[quote=Flight MAY 7, 1925]
THE AIR DEFENCES OF GREAT BRITAIN
Sir Hugh Trenchard’s Address at Cambridge University
THE address delivered by the Chief of the Air Staff, Air Chief
Marshal Sir Hugh Trenchard, G.C.B., D.S.O., A.D.C., before
the Cambridge University, on April 29, was an extremely
important one, and had space permitted, we should verv much
have liked to publish the address in full. This has not,
however, been possible, but it is hoped that the extracts
given in the following do not omit any vital point made by
the distinguished lecturer.
The President of the Union (Mr. G. Sparrow) occupied the
chair, and the audience included Sir Geoffrey Butler, M.P.,
Parliamentary Secretary to the Secretary of State for Air
General Costello, President of the Board of Military Studies’
Professor C. E. Inglis, and Professor B. Melvill Jones’.
Following are extracts of Sir Hugh’s address :—
" I do not want you to think that I look upon the air as a
blessing altogether. It may be more of a blessing for this
Empire than for any other country in the world, but I feel
that all the good it will do in civil life cannot balance the
harm that may be done in war by it and, if I had the casting
vote, I would say ’ abolish the air.’ I feel it is an infinitely
more harmful weapon of war than any other and it is a terrifically
powerful weapon, and therefore though my remarks
to-night will touch on technical and civil aspects, they will
necessarily deal with the service aspect of this great question."
Division of the Royal Air Force
Sir Hugh Trenchard then briefly outlined the divisions
of the R.A.F., pointing out the three main parts : The
section responsible for defence against aerial invasion, and
which is, in turn, divided into two sub-divisions—Home
Defence and Defence of the Empire as a whole, the Fleet
Air Arm, working with the Navy, and the Army-Co-operation
Squadrons, working with the Army. Dealing first with Home
Defence, Sir Hugh continued :
Home Defence of the Empire
" The Air Force for the defence of these islands is divided
into fighting squadrons, which are at present single-seaters
and will probably remain so. These are used for protective
purposes and attack any enemy which attempts an aerial
invasion of this country. Then there are the day bombers
and night bombers, these are the offensive aeroplanes.
I would now like to say that I have sometimes been asked
why we don’t use only defensive aeroplanes. My answer
is that if you play a game of football against an opposing
team, I take it your objective is to win. If the opposing
team commence to attack and the members of your team
are told only to defend their own goal, they could not possibly
win the match, and it is quite conceivable they would lose
it. Equally, if all your team were told to attack and not to
defend, one of the opposition might get a run through and,
if he did, he would find an open goal. A certain number of
defensive squadrons are necessary for the morale of our own
people. Nothing is more annoying than to be attacked by
a weapon which you have no means of hitting back at, but,
although it is necessary to have some defence in order to
keep up the morale of your own people, it is infinitely more
necessary to lower the morale of the people against you, as
nothing else can finish the war, and that can only be done
by attacking them wherever they may be.
" The Aeroplane as a weapon of defence".—There is one point
that I would like to emphasise -here, though this may not be
the right place for it. I would like to say that the aeroplane
is the most offensive weapon that has ever been invented.
It is a shockingly bad weapon of defence, but it is the only
defensive weapon against the aeroplane that has yet been
discovered, and even in these days of great scientific improvements
and inventions, I have grave doubts that any other
weapon will take its place for another hundred years, if then,
though the possibility of this must be looked into continually.
" Replacements.—Before I leave the subject of Home Defence
I will touch on another aspect of it which affects you more
closely. In the event of war, which I hope will not take
place "again in our time, and a war in which this country is
seriously attacked by an air power, the great problem to
be faced is that in the’ first clash of the opposing forces the
casualties will be very, very high, and the question of replacing
the reserves will be very difficult. In fact, they will be
almost insuperable, not only for this nation, but for any other
nation. Let me explain. Supposing the two forces consisted
of—let us take the figure of something like 100 aeroplanes
on each side. Within a month this figure would drop
to something like 20, or even 10 aeroplanes. How are the
casualties to be replaced ? For the first month you will have
your reserves, both pilots and machines, but beyond that
there will be no reserve that I can see—at any rate, that are
fit to take the field at once—and the two opposing armies
will go on fighting each other on the basis of 20 machines
a side instead of 100. From this you will see that whichever
side can re-equip first both in pilots and machines and get
back to the original number of 100 machines will probably
win the war. That is where you come in. The brains here
must so conceive and develop machines that the output
after the war has begun can be rapidly increased from what
it is at present, and if this is going to be done on an economical
basis, then the construction of the machines and engines
must be made more simple and easy to carry out. Some of
your minds in the future must be applied to that. It may
be that you will ask, ’ Why should we not keep sufficient
reserve to carry us on until the normal trade could put forth
sufficient machines to make up for our losses ? ’ The
answer to this is that in peace the wastage is 30 per cent,
per annum, while in war it is in the neighbourhood of 80 per
cent, per month. You can, therefore, see that if you kept
six months’ wastage at war rate most of the machines would
die of old age without ever having flown, and the waste of
money would be gigantic and, in my opinion, crippling.
