Saab 340B, Operation Manual, Page: 373 / 670

EMERGENCY EQUIPMENT
Oxygen
Aircraft Operations Manual
6/2.1
PAGE 5
Apr 01/15
There are three plug − in type oxygen outlets in
the cockpit: one for each pilot, located behind and
outboard of each pilot’s seat on the side panel; and
one for the observer, located on the left side wall
above the observer’s seat.
Flight crew masks (quick donning masks) are nor-
mally connected to their outlets so that they can be
put into immediate use. If a mask is disconnected
from its outlet, a check valve in the outlet prevents
line pressure from leaking.
When not in use, these masks hang from overhead
quick
− release holders behind the respective pilot to
be conveniently at hand for immediate donning.
Observer mask
Type and how to store it during flight varies with
national regulations.
All masks except the first aid mask, can be plugged
into the cockpit outlets.
Flight crew and observer masks can be used with
the large (310 l) portable oxygen bottle if desired.
However, they can not be used with the small
(120 l) bottle, which will only accept the first aid
mask.
The quick − donning masks are diluter/demand type
with mask mounted regulator and microphone.
Each mask is supplied with a red flow indicator
which disappears when oxygen is flowing.
The mask mounted diluter/demand regulator pro-
vides oxygen dilution and delivery pressure control.
The oxygen selector on the regulator enables the
mask to be supplied either with oxygen mixed with
ambient air (”NORMAL”) , or with 100% oxygen on
demand.
When the emergency selector is turned to ON, the
mask is supplied with 100% continuous flow oxy-
gen. This should be used for protective breathing
purposes (smoke in the cockpit etc.).
Smoke goggle (push − pull) vent valve is used in
conjunction with 100% continuous flow oxygen
(emergency selector ON) to divert a small flow of
oxygen from the mask cavity into the smoke goggle
cavity to vent smoke or noxious fumes which may
be present.
To ventilate:
− Turn emergency selector to ON
− Pull out the Vent Valve knob.
A11171
Fig. 5 Flight crew oxygen mask