S-Turns, Explained: How to Fly Even Half Circles Across a Road
S-turns are where the wind stops being a weather report and starts being something you can feel. You'll fly a series of half circles back and forth across a straight road, and the challenge is to make every half circle the same size, even though the wind is pushing you around the whole time.
It's a ground reference maneuver, which means you fly a path over the ground instead of just pointing the airplane in a direction. That's exactly what you do in the traffic pattern on every landing. Here's how S-turns work and how to fly them.
What are S-turns?
You pick a straight road, fence line or other line on the ground that runs at a right angle to the wind. Then you fly a series of 180 degree turns of equal size on alternating sides of it. From above, your path looks like a row of the letter S.
Every time you cross the road, your wings should be level and you should be crossing at a right angle. That's the check that tells you your half circles were the same size.
Why the wind changes everything
With no wind, S-turns would be easy: hold the same bank angle and you'd draw perfect half circles. But with wind, your speed over the ground changes as you turn. Heading downwind, the wind is pushing you along, so your groundspeed is high. Heading upwind, it's holding you back, so your groundspeed is low.
To draw an even half circle on the ground, you have to turn faster where you're moving faster. That means a steeper bank downwind and a shallower bank upwind. Getting that bank change smooth and gradual is the whole skill.
Before you start
Ground reference maneuvers happen low, between 600 and 1,000 feet above the ground, so the setup matters. Here's the checklist we use for both S-turns and turns around a point.
How to fly S-turns, step by step
| Step | What to do |
|---|---|
| 1. Find your road | Pick a long, straight road at a right angle to the wind, away from towers, houses and other airplanes. |
| 2. Set up | Fly between 600 and 1,000 feet above the ground at your cruise or training airspeed. Pick an emergency landing spot. |
| 3. Enter downwind | Cross the road heading downwind, wings level, at a right angle to the road. |
| 4. Steepest bank first | As soon as you cross, roll into your steepest bank, since your groundspeed is highest. Keep it at or below 45 degrees. |
| 5. Shallow it out | As you turn toward the wind, gradually shallow your bank. You'll crab into the wind halfway through the turn. |
| 6. Cross wings level | Roll your wings level just as you cross the road heading upwind, at a right angle. |
| 7. Reverse and repeat | Roll into a shallow bank the other way, then steepen it gradually as you turn back downwind. Cross the road wings level again. |
The checkride standards
Your examiner will pick one ground reference maneuver: a rectangular course, S-turns or turns around a point. Here's what the Private Pilot ACS asks for:
| Standard | What you're aiming for |
|---|---|
| Altitude band | Between 600 and 1,000 feet above the ground. |
| Altitude | Your chosen altitude, within 100 feet. |
| Airspeed | Your chosen airspeed, within 10 knots. |
| Bank angle | No more than 45 degrees at the steepest point. |
| Ground track | Equal half circles on each side of the road, with wind correction. |
| Situational awareness | Divide your attention between the airplane, the ground and other traffic, and always know where you'd land. |
Tips that make it click
Look at the ground, not the gauges. Your target is a shape on the ground, so that's where your eyes belong. Pick a spot on the far side of each half circle as an aiming point.
Change the bank gradually. A good S-turn has no sudden jumps in bank, just a smooth, steady change from steep to shallow and back.
Watch your altitude in the steep part. When you're banked steeply downwind, the airplane wants to descend. Add a little back pressure, just like in a steep turn.
| Mistake | The fix |
|---|---|
| Downwind half circle is too big | Start with a steeper bank as soon as you cross the road heading downwind. |
| Upwind half circle is too small | Start shallow and let the bank build gradually as you turn back downwind. |
| Crossing the road in a bank | Time your rollout so your wings are level exactly as you cross. |
| Losing altitude | Add back pressure as the bank steepens, and scan the altimeter often. |
| Fixating on the road | Keep scanning for traffic, towers and birds. You're low, so stay sharp. |
| Drifting off your road | Make sure the road really runs at a right angle to the wind before you start. |
Why it matters after the checkride
Every traffic pattern is a ground reference maneuver. When you turn from base to final with a tailwind, you'll need a steeper bank to line up with the runway, and you'll know why. S-turns train your eyes and hands to handle that without thinking about it.
Around Tampa Bay, the wind often picks up in the afternoon. That's great for ground reference practice, because a breezy day makes the bank changes easy to see and feel.
Ready to fly?
The best way to understand the wind is to fly in it. Book a $199 discovery flight at Tampa Executive Airport, and let's go fly.
