Embraer EMB145 Operation Manual page 2132

WING, STABILIZER AND ENGINE ANTI-ICING VALVES
OPERATIONAL LOGIC
Since the Bleed Thermal Anti-icing System is supplied by the
Pneumatic System, it is integrated to the functional logic that provides
automatic control and protection for the system.
The Wing and Stabilizer Anti-icing Valves receive an electrical input to
open when the following conditions occur:
− The Ice Detection Test Knob is set to 1 or 2, or
− The airplane is in-flight or attained a ground speed above 25 kt, and
− The Ice Detection Override Knob is set to ALL, or
− The Ice Detection Override Knob is set to AUTO or ENG and any ice
detector is activated.
NOTE: The Wing and Stabilizer Anti-icing Valves are inhibited from
opening on the ground and at a ground speed below 25 kt to
prevent structural damage caused by surface heating, except
during ice detection testing. The ice detection test should not
be activated for more than 15 seconds.
The Engine Anti-icing Valves receive an electrical input to open when
the following conditions occur:
− The Ice Detection Override Knob is set to ALL or ENG, or
− The Ice Detection Override Knob is set to AUTO position and any ice
detector is activated, or
− The Ice Detection Test Knob is set to 1 or 2.
The engine anti-ice system logic has a narrow range between normal
operating pressures and a low pressure value that, if reached, would
trigger an E1(2) A/ICE FAIL message on the EICAS. This message
may be presented in flight whenever the engines are set at low thrust
settings. This message may be cleared increasing the engine anti-ice
system pressure by advancing the thrust levers with Ice Detection
Override Knob in AUTO. If the message does clear and the related
Engine Air Inlet OPEN inscription remains illuminated, the system is
operating normally and the flight may be continued.
REVISION 39
AIRPLANE
OPERATIONS
MANUAL
ICE AND RAIN
PROTECTION
Page
2-15-10
3
Code
01