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83 Cards in this Set
- Front
- Back
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ice detector
- when used - power source |
- whenever MEAC is powered
- probe heater - MEAC - ICING light - MEDC |
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how does the ice detector work
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- reference chamber - one large hole, ram air pressure constant
- sensing chamber - 7 small holes, ram air pressure drops when they ice over - pressure switch is made, MEAC deices the probe in ~3 seconds |
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when does the icing detector probe receive power
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- armed whenever MEAC is powered
- MEAC actually used when the probe ices up |
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ICING light should normally stay on for how long
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~3 seconds (deicing time)
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AOA heat
- when - power source |
- chocks to chocks (on the checklist)
- MEDC |
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when does the AOA probe receive power
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thermostat uses MEDC to keep temp not higher than 121 C
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pitot heat
- when - power source |
- chocks to chocks (on the checklist)
- pilot - FEAC (with stepdown transformer) - copilot - 28V Fwd Ltg Bus (on MEAC) - caution lights - MEDC |
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when does pitot heat actually receive power
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constant heat when the switch is on
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what is unique about the power source for P/CP pitot heat
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pilot - FEAC (120V from the generators) goes through a stepdown transformer to get to 28V
copilot - FLB is already 28V |
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L or R HTR OUT pitot heat out light on
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Cause:
- electrical current flow to the pitot heater element has been interrupted - current flow detector is inoperative Action: - check respective CB and bus - monitor equipment for proper operation L - FEAC R - FLB (MEAC) (NATOPS 11-5) |
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bomb bay heat
- when used - power source |
- for Mk-46 torpedoes
- EMDC |
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bomb bay heat comes from...
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- right wing manifold
- can come from APU or engines 1 or 2 with fuselage shutoff valves open |
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can you use bomb bay heat with
- engine starts - ground a/c |
engine starts - no (not automatically monitored)
ground a/c - yes |
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the windshield has __ layers; which are heated?
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middle of 5 layers is heated
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center windshield heat panel is controlled by the ___ switch
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copilot (right)
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windshield heat
- when used - power source |
- chocks to chocks (on the checklist)
- front - MEAC / MEDC - side - Bus A / EMDC |
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L/R side windshield heat power source and rack location
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Bus A / EMDC
C rack |
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in very cold weather (<__ C), allow windshield to warmup (how) before using it in ___ power
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- below -40 C
- warm along with cabin temp before turning on, even in low |
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windshield override switch purpose
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turns heat on when temp is too cold to be in the operating range (less than approx -35 C)
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front windshield heat needs a __ min warmup before using in high
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10 min
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when can you use front windshield heat in high
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*most people won't use it due to likelihood of thermal shock and shattered windshield*
NATOPS: - ice forming on windshield (caution: if ice builds up first, thermal shock may happen) - icing anticipated near low end of icing range (0 to -25 C) - below 10,000 ft (1) below 0 C when birds are likely (2) descending into high humidity - anytime for anti-fogging purposes |
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if you have to fly with front windshield off
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- do not exceed 240 KIAS below 10,000 ft
- do not fly into anticipated icing conditions |
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___ windshield heat may take up to __ min to become effective
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- side
- 45 min |
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side windshield heat FAIL light on
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Cause:
- power relay and/or overheat control relay stuck in energized position when control switch is off Action: - Pull side windshield heat power CB on Bus A (NATOPS 11-5) |
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engine anti-ice
- when used - power source - test parameters |
when
ch. 2 - prior to entering areas where structural icing is likely to exist ch. 18 - <8 C with visible moisture on the ground ch. 8 (referencing loiter) - <10 C with visible moisture - MEDC (power required to turn it off) - normal or low rpm light comes on with a T.I.T. increase then a decrease |
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engine anti-ice heats the...
