Levelling off from a climb

During a climb you will probably be at full power and at a climb speed.

In an aeroplane or helicopter, when you reach the top of a climb, lower the nose to increase speed to cruise speed, reduce power to cruise power and trim the controls. 

APT - Attitude, Power, Trim

Gliding

It is assumed that there is no thrust.

Forces in a Glide

In a glide, there are only 3 of the 4 main forces present.  Weight, Lift and Drag.

The forward propelling force which was provided by thrust is now provided by a component of weight.  The Forward Component of Weight (FCW).

Lift/Drag Ratio

The ratio of lift to drag is known as the lift/drag ratio (L/D) and is a very important performance measure for an aircraft. 

The L/D ratio for a typical training aeroplane may be 12:1 whereas for a high performance glider it may be as high as 50:1.

For a given amount of lift, it is desirable to have the minimum amount of drag, i.e. the best possible L/D ratio. 

If 120 units of lift are required and the cost is 10 units of drag from the aerofoil, then L/D = 120:10 or 12:1, i.e. the lift is 12 times greater than the drag.