Cessna 150K - Stall Warning System Operation

3
7-+---""'"
Detail B
NOTE
Bug screen (7) should be inspected
and cleaned periodically.
1. Doorpost Cover
2. Horn Assembly
3. Scoop
4. Adapter
5. Felt Seal
6. Adjustable Plate
7. Screen
Figure 15-7. Stall Warning System
15-48. ACCELEROMETER.
15-49. DESCRIPTION. The Aerobat offers an
accelerometer to assist pilot in performing precision
aerobatics. The accelerometer continuously indi-
cates g forces being imposed on aircraft. The dial
display utilizes three pointers; one pointer indicates
instantaneous acceleration, another records maxi-
mum positive acceleration and the third records
maximum negative acceleration. Maximum instru-
ment markings range from lOG to 5G. A "PUSH TO
SET" knob, located on lower left corner of instru-
ment, is used to reset "Maximum Positive" and
"Maximum Negative" pOinters. If dual Nav/Coms
are installed, the accelerometer is installed in a
housing above instrument panel on pilot's side. When
aircraft is equipped with single Nav/Com, accelero-
meter is installed in the vacant Omni indicator instru-
ment space.
15-18
15-50. STALL WARNING SYSTEM. (Refer to figure
15-7. )
15-51. DESCRIPTION. The system is composed of
an adjustable plate on left wing leading edge, con-
nected to a reed type horn by means of plastic tubing.
The horn is actuated approximately 5 to 10 miles per
hour above stalling speed as a negative air pressure
area at wing leading edge causes a reverse flow of
air through horn. By moving adjustable plate (6) up,
actuation of horn will occur at a higher speed and
moving plate down causes actuation to occur at a
slower speed. Center adjustable plate opening in
wing leading edge upon installation, then flight test
aircraft, observing horn actuation during stall. Re-
adjust plate to obtain deSired results if necessary.
Approximately 3/32 inch adjustment of plate will
change speed at which horn actuation occurs by 5
miles per hour. To test horn operation, cover
opening in plate (6) with a clean cloth, such as a
handkerchief and apply a slight suction by mouth to
draw air through horn.