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- air scoops inlet / duct
- compressor inlet housing - torquemeter shroud |
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explain how engine anti-ice flow goes from the switch to the heated component
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1 switch
2 pilot valves 3 anti-icing vavles ONE solenoid-operated pilot valve activates ONE anti-icing valve, allowing air to... - air scoop, including... (1) inlet lip (2) top of duct ONE solenoid-operated pilot valve activates TWO anti-icing valves - LEFT anti-icing valve goes to the compressor inlet housing, including... (1) engine struts (2) guide vanes (3) CIT probe - RIGHT anti-icing valve also goes to the compressor inlet housing, in addition to the torquemeter shroud |
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how many thermal switches are there for engine anti-ice; how do they work
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2 per engine
- torquemeter shroud / compressor inlet housing - air scoop inlet duct - wired in series so the light comes on when both switches are hot enough |
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engine anti-ice thermal switches measure the temp of...
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the tubing, not the air
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explain the airflow for the air scoop anti-ice
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- enters the right side of the inlet lip
- flows across the bottom, back over the top and back out to a manifold on the right side - 12 passages through the double0skinned top half of the duct - vented into the nacelle through holes in the left side of the duct |
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explain the airflow of engine anti-ice around the compressor inlet housing / torquemeter shroud
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- two anti-icing valves send air to the left and right sides to the
(1) engine struts (2) guide vanes (3) fuel control CIP probe - connector line balances pressures in case one valve doesn't open - air is released into the air inlet duct - the right side tubing sends air to the torquemeter and drive shaft shroud; also released to air inlet duct |
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engine anti-ice shp / FF effects
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9% shp drop which requires 5% fuel flow increase to recover
500 pph more with BOTH engine and wing deice on (fuel planning) |
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engine anti-ice typically takes how long for the light to come on
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90 seconds
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engine anti-ice system test
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- low or normal (quicker) rpm
- switch on --> T.I.T. rise (T.I.T. rise on the ground, shp drop in flight) - light on (~90 seconds) - switch off --> T.I.T. drop - light out (NATOPS 8.13) |
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NO anti-icing advisory light on with control switch on
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Cause:
One or both areas of system may not be receiving hot air. Action: a. Check for horsepower drop. If normal, continue operation. b. If less than normal: (1) Check for ice buildup on air inlet scoop. If excessive, execute the Emergency Shutdown procedure. (2) If no ice buildup on air inlet scoop is observed, monitor shp, T.I.T., and fuel flow. Initial indications may be a gradual power loss followed by erratic operations. If either of these indications is observed, execute the Emergency Shutdown procedure, (NATOPS 11-5) |
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anti-icing advisory light on and control switch off
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Cause:
a. Abnormal heat in the area b. Loss of electrical power to the solenoid valve Action: On deck, investigate, secure engine, and return to the line. In flight, turn on anti-ice control switch. a. If a shp drop is observed, execute the Emergency Shutdown procedure b. If no shp drop is observed, continue engine operation. (NATOPS 11-5) |
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anti-icing advisory light remains on after system utilization
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Cause:
Failure of one or both thermal switches and/or anti-icing valves. Action: Allow sufficient time for thermal switch cooling prior to investigating. If no other abnormal indications exist, engine operation may be continued for the remainder of the flight. (NATOPS 11.5) |
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how many wing plenum chambers are there
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6 (3 per wing)
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- how does bleed air get from the engine to the bleed air manifold?
- what is the air in the bleed air manifold used for? |
- 14th stage bleed air valve (2 per engine)
- check valve - bleed air shutoff valve (SEDC) - bleed air manifold used for: - wing deice - engine starts - bomb bay heat - oil cooler augmentation Note: engine anti-ice and closing 5th and 10th have their own ports |
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how does air get out of the wing plenum chamber
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vents on the bottom rear of the nacelle
- inboard engine - inboard plenum - outboard engine - center & outboard plenums |
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pressure relief in the wing plenum chamber
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- pressure relief doors open at 5 psi
- built to withstand 10 psi |
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where are the LW/RW HOT switches
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one in each plenum chamber (6 total)
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are all plenum chambers the same temp? LW/RW HOT temps?
