Runway Sideslip Drill?

Discussion in 'Flight Following' started by whifferdill, Feb 27, 2015.

  1. vintage cessna

    vintage cessna Cleared for Takeoff

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    CT, you say " you can not fly sideways but it sure looks like it".

    I have a question for you, and I'm not trying to be smart, argumentative or convince you otherwise. I'm just curious.

    If the FAA Airplane Flying Handbook, the author of Stick and Rudder, any Flying text book you can find (Jeppessen, Gleim etc) says that in a side slip the airplane will move sideways, why would you reject that in favor of what a couple of people on an Internet forum would say? Particularly since they have no authoritative reference to back their claims.
     
  2. Henning

    Henning Ejection Handle Pulled

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    Heading is only where the nose is pointing when in coordinated flight. Correct the compass for the ball and you have heading. Heading is the inertial vector through the fluid.
     
  3. vintage cessna

    vintage cessna Cleared for Takeoff

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    There is no possible way anyone, other than Wiffy perhaps, can have a conversation with you on this subject if you are going to make up your own definitions.

    Since heading is where the nose is pointing, your statement makes no sense.
     
  4. Henning

    Henning Ejection Handle Pulled

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    Heading is the direction you are moving, not pointing. If you walk down the side walk sideways, are you heading down the sidewalk or across it?
     
  5. Silvaire

    Silvaire En-Route

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    No Henning, heading is what you read on the compass. There is no inertial vector correction protocol and there is no alternate definition. If you are flying a Piper Cub in a 100 mph headwind it's still what you read on the compass despite that being 180 degrees from the direction you are actually moving.
     
  6. Henning

    Henning Ejection Handle Pulled

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    Heading is what you read on the compass in coordinated flight. Heading is the uncorrected direction of inertial momentum.
     
    Last edited: Mar 1, 2015
  7. Dennis McKim

    Dennis McKim Line Up and Wait

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    head·ing\ˈhe-diŋ\
    noun
    : the direction in which a ship or aircraft points
     
  8. Silvaire

    Silvaire En-Route

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    Nope, there are no additional qualifications, it's what you read on the compass - where your nose is pointed.
     
  9. Henning

    Henning Ejection Handle Pulled

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    It assumes coordinated flight. A ship can't get uncoordinated.
     
  10. vintage cessna

    vintage cessna Cleared for Takeoff

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    This is an Aviation Pilot forum right? Heading has been defined for pilots so everyone know what it means in an aviation context.

    Many aviation words were derived from the seafarers. You have a nautical background, if you were on a ship, what would heading mean?
     
  11. Silvaire

    Silvaire En-Route

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    You're on final in a crosswind and in a side slip (uncoordinated) your nose is aligned with the runway but the crosswind is so strong that you are drifting off to the right despite full side slip control inputs.

    What is your heading?

    Henning's reply: Hold on a sec...

    [​IMG]
     
  12. FastEddieB

    FastEddieB Final Approach

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    I always thought it was simply where the nose was pointed.

    That seems to be almost exclusively how it's used in flying.

    In MH + RB = MB to the station, MH is simply what you read off your heading indicator or compass or whatever, with appropriate corrections for deviation if necessary. I've not been introduced to the need for an "inertia correction".

    Just like "Fly heading 090°" is an instruction that needs no contemplation of inertia.

    Or navels, for that matter!
     
  13. vintage cessna

    vintage cessna Cleared for Takeoff

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    Winston Churchill said the best argument against democracy is to talk to the average voter.

    Please tell me there is not an equivalent saying for pilots.
     
  14. Henning

    Henning Ejection Handle Pulled

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    Well, if you had an inclinometer instead of a ball, it would be as simple as correcting the compass with the angle of deflection, no more difficult than correcting for variation or deviation. To determine heading, you apply those compass corrections, right? No different for being uncoordinated, it is just another compass error.
     
