Effect of Density Altitude on Crosswinds

vintage cessna said:
Well that is the problem, you just used the word "turn" to describe the motion in a slip. I now know what you mean when you say that. In the vocabulary of aviation, I (and probably Silvaire, and most others) have never seen the word " turn" used that way. To us, turn means a change of heading, not a change of flight path. What does your rate of turn instrument indicate in a slip?
Click to expand...

No, "turn" means if your initial flight path is 090, and the next flight path is 100, you have "turned" 10 degrees right. It doesn't matter if your turn is pretty ("coordinated") or ugly, or upside down. A turn describes the path of the aircraft in two dimensions, if the path is straight, it's not turning, if it's curved, it's turning. The way you achieve that change in path is irrelevant.
 
Last edited:
Silvaire said:
My "nope" is in regards to you saying the slip is a turn. It's not a turn, you can hold it all day long and your heading will not change and you will certainly not fly in a curved path. I never said you would remain over the road, you will drift with respect to the ground (in a no wind condition) in the direction of the slip. I said your heading would remain constant. It's not a turn, it's a slip. It's exactly what you do every time you land in a cross wind, you slip the amount necessary to counteract the cross wind movement of the air but since there is no wind n this example you will drift left or right.

I don't understand why you are calling it a "turn" :dunno: if I were turning my heading would change.
Click to expand...

Can you point me to (and quote) where I said that "a slip is a turn"?
As I explained above, you may have slipping (uncoordinated) turns, but a slip simply tells us your attitude in the air, not your path through it. A turn is what your flight path is doing, not your attitude.
 
vintage cessna said:
If there is a wind of 270 degrees at 40 kts, and you fly and maintain a heading of 360 degrees, you will of course drift right. Are you in a continuos right "turn"?
Click to expand...

You will certainly drift sideways if you have a crosswind. Where did I say otherwise? As I explained above, a turn is what your flight path is doing (if it's not straight, it's turning), and is independent of your attitude. A slip has to do with your attitude.
 
Bobanna said:
Guys, guys...The confusion here is over what a previous poster noted to be the "frame of reference." That is, our flight path through the (moving) air mass may be curved (turning, if you prefer), while our track across the ground is roughly a straight line. The slipping airplane has a lateral movement associated with its forward movement and, thus, flies a curve through the air while (at the same time) following a path on the runway centerline: this is a "side-slip". A slip without crosswind corrections is used to lose altitude rapidly and is referred to as a "forward slip." Cross-controlling is at the heart of both, so I think a slip is a slip - but a small distinction exists. Just for the record. Blessings
Click to expand...

Actually I don't think that's true. If your flight path through the air is straight, it will be straight over the ground, regardless of winds, assuming the wind and airspeed are constant. (Same with curved flight paths.)
 
Last edited:
RotorDude said:
No, "turn" means if your initial flight path is 090, and the next flight path is 100, you have "turned" 10 degrees right. It doesn't matter if your turn is pretty ("coordinated") or ugly, or upside down. A turn describes the path of the aircraft in two dimensions, if the path is straight, it's not turning, if it's curved, it's turning. The way you achieve that change in path is irrelevant.
Click to expand...

Define "flight path" . Do you mean course, or track over the ground?
 
Bobanna said:
The slipping airplane has a lateral movement associated with its forward movement and, thus, flies a curve through the air while (at the same time) following a path on the runway centerline: this is a "side-slip".
Click to expand...
No, the slipping plane is not flying a curved path through the air. It is flying a straight path through the air. That path is just not aligned with the longitudinal axis of the plane, but it is not curved.
 
RotorDude said:
No, "turn" means if your initial flight path is 090, and the next flight path is 100, you have "turned" 10 degrees right. It doesn't matter if your turn is pretty ("coordinated") or ugly, or upside down. A turn describes the path of the aircraft in two dimensions, if the path is straight, it's not turning, if it's curved, it's turning. The way you achieve that change in path is irrelevant.
Click to expand...

Feel free to make up your own definitions, but you will have problems communicating with other pilots. Since you have a unique dictionary for aviation terms, you may experience a whole lot of issues with ATC.
 
vintage cessna said:
Define "flight path" . Do you mean course, or track over the ground?
Click to expand...

The path over the ground, or through the airmass around the plane. It doesn't matter which one as long as the wind and airspeed are constant. A straight path relative to either one will be straight relative to the other, and vice-versa for curved. IOW, a turn (curved 2D path) will be a turn both relative to the airmass as well as to the ground, given constant wind and airspeed.
 
