Pitot Heat Annunciation; Alternate Static Source - Cirrus SR22 Pilot Operating Handbook

S 7: A
ECTION IRPLANE AND
P -S S
ITOT TATIC YSTEM

Pitot Heat Annunciation

Illumination of the PITOT HEAT FAIL Caution indicates that the Pitot
Heat switch is ON and the Pitot heater is not receiving electrical current.
Illumination of PITOT HEAT REQD Caution indicates the system detects
OAT is less than 41 °F (5 °C) and Pitot Heat Switch is OFF. A current sensor
on the Pitot heater power supply wire provides current sensing.

Alternate Static Source

An alternate static pressure source valve is installed on the switch and
control panel to the right of the pilot's leg. This valve supplies static pres-
sure from inside the cabin instead of the external static port. If erroneous
instrument readings are suspected due to water or ice in the pressure line
going to the standard external static pressure source, the alternate static
source valve should be turned on. Pressures within the cabin will vary with
open heater/vents. Whenever the alternate static pressure source is
selected, refer to
altitude corrections to be applied.
7-68
S
YSTEMS
Section 5: Performance Data
C
for airspeed calibration and
P/N 13772-006
D
IRRUS ESIGN
SR22
Reissue A