Gliding and landing

Gliding

Let us next consider the flight of an aeroplane while gliding under the influ­ence of the force of gravity and without the use of the engine.

Of the four forces, we are now deprived of the thrust, and therefore when the aeroplane is travelling in a steady glide it must be kept in a state of equi­librium by the lift, drag, and weight only. This means that the total aerodynamic force – that is to say, the resultant of the lift and drag – must be exactly equal and opposite to the weight (see Fig. 6.1). But the lift is now at right angles to the path of the glide, while the drag acts directly backwards parallel to the gliding path.