New-York tribune., 1919-02-16

,,
lower, more generally of the order Of
6.9 to 10 indications that only seven
pounds can be sustained for each pound
of tractive effort developed.
Taking the present designs as a
basis of comparison and computation
the maximum range can be readily
computed at l ,975 miles. The distance
between Newfoundland and ireland is.
in round figures, 1000 miles. Thus,
machine OF the characteristics of the
Fol type would be just able to cover
the flying distance if the machine was
supplied with gasolene amounting to
so per cent OF its total gross load.
1.-The above results will be compared
with the performance of 10.00O-pound
flying boat (F-5-L) and deductions
made as to size. capacity and flying
speeds. The model in question carries
$50 United States gallons Of gasolene.
If equipped with two Liberty motors II
would have maximum speed OF about
40 miles an hour with efficient wing
cross -section). This gives a straight
ahead flying range OF $50 miles, botn
motors working. 1t is thus obvious that
at least four and one-half TO five times
as much fuel must be carried IN craft
of this type to make the trip possiDie'
Hence. the fuel load must be
$50 : 5-1;650 United States gallons OF
gasolene. on two-motor assumption.
This corresponds to a load OF lU,ioo
pounds.
If the machine were equipped with
more than two motors, the total gaso-
lene load in pounds would be 0,O''
times the number Of motors.
Four Motors Necessary
"'From the above considerations the
indications are that the new macnne
will be, roughly, two and one-haN 'hs
weight of the first and about one anu
three quarters as large. The morse. ,st.
power requirements may be reaoii!
computed to show that four motors als
necessary. Estimating on fouf-mo.
tored machine, for which the fuel mus'
now be computed at 10000 pounds sp.
proximately, the new machine weign'
can now be estimated as follows:
Pounds
rps, 10000
Four motors and equipment. .........' "'osO osO
Crew (three mem ....-......--...'. sos
Dead load OF machine. .-..........'.. 0''s.
ro,n, s9.o5O
"In the original type we had SVv
horsepower in two motors. II tne n.~
machine were to fly at 100 miles M sn
hour the effectiveness would be OF tio si,
order of 5.5. which would considerspy
lower the radius of flight. Inc eng
tiveness figures are obtained dlrec~!
from the characteristics of the pas.s
machine to which the comparisons alo
made. However, at 80 miles an nou, sa
a value of 60 may be realized lor ''''
effectiveness factor.
Furthermore, the horsepower -
ouirement at this speed is 320 as com, D,
pared to 900 for the basic machine, -
the new machine be equipped with ioui
motors of the high compressor '!Ps,
tn, available horsepower, considering
the efficiency of the propeller, IS l'sas.
This is equivalent TO 450 horsepoN'....
flying requirement in the basic macn'"s
at about 81 miles per hour. hehos
flying speed of 95 miles per hour lue,
be counted on with an efecVl'eHe''
of 6.
Could Cross in Twenty-four Hours
off the course, as laid out wess as
1000 miles and 300 miles be aiiowvs ;rs
! for variation. the trip would reeums
"a hours. With the four motors ~
ming continuously at full sreed M
total gasolene weight necessary w0s.s ~
] be l9,500 pounds. as compared WIN Wv
I 10000 pounds originally estima'ea.
.'The flight could then be sncrsSs. sos.
fully accomplished with flying Oys. 20
similar to existing types, OF about sour or'
600 pounds weight, equipped with ynaDIy tooi ot
motors and having a gasolene supP''
about $3.50 gallons. sds
"'The above computations were n I'sSs sSs
on the basis of minimum time. II .or. an
element of time be eliminated II from sp;,',ua, nun
sidcration. the problem of maSl"lhu !ism the
range becomes one of determinlhs. ,o.. ss
ity i' necessary for flight at which ss spsaS s1'S
the greatest range may be coVefeo' The
the hours available for fight, t,,, lower n
economic velocity ia consideraots, otss,nsble.
than the maximum velocity op'aa.StIrs ...ntors
It is that speed at which the mo'oaft .ns q
will consume the economic amouhs ams;ataucs
gasolene for the maximum dis'S's'
covered"