Pilots are not quite so difficult, but there is difficulty in that
direction too. Another place where you come in, which I
will refer to at the end, is in the Air Force squadron which I
hope will be formed at Cambridge, so that some of your
successors at this great university will be ready and able
to take their place if this country is ever called upon to
face an attack from the air.
The Auxiliary Air Force
" Now there is one interesting innovation we have made in
the Air Service with regard to Home defence. We feel very
much indeed the importance of trying to get the nation
intimately connected with the air service for Home defence,
and we feel that all good men of the different types—the
pilot, the engineer, the dashing motor driver, the literary
man and the scientific man—which so largely predominate
in the English public, all could be of use in the defence of this
country. We therefore decided to start in the Home Defence
squadrons six Auxiliary Air Force squadrons and seven
Special Reserve squadrons.
" What we call the Auxiliary Air Force squadron is on the
lines of what is familiar to you as the Territorials : that is,
a whole unit is raised by an area or a county with a small
nucleus of regular Air Force personnel, consisting of an
adjutant and a number of good tradesmen. These squadrons
will be run by the county associations just outside some
great industrial centre or large town, and thus would bring
flying close to that town and enable the inhabitants to come
and see it. I also hope that a good man who is working on
a bench in a factory will be able to walk across to another
bench in the Air Force unit, and, if we get a really good man,
within a few hours he should learn the work he has to do
in the Royal Air Force. My experience in the last war
proved that this was possible and, indeed, quite practicable.
Let me tell you of one amongst many mistakes I made—one
that happened to turn out to be a great success. A very
skilful fitter came to join up in 1914 when I was at Farnborough,
and so I agreed to take him on. The next morning
I saw a man who I took to be a rigger. I told him to rig a
Henry Farman which was lying in parts on the ground. I
gave him a ’ Blue print’ which showed the aeroplane rigged
to scale. The man got to work and rigged the machine, and
in a few days it flew fairly successfully several times.
" Later I found out that the man who I had thought to be
the rigger was my newly joined fitter, who knew nothing
about rigging but was able to read a ’ Blue print,’ and so
managed to do the work which I had set him.
" Of course, he was an exceptional case. I will tell you of
another case. I had two new types of engines sent me, and
I also had two men fresh from civil life. I told them that
the engines would not work and that I wanted them to make
them run. Within a few hours both engines were running.
Both these cases show that men from civil life can come
straight into the Air Force and take their place.
’’ The squadrons which will, I hope, be started this year will
be located as follows :—
“Two at Northolt (which will be under the City of London
and the County of London).
” One at Renfrew, near Glasgow.
" One at Turnhouse, near Edinburgh.
" One at Aldergrove, near Belfast.
“One at Waddington (Lincoln).
” This accounts for six. It leaves seven more. I cannot
at present give you the location of the remaining ones as it
has not been definitely decided yet, but they will be scattered
about at suitable places. I hope that all present who happen
to be in those parts of the country where these units are to be
formed will do their best whether to join one of these squadrons
or influence their friends to join and help to make it a
success.
" Remember that if we get the best and, in the future, if it is
looked upon as much of an honour to belong to one of these
auxiliary Air Force squadrons as it is to belong to a good club
or a good university, so will it be a great means of enabling
the spirit of aviation to be spread throughout the country for
civil purposes and for service purposes. It will also give all
the brains of the country a chance of being used for aeronautical
purposes which will be an important factor in home defence.
