enough left rudder (balance ball is left), the nose is too much outwards and the nose follows a trajectory with a larger radius than the tail. The aircraft moves sideways, to the left, through the air. This is called slipping into the turn.
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Originally Posted by PompeyPaul
Therefore before hand I was slipping INTO the turn (i.e. turning more left) ?
You try and steer to the left - but as the wheels don't provide enough grip you skid towards the outside of the turn. You have moved the steering wheel too far left for the turn the car is actually making.
Compare this to a left turn with wings level - i.e. rudder only (yes I know you'll need right aileron to resist the roll - ignore it for the moment)
This time you are driving across a sloping car park covered in ice. The car wants to slide down the slope (left) and you are steering right to prevent it. Due to lack to grip the car slips into a turn to the left. In this case you have the steering not enough to the left (or too much to the right) for the left turn the car is actually making.
Compare this to being banked left and flying straight on with a load of right rudder to prevent any yaw.
For steering subsitute rudder. For the slope of the road / car park substitute bank. If you draw the force vectors you'll find its very similar.
Any clearer?
OC619
[Just realised while I was composing this another couple of posts got there first]
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I think your difficulty in this question came from the terms used in the answer options.
"Skidding out of the turn" seems to me to be a loose description of excessive yaw to the left during a left turn, though I agree it's a correct one.
I think I might also have selected B, thinking of the left yaw as slipping into the turn.
Rather deceptive question, IMO.
"Skidding out of the turn" seems to me to be a loose description of excessive yaw to the left during a left turn, though I agree it's a correct one.
I think I might also have selected B, thinking of the left yaw as slipping into the turn.
Rather deceptive question, IMO.
It seems to me to be a matter of the definition of 'into' and 'out of' If you are turning left but the aircraft is actually slipping to the right of your desired path it stands to reason that you are slipping out of the turn. How this (IMHO) simple definition got turned on its head beats me. What the hell, just boot the ball.
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One day when flying along straight and level try pushing either the right or left rudders and see what the ball does, quite safe at cruise speed and quite educational. Much easier to do this and feel/see what is happening rather than trying to work it out on the ground.
ZA
ZA
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When an aircraft SLIPS in a turn, turn indicator and the ball will give 'same side' indications.
When an aircraft SKIDS in a turn, the turn indicator and the ball will give 'opposite side' indications.
That's all you have to remember to answer the question correctly.
The ball is a device that merely indicates the direction of the g-forces. During a turn, the ball takes up a position in line with the resultant of weight and centrifugal force. In a balanced turn this resultant is in line with the load factor (equal and opposite to lift during a level turn) and the ball will be in the centre. In an unbalanced turn, the relationship between CFF and weight determines where the ball will be. In a slipping turn the CFF is less than in a balanced turn and the ball will be on the side of the low wing. In a skidding turn the CFF is greater than in a balanced turn and the ball will be on the side of the high wing.
Clear as mud?????? Just remember the first two paragraphs and you will get the question right every time..
When an aircraft SKIDS in a turn, the turn indicator and the ball will give 'opposite side' indications.
That's all you have to remember to answer the question correctly.
The ball is a device that merely indicates the direction of the g-forces. During a turn, the ball takes up a position in line with the resultant of weight and centrifugal force. In a balanced turn this resultant is in line with the load factor (equal and opposite to lift during a level turn) and the ball will be in the centre. In an unbalanced turn, the relationship between CFF and weight determines where the ball will be. In a slipping turn the CFF is less than in a balanced turn and the ball will be on the side of the low wing. In a skidding turn the CFF is greater than in a balanced turn and the ball will be on the side of the high wing.
Clear as mud?????? Just remember the first two paragraphs and you will get the question right every time..
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A bit of wool on a the canopy/nose is far more accurate than a slip ball which can lag ... no good with a prop up front though 
.... Which makes me wonder, do any twin owners use a bit-o-wool as a cheap more accurate slip indicator?
SS
.... Which makes me wonder, do any twin owners use a bit-o-wool as a cheap more accurate slip indicator?SS
