by Charles Gulick
Slowflight/Normal Cruise Transition
Eagle Field Training Base (Local)
North: 17280. East: 7521. Altitude: 2000.
Pitch: Cessna 0. Pitch: Piper 359. Bank: 0.
Heading: 330. Airspeed: Cessna 80. Airspeed: Piper 84.
Throttle: Cessna 12287. Throttle: Piper 6144.
Rudder: 32767. Ailerons: 32767. Flaps: 0.
Elevators: Cessna 39679. Elevators: Piper 40959.
Time: 8:30. Season: 2. Cloud Layer 1: 10000, 7000.
Surface Wind: 3 kn., 330 deg.
Being able to “slowfly” the airplane is of great importance in your overall proficiency. You should make the transition from normal flight to slowflight every time you approach an airport and when you fly an airport pattern. You'll make far better landings if you plan them from slowflight configurations. And slowflight is an absolute prerequisite for certain phases of instrument flying, such as during an ILS approach or when you're one of a “stack” waiting clearance to land.
You can regard your present configuration as standard for slowflight in your airplane, though it is possible to fly quite a bit slower than this.
Do your instrument scan thoroughly. In Cessna, you'll recall, your KIAS (Knots Indicated Airspeed) is lower by about ten knots than your instrument reading, so although you're indicating 70, you're doing about 80. In Piper you are reading 84. Note that your altimeter and your vertical-speed indicator both confirm that you're not losing or gaining altitude significantly. Note that your RPMs are lower than at cruise speed, too—1505 in Cessna, 1250 in Piper—so that to stay level you've had to trim the elevators up considerably.
Your exact throttle and elevator setting for slowflight will depend on your altitude when you make the transition. But as a general rule you'll reduce throttle by four notches in Cessna, seven notches in Piper. Then as the plane starts to descend, you'll trim the elevators up to hold your altitude. We'll practice this in a prescribed manner shortly.
But first, let's see how to transition from slowflight back to normal cruise. I'll describe it for each aircraft separately.
In Cessna, increase your throttle setting by four notches, for an RPM reading of 1905. Watch your VSI, and when it indicates about 400 FPM, apply two quick notches of down elevator. The VSI will indicate better than 500 FPM, then the needle will start down again, then up again, at which time give two more quick notches of down elevator. The VSI will indicate a descent briefly, then start to climb again. So, again apply two quick notches of down trim. The VSI will oscillate a bit, and then stop at the zero indication, and you'll be close to your original altitude. Your elevators will be at operational neutral. If you're more than 20 feet off your original altitude, add or subtract power briefly to restore the difference.
In Piper, increase your throttle setting by seven notches, for an RPM reading of 1950. Watch your VSI, and each time the needle flips up to indicate a climb, give one notch of down elevator, for a total of just four notches, which returns your elevators to operational neutral. The airplane will settle close to your original altitude. If you're more than 20 feet off, use power to correct.
You're now back to straight-and-level flight at your cruise speed and altitude, which is confirmed by both your instrument scan and your out-the-windshield views.
Transition to slowflight whenever you're ready. Here's how:
In Cessna, without rushing it, reduce your throttle setting four notches. Your RPMs will slow to 1505. Let the VSI needle indicate about 500 FPM down, then give two quick ups on your elevator. The VSI will swing to the up side, to about 500 FPM, then swing down again. When it indicates 500 FPM down, give two quick notches of up elevator. The VSI will go through the same oscillation. When it indicates close to 500 FPM down again, apply two final quick notches of up elevator. Then just wait. Things will settle down into the slow-flight configuration you witnessed at the beginning of this flight. If your altitude is off a bit, again use one notch of power briefly—but no additional trim—to correct.
In Piper, without rushing things, reduce your throttle setting seven notches. Shortly, the VSI will indicate a descent of several hundred feet per minute. Counteract that with a notch of up elevator. Wait while the VSI swings up and then down again, and counteract with a second notch of up elevator. Repeat this procedure for two more—or a total of four—notches and then wait. You'll settle into the slowflight configuration that began this flight. If your altitude is off a bit, use a notch of power briefly—but no additional trim—to correct.
I recommend you use the Recall key to practice these transitions—from slowflight to normal cruise to slowflight—several times. With experience, you'll get a feel for when to execute your trim for the smoothest possible transition. But remember, whichever way you're transitioning, make your power change first; use elevator to get the desired result.
It's possible, certainly, to make smoother transitions than I've described here—if you have all the time in the world to make them. But these are speedy and efficient, use specific parameters you can rely on as standard, and hold your altitude within very reasonable limits.
By now you've probably had about all the practice you can take, learned all the techniques demonstrated, and are itching to fly and try everything for yourself under normal flying conditions.
Well, you should have sufficient basic flying skill now to take instruction in the air. So from here on out, you'll do the flying—all the way.