  15. Henning

    Henning Ejection Handle Pulled

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    Where the nose is pointing in coordinated flight is where the plane is heading, 'that way', uncoordinated flight introduces a compass error if you are using that as a reference.
     
  16. FastEddieB

    FastEddieB Final Approach

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    We're very, very close to debating how many magnetic angels it would take dancing on a compass card to affect an aircraft's heading.

    As such, I may sit this one out for a while.

    Until my return, one bit of advice...

    [​IMG]
     
  17. whifferdill

    whifferdill Line Up and Wait

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    Here is where communication falls to pieces here. You say going from a crab to a slip alters your ground track. Most of us think of ground track as your path along the ground, not where the nose is pointed. Do we at least agree there? I cannot understand how you can say going from a crab to a slip in x-wind causes your track to change. The whole point of a x-wind landing approach is to transition from a crab to a slip while staying on the runway track. What am I missing? The picture below is how most pilots land in a x-wind...track the runway in a crab and at some point before touchdown slip to align the nose, without changing track. You say you alter your track when entering a slip. So you do the runway drill angled approach method? That would be an unusual method.

    You give the example of wind increasing and decreasing. If you're on short final in a x-wind, slipped, tracking, and aligned with the runway and all of a sudden the x-wind increases, causing you to drift downwind of centerline, what's your solution? To slip harder, further deflecting both the aileron and rudder? That will do nothing to stop the drift. You will need to turn your flight path more into the wind to compensate for the increased x-wind. You DO need to turn.

    If the wind picks up and you're starting to drift, you need to do a slight slipping TURN into the wind to realign your flight path to track the runway. You do this by either reducing the rudder input or increasing aileron deflection. You need to change your ground track if you are drifting off centerline. Just as doing slips in no wind, like I've done in my videos, adding more aileron and rudder to the slip doesn't change your ground track, it just causes a greater yaw displacement.

    I wish we could get back to the real world of slips and x-wind ops and forget this type of "side slip" where from coordinated flight you enter a slip without changing your heading. Again, I don't know anyone who does this in the course of normal operations. Yeah, the drill is just a drill. Let's try to talk about real world, typical ops.

    When you go from a crab to a slip, all you're doing is yawing the nose for a smoother landing. You don't change your track. The aileron into the wind is NOT causing the airplane to "compensate for the x-wind". It's simply preventing the airplane from turning in the direction of the rudder used to align the nose. If you just skid with rudder, the airplane will move that way, wind or no wind. If you think the aileron is what's compensating for the x-wind, then using rudder alone (no aileron) in an effort to go from a crab to aligned with the runway should cause you to ONLY drift....not change heading. But if you do nothing but yaw the airplane with rudder, the airplane will start a constant TURN toward the downwind edge of the runway, and it will continue.

    All the aileron is doing when going from a crab to a slip is balancing the horizontal turning force of the rudder with the horizontal turning force of the ailerons. Until we recognize this, this conversation will theoretically spin in circles for eternity.

    PS: I believe you once said that if you are in a crab, tracking the runway in a LEFT x-wind, that if you enter a slip with right aileron and left rudder that you will drift off track, right of the runway centerline. Do you still believe this? I'm not talking about a slipping turn. I'm talking about a slip where the rudder and aileron forces are balanced. Normal constant flight path slip.

    [​IMG]
     
    Last edited: Mar 1, 2015
  18. CharlieTango

    CharlieTango Line Up and Wait

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    That simple definition works fine until you introduce yaw/side slips then you need a more precise definition that corrects for the yaw.

    If your destination was 10* left and you yawed 10* left you would never arrive for lack of a turn.
     
  19. Silvaire

    Silvaire En-Route

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    Okay, I at least see you have a sense of humor :wink2:
     
  20. Lindberg

    Lindberg Pattern Altitude

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    Are you using a different definition of "inclinometer"?

    http://en.wikipedia.org/wiki/Inclinometer
    http://www.aircraftspruce.com/menus/in/inclinometer.html
     
  21. Dennis McKim

    Dennis McKim Line Up and Wait

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    It assumes nothing beyond an understanding of the English language.
     
