What is it + How To: S-Turns
In preparation for our first attempt at performing S turns, we're going to take a few minutes to discuss the key elements of the maneuver. As with all other maneuvers, an S turn has three main areas that the pilot needs to concentrate on, directional control, altitude control, and airspeed control.
The primary intent of performing S turns is to teach pilots how to compensate for the effects of wind on the plane's ground track by using varying bank angles. This means bank control will be the central feature in this maneuver heading. References will be used more for orientation than for any other purpose because the pilot's attention will be primarily on the reference line and the plane's position relative to it. To break the maneuver down in a simple way, think of it as making 2, 100 and 80 degree turns in opposite directions. The first 100 and 80 you will be making is on the downwind side of the reference line, the other is on the upwind side.
On the downwind side the bank will be continually decreasing and on the upwind side the bank will be continually increasing. You enter the turn on a downwind. During your first turn you'll start with your maximum bank not to exceed 45 degrees AZ. Your wings cross the reference line as the tailwind changes to a crosswind and then to a headwind. The bank angle must be reduced accordingly. To maintain the symmetry of the turn. Begin reducing that bank in a way that will result in a symmetric half circle.
On the up one side it's just the opposite. You will start with your minimum bank as your wings cross the reference line and continually increase the bank until right before you cross over the reference line going the opposite direction. At that point you will need to rapidly roll out the bank so that the wings are level as you cross over the line. Because your ground speed is greater on the downwind portion of each turn, your rate of turn will have to be greater. This means you will have less time to complete those segments of the turn compared to the upwind portions. During this portion of the turn, the nose of the airplane will need to be crabbed progressively towards the reference line to keep the radius of the turn from increasing. On the upwind portion the airplane will be turned in a crab away from the reference to keep the radius of the turn from decreasing. The stronger the wind, the more noticeable this will be. You should be aware of this aspect of the maneuver and avoid the tendency to try and hurry the upwind portion.
Additionally, do not try to hurry or slow the turns by using more or less ruder than that required for proper coordination. Although you can use the rudder to yaw the plane one way or another, failure to maintain proper coordination will be considered unsatisfactory performance.
S turns should be performed at 1 thousand feet AGL. Establish your altitude. Prior to entering the maneuver, pick a suitable reference line based on the wind, being perpendicular to the wind. Roll into the first turn, pivoting about a point on the horizon. Use primarily visual references, but also cross-check your instruments to confirm you are maintaining altitude. The primary flight instrument you'll be using to control the pitch is the attitude indicator. Since the bank varies throughout the maneuver, the back pressure on the yoke will have to be increased when flying downwind where you use the greatest bank and decreased when flying upwind where you use the shallow bank back up the attitude indicator with your altimeter and VSI to maintain your altitude. If you lose or gain altitude, make the appropriate pitch and power adjustments but do not change the bank angle from what is required to complete the maneuver. Satisfactorily.
The airs speed to be used for S turns as 100 knots. Once you have selected your reference line and are established at 1 thousand feet. AGL set the power to approximately 2200 rpm to maintain 100 knots. Trim the airplane for that speed. A slight increase in power may be necessary if you roll into 30 degrees or more a bank, but be sure to reduce that power when the bank is less than 30 degrees. Normally only small power adjustments will be needed to maintain the airspeed within ten knots of the entry speed.
When the plane is directly over the reference point roll into your steepest bank not to exceed 45 degrees. It is recommended that you make the first turn to the left so that you have a better view of the ground track, but a turn in either direction is permissible. As the plane turns, the bank will need to be reduced gradually to keep the radius of the turn constant. Remember, the ground speed of the airplane determines how much bank will be needed. The faster the ground speed is, the deeper the bank required. The slower the ground speed is, the shallower the bank required.
As the plane passes through the 90 degree point of the turn, note your distance from the reference line. This is the same distance that you will need to be on the upward side of the reference line. From this point, the bank will continue to be gradually reduced so that the plane is perpendicular to the reference line as you cross over it. Now that the plane is flying directly into the wind, your ground speed is at its lowest, which means the bank angle will be at its shallow roll in the bank at a rate that will allow the plane to get the same distance from the reference line as you were on the downwind side. For the last 90 degrees of the turn, the bank will be increased as the ground speed increases. Just prior to reaching the reference line, the bank will need to be rolled out rapidly so that the wings are leveled just as the plane crosses the line. After completing the second turn, set the cruise power re-trim as necessary and complete the cruise checklist.
Summary/Testing Your Knowledge:
1. Select a suitable ground reference line.
2. Plan the maneuver as to enter at 600 to 1 thousand feet AGL perpendicular to the selected reference line.
3. Apply adequate wind drift correction to track a constant radius turn on each side of the selected reference line.
4.Reverse the direction of the turn directly over the selected reference line.
