This is caused by such a
decrease of speed that the aeroplane, though still moving forward,
begins to drop downwards. When the pilot finds that this is taking
place, he points the nose of his machine at a much steeper angle, and so
reaches his normal flying speed, and is able to effect a safe landing.
If he were too near the earth he would not be able to make this sharp
dive, and the probability is that the aeroplane would come down flat,
with the possibility of a damaged chassis. It is considered faulty
piloting to make a pancake descent where there is ample landing space;
in certain restricted areas, however, it is quite necessary to land in
this way.

A far more dangerous occurrence is the SIDE-SLIP. Watch a pilot
vol-planing to earth from a great height with his engine shut off. The
propeller rotates in an irregular manner, sometimes stopping altogether.
When this happens, the skilful pilot forces the nose of his machine
down, and so regains his normal flying speed; but if he allowed the
propeller to stop and at the same time his forward speed through the air
to be considerably diminished, his machine would probably slip sideways
through the air and crash to earth. In many cases side-slips have taken
place at aerodromes when the pilot has been rounding a pylon with the
nose of his machine pointing upwards.

When a machine flies round a corner very quickly the pilot tilts it to
one side. Such action as this is known as BANKING. This operation can be
witnessed at any aerodrome when speed handicaps are taking place.

Since upside-down flying came into vogue we have heard a great deal
about NOSE DIVING. This is a headlong dive towards earth with the nose
of the machine pointing vertically downwards. As a rule the pilot makes
a sharp nose dive before he loops the loop.

Sometimes an aeroplane enters a tract of air where there seems to be no
supporting power for the planes; in short, there appears to be, as it
were, a HOLE in the air. Scientifically there is no such thing as a
hole in the air, but airmen are more concerned with practice than with
theory, and they have, for their own purposes, designated this curious
phenomenon an AIR POCKET. In the early days of aviation, when machines
were far less stable and pilots more quickly lost control of their
craft, the air pocket was greatly dreaded, but nowadays little notice is
taken of it.

A violent disturbance in the air is known as a REMOUS. This is somewhat
similar