WHAT’S THE POINT OF GROUND REFERENCE MANOEUVRES?
Acknowledgements: John Zimmerman (SPORTY’S STUDENT PILOT NEWS)
“Confession: I hated ground reference manoeuvres as a student pilot. S-turns, turns around a point, rectangular courses - it all seemed like busy work; a way to rack up flight hours without learning anything or having any fun. I wanted to perfect my landings and learn how to fly 200-mile trips, and all this time locked in the practice area wasn’t helping.
Or so I thought. While it did take a while, my flight instructor finally broke through and explained why we were spending so much time on ground reference manoeuvres. He told me to stop focusing on the minutiae and the rigid test standards, and to start focussing on the bigger picture. We were really learning how to read the wind, how to visualise the airplane’s track over the ground, and how to coordinate control inputs. It was about aircraft mastery, and making it go exactly where we wanted no matter what the wind conditions.
This little speech worked. I didn’t instantly love turns around a point, but I did begin to appreciate that doing this simple manoeuvre really well was going to help me make better landings.
If your flight instructor hasn’t explained why you’re doing all these seemingly arbitrary manoeuvres (and I suspect many don’t), you may feel the same way I did. So instead of memorising a checklist or obsessing about two degrees of bank, let’s review the point of these exercises.
· Rectangular course
This one seems simple, and it really is, but that doesn’t mean it isn’t important. The whole idea here is to learn how to fly a perfect traffic pattern, which matters because a good landing results from a good approach. That’s harder than it sounds, as you’ll see if you attend a fly-in sometime, where patterns can vary wildly from perfect rectangles to abstract art patterns.
The key is to adjust for wind, and to do it almost without thinking. As obvious as it may sound, the first step to doing that is recognition .... you need to experience the effects of wind on ground track in relation to a ground reference point. That means choosing an appropriate reference point (the runway is an obvious one in the pattern) and adjusting to stay a consistent distance from it. Vary both heading and bank angle to keep the pattern rectangular throughout. But don’t just guess - have a rough idea of wind conditions before you start the manoeuvre, so you can start out with wind correction in place.
I’d also suggest you really focus on the first turn, simulating the downwind-to-base leg. This will require a steeper bank and a turn of more than 90 degrees, so that when you roll out on base you are correcting for the crosswind. Many pilots - even experienced ones - get sloppy here, and the result is overbanking on the base-to-final turn to get lined up on final. This not good and can set you up for a loss of control event.
Don’t stress about finding a perfectly square field and don’t stress about the length of the pattern. Focus on correcting for drift and making smooth, coordinated turns.
· Turns around a point
This is a nice complement to the rectangular course, because it allows you to practice those all-important turns in the pattern without levelling the wings. The goal is the same - keep the airplane a constant distance from your reference point (water towers are my favourite here) - but the technique is slightly different. You can’t crab into the wind with the wings level, so your only tool is bank angle.
The challenge here is to juggle a number of tasks simultaneously .... A common error is failure to divide attention between airplane control and orientation. It’s one thing to visualise your ground track throughout the manoeuvre, but it’s another to keep this updated while you’re varying the bank angle. If you find yourself focussed on one of those tasks for more than about 10 seconds, it’s probably time to check the other.
This is great practice for the traffic pattern, when things can get busy in a hurry and you must divide your attention. So, if you’re burned out on turns around a point, remind yourself that this is all about making better base and final turns - it’s not just academic.
· S-turns
The last of the “big three manoeuvres” was always my nemesis as a student pilot. It’s easy to visualise, but there’s actually a lot going on. This time the emphasis is learning to manage the effects of bank angle and groundspeed on both the rate and the radius of turn. A good S-turn is really just a turn around a point that’s been split in half, with one turn to the left and one to the right, so step one is to apply the lessons of the previous manoeuvre to this one. Visualise your ideal track, consider the wind, and decide ahead of time which turns will be steeper and shallower.
Once you have a plan in mind, start the manoeuvre over a nice, straight road or other landmark. Just like with the first two manoeuvres, try to start out headed downwind, so the first turn is the steepest (the downwind-to-base turn, once again). As you pass through 90 degrees, slowly but steadily shallow the bank until you’re wings level as you pass back over the road.
A challenge with S-turns is to stay co-ordinated. As you’re trying to adjust your ground track and vary the bank angle, it’s easy to either forget to use rudder or overdo it. You may think you’re “forcing” the nose to go where you want, but it’s not precise flying and could lead to bad habits. You always want to fly with the ball centred in the pattern. Always.
· Two advanced tips
By your third lesson, you’ll probably have been introduced to some or all of these manoeuvres; and as you gain experience, you should be increasing your proficiency and confidence.
1. Something I learned by accident one day might be helpful here: after you’ve learned the basics, go fly these manoeuvres when there’s some real wind. I found it pretty hard to see drift with 4 knots of wind, but during one lesson when it was blowing over 25 knots at 1000 feet AGL, the lightbulb went off. This might mean a tougher landing, maybe even one the flight instructor has to make, but I think you can learn a lot from such conditions.
2. You can also use modern technology to help you evaluate your performance much more precisely than I could 25 years ago. The easiest is ForeFlight’s track log feature, which allows you to record your ground track using your iPad’s GPS and then review it after your lesson. This is automatic and doesn’t have to distract you from flying, but it can really make a post-flight debriefing session come alive. Was your S-turn perfectly symmetrical? The track log doesn’t lie.
If you really want to geek out, use a GoPro to record video of your control inputs and panel instruments. You can load this into an app like CloudAhoy and see both your ground track and controls at the same time. Or use a Stratus to record complete flight data, including pitch and roll. This will allow you to see a glass cockpit instrument overlay while you play back your flight. Just remember to use these tools as enhancements to your training, and don’t let them get in the way of your flight instructor’s guidance!”
FLY SAFE!