One of the most basic operations in flight is making a change in altitude. Learning how to manage your energy in a climb or descent is an important basic skill for every pilot to master.
How to Climb
Just pull back to climb, right? WRONG!
Climbing to a higher altitude adds more potential energy to our aircraft, but energy isn’t free. So to get more energy we need to add energy using the engine.
Consider a plane cruising straight and level with a stable altitude, airspeed, and power setting. If the power is increased this aircraft will begin climbing at the same airspeed it was at before.
This is because the shape of the plane determines the airspeed, and the power setting does not change the shape. The flight controls, including the trim, DO change the shape of the plane.
The other way to climb is to trade forward kinetic energy for vertical kinetic energy. If we are flying forward at 100knots and we pitch up to maintain a speed of 90 knots (without changing the power setting) then we will begin to climb.
So there are two ways to climb by moving just one control. Changing speed is a bit different.
How to Change Speed
There is only one way to change speed, by changing the shape of the plane. This is generally done by changing the pitch of the aircraft using the yoke and trim. You can also change the shape using the flaps to create a stable change in speed, or even using the aileron and rudder (in a forward slip).
But if you want to change your speed without changing altitude (or climb rate) you will need to change your power setting.
If you want to slow down you will need to pitch up to change speed and then reduce power to keep from climbing.
Conversely, if you want to go faster you will need to pitch down to pick up more airspeed, but then add power to keep from descending.
The Power-Pitch Relationship
It is important to understand how pitch and power relate to each other when climbing and descending.
The most common mistake is to think that power changes airspeed and pitch changes altitude…because at first glance it looks like that is how an airplane would work.
If you are guilty of thinking about climbing and descending backwards like this make it a point to get some flying time in practicing changes in altitude and airspeed using power and pitch respectively.