ice protection/detection Flashcards
what sources are used for aircraft anti-ice and de-icing?
bleed air heat
electric heat
what uses bleed air (from the engine) for ice protection
engine LIPS
3 outboard slats (slat 2,3, and 4 on each wing)
what uses electric heat for ice protection
smart probes
TAT probes
windshields
water lines
pressurization static port
what does the ice protection system include?
wing anti-ice system
engine anti-ice system
windshield heating system
air data smart probes (ADSP/TAT) heating system
windshield wiper system
if an engine fails does the opposite wing and engine receive ice protection?
yes the crossbleed valve opens to provide symmetrical ice protection for both wings
the failed engine does not receive heat to the engine lip
how many ice detectors must be working to have ice detection?
one. there are two for redundancy
how long will the de-icing system remain on after icing is no longer detected?
5 minutes
if ICING on the MCDU is set to OFF and on takeoff roll, icing conditions are encountered, will the de=icing system turn on?
not until 1700 ft. or 2 minutes after takeofff, whichever happens first
can the APU be used to provide bleed air for anti-icing
no
what is protected from ice and rain?
engine inlets
wing leading edge
smart probes and total air temperature probes
windshields
water and waste drain systems
is the ice protection system automatic?
yes, under normal conditionsc
can the pilot over ride the automatic system?
yes
how is ice detected in flight?
2 ice detectors
vibrating sensor element that changes frequency when ice builds up around it
once ice is detected, the sensor element heats, the ice melts, the normal vibrating characteristics are restored, and the heating process stops. the cycle repeats as ice rebuilds on the probes
what compressor stage is bleed air tapped for anti-icing operations
10th high stage valve (HSV)
how is bleed air directed for pneumatic anti-ice?
engines independent
wings onside bleed
what happens if there is a single bleed source failure?
the crossbleed automatically opens
how should teh MCDU be set if there are icing conditions present on the ground?
ALL
what does selected ALL on the MCDU provide?
Engine Anti-Ice
ON when engiens are running
wing anti ice - ON at 4 kts wheel speed
if ALL is selected on the ground, at what point will the anti-ice system become automatic?
1700’ AGL or 2 minutes after takeoff (whichever happens first)
if OFF is selected on the ground, at what point will the anti-ice system become automatic?
1700’ AGL or 2 minutes after takeoff (whichever happens first)
how does the failure of one of the two power sources affect the windshield heating system?
on ground inhibited
in flight - left side is heated (right heats if left has failed)
what does the TIMER selection on the windshield wiper switch do?
activates the associated wiper in 8 second intervals
what happens if teh wiper is operated on a dry windshield?
the wiper will stop
to reset wiper, move switch to OFF
when do the smart probes heat?
when an engine is running
is there a test for the anti-ice system?
YES but maintenance performs it
how should the aircraft be configured for de-icing?
bleeds OFF
packs OFF
stab trim - full nose down
FLAPS UP
engines and APU ON OR OFF
what temperature do we takeoff with Anti-ice on ENG
5-10 degrees celsius
what temperature do we takeoff with anti-ice on ALL
less than 5 degrees C
when does the wing anti-ice system test itself? how long does it take?
10 min after takeoff or at 10,000’ AGL (whichever occurs first)
60 seconds max