Last edited:
RotorDude said:
...a turn is what your flight path is doing (if it's not straight, it's turning)...
Click to expand...

This is apparently your own personal definition. For myself a turn is a maneuver that will result in a different heading from where you began and furthermore will result in a constantly changing heading for as long as you are in the turn. It will also register as a turn by the rate gyro in your turn indicator. A slip will accomplish none of these and therefore is not a turn - it's a slip.
 
Bobanna said:
Guys, guys...The confusion here is over what a previous poster noted to be the "frame of reference." That is, our flight path through the (moving) air mass may be curved (turning, if you prefer), while our track across the ground is roughly a straight line. The slipping airplane has a lateral movement associated with its forward movement and, thus, flies a curve through the air while (at the same time) following a path on the runway centerline: this is a "side-slip". A slip without crosswind corrections is used to lose altitude rapidly and is referred to as a "forward slip." Cross-controlling is at the heart of both, so I think a slip is a slip - but a small distinction exists. Just for the record. Blessings
Click to expand...

What is the point of reference to determine if a path is curved or straight in the air?
 
vintage cessna said:
Feel free to make up your own definitions, but you will have problems communicating with other pilots. Since you have a unique dictionary for aviation terms, you may experience a whole lot of issues with ATC.
Click to expand...

Give me an example where "my definition" would be at odds with ATC's.
 
RotorDude said:
No, "turn" means if your initial flight path is 090, and the next flight path is 100, you have "turned" 10 degrees right. It doesn't matter if your turn is pretty ("coordinated") or ugly, or upside down. A turn describes the path of the aircraft in two dimensions, if the path is straight, it's not turning, if it's curved, it's turning. The way you achieve that change in path is irrelevant.
Click to expand...

Do you think then, that if you were to plot the position of an airplane maintaining a contatant slip on a map you would see a curve?
 
Silvaire said:
This is apparently your own personal definition. For myself a turn is a maneuver that will result in a different heading from where you began and furthermore will result in a constantly changing heading for as long as you are in the turn. It will also register as a turn by the rate gyro in your turn indicator. A slip will accomplish none of these and therefore is not a turn - it's a slip.
Click to expand...

We actually agree about much of that.
As I mentioned above, a slip is an attitude of an aircraft, just like being upside down, or flying tail first, and is certainly not a turn.
You can turn while your aircraft is in any attitude.
A turn generally means that your flight path in 2D is changing, i.e. it's not a straight line.
Your heading as indicated by your compass or DG is a bit trickier, since it can be affected by your attitude, e.g. if you keep flying straight over a road but somehow manage to flip over and fly tail first, even though your path over the ground is still the same, your "heading" will now be 180 degrees off. Being in a slip affects your indicated heading the same way, though less drastically. But it's important to distinguish between your flight path through the air (or over the ground if you compensate for wind and airspeed) and your indicated heading, which is a function of where your nose happens to be pointing, in either coordinated or uncoordinated flight.
 
RotorDude said:
Give me an example where "my definition" would be at odds with ATC's.
Click to expand...

If ATC instructed you to start a left turn, they would want the nose to start moving left, not for you to put the plane in a slip to the left. Since you have your own definition of "turn", one could only imagine what other non standard definitions you use.
 
vintage cessna said:
If ATC instructed you to start a left turn, they would want the nose to start moving left, not for you to put the plane in a slip to the left. Since you have your own definition of "turn", one could only imagine what other non standard definitions you use.
Click to expand...

Leaving imagination aside, can you point me to where my definition of turn is different from ATC's, or where I said that turning left means to slip to the left?
 
RotorDude said:
Leaving imagination aside, can you point me to where my definition of turn is different from ATC's, or where I said that turning left means to slip to the left?
Click to expand...

Yes, I'll point you to it. Read your own posts. Where do you think all the heartburn is coming from?
 
Anybody ever watch the old "Burns and Allen" show. That is what this reminds me of.
 
vintage cessna said:
Yes, I'll point you to it. Read your own posts. Where do you think all the heartburn is coming from?
Click to expand...

Can you be more specific? Where did I say (please quote) anything that conflicts with ATC's definition?
 
vintage cessna said:
Do you think then, that if you were to plot the position of an airplane maintaining a contatant slip on a map you would see a curve?
Click to expand...

Again, slip is attitude, and is independent from flight path.
You can have coordinated or uncoordinated flight, either straight or curved.
 
vintage cessna said:
What is the point of reference to determine if a path is curved or straight in the air?
Click to expand...

I replied to this above. Assuming the wind and airspeed are constant, a straight path would remain straight regardless of reference, and same for curved.
 
