'Military report on Tehran and adjacent Provinces of North-West Persia (including the Caspian Littoral)' [‎93v] (191/610)

A small quantity should be rubbed over the surface of the
body and into the seams of clothing.
1. Tn the
C*»plan
provinces.
2. On the
plateau.
D.—Conditions Affecting Aviation.
The (Caspian provinces and Persian plateau present totally
differeat aviation conditions.
In the Caspian provinces flights have only been made in
Gllan, over the Jangali co mtry and along the Kazvln-Rasht-
Enzali-Astara-Tabriz routes.
Thp conditions are :—
1. Thick clouds of fog frequently hang over the mountains
from 1000' to 8000'.
2. Even in fine weather the jungle, especially when in leaf
from March to November, screens enemy concentra
tions and renders aeroplane reconnaisance difficult
or ineffective.
3. Forced landings in such close country inevitably mean a
crash.
4. The humidity in summer might affect aeroplanes.
Conditions on the plateau, due to its altitude and to the
height of the mountain ranges crossing it, are special and dis
tinctive.
They are :— : 1
1. Owing to the rarefied atmosphere machines require a
larger run “ to take off ” and aerodromes must be
larger than the orthodox 400 yards square. The
affect on landing is less.
2. Snow may cover the aerodromes in winter. The sou
is soft, without any covering of grass, and.when
wet and sticky clogs a plane and makes starting
difficult. ,
3. To clear the mountain ranges an average altitude ol
12,000' must be maintained when flying.
4. Under severe winter conditions, flying at this altitude
and crossing ranges of 10,000' is difficult and
dangerous.
5. Pockets in the air cause “ bumps ” especially in winter.
These are often so violent as to produce a sensation
of “ mal de mer” in pilots fresh to Persia. The
period for comfortable flying is limited to 4 hours
daily, 2 hours after sunrise and 2 hours before sunset,
when these “ bumps ” are less pronounced.