e
number of its revolutions per minute, the consequent reduction of the
propeller draught, as it acted on the tail of the machine, would cause
this tail to droop, and the machine to assume very quickly a dangerous
position. And when once it began to get tail-down, as pilots found to
their cost, there was nothing to be done. The machine lost what little
forward speed it had, and either fell tail-first, or slipped down
sideways. Such risks as these, which were very real, were rendered
worse owing to the fact that, in much of the cross country flying of
the early days, pilots flew too low. They lacked the confidence of
those who followed them, and were too prone to hug the earth, instead
of attaining altitude. It was not realised clearly then, as it is now,
that in height lies safety. And so when a machine lost headway through
engine failure, and was not put quickly enough into a glide, it
happened often that it had come in contact with the earth, and had
been wrecked, before there was any chance for the pilot to regain
control, or for the machine itself to exhaust its side-slip, and come
back to anything like a normal position.

But the failure of the human factor in flying, the lack of skill of a
pilot that may lead to disaster, is shown by statistics to play no
more than a small part, when accidents are studied in numbers and in
detail. Some time before the war, in an analysis of the accidents that
had befallen aviators in France--accidents concerning which there was
adequate data--it was shown that only 15 per cent. of them could be
attributed to a failure in judgment or skill on the part of the pilot.

Apart from errors, however, in what may be called legitimate piloting,
there have been regrettable accidents due to trick or fancy flying.
Putting a machine through a series of evolutions, to interest and
amuse spectators, is not of course in itself to be condemned. In such
flying, and notably for instance in "looping the loop," facts were
learnt concerning the navigation of the air, and as to the apparently
hopeless positions from which an aeroplane would extricate itself,
which were of very high value, from both a scientific and practical
standpoint. Public interest in aviation was increased also by such
displays; and it is very necessary that there should be public
interest in flying, seeing that it is the public which is asked to pay
for the development of our air-fleets. But the man who undertakes
exhibition flyi