RotorDude said:
...Your heading as indicated by your compass or DG is a bit trickier, since it can be affected by your attitude, e.g. if you keep flying straight over a road but somehow manage to flip over and fly tail first, even though your path over the ground is still the same, your "heading" will now be 180 degrees off...
Click to expand...

As absurdly silly as this example is it further shows an astonishing lack of understanding about the basic fundamentals of flying. First of all Heading is what you read on the compass and has nothing to do with anything else. There is no alternative definition. You could be in a J3 Cub on a heading of 270 deg doing 65 mph in a 100 mph headwind. You may be moving East at 35 mph but your Heading is 270 - period. It most definitely is NOT 180 degrees off and there's nothing "tricky" about it.

The more you post the more I scratch my head wondering where you are pulling all of this stuff out of :rolleyes:
 
Bobanna said:
For sure, but if it's in a crosswind, the "straight" groundtrack won't be keeping you on the (extended) runway centerline.
Click to expand...

That would depend on the track. If you properly compensate for the crosswind, you'll remain right over the runway, in either coordinated or uncoordinated flight. The only reason we fly uncoordinated over the runway is to align our gear to prevent sideload.
 
Silvaire said:
As absurdly silly as this example is it further shows an astonishing lack of understanding about the basic fundamentals of flying. First of all Heading is what you read on the compass and has nothing to do with anything else. There is no alternative definition. You could be in a J3 Cub on a heading of 270 deg doing 65 mph in a 100 mph headwind. You may be moving East at 35 mph but your Heading is 270 - period. It most definitely is NOT 180 degrees off and there's nothing "tricky" about it.

The more you post the more I scratch my head wondering where you are pulling all of this stuff out of :rolleyes:
Click to expand...

A "heading" generally means what you see on your DG.
But for ATC purposes, they expect you to be in coordinated flight, and expect your DG to be properly updated to match your compass, and the compass to be properly calibrated.
The "trickiness" is not the wind correction angle, ATC expects that.
But if you fly uncoordinated, or have a compass issue, that's not something they would know and could lead to confusion.
The point I was making about heading in relation to slips, is that a slip, which is by definition uncoordinated flight, will cause your indicated heading to be off as compared to your flight path, similar to your DG or compass being off.
 
RotorDude said:
I replied to this above. Assuming the wind and airspeed are constant, a straight path would remain straight regardless of reference, and same for curved.
Click to expand...

The only point of reference you can have to determine if a path in the air is straight or curved is the ground. So , I will ask you again, if you were to plot on a map the positions of a plane in a constant slip, and connect the plots with a pencil, would it reveal a curve or a straight line?
 
vintage cessna said:
The only point of reference you can have to determine if a path in the air is straight or curved is the ground. So , I will ask you again, if you were to plot on a map the positions of a plane in a constant slip, and connect the plots with a pencil, would it reveal a curve or a straight line?
Click to expand...

Again, a slip is just your attitude, not your flight path.
You could be in a constant slip while turning, or while going straight.
Either way it would "uncoordinated flight".
 
RotorDude said:
A "heading" generally means what you see on your DG.
But for ATC purposes, they expect you to be in coordinated flight, and expect your DG to be properly updated to match your compass, and the compass to be properly calibrated.
The "trickiness" is not the wind correction angle, ATC expects that.
But if you fly uncoordinated, or have a compass issue, that's not something they would know and could lead to confusion.
The point I was making about heading in relation to slips, is that a slip, which is by definition uncoordinated flight, will cause your indicated heading to be off as compared to your flight path, similar to your DG or compass being off.
Click to expand...

Uncoordinated flight will not make your compass or DG be off. You have fluid and gyros to take care of that. And ATC a doesn't care or know if you are uncoordinated and they don't care about any wind correction angle.
 
vintage cessna said:
Uncoordinated flight will not make your compass or DG be off. You have fluid and gyros to take care of that. And ATC a doesn't care or know if you are uncoordinated and they don't care about any wind correction angle.
Click to expand...

Wrong. If you fly with your nose constantly 10 degrees right of your flight path, your heading will be off by that amount. No fluid or gyro will compensate for that.
And if ATC then asks you to fly due North, and you put that on your DG, you'd be off by 10 degrees from what they expect from you.
Just like if your compass is uncalibrated (e.g. chunk of iron nearby), or you forgot to adjust your DG (assuming non-slaved).
 
RotorDude said:
Again, a slip is just your attitude, not your flight path.
You could be in a constant slip while turning, or while going straight.
Either way it would "uncoordinated flight".
Click to expand...

