The daily star-mirror. (Moscow, Idaho) 1911-1939, 1921-11-08
BRITISH CRAB
GERMAN IDEAS
Secrets From Surrendered Planes
Used in New Craft.
ENGINES now ARE GROUPED

Altitude and Speed Are Sacrificed t
the Handling Of Explosives stron
Tendency to Keep to the singI
Engine Type for Commercial Ma
chines-Two-E Engine Machines Fai
in Ministry Trials = HandIey-Pag
Alone Went Through Satisfactorily
The new airplane building at thu
Bristol Aeroplane company, writes
Maj. G. c. Turner in the London Daily
Telegraph, is the latest expression OF
method evolved by the Germans
during the war, with view to long
distance bombing. Instead OF the en-
gines being separated from each other
In the wings of the machine, as they
are In most airplanes with two OF
more engines, they are grouped In an
engine room In the body, driving one,
two or more propellers through shaft
ing and gears.
Among the surrendered German air
planes were several examples illustrat-
ing this method A feature Of these
designs was the low power, as com
pared with British machines a Ger
man four-engine machine seldom had
greater power than 1000 horsepower
whereas a British four-engine type
usually had half as much again. The
gears Of the German machines were
heavy. The engineer, standing In the
engine room, where four engines were
grouped in two tiers, was In the mid
die OF maze Of cylinders, rods and
tubing and must have worked In ex-
tremely distressing conditions. At
great expenditure Of fuel such ma
chimes were designed to carry big
load Of bombs, but unless the return
journey was to be left very much to
chance the distance Of the objective
could be little greater than that at
tainable by two-engine machines
These machines would hardly be
suitable for commercial purposes.
Big Load In Center.
Much is to be said for the grouping
of the principal load at the center, for
It's separation to the right and left, as
In most twp-engine types, Is apt to
prove embarrassing in the case Of one
engine falling. The advantages OF the
group system include that Of reduced
head resistance as compared with ex-
posing each engine to the air separ-
ately. The accessibility Of the engines
during flight Is an important advan-
tage. The gearing Of the propellers
is also valuable, but full advantage |
cannot be taken of it until propellers
of variable pitch are used.
The massingo of the engines in the
body will be detrimental to the COM
fort Of passengers, unless cabins are
provided elsewhere. A disadvantage
of the group system Is the enormous
weight at the center, which seems
likely to call for increased weight of
wings or a strict limit to the span
from left to right This may, however,
be partly counteracted by adopting the
triplane or quadruplane system Gas in
the new Bristo), which, on the other
hand, has its own disadvantages.
The altitude capacity and the speed
II the big German machines were low,
,ut doubtless at the present time 4
improvement in these re-
,pects is possible. The landing Of
Juch machines is apt to be difficult
N account Of their great weight and
hey must have airdromes Of hard
urface.
The two-engine airplane 10 a pc
uliar class, inasmuch as the contin-
ency Of one engine failing leaves it
With only half It's power but all its
weight, and the half Of It's power ex-
rted at thrust point away from the
enter, with the result that a turning
endency has to be overcome /
Failed In Trials.
For the reasons mentioned the two
ngine machines engaged in the Air I
[inistry competition last year, with '
ne exception, failed in trials In which I
ne or the other of the engines had q
, be stopped These trials included 8
stting up in a limited space and d
in the air 1t was in la
ructive to note that the one machine r
at went through satisfactorily was
e Handley Page VS., which was n
'lVou Dv engines giving more power q
relation to the total weight of the Il
achine than It's competitors. In it's
Sc there were only 111a pounds to o
e horsepower, whereas the nearest q
the others had no less than 151s 81
unds to the horsepower. Thus the ii
g, even with one engine idle, had
load power ratio not much higher
an that of a single engine machine.
The Farman Goliath is a compare VI
ely low-powered two-engine ma n
Inc and its constructors have 81
ought out practically the same ma r.
Inc driven by three engines, with n.
w to overcoming It's drawbacks. +,
rhe present situation is that, for !,
nmercial machines there is strong 81
ldency to keep to the single engine
,e.
0ianoa and Cr}v4A