Evening star., 1926-06-03
The Route 10 Pulharn.

The Route to Putnam.
When Ia uding near LeninRrad was
herided on the route became as fol
lows:
From Rome the ship should sal
along the Italian Coast. cross the
northwestern part Of the Mediterra- :
mean, fly along the western part of
the French Riviera. cross southwest
arm France. follow the French west
coas, IN 10 Rochcfort and from there
. direct as possible go tn the British
aerodrome in Pulham. northeast or
London In Norfolk.
Il might, however. ne necessary tn
land in France il the weather condi-
tions on the flight from Rome 10 Ful-
ham should be had Therefore. the
expedition asked the French author'-
ties for permission. in case Of such
situation to go down into one OF the
French sheds We received the same
friendly answer as We got when We
requested the British government for
permission to use the shed al Pu'ham
From Pulham to LenInGrad the ship
had to hv by way Of the Norwegian
capital Oslo. where nloorlng mast
was erected When 1t is stated that
In Kings Bay in SpitZbergen during
the Winter both a moOrlpg mast ana
hangar were bnilt. an idea Is given
nf the preca utions that were taken t"
make sure ~ a safe landing for the
shin on the 1igh, 10 SpitZherGen from
Rome.
Weather Service Organiyed.
or equal importa nee was the MAIN
tenance Of security as far as possible
when the ship was in the air. There
fore we shall mention the meteoroloS
ica, auxiliary service that was 90
tahltshed for the expedition its need
having been shown by our experiences
IN our examination flight last summer
The organization Of the weather
service this wear vas built npon prln-
ciplee TO certain extent similar I"
those utilized last year. The greatest
difference between the meterologlcal
service of the two expeditions was that
on the 1925 expedition the meteor"'"s-
icaI expert was on board the ship.
We shall try to explain to our read
ers the difficulties that threaten an
airship when il has to pass over re-
cions in which the weather Is IRE
ouently changing. We will also reveal
the risks that threaten fiying I'm fog
end snow and with the ship encrusted
in ice. In fact. an airship Is very ne-
pendent upon the weather i'm starting
or la nding as well as during flight.
Trouble Caused by Wind.
One of the greatest troubles comes
from the wind II is Impossible To
take a dirigihle ont of it's shed or take
I, in when a strong wind Is blowing.
The most dangerous wind during s'lch
maneuvers is that coming from the
sides Their the ship runs the RISK "l
not clearing the hangar doors and az
heinc forced against ono " the doof
frames. The construction M an alr-
s,t,
pressure will hreak it's steel skeleton.
During the flight with the Norge IN
Alaska II happened three times that
the wind WAS tho strong around the
hangar 10 ALLOW taking the shin out OF
the she'd Otherwise the meteoroloEl-
cal conditions we're favorable for fly
ing.
Attemn,s have been made TO lessen
the starting and landing difficulties
for airshins by the erection of moor
ing masts. which allow the ship TO
start and land in rather high wind
velocities These masts also make the
ship more independent of the wind
direction AT The moorinc places.
However. it is not only a the start
and landing that the wind makes II
difficult to maneUver airships. Their
speed will never he as great as that OF
airplanes our average speed with the
Norge on the longer distances was not
more than - miles an hour. II is
obvious that with such slow speed
even moderate head wind will con
sjderahlv extend he flight whHe
IA vorab BILE wind will shorten 1t.
Very strorc winds arc never advan-
taeeous even II they are following.
The reason is that q heavy wind al
WAYS is ACCOMPANIED by worthless and
other disturbances in the air. Ac-
cordinylv the different parts Of the
sensitive airship may come into winds
Of various NeIocitiec and direction. So
that in the worst easrs the result may
he the breaking down Of the whole
fabric.
Dangers Of lee Forming on Ship.
The wind however is not the only
element that may he. dangerous for an
airship. There are also several forms
of precipitation that can he rather
unplea SAINT during hying. All kinds
Of precipitation diminish visibility,
though not so much Is real fog dDes.
Precipitation increases the difficulties
for the navigator. and they may ne
come dangerous If the precipitation
lasts for long time.
The case becomes dangerous when
the precipitation deposits on the ship
itself This may happen with wei
gnNW. tSlt Inc nlOSl peElhuS I'''' -
in crust Ire that easily collects on all
parts Of the ship that are exposed I"
the wind.
This ice crust may he formed in
msnv wa,s. For example. by rain
Hrops, cooled below the freezing point
40 that they freeze Immediately after
touching the ship. and by fog. con-
sisting NJ similar under-cooled YET
snoaller water drops. which also freeze
when they are deposited on the MI
ferent parts Of the ship.
The ice crust loads the airshlp down
IN very short time. 1t makes the
ship's bow heavier than the stern.
since the ice forms more readily on
the bow. The new ice crust danger
threatens chiefly At temperatures
little below the freezing point. Al
lower temperatures the risk is smaller
hut even al rather low temperatures
heavy rime crust may fasten on the
ship. ~
The building Of this ice crust has
To he avoided in some way. II can he
done bv choosing another height for
nvjnR. II may. for insta nee. he pos
Sihle to go over and under cooled
fog The route may he changed and
have IN effect. especially when IT is
possible 10 go over land instead of
water. and vice versa.
II. however it seems impossible Ia
avoid the ice crust and the ship is far
from its destination. the only thing to
do is to return. for il is quite impossi-
hle for an airship to stay in the air
for long time with ice building
going on.
Visibility rs an Essential.
We have already mentioned the i''
huence Of the wind and precipitation
on an airship. We have now 10 con-