The Special Reserve
"The special reserve squadrons are to be much the same as
the auxiliary air force squadrons—that is to say, they will be
located near an industrial centre, but they will be a little more
like regular air force squadrons in so far as they will consist
of three flights, one flight being composed entirely of regular
air force personnel, the other two flights being recruited
locally. They will, moreover, be under the same control as a
regular unit and not under the county association.
’’ In some ways this will resemble the Special Reserve as it was
in the Army before the war, but it is not intended that the
Special Reservists should necessarily do any annual training.
I hope that the personnel will be very highly skilled tradesmen
who, with the small amount of training they will be
required to do from time to time, will keep themselves efficient
and able to take their place should they be required for the
defence of this country. As with the auxiliary Air Force,
I hope the greatest local interest and pride will be taken in
them. I hope that we shall be starting some of these squadrons
this year, though we have been delayed by the difficulty
of obtaining suitable grounds.
Empire Defence
" The air defence of this Empire. What is really the meaning
of the word ’ Empire ‘? I defined it recently as our territories
and our trade. “What asset has our trade ? Is it not
our outlying territories and their ports ? Is it not one of the
great assets to our trade that we have friendly ports not only
where the trade can come from but where it can also go into
for refuge from an enemy or from weather or for supplies ?
I therefore look upon these territories, anyhow those in the
eastern hemisphere, as a great asset. Take the map of the
world and look at it, especially that part from the west of
Ireland to the east of Newfoundland. I look upon it as the
greatest asset to the Air Service of this Empire, and this
Empire alone is peculiarly situated to employ its air to its
maximum. If there were aerodromes suitably arranged and
built, even though they cost a few millions, it would save in
expenditure. You need not tie air squadrons in every spot
of the British Empire to defend it, and so long as you have
these facilities and arrangements the actual unit becomes very
mobile and will be a thousand times still more mobile when the
great aircraft carriers of the future—the airships—come into
being. Let me say now that, so far as I am concerned, the
great problems of the world are economic, and I say that if the
Air Force cannot carry out the defence of the Empire, anyhow
in parts of the Empire, as cheaply or more cheaply and as
efficiently as the older services have done for hundreds of
years past, then there is no justification for using it. But if,
as I claim, it can carry out the defence of many parts of the
Empire more economically and as efficiently as the other
services, then what chances are opened up with our Empire
situated as it is ?
” In this connection, I feel that one of the great principles
which I have striven to keep to is that every pilot must understand
his engine and aeroplane, and though for years after
the war it was difficult to get sufficient education, I feel that
in another five or ten years’ time, every pilot, flight lieutenant
and squadron leader will know enough about his engine,
machines and accessories to keep them in running order and
find out the trouble when anything goes wrong.
" I would ask you to look at what has happened in Iraq,
which was formerly called Mesopotamia, where we really
have reduced expenditure from many millions to three or
four millions and with less casualties to our own people than
before and also with less casualties to the enemy. I therefore
claim for the air that it is a humane weapon. “I look upon
it as most humane in running countries like Iraq where,
perhaps, six aeroplanes can go out at once and deal with a
truculent tribe.
” Another way the air avoids making war is that if a hundred
of you are killed all your relative? would be very bitter
and some will vow revenge. This is a greater weight on the
side of war than if only ten of you were killed. Another thing
is that the air does not live on the country and eat-up the
country.
" In India, the air is increasingly proving its value, and
tribes are coming in and making their submission for wrongdoing,
which in the past had meant punitive columns with
vast expenditure in money and lives.
" All the foregoing has been on the effect of air on a power
with no air. This is a different problem to the use of air
power on a nation that is an air power. In fact it is entirely
different. So far I have only touched on the use of air power
in the defence of the Empire. Now what about the use of
air power with regard to the defence of our territories and
trade in the eastern hemisphere from aggression. If you
will study the trade routes of the world you will see the
number of places they go into and how close they run to the
shore in many parts. You know the submarine brought
us to the verge of disaster in the last war by attacking our
trade near our ports or near shore. The aeroplane was a
good weapon against the submarine. Merchant ships under
the convoy of the air in the narrow waters close to the shore
are less vulnerable to submarine attack than they are farther
out. Though no doubt the navy have their part to play, I
am asking you to think whether the British Empire does not
lend itself to the protection of our trade in many parts of the
world and also for attacking, if necessary, anyone else’s trade.