  22. Henning

    Henning Ejection Handle Pulled

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    Only in such that it is built to give a numeric ° reference rather than, 'ball in cage'- 'ball out of cage' level of information.
     
  23. FastEddieB

    FastEddieB Final Approach

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    I'm back!

    [​IMG]

    Mine, at the top center, shows more than that!

    I'm gone again!
     
  24. eetrojan

    eetrojan Cleared for Takeoff

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    I still think it works fine. In fact, isn't that just an example of why we speak of both "heading" and "course"? :D
     
  25. Henning

    Henning Ejection Handle Pulled

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    We use course when we reference a destination, we use track when we reference the surface, we use heading when we reference the fluid we are operating in. All three reference the inertial moment of the object.
     
  26. eetrojan

    eetrojan Cleared for Takeoff

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    While I just learned something about the subtle difference between course and track, I think I generally understand about heading, course, track, and even bearing.

    On the last sentence, moment or momentum? In either case, it doesn't make sense to me that directional concepts like heading, course, track, and bearing change based on such complications. Can you explain more?
     
  27. CharlieTango

    CharlieTango Line Up and Wait

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    I'm not referring to heading vs course but heading ( direction through air mass ) corrected for yaw. If you claim the DG shows heading and without that changing there is no turn then you have a conflict.

    You can do the side slip drill while keeping the runway heading on your DG and claim the changes in flight path are not turns because the simple definition of heading being used doesn't work.
     
  28. Henning

    Henning Ejection Handle Pulled

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    Bearing is the direction you are pointing regardless coordination or motion.

    Heading, course, and track all reference motion, they all lead somewhere, bearing is just a direction away from a position.

    It is not a necessary complication in planes, on ships where you have limited ability to counter the effects of the fluid environment moving, you have to do set and drift calculations and relay instructions in advance. There it is necessary to be accurate otherwise you end up aground.
     
    Last edited: Mar 1, 2015
  29. Lindberg

    Lindberg Pattern Altitude

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    How is this ever going to work if people keep making up their own definitions for commonly-understood words?
     
  30. vintage cessna

    vintage cessna Cleared for Takeoff

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    One reason you can claim it is not turn, is becuase if it were a turn , you could side slip and move about in a circle without changing your heading. And that is why the definition does work.

    Do you get that?
     
  31. vintage cessna

    vintage cessna Cleared for Takeoff

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    They are either making them up, or never understood what they meant in the first place.
     
  32. Henning

    Henning Ejection Handle Pulled

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    The problem is the 'commonly known' definitions are often incomplete or incorrect. When I started using Jack Thelander as a CFI and we went into aerodynamics (he was Chief Aerodynamics Engineer for Douglas) he said, "Everything you've learned about aerodynamics to this point, forget it, it's all wrong.":lol:
     
  33. Henning

    Henning Ejection Handle Pulled

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    I will bet I have a pretty decent grasp on these definitions using them professionally for over 30 years. When you have to use these terms to tell people how/where to drive, you need to have them right.
     
  34. vintage cessna

    vintage cessna Cleared for Takeoff

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    Except, heading, bearing, course etc are not aerodynamic terms, they are navigational terms.
     
  35. CharlieTango

    CharlieTango Line Up and Wait

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    The turn is limited by rudder authority. You can turn left or right ~15* and any further you could not maintain the 'heading' on your DG. A 360 is not possible but a 15* turn is.
     
  36. vintage cessna

    vintage cessna Cleared for Takeoff

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  37. Henning

    Henning Ejection Handle Pulled

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    Exactly, but they are still not being taught correctly.
     
  38. CharlieTango

    CharlieTango Line Up and Wait

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  39. vintage cessna

    vintage cessna Cleared for Takeoff

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  40. Vance Breese

    Vance Breese Line Up and Wait

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    I was taught that the rudder was for managing yaw and bank was for turning.
    Has this changed?