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plenum not higher than temp / W HOT light on at / off at
inboard / center: 49 C / 88 C / 79 C *FUS DUCT HOT also 88 C / 79 C outboard: 63 C / 104 C / 96 C |
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where is temp measured for FUS DUCT HOT light? what temp?
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overheat warning switches near the...
- cross-ship duct - APU bleed air duct - bomb bay heat duct light on above 88 C, out by 79 C (same as inboard / center plenums for LW/RW HOT lights) |
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when is pressure buildup in the bleed air manifold a concern
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slow buildup - not a concern
quick buildup - may be a serious leak or broken duct |
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where / what are the NACA vents
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- one each just outboard of the engine (intake)
- vents out through beaver tail - ventilates between the wing and engine tailpipe shrouds - prevents fuel vapor entrapment - cools the wing skin |
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wing deice
- when used - power source - test parameters |
ch. 18 - whenever structural icing conditions are encountered in flight
ch. 2/18 - when ice on the leading edge builds up to approximately 1.2 inch mod valves - EMDC 10 C T.I.T. with corresponding wing temp rise (must be in normal rpm) |
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is wing deice antice or deice? why?
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- designed as anti-ice, but used as deice because of the power loss it causes
- potential damage to leading edge if used continuously - potential to have melted water refreeze on the wing |
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how is bleed air cooled before being used to heat the leading edge? what temps?
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- bleed air is ~282 C
- piccolo tubes draw air from wing plenum chamber to mix with bleed air, which drops it to ~135 C |
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when goes wing deice air pass through the mod valves
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- when powered by EMDC (switch on)
AND - when the pneumatic thermostat opens them (keeps the temp below a limit) limits: inboard / center: 49 C (W HOT light at 88 C) outboard: 63 C (W HOT light at 104 C) |
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where does the air actually go that deices the wing
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- hot bleed air from the bleed air manifold (~282 C)
- piccolo tube draws in plenum air to cool bleed air (drops to ~135 C) - vented along leading edge up and down, then back - dumps back into plenum chamber; mod valve thermostat reads temp at this discharge |
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how to deice the wing
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- wait for 1/2 inch of ice (up to the black line)
- open all 4 bleed air shutoff valves - open each section one at a time, starting with the outboards --> wait 20-30 seconds (until ice melts off) --> leading edge temp rises at least 10 C - repeat for other two sections |
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wing deice system test
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- normal rpm
- open bleed air valve --> no T.I.T. or LE temp change - open one mod valve --> 10 C T.I.T. rise - close the mod valve --> check LE temp rise - repeat the other two - close bleed air shutoff valve --> recheck for original T.I.T. (NATOPS 8.14) |
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wing leading edge temp gauge power source
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MEAC
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where is leading edge temp read for LE HOT light
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in the inner skin of the leading edge section (3 per wing)
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emp deice
- when used - power source - test parameters |
ch. 2 - when structural icing is evident
- used in conjunction with wing deice parting strips - Bus A cycling strips - Bus B timer motor - MEAC control relay - EMDC - same power, high speed motor, 44 seconds test vs. 176 seconds normally |
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emp deice timer motor switch power source
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MDC
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emp deice fault gauge power source
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Bus A and Bus B
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how many parting strips / cycling strips are there?
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5 parting strips (inboard and outboard on each horizontal stab, one on vertical stab)
20 cycling strips (2 on either side of each parting strip) |
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explain the emp deice cycle
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parting strips - continuously powered
cycling strips - 8 second dead band - 20 x 8 seconds per strip - 8 second dead band 176 seconds total (+/-10%) |
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what does the emp deice gauge show during each __ second cycle (normal, not test)
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first 8 seconds - dead band (no cycling strips), shows parting strip power
next 160 seconds - 8 seconds for each cycling strip last 8 seconds - dead band, shows zero |
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how long do you leave emp deice on
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until ice breaks off, but at least one full 176 (~3 minutes) second cycle
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3 indications shown on emp deice gauge
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stays at zero - no power to that strip
OK range - balanced phases faulty range - unbalanced phases (possible short in one phase) |
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emp deice test
- how - what happens |
- turn switch on - EMP DEICE light due to being on the ground
- hold switch in TEST until fault gauge starts indicating (after first 2 second cycle) - 2 sec (holding switch) - low speed motor test - no fault gauge indication - 2 sec parting strips (deenergized for remainder of test) - 20 x 2 sec cycling strips - 2 sec dead band ----- 2 sec holding switch, then 44 sec test |
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if you need to test emp deice multiple times on deck...