As you can see for yourselves, nearly all the naval battles
of the past have been fought close to the shore for obvious
reasons. In fact I do not think that any have been fought
100 miles out for the past 250 years. What will be the effect
of the air with regard to this ? I ask you to think. To
turn to the Air Defence of the territories of the Empire. In
the past we have had fixed defences. Great guns have been
installed and now the guns are still greater and can only fire
blindly unless they have an aeroplane to observe. A ship
that bombards is hull down to the port it bombards, therefore,
without the aeroplane the shore batteries cannot shoot
at the ship, and what is easier than when that aeroplane goes
out to see where the ship is for the ship to steam out of range
until the aeroplane has to go back or else it calls upon its own
gun to open fire as a counter bombardment; but this does not
stop the bombardment. Is it not possible to attack with
the aeroplane ? It may not sink, but it may damage ships
250 miles out and so prevent bombardment instead of using
counter bombardment. Even so, I don’t want you to think
the air will prevent all bombardment, but it will act as a great
deterrent and a very economical one when the aeroplane
can go from one port to another.
Future Development of Defences
"Now, I have spent perhaps too much time on that side of
the question, and I would like to conclude it by saying that
it seems to me, in another 50 or 100 years the British Empire
will have to be defended by air, as the only practical method
of doing it on an economical and efficient basis. When
you think of the cost of the few squadrons necessary for such
a defence, as against the cost of any other means, and when
you think of the percentage of hits by torpedo and bombing
machines is far in excess even now in its infancy than the
percentage of hits by any other means, is the assumption I
have just made likely to be wide of the mark ? The present
development of the air may be compared with that of gunnery
prior to the South African War. In another 10 or 15 years,
when we have vastly improved bomb sights, what may be
the accuracy of bombing ? Is it not bound to be more
accurate than a gun firing at 40,000 yards, when an aeroplane
can drop its bomb straight on to the target from perhaps
10,000 ft. ? Consider all the mechanical errors of the gun,
the atmospheric conditions, the necessity for observation,
and I will leave it to you yourselves to decide which method
is likely to become the most accurate.
" I must touch on another side of the air in connection with
the Service which, as you will see for yourselves, has its
reactions on this university, and in fact on the nation as a
whole, and that is the subject of strain. I feel that in the
future, if war ever comes again, the defence of these islands
will not lie entirely, or even principally, in either the hands of
the Air, the Navy, or the Army. It will lie just as much in
your hands, and in those of the people who have to run the
vital services of the country. What is the good of the most
perfect air weapon to defend the country and to fight if the
vital services of the country are vulnerable to enemy attack
and are liable to be paralysed without the means of repairing
them and keeping them going. In other words, if the nation
is disorganised and beaten, what is the use of the fighting
forces being still intact ? I, for one, shall always advocate
that the first claim on the resources of this nation at the beginning
of a war in which air will attempt to attack this country,
will be the claim on the brains and manhood of the nation to
keep the vital services running under difficult conditions.
Therefore, I feel that we must bring the nation again into
touch with the air so as to make it realise this point, and also
that it may give to the air of its best both in brains and
physique. People must realise that flying training still
requires a high degree of skill and concentration.
Accidents
"One of the greatest difficulties which we have to face, in
which I hope you will be able to help, is that of the regrettable
accidents which take place from time to time in the Air
Service. You say, and rightly, that great inventions will
lessen them. Well, it is up to you and your inventive geniuses
to go on in that direction ; but when" this has all been done
there will still be accidents, and the more flying increases the
more will accidents increase, and the more the public sees of
aviation, the more will it see of that side of it. And yet,
there will be a considerable reduction in the number of accidents
as compared with the amount of flying, and as time goes on
the proportion will slowly widen. But there are two kinds
of accident—those due to mechanical failures and those due
to human error. The first could be, and probably will be,
eliminated, but, although the human errors may be to a large
extent counteracted by improvements in design, I believe
that the actual standard of human error will remain constant
for all time. In speaking of human error I do not mean
human incompetence, however. The more firing pilots do
the more competent they will become, and the less chance,
there will be of accident. I feel that we shall not make progress
in the development of air unless all those who are responsible
for such development have source knowledge of the difficulties
of being in the air.
" There is one further point with which I wish to deal, and
that is of very considerable importance. We cannot make the
R.A.F. the great weapon it must be unless we have the backing
of the whole country behind us. How are we to get this
backing ? You will have read in the newspapers the important
debates on air estimates, and realised from them that the
Government and members of Parliament fully realise the
value of this new weapon in war.
