Wind correction / wings level

[Keith Black]

Thanks for the insight Don, great info. 

I have a question about stall turns and tail wobble after the 180 deg rotation. What's the best way to prevent the tail wobble, both in windy and calm situations?

Thanks,
Keith
  ----- Original Message ----- 
  From: Don Szczur 
  To: discussion at nsrca.org 
  Sent: Thursday, August 19, 2004 10:02 PM
  Subject: Re: Wind correction / wings level


  Ailerons are adjusted continuously.  For the Quique technique, the most dificult transition point is the top of a vertical 8, with half rolls at the crossover, entering inverted., for example, the Don Lowe final known..  The high altitude makes it difficult to see the wings (and difficult to adjust the roll rate to keep the wings constantly level).

  Comparing notes, for standard loops, like the 2 loops in Sportsman, my technique is to use the following steps:.  At 7 and 5 O'clock points, I adjust the ailerons to "spiral" the plane into the wind.  At the 10 to 2 O'clock positions, I adjust the rudder to "straighten" the fuselage with respect to the ground.  The net effect?  If there were no wind, the plane would be spiraling along the Z axis (coming in or going out). In the cross-wind however, the plane remains at exactly the same distance out.

  On vertical lines, I like to slip the plane.  In other words enter the part loop letting the nose come into the wind during the radius.  For example, pullng up on the left side of the box just let the plane naturally weather vane into the wind during the radius.  Now with the wind blowng from behind, at the completion of the radius, with no other inputs the plane will follow  a track that will find it coming toward the flight line pretty severely (with respect to the ground).  This is very obvious as a characteristic of smaller planes (you see this a lot on pull ups going into the stall turn during sportsman).  Now, what to do? As the plane completes the quarter radius, add in right rudder.  What the airplane is doing (if there was no wind at this exact moment) would be slipping through the vertical line at semi knife edge.  However, when you add in the crosswind component the plane tracks exactly vertical (with respect to the ground) yet will not drift with the wind.  I stress the importance of rudder-to aileron and rudder-to- elevator mix (knife edge) even in Sportsman because it will improve your stall turns- yes, knife edge mix (if your plane needs it) will improve your stall turn scores.  

  Holding a little rudder in until the stall turn is reached will continue this "slip" all the way to the  apex.  At this point, stop the right rudder and ad left rudder for the stall turn, which makes a clean, very well presented stall turn maneuver.  It took me 22 years to figure this out, first being at awe when watching Dave Brown do this in a Figure M at the 1983 nationals.

  See you,
  Don
    ----- Original Message ----- 
    From: Jim_Woodward at beaerospace.com 
    To: discussion at nsrca.org 
    Sent: Monday, August 09, 2004 9:12 AM
    Subject: Wind correction / wings level



    Hi All, 

    I want to bring up a discussion point about wind correction.  This may seem obvious to some but I want to ensure I have the right picture in my mind (started thinking about this since Don S. posted his comments about Q.S. flying wind correction in finals, and confirmed during some practice yesterday).   
    1.  Wind correction is supposed to be done while maintaining wings level. 
    2.  You are supposed to use the yaw angle to correct for the wind.   
    Situation:  Pilot is flying a square loop ( at center).  Wind is blowing 90 degree out 20 mph.  Pilot fly's past center at a some yaw angle in to compensate for the wind blowing out.  The pilot pulls a 90 degree radius to a vertical upline.  The fuselage is canted in to the wind to compensate for the wind blowing out.  *Point of discussion:  If the pilot were to pull another 90 degree radius, the wings would become "unlevel" as the plane reaches the top leg of the square loop.  *Point of discussion:  So, if the pilot is using the correct technique for wind correction (wind correcting force being yaw angle), then every time the pilot creates a radius, you should definitely "see" the ailerons moving the wings through the radius to ensure that as the radius is finished, the wings are level for the next line and the fuselage is yawed for wind correction.  Same thing next radiu s;  The pilot adds pitch, moves the wings,  and adds the correct rudder to transform the top of the box line to the next downline (wings level, yawed into the wind), etc.   

    *Point of discussion:  We spend a lot of time concentrating on wings level for normal pattern flying and usually "any" type of aileron or wing movement is a visual key for a downgrade using the 1 pt / 15 degree rule.  However, this is false to accurately judge flying on a windy day.  In order to fly in a crosswind, nearly EVERY radius will have some amount of roll induced (and necessary) to ensure that the "lines" can be flown with wings level and in order to utilize yaw as the wind-correcting force.   

    That said/ when and how much roll should be used?  I would guess that you would want to seamlessly input the pitch, aileron, and rudder so that the plane just appears to go from one wind corrected line to the other magically.  What is the judging criteria for inputting a roll function in the radius to ensure the wings stay level & fuselage stays canted (yawed) into the wind from one wind corrected line to another?  Should the amount of aileron needed to go from one wind corrected line to another line start and finish corresponding to the actual duration of the radius?  What if the pilot only correct s the wing as the plane is nearing the end of the radius, is this some downgrade because the correction was placed near the end of the radius instead of "evenly-througout" the radius? 

    I'm sure I'm exaggerating this situation and I am purposefully, to stimulate some talk on the subject.  Again, my contention is that for some wind conditions, in order to maintain the overall geometry of the maneuver that there MUST be roll correction during radii to seamlessly move from one wind corrected line to another, and this roll correction should not be downgraded.   

    Any takers? 
    Jim W. 
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