Embraer EMB145 - Page 2130

AIRPLANE
OPERATIONS
MANUAL
ICE AND RAIN
PROTECTION
REVISION 39
2-15-10
Page
1
Code
01
AOM-145/1114
BLEED AIR THERMAL ANTI-ICING SYSTEM
The bleed air thermal anti-icing system is supplied with hot air tapped
from the engines. In the automatic mode, the system is turned on
through activation of either ice detector. Manually, setting the
OVERRIDE Knob to the ALL position activates the system.
Adequate ice protection for the wing and horizontal stabilizer leading
edges and engine air inlet lips is ensured by heating these surfaces.
Hot air supplied by the Pneumatic System is ducted through perforated
tubes, known as Piccolo tubes. Each Piccolo tube is routed along the
surface, so that hot air jets flowing through the perforations heats the
surface. Dedicated slots are provided for hot air exhaustion after the
surface has been heated.
During night flights, inspection lights, installed on the wing-to-fuselage
fairing, illuminate the wing leading edges, allowing the crew to check
for ice accumulation.
Each subsystem comprises an anti-icing valve (pressure
regulating/shutoff valve). A restrictor limits the airflow rate supplied by
the Pneumatic System. It is monitored by pressure sensors, that
indicate abnormal low and high air pressure conditions. The pressure
sensors protect the respective subsystem against either insufficient or
excessive airflow rate.
The wing and stabilizer low pressure protection mode has a redundant
detection by means of a second low pressure sensor on the stabilizer
system and a differential pressure switch (± 2 psi) that compares root
pressure on the left and right half-wing Piccolo tubes.
Air leakage is detected by thermostats installed close to each duct
connection. Low pressure switches provide an additional protection
against unacceptable leakage level.
The Piccolo tubes integrity is monitored as follows:
Horizontal stabilizer: By one differential pressure switch comparing the
left and right Piccolo tubes pressure.
Half-wing: It depends on the airplane model. By one differential
pressure switch in each Piccolo tube comparing the root and tip
pressures or, by manometric switches measuring the tip pressure only.