" But it is up to me and my colleagues at the Air Ministry to
do all in our power to assist in educating the general public in
this respect so as to induce the best material to come forward
into the Air Force. I am convinced that one of the most
important means by which this may be achieved is through
the great seats of learning, the universities, who are turnng
out into the world the young men of the country who will
have such a great influence on its future. For this reason we
are anxious to start at Oxford and Cambridge Air Force Units,
as a beginning, and hope to do the same at other universities
at a later date.
“At Cambridge, thanks to the assistance of Sir Geoffrey
Butler, and the advice and encouragement we have received
from your Vice-Chancellor, the President of the Board of
Military Studies, General Costello, and many of your senior
members who have been consulted in the matter, we have
drawn up a rough outline of a scheme for the formation of an
Air Force squadron at Cambridge.
” This Air Force squadron which, during term time, must be
mainly kept alive by means of courses of instruction in engines,
rigging, wireless, etc., and by lectures, with possible flying as
observers at Duxford or some other Air Force station during
the term, if the university authorities will allow this, and with
further flying during the long vacation, will, I trust, be the
mean* of stimulating interest in the air as a whole at the
university, and that the interest will be continued after
members have gone down from the university and gradually
throughout the country.
" It is impossible for me to say definitely when this unit will
be formed, but I hope for October this year. Anyhow, when
it is formed, I feel sure that I may count on the backing of the
members of the university and the undergraduates to make
the movement a success, and that they will do all in their
power to impress on the nation as a whole the value of this
arm.
"There is, I think, in this country an exaggerated idea as
to the danger of flying. I am not going to say there is no
danger, but I do say that in ordinary, straightforward flying
the danger is small, and that when one takes into consideration
the number of hours flown, the aerobatics performed, and other
factors, 1 think the accidents may be said to be exceedingly
few."
Professor C. E. Inglis, proposing a vote of thanks to the
Air Chief, said that a certain sister University had sometimes
been referred to as the home of lost causes, but the speaker
did not think Sir Hugh Trenchard had come to Cambridge
with any such housing proposition. Rather he seemed to
consider Cambridge as a sort of national incubator for
hatching out new and progressive ideas. On the subject
of the proposed Cambridge University Air Squadron, Professor
Inglis thought that, granted goodwill on the part of
the University officials (and he thought there was every
evidence that this goodwill would be forthcoming) there was
no doubt about the success of the scheme. Professor Inglis
caused much merriment by saying " I think there is no town
in this country where there is a greater superabundance of
excellent raw material. We rather senior aborigines of this
ancient borough realise that—perhaps to our cost, for are we
not rapidly and ruthlessly being divided in two classifications,
which someone has somewhat prettily described as " the
quick and the dead ? "—the quick being those who are able to
hop out of the way of motor-cycles, and the dead being those
who do not possess sufficient agility to do so."
Professor B. Melvill Jones seconded the vote of thanks,
which was carried with acclamation.
In replying Sir Hugh Trenchard assured his hearers that
although red tape was supposed to be the predominant feature
of most Government departments, he would do his best to
ensure that it would not in any way choke the development of
the Cambridge aviation scheme.
The Chief of the Air Staff was entertained to dinner by the
R.A.F. Engineering Course and ex-R.A.F. officers who are at
the University, Flight-Lieut. E. L. Howard-Williams, B.A.,
M.C., R.A.F. (who is President of the Cambridge University
Aeronautical Society), presiding. Some 40 guests assembled to
honour Sir Hugh Trenchard, among whom were : General
Costello, V.C., who commands the O.T.C. at Cambridge, Professor
C. Inglis, Professor B. Melvill Jones, Col. Stratton,
Col. the Hon. Ian Campbell, Col. Knox Shaw, and Wing-
Commander C. Bradley (of Duxford).
During the morning Cambridge was bombed with pamphlets
in four air raids, in which Duxford excelled themselves, putting
up a fine performance in aerobatics at the same time. Altogether
the meeting can truthfully be described as a great
success, and the progressive spirit in which those concerned
accepted the new ideas seems to augur well for the future. It
is conceivable, and even probable, that the time will come
when the occasion of Sir Hugh Trenchard’s address will be
looked back upon as having marked a milestone in the history
not only of Cambridge but of the R.A.F.[/quote]
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