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let it cool for 5 minutes
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emp deice overheat condition
- when does power come back to the system - when will the EMP DEICE light go out |
- deenergizes control relay until the thermal sensor says it's cool enough, then it restores power
- EMP DEICE light stays on until you turn the switch off (resets the light) - thermal sensor relay in C rack has a light that is on during overheat and goes out when it is cooled |
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prop deice
- when used - power source - test parameters |
ch. 2 - whenever structural icing is evident
gouge - donut on the prop dome heater elements - Bus B control - EMDC - reduced voltage, same speed (160 sec cycle) |
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name the sections of prop deice
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- front spinner - cone out front
- cuffs - front edge of base of each blade - islands - protruding part lining up with cuffs - aft spinner / skirt - extension of front spinner behind the blades |
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explain the prop deice cycle
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front spinners - continuous through slip rings
8 x 20 seconds each... #1 cuffs #1 islands and aft spinner repeat for #2, #3, #4 |
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which phases power which parts of prop deice
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Bus B phase A - continuous to outboard front spinners
Bus B phase B - cycled through cuffs, islands, and aft spinners of all 4 (8 x 20 sec each) Bus B phase C - continuous to inboard front spinners |
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prop deice timer power source and location
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Bus B / EMDC
MLC |
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prop deice gauge power source
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Bus B
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normal amp range for prop deice
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normal / test
front spinners - 76-100 / 74-100 cuffs - 51-72 / 48-72 islands and aft spinners - 63-82 / 58-82 |
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prop deice troubleshooting - low amps on outboard spinners
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- pull #1 spinner anti-ice CB
- record amps (test and normal) - reset #1, pull #4 CB - record amps (test and normal) - lastly, pull suspected bad CB and run a complete cycle to confirm |
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prop deice troubleshooting - low / zero amps on cuffs and islands
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if no solid state timer motor (doesn't start over each time):
- turn off as soon as amps are bad - pull all 4 Bus B CBs - turn on and reset each CB to see which one gives it power (this is the bad prop) - compare to next cycle to see if it is cuffs or islands for zero amps, do the same thing on the next cycle either one, pull the bad CB and run a full cycle to confirm |
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time / voltage / amp difference for emp and prop deice tests
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emp deice
- high speed timer motor (44 sec vs. 176 sec) - same voltage prop deice - same time, same amps on gauge - 11 V power from aft lighting bus instead of normal 120 V from Bus B |
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if you turn emp deice off, what does the timer motor do? prop deice?
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emp
- starts over prop - solid state motor - starts over - other motor - resumes where it left off |
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emp deice gauge shows...
prop deice gauge shows... |
emp - how balanced the 3 phases are
prop - amps in use |
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when should prop and emp ice control systems be checked...
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when use of these systems is anticipated
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which anti-ice / deice can be tested without engines running
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- emp - yes
- prop - no (slip rings won't work for front spinners) - engine - no (need engine bleed air) - wing - could do it off the APU if necessary (select an engine or turn on bomb bay heat; caution: full operation on the ground is prohibited) |
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can we use wing deice on takeoff
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Caution: full operation on the ground is prohibited
Power loss is too large to use on takeoff anyway. |
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what anti-ice / deice do you use when taking off into icing conditions
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- engine - on (<8 C w/ visible moisture)
- prop - as soon after takeoff as practical - wing - shall not be on (power loss) - emp - with wing when needed |
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can you use wing deice and engine anti-ice on landing
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wing - no, just run it one last time before landing (so you don't have the power loss)
engine - yes, but watch for NTS at flight idle |
