Stall Warning System; Avionics Support Equipment; Radio Selector Switches; Static Dischargers - Cessna 150 COMMUTER 1976 Pilot Operating Handbook

- SECTION 7
AIRPLANE & SYSTEMS DESCRIPTIONS
CODE
c::J
INLET AIR
E:;:::::::::::::3
V ACU U M
~ DISCHARGE AIR
SUCTION
GAGE
ATTITUDE
INDICATOR
CESSNA
MODEL 150M
OVERBOARD
VENT LINE
I~\
VACUUM
PUMP
VACUUM RELIEF VALVE
\~I
o 0
0 0 0
o
0 0
o
0 0
o
0 0 0
o
0 0
co <:» co
00
I
t \
VACUUM SYSTEM
AIR FILTER
Figure 7-9. Vacuum System
7-30
CESSNA
MODEL 150M
SECTION 7
AIRPLANE & SYSTEMS DESCRIPTIONS
ST ALL WARNING SYSTEM
The airplane is equipped with a pneumatic-type stall warning system
consisting of an inlet in the leading edge of the left wing, an air-operated
horn near the upper left corner of the windshield, and associated plumbing.
As the airplane approaches a stall, a low pressure condition is created
over the leading edge of the wings. This low pressure creates a differen-
tial pressure (vacuum) in the stall warning system which draws air through
the warning horn, resulting in an audible warning at 5 to 10 knots above
stall in all flight conditions.
The stall warning system should be checked during the preflight in-
spection by placing a clean handkerchief over the vent opening and apply-
ing suction. A sound from the warning horn will confirm that the system
is operative.
AV IONICS SUPP OR T EQUIPMENT
The airplane may, at the owner's discretion, be equipped with vari-
ous types of avionics support equipment such a s radio selector switches
and static dischargers. The following parag raphs discuss these items.
RA DIO SELECTOR SWITCHES
Operation of the radio equipment is normal as cove r ed in Section 9 of
this handbook. However, when more than one r adio is installed, an audio
switching system is necessary (see figure 7-1 0). The operation of this
switching system is described below.
TRANS COM
r
1
2 AD FI SPEAKER
~ ~ ~ ~
olF
L
2 l )
PHONE
L.EAKER-PHONE SWITCH (TYPICAL)
TRANSMITTER
SELECTOR
SWITCH
Figure 7-10. Radio Selector Switches
7-31