[NSRCA-discussion] Wind correction

[Earl Haury]

Throttle management in the wind can be mind boggling! The pilot / judges are 
observing the ground speed of the aircraft - yet the aircraft only knows 
airspeed - changing airspeed in a headwind / tailwind to provide "constant" 
ground speed will have a big effect on control "feel" and input "timing".

Really interesting things occur in uplines / downlines with the presence of 
significant wind. Power required to draw a vertical line (vector) of some 
speed without wind = X, add some attitude (pitch / yaw) into a wind and that 
vector portion (from vertical) requires Y power. For like speed, vertical 
lines in the wind power requirement is X + Y. Or, use X power and the allow 
the line to be slowed by the power used for Y to maintain track, but the 
slowing will require even more pitch / yaw.  We probably all need to think 
more about downlines also - attitude change of a "falling" airplane in a 
moving body of air has little effect without power to compensate for the air 
mass movement. Oh - and in both cases higher speed provides less time for 
the wind to effect the track so less windage vector is needed. Comments?

Earl




----- Original Message ----- 
From: "Adam Glatt" <adam.g at sasktel.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, August 14, 2006 9:14 AM
Subject: Re: [NSRCA-discussion] Wind correction


> Hi John.  Welcome to the game of wind correction.  There's flying
> pattern, and then there's flying pattern in the wind.  The difference is
> that in the wind you have to mentally trace the change in position of
> the airplane to determine the correct pitch and yaw to fly at.  In calm
> you simply point the plane where you want to go.
>
> Perfect wind correction in pattern requires the wings be held level with
> the horizon for all normal flight, and during rolls the points are still
> perfect 45 or 90 degree banks from level with horizon.  Wind correction
> is completely in the yaw and pitch.  In practice, this results in
> techniques like always-present yaw angle in a crosswind; slight pitch
> angles in any and all uplines, 45s, and loops in the presence of a down
> the runway wind.
>
> There are more techniques that you will need to be perfect at it.  The
> more advanced ones include higher throttle while flying upwind and lower
> while flying downwind, varying elevator position throughout any and all
> looping segments in a down the runway wind to achieve a truly round loop
> (if, during the loop, you go from straight up to upwind you will need to
> decrease your elevator input, as the plane will have a high airspeed by
> low ground speed; if, during the loop, you go from straight up to
> downwind you will need to increase your elevator input), and  the
> trickiest of all, aileron correction during a yaw'd pitch change (i.e.
> every time you use elevator in a crosswind).
>
> That last one is often completely overlooked until someone tells you
> about it.  The best way to realize this correction is needed is with a
> stick plane or hand plane. Fly a level horizontal at a huge yaw angle to
> compensate for a huge crosswind.  So, fly straight but have your plane
> yaw'd 45 degrees.  Now pull elevator.  Remeber, the elevator raises the
> noise relative to the tail.  As the nose lifts and eventually gets to a
> vertical, and if you've been honest with yourself, the ailerons are now
> banked.  The only solution to this is aileron input during the elevator
> input.
>
> Have fun in the wind.
>
> -Adam
>
> John Konneker wrote:
>> I'm new at this.
>> OK, not really but it's been over 20 years.
>> Yesterday while practicing in enough crosswind (blowing in) to have a
>> noticeable effect I was having difficulty keeping the plane form coming 
>> in
>> too close.
>> I am confused about what the acceptable techniques are to maintain 
>> position
>> and ground track.
>> Is it acceptable to fly a maneuver with less than wings level to 
>> counteract
>> the crosswind?  This has the effect of corkscrewing the loops, etc.
>> In the stall turns while going up trying to hold the plane into the wind 
>> it
>> will begin to yaw early giving the impression that the turn is being 
>> "lead"
>> and is starting too early.
>> Is this acceptable.
>> Like I said, I'm confused as to what is wind correction and what starts 
>> the
>> "1 point per 15 degree" deductions.
>> Thanks!
>> JLK
>>
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