Maneuvers and Wind Direction

8 Answers

1. 
   

   
   

   Nibake on Jan 04, 2015

   The reasoning for entering downwind on the rectangular course is clear, because it represents the basic elements of a traffic pattern. Also, turns around a point could be a precursor to steep spirals which also should end up putting you on downwind in the pattern. As far as S turns, I don’t know, maybe just to keep things consistent? Maybe just to make sure the student has even considered what the wind is doing at all?

   0 Votes 0 Votes  0 Votes

2. 
   

   
   

   Mark Kolber on Jan 04, 2015

   Dan said,
   After all, you can determine the max. bank later in the maneuver verse at the beginning of the maneuver.

   What bank will you use for that first turn starting from an upwind? What will the consequences of that selection be when you try to create a path of equal radius when you head downwind.

   Think it through.

   0 Votes 0 Votes  0 Votes

3. 
   

   
   

   Dan Chitty on Jan 04, 2015

   Turning upwind (headwind) in the S Turn case will result in a shallower bank.Turning downwind (tailwind) in the S Turn case will result in a steeper bank.

   Either way one would always be compensating as appropriate to maintain constant distance (radius) from reference point.

   For the S-Turn example, I respectably do not see the advantage or reason for beginning the maneuver with a tailwind.

   Let me know what I am missing.

   0 Votes 1 Votes  1 Votes

4. 
   

   
   

   Dan Stanchek on Jan 04, 2015

   The amount bank you use to start the maneuver will dictate the amount of bank required when going in the opposite direction in order to maintain equal radius. If you start the maneuver upwind and use a steep bank, then you will need to use an extremely steep bank (if significant wind exists) when the turn progresses into the downwind. When you start the maneuver downwind, you are using the steepest bank at the onset, and your required bank angle will steadily decrease as you enter the upwind. This will prevent you from starting the maneuver at too steep a bank angle, forcing you to possibly have to use an unsafe bank angle later in the maneuver in order maintain equal radius.

   +3 Votes 3 Votes  0 Votes

5. 
   

   
   

   Dan Chitty on Jan 05, 2015

   Thanks to all for the feedback.

   However, the objective is for the pilot to judge and adjust bank angle accordingly to maintain a constant radius from the road. So, it should make no difference if this maneuver is started with a tailwind or headwind. Either way, the airplane will encounter both a headwind and tailwind at different times during this maneuver of which will expose the pilot to adjust bank angle accordingly.

   Any additional thoughts appreciated.

   -1 Votes 0 Votes  1 Votes

6. 
   

   
   

   Mark Kolber on Jan 05, 2015

   Dan, what you are missing is that there is in fact a maximum bank for the maneuver. Although the PTS no longer specifies approximately 45° as the maximum, the description of the maneuver in the AFH does. At best, the examiner will either specify the maximum bank or ask the applicant to say what it is.

   So, you are taking the checkride and using the 45° maximum bank. If you enter on the downwind, no problem. Enter the maneuver, crank in the 45° and you are good to go.

   But let’s say you enter on the upwind – this is why I asked you earlier what bank you will start with (and I notice you didn’t answer it) and pick a nice, safe 30°. The winds are, oh, say, 10 knots so your nice 30° bank at an entry IAS of 90 is done at a GS of 80; You make your turn and your GS inreases to 100, requiring a pretty substantial bank, likely exceeding your max 45° bank. So now you are doing overbanked steep turns, perhaps needing to exceed your 45° to maintain your ground track while using throttle and pitch to handle the increased load factor and maybe even entering an accelerated stall since you art trying to keep both altitude and IAS constant. All within 600-800 AGL.

   Yes, it would be a wonderful test of pilot skills. Frankly, I’d prefer to do lazy 8s – they’d be much easier.

   Fortunately, the PTS requires the pilot to understand and plan the maneuver so that he or she will not exceed tolerances. And the best planning is to enter upwind so that the maneuver is a pleasant easy one. that one can do while sightseeing over a battleship of Lanai (don’t know if this list will allow images but…)

   https://www.dropbox.com/s/0isv2kmsu97ufzc/Turns%20About%20a%20Battleship%20Small.jpg?dl=0

   +1 Votes 1 Votes  0 Votes

7. 
   

   
   

   Kris Kortokrax on Jan 05, 2015

   Mark,

   The AFH does list 45 degrees as a max for Turns around a Point and Rectangular Course, but not for S Turns. I’m looking at FAA -H-8083-3A.

   AFH states that you “should” enter downwind. Not mandatory language.
   PTS doesn’t contain a requirement to enter downwind.

   Dan,

   There is a requirement that the radius be radius be the same on both sides of the road. While you might conceivably enter into the wind and maintain a constant radius turn on the upwind side of the road, you would not necessarily be able to maintain the same radius on the downwind side while observing a reasonable maximum bank. At steeper bank angles, things happen faster. Your chances of arriving at the 180 point with wings level and perpendicular to the road would be less.

   You can go out and practice the maneuver any way you want, however, when it comes time for a practical test when you must demonstrate it or teach it (CFI ride), what’s the problem with following the recommended procedure?

   If you are seeking the FAA logic (an oxymoron) for the maneuver, your best bet would be to send an email to AFS630comments@faa.gov, the email address shown on page iii of the AFH. When you get an answer, please share it with us.

   +1 Votes 1 Votes  0 Votes

8. 
   

   
   

   Dan Chitty on Jan 07, 2015

   Much appreciated for the feedback. Very helpful.

   0 Votes 0 Votes  0 Votes