Forward slip

saracelica

saracelica

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saracelica
So a forward slip is one where the aeilron and rudder are opposite right? (Left aielron and right rudder)

Is there any other type of slip in an airplane you can do?


**This should not be a long thread**
 
A slip as a slip as far as I'm concerned...control configuration is the same across the board. I never understood the breakdown between the different "types". This should be interesting.
 
A “forward slip” is one in which the airplane’s
direction of motion continues the same as before the
slip was begun.

....................................

A“sideslip” is entered by lowering a wing and applying
just enough opposite rudder to prevent a turn. In a
sideslip, the airplane’s longitudinal axis remains parallel
to the original flightpath, but the airplane no
longer flies straight ahead. Instead the horizontal
component of wing lift forces the airplane also to
move somewhat sideways toward the low wing.
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http://www.faa.gov/library/manuals/aircraft/airplane_handbook/media/faa-h-8083-3a-4of7.pdf
 
Uh okay thanks Dan. Anyone care to explain the difference?
 
saracelica said:
Uh okay thanks Dan. Anyone care to explain the difference?
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In a forward slip, you take out a lot of throttle so that you lose the altitude you don't need.
 
If you're on final to land:

A forward slip: The nose of the aircraft turns away from the runway center line. Use this to lose altitude.

A side slip: The nose of the aircraft stays aligned with the runway center line. Use this for crosswind correction.
 
It's all about where you're aimed. Same control inputs, different ground track. ;)
 
TedR3 said:
If you're on final to land:

A forward slip: The nose of the aircraft turns away from the runway center line. Use this to lose altitude.

A side slip: The nose of the aircraft stays aligned with the runway center line. Use this for crosswind correction.
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Best explanation I've heard so far. Either way aircraft tracks runway centerline.
 
Sac Arrow said:
Best explanation I've heard so far. Either way aircraft tracks runway centerline.
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Optimist! If aircraft is operated somewhere in the vicinity of the airport and vaguely in the general direction of the centerline then I'll accept the descriptions. :D
 
saracelica said:
Uh okay thanks Dan. Anyone care to explain the difference?
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There are good graphics in the citation.

Consider where the nose is in relation to a ground reference to distinguish between the two.

nevertheless, it's a joyous wonder when a pilot can actually do a slip -- forward or side.

Slips are too rarely taught or employed.

Most ignorance has been caused by the "There's a slip prohibition with full flaps!" nonsense.
 
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Ain't no difference as far as the airplane is concerned. Rudder one way, stick the other. The difference is in the "intent" and in the FAA wordsmithing. In a "side slip", you are (in theory) trying to slip to keep the longitudinal axis in line with the ground track (compensate for a crosswind). In theory, a "forward slip" is to loose altitude and you no longer have the longitudinal axis of the aircraft aligned with the ground track.

The way to remember the which is which is to be aware that the whole point of trying to claim that they are different is nonsense, so it makes sense that the names of them are backward from what you are really doing - in a "side slip" you are looking forward to see where you are going. In a "forward slip" you look out toward the side to see where you are going.
 
I think of it like this: without the wind. Not thinking of a crosswind correction.

On final, no wind, no flaps (or full flaps) and you're high, so you cross the controls, either way, but the common way would be nose right (right rudder) and enough left aileron to keep the airplane from moving right. This cause drag and looses altitude, and you are still moving forward in the same original straight line in final that you were on. A forward slip.

On final, no wind, but you are on final for Runway Right on an airport with 2 parallel runways, and you decide (or tower tells you) to switch to Runway Left. You don't make a coordinated turn, but you lower the left wing with left aileron and apply enough right rudder to keep the nose parallel to the runways, and slide (or slip) left to re-align with the runway. This is a sideslip.
 
considering that airplanes fly relative to air-masses and don't much care where the ground is, there is no difference.
 
bartmc said:
considering that airplanes fly relative to air-masses and don't much care where the ground is, there is no difference.
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Except where the airplane moves (or doesn't move) relative to that ground.
When movement relative to that ground is important, like during TakeOff & Landing.
 
nosehair said:
Except where the airplane moves (or doesn't move) relative to that ground.
When movement relative to that ground is important, like during TakeOff & Landing.
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I've never seen an airplane change aerodynamic principals while in flight due to the location of some arbitrary point on the ground.

If you say forward slip vs side slip. I know the difference in the pilots motives for using a slip, the plane doesn't.
 
dmccormack said:
Most ignorance has been caused by the "There's a slip prohibition with full flaps!" nonsense.
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Indeed, I only slipped once in my 70 hours. My DPE set it up so that I had to slip for an engine-out procedure, and I remember being ridiculously clumsy about it. After the checkride, however, I used slips a lot, because on reflection I decided that I like that method better than kickout and I re-taught myself. I am not so sure about the roots of it though. I think I was too unreceptive to instruction and so was barely taught necessary basics. We accumulated a number of "postponed" items: accelerated stall, spins (our Cherokees are approved for spins when loaded within the utility category), IMC, timed turns (did those later). The lack of slips was definitely not rooted in a fear of slipping with flaps, and not even in a fear of snapping over if upwind wing stalls first.

