Ground Reference Maneuvers are low-altitude maneuvers designed to get you to understand the effects that wind has on your airplane while it is in flight.
The point of ground reference maneuvers is not just so that you understand the effects of winds, but that you can correct for the winds effect and make the plane do what YOU want it to do instead of just what it wants to do. In these maneuvers, you truly become a pilot, not just someone along for the ride.
For these maneuvers, your goal is to maintain a constant altitude and a constant airspeed. You should perform these maneuvers at an altitude between 600 & 1000 feet above ground level (AGL), and maintain the entry altitude you chose within 150 feet. Your airspeed goal is to maintain your entry airspeed within 10 knots indicated airspeed (KIAS).
There are three ground reference maneuvers you will do for your Private Pilot Certificate (or Sport, or Recreational, if that’s your thing):
- Turns Around a Point
- S-Turns
- Rectangular Course
This series will talk about all three of these maneuvers, and to kick it all off, we’ll start by talking about Turns Around a Point.
Turns around a point is, simply, a circle with a constant radius from a central point. Your job as the pilot is to correct for the wind and make sure that you maintain a constant distance from the selected point so that the airplane flies a perfect circle around it.
There are 4 “critical” points, but this maneuver is really about finesse and a constantly changing bank angle and wind correction. If you understand what each of the four critical points should look like and why, the rest of this maneuver will fall together pretty easily.
So let’s take a look at those critical points, shall we? Reference the image at the top:
Point 1: This is the beginning, or “entry” to the maneuver. It is “downwind,” meaning the wind is directly behind you, pushing you. You’ll choose a point to use, and then when the plane is “abeam” (to the side of) the point, you will start your turn. The reason this maneuver is generally started on the downwind leg is because your “ground speed” (actual speed over the ground) is fastest when you are downwind, so your rate of turn needs to be highest to maintain your distance from the point. This also (and most importantly) means that your bank angle will be steepest here. Keep in mind that “steepest” in regard to bank angle is relative – all this means is that your bank for the rest of the maneuver will never be steeper than at this point. It does not mean that you will be in a “steep turn,” which is a totally different maneuver!
Point 2: The next point is 90 degrees further around the circle, and is a direct crosswind. Here, your ground speed is slower than at point 1, and faster than it will be at point 3, so you will have a “medium” bank here, and you will have the airplane “crabbed” into the wind to maintain the track of the circling maneuver. You should have been slowly changing your bank and your crab angle the whole time from point 1 to point 2, and you will continue to slowly change them between point 2 and point 3.
Point 3: At point 3, you are 180 degrees from where you started, which means you are now pointed directly “upwind” (or into the wind). This means you will have the slowest ground speed, and commensurately, the “shallowest” bank angle relative to the rest of the maneuver. Also, notice that during upwind – point 3 – (and downwind – point 1), you have no “crab angle” like you do at points 2 & 4. This is because there is no crosswind at these points for you to correct for – you are flying directly into (or directly with) the wind. Point 3 is like the opposite of point 1 as far as ground speed and bank angle are concerned (point 1 = highest ground speed & steepest bank; point 2 = lowest ground speed & shallowest bank).
Point 4: At point 4 you have nearly completed the maneuver – you are again in a direct crosswind, so your ground speed will be faster than at point 3 (but still slower than point 1), meaning you will be in a medium bank here. You will also be crabbed into the wind here, similar to point 2. Notice that in point 2, however, you were crabbed toward the inside of the circle, but in point 4 you are crabbed toward the outside of the circle. Your crab angle will always point the nose of the plane into the wind.
The main thing to remember here is that your bank and crab angles are constantly changing to do this maneuver correctly… you don’t hold your steepest bank until you reach point 2, then change to a medium bank and add crab, then hold that until point 3, etc. Essentially, you will be thinking ahead of the plane and making slight, minute adjustments to get you from the configuration you need at point 1 to the configuration you know you will need at point 2, and so on.
There also is no “secret recipe” to getting this maneuver perfect every time. Each day you fly, the winds will be a little different – they may be higher or lower speed than they were last time, or they might be gusty, or you might be in a different plane than you were in last time you did turns around a point… the moral of the story is, you’re the pilot! You’ll need to estimate and correct to get it right – so if you find that the bank angle or crab angle you choose is too much or not enough, make the change and fix it!
There is at least one modification / alternative to this maneuver that I want to discuss, but that will have to wait for another post, so keep an eye out!
Do you have any tricks or suggestions on how to execute a perfect turn around a point every time? Turn them out in the comments, below!
Andrew Hartley is a certificated flight instructor in Columbus, Ohio.
PD Combs CFIA / ATP says
It is customary to depict and train a pilot to sight from the Left window for the first few maneuvers, since it is usually easier for them to see the ground and maneuver from that side- especially if in a side by side aircraft like a C-150, , or Cherokee, or other similar training airplane.
For this reason I believe that your depiction would be BETTER if it showed position #1 on the RH side, and position #3 on the LH side.
Also in the checklist FIRST should be to have the student clear the area, then TWO, locate his emergency landing site,THEN third locate the ground reference- because we all know the examiner will require a low altitude emergency from one of the (low altitude), ground reference maneuvers.
Les Glatt says
Just to let you know, one can derive the exact solution to the turn around a point. For any given wind speed the solution to a precise turn around a point is a function of the wind speed ratio Vwind/VTAS. This solution has never been published in the open literature. I have written a White Paper entitled “A New and Novel Approach to Understanding and Flying a Precision Turn Around a Point”. The exaction solution provides the exact bank angle and rate of change in bank angle that the pilot must utilize around the circle to execute a perfect turn around a point. This solution shows how the required bank input is truely very complex when making a precision turn around a point. If you are interested in this White paper, send me an email and I will send you a electronic copy.
Terry says
Mr Glatt, I would be very interested in receiving a copy of your paper. I’m a student pilot & have just started this portion of the training. My email is cs500@lycos.com. Thank you very much
Andre Middel says
Dear Les, I am interested and would like a copy of your white paper “A new and novel approach to understanding and flying a precision turn around a point” Thank you kindly, Andre Middel
Les Glatt says
Hi Andre,
Send me an email to lgtech@roadrunner.com and I will attach a copy of the white paper and email it back to you
Marvin says
Les,
Please forward your white paper “turns around a point”
Thank you in advance…
Marvin
Les Glstt says
Can you provide an email address.
Will forward this evening.
Les
Les Glatt says
Marv,
Please send me your email address and will reply with the attached white paper.
Regards
Les Glatt
Adam says
I would love a copy Mr. Glatt.
Adamb231986@gmail.com
Thanks