I still remember how nervous I was, the only person in the group taking a motorcycle safety course who had never been on a motorcycle before. An hour in, two members of the group had tipped their bikes over. I asked one, “How long have you been riding?” He proudly said, “Almost 20 years now.” I was doomed.
We practiced maneuvers in the parking lot of the community college. This included figure eights, obstacle swerves, and sharp turns from a stopped position. We hadn’t gone above 20 miles per hour all day. The practice was great, not to mention challenging, but I couldn’t wait to go faster. Then our instructor said the magic words, “In this exercise, we’ll practice shifting gears, making sure it’s done smoothly without altering the course of the motorcycle.” I couldn’t wait.
My first clue should have been that we were still in the parking lot. Driving in an oval pattern in second gear, our instructor told us to increase our speed to roughly 25 miles per hour and shift into third gear on the straightaway. Within seconds, we were told to downshift into second and make a normal turn around the cones. We practiced this exercise for about five minutes. It was the only time I got the bike into third gear during the course.
Before my driving test the following day, I asked our instructor why we never drove faster than parking-lot speeds. I also wanted to know why we spent so much time practicing figure-eight turns at such slow speeds that unless you were trying to do tricks or show off at some motorcycle show, you’d never perform them after completing the course. He responded with two simple questions.
Ever see someone tip over going down a highway? Ever see someone tip over, fall off, and smack their head on the pavement in a parking lot? The fact is it’s difficult to go slow on a motorcycle—or in an airplane. We love to go fast because it’s fun, but also because it’s easy to do. Going slow requires focus and skill. It takes time and practice to do it well.
Loss of control accounted for nearly 70 percent of all fatal general aviation accidents from 2001 to 2011, according to the FAA. Many of those occurred while the airplane was going slow. So mastering slow flight could keep you from smacking your head on the pavement.
Know slow. It all begins with knowing how and why the airplane flies slow. Start by learning what the white and green bands mean on the airspeed indicator. The white band is the flap operating range of your aircraft. The beginning of the white band is the power-off stall speed with flaps and landing gear fully extended. This speed is referred to as VSO. The end of the white band moving clockwise is referred to as VFE. This is the maximum speed that the airplane will fly safely with flaps fully extended.
The green band on the airspeed indicator is the normal operating range of the airplane. The beginning of the green band is the power-off stall speed with flaps up and landing gear retracted. This speed is referred to as VS1. Moving clockwise, the end of the green band is called VNO. This is the maximum speed the airplane should be flown in smooth air. Obviously, during slow flight, you won’t have to worry about approaching this speed. We’re going to take it nice and slow.
The next step is to understand the two types of drag associated with flying your airplane: induced and parasite drag. Parasite drag is anything on your airplane that stops air from moving freely. Landing gear, radio antennas, seams, and even dirt are all sources of parasite drag. Here’s the most important point: Parasite drag increases as speed increases. It increases so quickly that doubling your airspeed quadruples the parasite drag. It’s also much harder for your airplane to overcome than induced drag.
Induced drag is the byproduct of lift. You induce drag each time you create lift through the angle of attack. As the nose pitches up, a portion of your airplane’s total lift acts rearward and increases your total drag. The more total lift, the more your airplane’s total lift acts rearward, increasing drag. As airspeed increases, induced drag decreases at the square root of the speed. This is opposite of parasite drag. This will be of major importance during slow flight, since slowing down increases induced drag.
One final thing you should know before taking to the skies and going slow: the power curve. The graph on page 44 demonstrates the amount of power (engine rpm) required to maintain altitude as airspeed increases. As you slow down to the lowest point in the power curve, called the maximum endurance speed, the amount of power required to maintain altitude decreases. This is fairly straightforward. What isn’t so obvious is what happens when you slow down below this speed. Welcome to the region of reverse command, otherwise known as the back side of the power curve.
To maintain altitude while decreasing your speed below the maximum endurance speed, the amount of power required actually increases, hence the name. As airspeed decreases, the power required to maintain altitude increases. This leads to an extremely important point—a climb is initiated by adding more power, not necessarily by pitching the nose up.
The greater the angle of attack, the greater the drag. By pitching the nose up, all you’re doing is increasing the power required to overcome all of the induced drag you’re creating. It also slows you down. By lowering the nose, you increase your airspeed, decrease the drag, and decrease the power required to overcome it.
Slow go. Now it’s time to take off and practice. From straight-and-level flight at cruise speed, turn on the carburetor heat (for carbureted engines) and reduce power to around 1,500 rpm. Let the airspeed decrease to VFE and extend flaps.
It’s important to adjust your pitch to maintain altitude as the airspeed decreases. As airspeed decreases below maximum endurance speed, the speed at which minimum power is needed to maintain altitude, add power to maintain altitude. Re-trim the airplane for more precise control of the elevator as the speed decreases, and adjust the pitch to maintain the airspeed about three to five knots above VSO. Apply right rudder as necessary to compensate for the strong yawing tendency at this airspeed.
At this speed you should notice the flight controls are much less effective and the sound of the airflow over the wings falls off sharply in tone. It’s important to monitor the airspeed indicator, as even a slight decrease in speed can produce a stall. If the speed is decreasing, pitch the nose down slightly to increase the airspeed while adjusting the throttle to maintain altitude. Monitor the altimeter frequently to verify you’re maintaining a steady altitude, and check your heading indicator and outside visual references to maintain a constant heading. If you’re descending, remember to add power and not pitch up. Think reversed commands. Think induced drag. Think about how much fun it is to go slow.
After practicing straight-and-level flight, try some turns in the same manner. Increasing bank angle increases the risk of a stall, so make sure to use only slight control movements to prevent banking into a turn too quickly. Apply rudder and power as necessary to coordinate the turn and maintain altitude.
To exit slow flight, pitch the nose down slightly and apply full throttle. Let the airspeed increase to VS1 before you retract the flaps in increments.
Slowing down may be difficult to do, but it’s a challenge worth taking. We all love to go fast. We need to love going slow.
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