When I was small my father used to say that you can learn better and remember things longer if you write them down instead of just verbal recitation.
He was right. He view is right even when we learn to fly.
Remembering the pitch, power and airspeed settings can be tricky, but it can be made simple if you plot it in a graph like this.
A handwritten note for a flight lesson in Cessna 152 long time ago detailed about engine-power and airspeed data which was collected on that day. The data is sketched in a power graph curve.
Have you created a power curve for your training aircraft? This exercise will provide numerous benefits for a long time to come.
When you plot the power curve, it will be easy for you to correlate different factors affecting your aircraft’s flight such as angle of attack (AOA) and lift and drag, with the power settings and pitch used by you during flying and how the aircraft responded to your inputs.
Maintaining the correct airspeed and assigned altitude in flying is all about pitch and power combination. When you will plot the power curve you will learn about the approximate power settings required for a specific airspeed.
You will not waste time in future training flights in guessing about the pitch and power combination to maintain the altitude that has been assigned.
This power curve should be plotted when you establish level flight with flaps-up at the low cruise airspeed range of your training aircraft. After that reduce the airspeed by 10 knots at the same altitude. Repeat till you come up with minimum-controllable airspeed. These power setting can be recorded by your instructor at every step down airspeed.
This activity will not take much time. When you return from flight, plot the manifold-pressure or Rpm settings on a vertical axis and the airspeed on the horizontal axis, as shown. You will come up with a graph when you connect the dots.
According to what is mentioned in the notes, a Cessna 152 can fly at 90 knots at a power setting of 2,200 RPM. When the power setting is reduced to 2,050 RPM that aircraft will slow down to 80 KIAS. When the power setting is reduced further to 1,900 RPM the aircraft will slow down to 70 KIAS.
The airspeed of the aircraft can be further reduced to 60 KIAS and 50 KIAS with the power reduced by 100 RPM at every change. On the other hand, the angle of attack of the aircraft will enter into a realm of higher lift to drag.
This realm is the recommended best-glide airspeed of the aircraft.
When the Cessna 152 is slowed further to 40 KIAS, the power need to be increased by 100 RPM. This is because the induced drag will increase as the aircraft reaches critical AOA.
To maintain 60 KIAS airspeed at level flight the aircraft requires 1,800 RPM power setting. The same power setting is required to fly the aircraft at minimum-controllable 40 KIAS once the downward trend is reversed in the power curve.
When you construct a power curve you will sharpen your skills to adjust airspeed quickly. After that it will depend on practice to get right on constant-airspeed climbs and descents.
When you have to change your vertical speed by 100 feet per minute, change the power setting by 100 RPM. Provided the aircraft is trimmed correctly, it will enter the desired descent or climb almost at the last maintained airspeed. The student pilot is not required to change the pitch of aircraft.
Learn More About Pitch and Power Setting in aircraft: