Art of the Turn

Friends- This one is important. This one, you have to read. This one can save your life. Ever since people began keeping records, one third of the fatal aviation accidents have been caused by aircraft stalling and spinning into the ground when the pilot tried to make his last turn or two to line up with the runway. I’m not just talking about gliders. I’m not just talking about small personal aircraft. I’m not just talking about US pilots, or last year’s accidents. I’m talking about a statistic that hasn’t changed in 100 years, regardless of education programs and training requirements. Now we all know how to make our gliders turn. And we all know how to make our gliders stall. There are aircraft out there that are much more easily stalled than out gliders, and there are aircraft out there that are much more willing to spin than our Grobs, but very few aircraft designed since the 1920s will spin or even stall without the pilot putting in some unusual control inputs. An aircraft will not stall unless its nose is held fairly high. In fact most wings have a critical angle of attack of about 17 degrees. That is significantly higher than in normal flight. Most general aviation aircraft, give a pilot a lot of warning before they stall. Getting most aircraft to spin is even more difficult. Not only do you need to stall at least part of the wing, but you need to force the matter by using too much rudder to skid the aircraft into the turn. At PGC, we make a point of teaching our pilots to recognize the signs a glider gives before it stalls: You have to be pulling back on the joy stick to force the glider to slow down, so the first sign is excessive back stick pressure. That makes the glider’s nose rise higher than it is in normal flight, so the second sign is simply seeing that the nose is high. Once you pull back on the stick and make the nose rise, the glider starts to slow down. If you glance at the airspeed indicator, you will notice that the glider is flying slower (40 knots or so) than in normal flight. If you are not looking at the air speed indicator, you will notice that the glider is flying slowly because you will hear that it is getting quieter. When we are flying slower than normal, there is less air flowing across our control surfaces, so you will notice that the controls feel mushy. It takes bigger movements of the joy stick or rudder peddles to make the glider respond. Finally, if you fly slow enough and the wing starts to stall, you will feel buffeting as the air separates from the top of the wing, and the turbulence flows across the elevator. So if we have to do some unusual things to make a glider stall, and the glider gives us so many clues that it is about to stall, I use to wonder how anyone could ever stall and spin a glider into the ground. After a few years of instructing, the answer became obvious. When a new student learns to fly any aircraft, their first challenge is learning to make a good turn. It is the lift from the wing that turns the aircraft, so you have to move the stick to the left or right to bank the wing. When you do that, the extra forces needed to both lift the aircraft and turn it cause the nose to want to drop, so you have to pull back on the stick to maintain your pitch attitude (speed). The drag produced by the ailerons causes adverse yaw, turning the nose of the aircraft away from the intended turn, so you have to use the rudder to coordinate the turn. Once you have turned to the direction you want to go, you have to reverse all of these motions to return to straight and level flight. Every new student struggles to coordinate their turns. We go up to a high altitude and we practice again and again until the action becomes smooth and natural. Whether I am flying with a new student, or an a professional pilot who has hundreds of hours in gliders, when we go up to altitude and ask them to show me some turns, they look around to clear the turn, and then they look straight ahead thru the yaw string and focus on the horizon. Good pilots make the glider behave as if the yaw string was painted on the canopy, and the glider was on rails. New student struggle, pulling back on the stick when they see the nose of the glider dipping, and stepping on the correct rudder peddle to bring the yaw string back to center. Eventually, everyone gets it, and the skill becomes natural. It seems impossible for anyone with that skill to accidentally stall and spin. What amazed me as a new flight instructor was seeing pilots who make wonderful turns at altitude, make horrible turns when they are getting ready to land ten minutes later. Suddenly they start flying too fast or too slow, and the yaw string starts acting like a wind shield wiper. Usually they pull back on the stick when they pull into the turn and the glider starts flying too slow. I found myself reminding pilots to watch their yaw string, and watch their airspeed. I know that the glider does not behave any differently when it is close to the ground, so I had trouble understanding how pilots could suddenly loose the skills to turn. It took awhile, but the answer is obvious. A power flight instructor sitting next to their student does not have the advantage that I have sitting in the rear seat. I can see where the student is looking, and that makes all of the difference. Remember, I said that at a high altitude a pilot will look straight ahead through the yaw string, focusing on the horizon while they make a turn. If their nose starts to drop, or rise, they will see it, and make an instant correction with the stick. If the yaw string starts to wander, they will see that and make an instant correction with the rudder peddles. The response is completely natural. Most pilots are not using those same skills in the landing pattern where they matter the most. Instead of looking through the yaw string, focusing on the horizon while they make a turn, THEY ARE LOOKING AT THE RUNWAY. They might as well be closing their eyes. When I point out that they got slow during their turn, they are completely surprised. When I tell them that their rudder was uncoordinated in the turn, they were totally unaware. I’m not talking about student pilots on their first attempt at landing. I see this with pilots of all backgrounds and levels of experience. Many are surprised by my comments. To make matters worse, the more stress the pilot is under, the more likely he is to make a bad turn without even noticing. If he is feeling a little low, his arm muscles will tense up and he’ll pull back on the stick. He’ll rush the turn with too much rudder without even noticing. From the rear seat it became obvious to me how a pilot could let a bad turn become a stall and spin without any clue that it was about to happen. So what is the cure? It’s easy and free. We can stop pilots from ever having stall/spin accidents in the landing pattern again. All we have to do is learn to make our turns in the landing pattern the same way we do when we are flying with an instructor at 3000 feet. LOOK STRAIGHT AHEAD THROUGH THE YAW STRING AND FOCUS ON THE HORIZON. If the nose starts to come up, we will see it happening and correct for it. If the yaw string is off center we will see that and correct for that too. You wouldn’t drive your car into a median strip if you were looking straight ahead, but you might if you were looking out the side window. I know that there is a natural desire to look at the runway we are trying to land on. We look at it while we are on down wind so we know when to make our turn onto final. We look for traffic in the pattern in front of us, and for traffic on the runway. We look at the runway to see if we are too high or too low. BUT for the 5 seconds it takes to make a 90 degree turn, we need to look straight ahead through the yaw string, focusing on the horizon. The runway is not going to go away during those 5 seconds. It will still be there for you. This is even more important when things are getting tough. If you are feeling low, if the winds are kicking, if there is other traffic competing for the runway with you, or if you are making the turn back to the runway after a rope break, it is even more important that you get that turn under control. Yes, I am on my soap box, because this is important. Whether you are flying a Grob, a Cessna, or a Boeing, look straight ahead while you make your turn onto base, and then again while you make your turn onto final. Thanks for listening. Phil Klauder