P.S. I remember back then I read how Henning wrote that a "quick slip on final" was a great way to get rid of excess energy, and knowing that I would not be able to do it. It took me an intense thought process and concentration to figure out what inputs to enter in order to initiate slipping. It would not be "quick". So nostalgic.
 
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zaitcev said:
P.S. I remember back then I read how Henning wrote that a "quick slip on final" was a great way to get rid of excess energy, and knowing that I would not be able to do it. It took me an intense thought process and concentration to figure out what inputs to enter in order to initiate slipping. It would not be "quick". So nostalgic.
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Hmm, not sure I'm tracking you on this one. Slipping is indeed quick: rack the ailerons and push forward while stepping hard on the opposite rudder. Maybe you're really saying it's quick and I just don't track your comments. Slipped lots of times on short final to fine tune things...high and fast isn't so bad when you've got a fix.
 
bartmc said:
I've never seen an airplane change aerodynamic principals while in flight due to the location of some arbitrary point on the ground.

If you say forward slip vs side slip. I know the difference in the pilots motives for using a slip, the plane doesn't.
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But I'm not talking to the plane. I'm trying to describe the 'difference' between the forward and sideslip. Saying to a student 'there is no difference' isn't exactly correct.

You are making the aerodynamic point that here is no difference in the air mass, but there is a difference in movement over the ground as I described it, and in the 'difference' in the two movements.

A sideslip, in no wind, produces a sideward motion over the ground towards the lowered wing. If this lowered wing is to combat a crosswind, there will be no apparent sideways motion over the ground, so the airplane appears to move forward in straight line while in a sideslip. This, I think, is the confusing factor for most students who ask that question.
 
Sara, does it make sense to you yet? That's really the question at this point......
 
nosehair said:
But I'm not talking to the plane. I'm trying to describe the 'difference' between the forward and sideslip. Saying to a student 'there is no difference' isn't exactly correct.

You are making the aerodynamic point that here is no difference in the air mass, but there is a difference in movement over the ground as I described it, and in the 'difference' in the two movements.

A sideslip, in no wind, produces a sideward motion over the ground towards the lowered wing. If this lowered wing is to combat a crosswind, there will be no apparent sideways motion over the ground, so the airplane appears to move forward in straight line while in a sideslip. This, I think, is the confusing factor for most students who ask that question.
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I can side slip or forward slip in any wind condition without a thought to what's on the ground. The only "difference" is which window I chose to look out of.

If I go up to 9,000' AGL cross control the plane with no care in the world of what's on the ground, what am I doing? If I look out the side window, I'm forward slipping, if I look out the front window I'm side slipping.
 
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Obstacles at the approach end of a short field (trees, etc). I much prefer forwards slips to riding the stall horn down. Setup at normal short field speed, flaps full, just as you come over the trees, put in a full slip, drop it down and land normally.

Makes it super easy IMO.
 
During a side slip, the longitudinal axis of the airplane remains parallel to the runway centerline. In a forward slip, you'll see the runway out of the side window.

Forward slips are mostly for losing altitude. Side slips are mostly for cross winds.

Here's a very famous forward slip:

http://en.wikipedia.org/wiki/Gimli_Glider
 
Kiloalphadriver said:
During a side slip, the longitudinal axis of the airplane remains parallel to the runway centerline. In a forward slip, you'll see the runway out of the side window.

Forward slips are mostly for losing altitude. Side slips are mostly for cross winds.

Here's a very famous forward slip:

http://en.wikipedia.org/wiki/Gimli_Glider
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What if I'm high (due to obstacles) and dealing with a cross wind, then what am I doing?
 
bartmc said:
What if I'm high (due to obstacles) and dealing with a cross wind, then what am I doing?
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Not giving a hoot in hell what kind of slip you're doing. :) ...as should be the case in general. I think it's funny that people dwell on this silly side/forward slip thing, as if you're ever going to be on final approach, and ask yourself, "hmm, which one should I do?" ;) Pointless distinction, IMO.
 
bartmc said:
I can side slip or forward slip in any wind condition without a thought to what's on the ground.
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Yes, you can, but your movement over the ground will still be effected by the wind or no wind. You can slip without a thought to what's on the ground, but if you are aligning with a line on the ground, such as a runway, you have to have a thought about what's on the ground when you slip. Your control inputs cause the forward or sideward movement through the air, but your movement over the ground helps us understand that movement through the air.

