Saab 340B, Руководство по эксплуатации

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ICE AND RAIN PROTECTION
Description
Aircraft Operations Manual
11.1
PAGE 3
Jun 01/17
− Pressure remains on in Left and Right inboard
wing or Left and Right outboard wing boot zones
after more than 8 seconds.
On a/c s/n 160 − 239:
The following additional faults triggers the TIMER
light:
− Control power to timer is lost. If the W OUTB
push button is depressed the TIMER light will go
out. When the button is released the light will
come on again
.
On a/c s/n 240 − up:
The following additional faults triggers the TIMER
light:
− Pressure remains on in any boot zone
(AUTO CYCLING switch in ONE CYCLE or
CONT).
− Control power to timer is lost.
− Depressing any of the Manual push buttons while
in CONT or during a one CYCLE sequence will
result in the TIMER light coming on momentarily.
In CONT, ONE CYCLE or by manually overriding
the timer the inflation sequences can be monitored
by following the illumination of the green indication
lights which will come on whenever the respective
boot zone is pressurized if BOOT IND switch is in
ON position. In OFF position no illumination will oc-
cur.
2.2 Engine anti − ice system (Fig. 3)
2.2.1 General
An engine anti − ice system prevents ice formation
on certain areas of the engine where ice buildup
otherwise could be expected. These areas are the
inlet lip, intake ducts including Inlet Protection De-
vice (IPD) with exhaust nozzle which are electrically
heated, and the splitter lip and inlet guide vanes,
which are heated with bleed air.
Both the electrical and the bleed air parts of the
system are controlled by the same L/R ENGINE
anti
− ice switches.
In order to increase the engine stall margin at low
power operation, bleed air is bled from the 5th com-
pressor stage and via the HMU operated sleeve
valve ported to the Splitter Lip, the inlet guide vanes
and the Inlet Particle Separator Ejector Duct. When
power is increased the bleed air reduces and at
90% Ng corrected (temperature related) the sleeve
valve is fully closed. With engine anti
− icing switched
ON at low power settings some air is routed from
the Sleeve Valve via the Electronic Solenoid Valve
to the Splitter Lip and inlet guide vanes while the
rest is routed direct from the Sleeve Valve. When
power is increased relatively more air is routed via
the Solenoid Valve and at high power settings all
bleed air for anti
− icing is routed from the Sleeve
Valve via the Solenoid Valve.
The electrical inlet duct heating uses 115VAC, wild
frequency, supplied directly from each engine’s own
AC generator only. Therefore, there can be no
cross
− feed from the other AC generator in case of
malfunction.
2.2.2 Upper and Lower duct
(Applicable to A/C with LUCAS intakes
(without mod. no. 2095)
In the lower leading edge section the duct is pro-
vided with a temperature control sensor, an under
−
temperature sensor and an over − temperature sen-
sor. These sensors are connected to an inlet duct
heater controller located in the engine nacelle
equipment compartment.
The normal temperature control sensor has preset
control levels for inlet heat controller to ”cut in” at
60

C (140

F) and to ”cut out” at 80

C (175

F). A
failure in the inlet ice protection system is indicated
by L or R INTAKE light coming on.
The light comes on if:
− The over − temperature sensor senses a tempera-
ture exceeding 125

C (257

F) in which case the
inlet heat controller will ”cut out” power to the
heaters. (If the L/R ENGINE switch is left ON the
light will go out when power is ”cut in” at 40

C
followed by a new overheat.)
− The under − temperature sensor senses a temper-
ature below 10

C (50

F). (Inhibited for 25 sec
when switching on the system to avoid nuisance
warnings).
− Loss of power in one or more phases in the
three
− phase power supply system.