Embraer EMB145 Operation Manual page 2142

SENSOR HEATING SYSTEM
The Sensor Heating System provides automatic operation for the
heater elements of Pitot tubes 1 and 2, Pitot/Static 3, Pressurization
System and ADS Static Ports, TAT sensors 1 and 2, and AOA vanes 1
and 2, thus providing constant temperature and ice-free operation
during all flight phases.
All the sensors are electrically heated and controlled by three buttons,
located on the overhead panel.
In the automatic mode, the sensor heating system operates according
to three functional logics:
− Pitot 1 and 2 and Pitot/Static 3, AOA 1 and 2, ADS Static Ports 1, 2,
3 and 4, and Pressurization Static Ports 1 and 2 are heated
whenever at least one engine is running (N2 above 54.6%).
− A separate logic assures Pitot/Static 3 and Pressurization System
Static Port 2 heating in any flight condition.
− For airplanes Pre-Mod SB 145-30-0028, TAT 1 and 2 are heated
provided either Engine 1 or 2 anti-icing subsystem is functioning or
airplane is in flight (the TAT sensor normal range of operation is from
- 99ºC to + 99ºC).
− For airplanes Post-Mod. SB 145-30-0028 and on, TAT heating is on
when Thrust Levers are set above 65º position or when the airplane
is airbone.
NOTE: For airplanes Pre-Mod. SB 145-30-0028, when operating in
icing conditions on the ground with the Engine Anti-Ice
turned ON, if a TAT invalid indication is displayed on the
MFD due to temperature values beyond the sensor normal
range (TAT digits replaced by three amber dashes) with the
consequent AHRS reversion to the Basic Mode, disregard
the information and continue the takeoff normally. The TAT
invalid indication and AHRS reversion will remain until the
airplane reaches a sufficient speed to bring the TAT sensors
into the normal range of operation. This may occur on the
ground or when airplane is airborne and the airplane will
return to the normal condition (AHRS Full Performance) and
no pilot's or maintenance personnel's action is required.
REVISION 39
AIRPLANE
OPERATIONS
MANUAL
ICE AND RAIN
PROTECTION
Page
2-15-10
13
Code
01