You have said a curved flight path is a turn. You have further said that when slipping with no wind you " turn" from your previous flight path. Ergo, a slip is a turn. Is that not what you have said? So, you must believe that if you were to plot on a map the positions of a slipped aircraft in no wind , the plots would reveal a curve?
 
RotorDude said:
Wrong. If you fly with your nose constantly 10 degrees right of your flight path, your heading will be off by that amount. No fluid or gyro will compensate for that.
And if ATC then asks you to fly due North, and you put that on your DG, you'd be off by 10 degrees from what they expect from you.
Just like if your compass is uncalibrated (e.g. chunk of iron nearby), or you forgot to adjust your DG (assuming non-slaved).
Click to expand...

Dude, in all sincerity, you've got some serious comprehension problems with this stuff. You need to sit down with the best ground / flight instructor you can find . Try to find someone who teaches ground school on a regular basis.
 
Last edited:
RotorDude said:
A "heading" generally means what you see on your DG...
Click to expand...

Not "generally" that's what it is, period.

I think I've finally got this figured out:

cliff-one.jpg
 
vintage cessna said:
You have said a curved flight path is a turn. You have further said that when slipping with no wind you " turn" from your previous flight path. Ergo, a slip is a turn. Is that not what you have said? So, you must believe that if you were to plot on a map the positions of a slipped aircraft in no wind , the plots would reveal a curve?
Click to expand...

If you are flying straight and level along a road, and then start a slip, with your nose pointed forward along the road, you will start a turn away from the road.
That's a very specific case. A slip is just an attitude, just like a bank (roll).
If you lower your wing in a coordinated turn, you'll also start a turn.
But the above doesn't mean you can't slip in a straight line, or bank in a straight line. Again you can fly straight or curved (turns) in either coordinated or uncoordinated flight. Slips = uncoordinated.
 
Silvaire said:
Not "generally" that's what it is, period.
Click to expand...

No, I said "generally" because when flying under ATC monitoring, "heading" is what ATC expects, not what your DG instrument might show.
And your DG might be off for various reasons, that I enumerated above.
Being in uncoordinated flight could be one of them.
 
vintage cessna said:
Dude, in all sincerity, you've got some serious comprehension problems with this stuff. You need to sit down with the best ground / flight instructor you can find . Try to find someone who teaches ground school on a regular basis.
Click to expand...

:rolleyes2:
 
RotorDude said:
No, I said "generally" because when flying under ATC monitoring, "heading" is what ATC expects, not what your DG instrument might show.
And your DG might be off for various reasons, that I enumerated above.
Being in uncoordinated flight could be one of them.
Click to expand...

If you decide to talk to ATC they do expect a certain level of knowledge and airmanship. Not as much from a GA pilot as professional though. If ATC assigns you a heading and you fly uncoordinated, they might not see the track they wanted. So they will assign you a new heading. For you to get to that new heading, you have to move the nose around to that new heading, no other way to comply. You could use only rudder or only aeileron, but you have to move the nose around. You need to understand that your DG will show the correct heading whether coordinated or not.

Your have these terms and concepts all jumbled up. You need to start over from the beginning.
 
vintage cessna said:
Well that is the problem, you just used the word "turn" to describe the motion in a slip. I now know what you mean when you say that. In the vocabulary of aviation, I (and probably Silvaire, and most others) have never seen the word " turn" used that way. To us, turn means a change of heading, not a change of flight path. What does your rate of turn instrument indicate in a slip?
Click to expand...

My thoughts exactly.
 
vintage cessna said:
If you decide to talk to ATC they do expect a certain level of knowledge and airmanship. Not as much from a GA pilot as professional though. If ATC assigns you a heading and you fly uncoordinated, they might not see the track they wanted. So they will assign you a new heading. For you to get to that new heading, you have to move the nose around to that new heading, no other way to comply. You could use only rudder or only aeileron, but you have to move the nose around. You need to understand that your DG will show the correct heading whether coordinated or not.

Your have these terms and concepts all jumbled up. You need to start over from the beginning.
Click to expand...

While it is true that flying uncoordinated by more than a few degrees is unlikely, having a non-slaved DG drift off, or the compass calibration being off, is quite common, and will cause ATC frustration as they try to vector you.
The point again is that when ATC gives you a vector, they expect that to become your flight path though the airmass you are in, which normally should be the direction of your nose relative to magnetic North at your location, in coordinated flight. Any significant deviation from that will cause confusion.
 
Last edited:
You must log in or register to reply here.
Back
Top