You sideslip through a mass of air by applying aileron first, then enough opposite rudder to prevent the nose from following the lowered wing. If the air mass is not moving, the airplane will slip sideways over the ground to re-align with another ground reference, such as another runway. If there is wind, or a movement of the air mass you are slipping sideways through at, say, 10kts, and you effect a sideways movement through the air mass in the opposite direction at 10kts, you are staying laterally over the same place and looking straight out in front out the front window. With left aileron and right rudder.

If you are high and there is no wind and you apply rudder to off-set the nose, either way, and apply enough aileron to prevent the airplane fuselage from drifting away from centerline, and now you are looking out the left or right window at your ground reference point is not exactly choosing which window you look out as a 'difference'. It does point to one of the differences in the pilot's viewpoint diring either side or forward slip, but is not really all there is, since it matters about the wind.

If there is no wind and you are sideslipping, close to the ground, you would be looking out the side towards which you are slipping. If there is wind, and you are slipping to counter that wind, and you are close to the ground, you will be looking forward towards where the airplane is tracking.
[/QUOTE]
 
bartmc said:
What if I'm high (due to obstacles) and dealing with a cross wind, then what am I doing?
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I would forward slip over the obstacle, then go into a crab for the last bit to the runway, then kick it straight (cross wind landing technique). This way, you'll stabilize the high rate of descent before landing.

Also, I don't believe in side slips down final in x wind. Always a crab.
 
nosehair said:
Yes, you can, but your movement over the ground will still be effected by the wind or no wind. You can slip without a thought to what's on the ground, but if you are aligning with a line on the ground, such as a runway, you have to have a thought about what's on the ground when you slip. Your control inputs cause the forward or sideward movement through the air, but your movement over the ground helps us understand that movement through the air.

You sideslip through a mass of air by applying aileron first, then enough opposite rudder to prevent the nose from following the lowered wing. If the air mass is not moving, the airplane will slip sideways over the ground to re-align with another ground reference, such as another runway. If there is wind, or a movement of the air mass you are slipping sideways through at, say, 10kts, and you effect a sideways movement through the air mass in the opposite direction at 10kts, you are staying laterally over the same place and looking straight out in front out the front window. With left aileron and right rudder.

If you are high and there is no wind and you apply rudder to off-set the nose, either way, and apply enough aileron to prevent the airplane fuselage from drifting away from centerline, and now you are looking out the left or right window at your ground reference point is not exactly choosing which window you look out as a 'difference'. It does point to one of the differences in the pilot's viewpoint diring either side or forward slip, but is not really all there is, since it matters about the wind.

If there is no wind and you are sideslipping, close to the ground, you would be looking out the side towards which you are slipping. If there is wind, and you are slipping to counter that wind, and you are close to the ground, you will be looking forward towards where the airplane is tracking.
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[/QUOTE]


My point is, the maneuvers are identical. The only difference I can see with the pilot and plane would be which directions the pilots head was turned. The flying lesson here is that a slip is a slip, the rest is a vocabulary lesson.
 
My point is, the maneuvers are identical. The only difference I can see with the pilot and plane would be which directions the pilots head was turned. The flying lesson here is that a slip is a slip, the rest is a vocabulary lesson.
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Yes, it is that- a vocabulary lesson. That is what the original question was from the OP. There is a subtle difference, and the OP wanted to know.

The off handed response that there is no difference because the control inputs are the same, does the student-and instructor, no good.

But maybe this discussion has?
 
One of my very favorite Youtube airplane videos, he makes airplane handling a thing of beauty....

http://www.youtube.com/watch?v=wW8GRJI6Kz4

I was practicing slipping from abeam the numbers to the numbers last week. I'm not as pretty as him and I break the slip quite a bit higher, but I'm working on it.
 
That high tail taxi made me a bit squeamish with the notion of nosing over! But the slip was sure pretty
 
This has gone on for 20 more posting then I was hoping to read. Thanks everyone. Maybe I'll just go fly and ask the instructor for the difference (I was hoping not to have to ask)
 
If its a banana peel, you usually Foward Slip... Ice, on the other hand, usually results in a gymnastic split. Now, if, when that happens, your legs split left and right, its a side slip. If one goes forward and the other goes backward (as you fall on your face) that is referred to as a foward slip. :D
 
saracelica said:
This has gone on for 20 more posting then I was hoping to read. Thanks everyone. Maybe I'll just go fly and ask the instructor for the difference (I was hoping not to have to ask)
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Good thing you didn't ask about a 200nm cross-country...
 
saracelica said:
This has gone on for 20 more posting then I was hoping to read. Thanks everyone. Maybe I'll just go fly and ask the instructor for the difference (I was hoping not to have to ask)
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You asked, folks gave you different, yet mostly complementary, descriptions.

What's wrong with that?

:confused:
 
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