In preparation for our first attempt at performing S turns, we're going to take a few minutes to discuss the key elements of the maneuver. As with all other maneuvers, an S turn has three main areas that the pilot needs to concentrate on, directional control, altitude control, and airspeed control.
The primary intent of performing S turns is to teach pilots how to compensate for the effects of wind on the plane's ground track by using varying bank angles. This means bank control will be the central feature in this maneuver heading. References will be used more for orientation than for any other purpose because the pilot's attention will be primarily on the reference line and the plane's position relative to it. To break the maneuver down in a simple way, think of it as making 2, 100 and 80 degree turns in opposite directions. The first 100 and 80 you will be making is on the downwind side of the reference line, the other is on the upwind side.
On the downwind side the bank will be continually decreasing and on the upwind side the bank will be continually increasing. You enter the turn on a downwind. During your first turn you'll start with your maximum bank not to exceed 45 degrees AZ. Your wings cross the reference line as the tailwind changes to a crosswind and then to a headwind. The bank angle must be reduced accordingly. To maintain the symmetry of the turn. Begin reducing that bank in a way that will result in a symmetric half circle.
On the up one side it's just the opposite. You will start with your minimum bank as your wings cross the reference line and continually increase the bank until right before you cross over the reference line going the opposite direction. At that point you will need to rapidly roll out the bank so that the wings are level as you cross over the line. Because your ground speed is greater on the downwind portion of each turn, your rate of turn will have to be greater. This means you will have less time to complete those segments of the turn compared to the upwind portions. During this portion of the turn, the nose of the airplane will need to be crabbed progressively towards the reference line to keep the radius of the turn from increasing. On the upwind portion the airplane will be turned in a crab away from the reference to keep the radius of the turn from decreasing. The stronger the wind, the more noticeable this will be. You should be aware of this aspect of the maneuver and avoid the tendency to try and hurry the upwind portion.
Additionally, do not try to hurry or slow the turns by using more or less ruder than that required for proper coordination. Although you can use the rudder to yaw the plane one way or another, failure to maintain proper coordination will be considered unsatisfactory performance.
S turns should be performed at 1 thousand feet AGL. Establish your altitude. Prior to entering the maneuver, pick a suitable reference line based on the wind, being perpendicular to the wind. Roll into the first turn, pivoting about a point on the horizon. Use primarily visual references, but also cross-check your instruments to confirm you are maintaining altitude. The primary flight instrument you'll be using to control the pitch is the attitude indicator. Since the bank varies throughout the maneuver, the back pressure on the yoke will have to be increased when flying downwind where you use the greatest bank and decreased when flying upwind where you use the shallow bank back up the attitude indicator with your altimeter and VSI to maintain your altitude. If you lose or gain altitude, make the appropriate pitch and power adjustments but do not change the bank angle from what is required to complete the maneuver. Satisfactorily.
The airs speed to be used for S turns as 100 knots. Once you have selected your reference line and are established at 1 thousand feet. AGL set the power to approximately 2200 rpm to maintain 100 knots. Trim the airplane for that speed. A slight increase in power may be necessary if you roll into 30 degrees or more a bank, but be sure to reduce that power when the bank is less than 30 degrees. Normally only small power adjustments will be needed to maintain the airspeed within ten knots of the entry speed.
When the plane is directly over the reference point roll into your steepest bank not to exceed 45 degrees. It is recommended that you make the first turn to the left so that you have a better view of the ground track, but a turn in either direction is permissible. As the plane turns, the bank will need to be reduced gradually to keep the radius of the turn constant. Remember, the ground speed of the airplane determines how much bank will be needed. The faster the ground speed is, the deeper the bank required. The slower the ground speed is, the shallower the bank required.
As the plane passes through the 90 degree point of the turn, note your distance from the reference line. This is the same distance that you will need to be on the upward side of the reference line. From this point, the bank will continue to be gradually reduced so that the plane is perpendicular to the reference line as you cross over it. Now that the plane is flying directly into the wind, your ground speed is at its lowest, which means the bank angle will be at its shallow roll in the bank at a rate that will allow the plane to get the same distance from the reference line as you were on the downwind side. For the last 90 degrees of the turn, the bank will be increased as the ground speed increases. Just prior to reaching the reference line, the bank will need to be rolled out rapidly so that the wings are leveled just as the plane crosses the line. After completing the second turn, set the cruise power re-trim as necessary and complete the cruise checklist.
Summary/Testing Your Knowledge:
1. Select a suitable ground reference line.
2. Plan the maneuver as to enter at 600 to 1 thousand feet AGL perpendicular to the selected reference line.
3. Apply adequate wind drift correction to track a constant radius turn on each side of the selected reference line.
4.Reverse the direction of the turn directly over the selected reference line.