SYSTEMS Flashcards
1
Q
How are the outboard tanks structured?
A
divided into 3 sections by baffles
2
Q
What do the main tank surge boxes do? Where is it located?
A
prevents fuel boost pumps from becoming fuel starved during nose-down, wing-down, or negative-g attitudes by keeping the boost pumps submerged in fuel
Inboard aft corner of each main tank
3
Q
How many transfer pumps are in the aux tanks?
A
1
4
Q
How many transfer pumps are in the external tanks?
A
2
5
Q
What is the purpose of the fuel tank vent system?
A
vents all fuel tanks to the atmosphere to equalize pressure and prevent damage to the wing or tank
6
Q
What kind of vent system do the inboard and aux tanks have?
A
wrap-around vent system
7
Q
How are the outboard tanks vented?
A
vented by float-controlled vent valves
8
Q
How are the external tanks vented?
A
vented through the space at the top of the baffles, separating the tank compartments, and through the fuel vent line
9
Q
What do FLCVs do?
A
automatically stops fuel from flowing into the tank when its full
10
Q
How many FLCVs are in each tank?
A
3 in 1 and 4
1 in all the others
11
Q
If the FLCVs lose electrical power, what position do they fail in?
A
spring-loaded closed
12
Q
What is the boost pump rated at?
A
15 to 24 psi
13
Q
What is the transfer pump rated at?
A
28 to 40 psi
14
Q
Do both transfer pumps in the external tank run at the same time?
A
No they alternate. They only run at the same time during fuel dumping
15
Q
The compensators in the fuel tanks measure what to get a more accurate fuel level reading?
A
density of the fuel, not the quantity
16
Q
What monitors and controls the basic aircraft fuel system?
A
the dual channel Fuel Management Controller (FMC)
17
Q
What buttons in the cockpit control the FLCVs? The transfer pumps?
A
TO button
FROM button
18
Q
What turns on the boost pumps?
A
selecting the ENGINE START switch to RUN
19
Q
In case of power failure, the fuel valves fail to what position?
A
hold the last energized position
20
Q
The dump valve switches control which valves?
A
dump mast shutoff valves
interconnect valves
21
Q
If the AR pumps are being used for dumping, what do the interconnect valves do and why?
A
Remain close or close upon activation to prevent high pressure fuel from entering the cross-ship manifold
22
Q
Where is fuel returned to from the SPR manifold?
A
Tank 3
23
Q
Placing the SPR DRAIN switch to ON does what?
A
opens the drain valve, closes the SPR valve, and activates the drain pump to initiate the drain cycle.
24
Q
How long does the fuel drain cycle run? How many cycles are required to completely drain the SPR manifold?
A
2.5 mins
2
25
What do the interconnect valves do?
Isolates the AR manifold and the cross-ship manifold during AR
26
Why do we not want to land with fuel in the externals?
to prevent pylon fatigue cracking
27
Fuel Weight
Tanks 1 and 4
8310
28
Fuel Weight
Tanks 2 and 3
7650
29
Fuel Weight
Aux Tanks
5810
30
Fuel Weight
External Tanks
8900
31
Fuel Weight
Fuselage Tanks
24390
32
What is the APU starting altitude envelope?
-1000 to 20,000 ft
33
What degree does the APU air intake door open on the ground? in flight?
35
| 15
34
What does the Auxiliary Start Relay on the APU do?
acts as a holding relay until the APU reaches 50%, then it is de-energized
35
Fuel for the APU comes from where and how does it get there?
Gravity fed from Tank 2
36
How much fuel must be in tank 2 IOT feed the APU without turning the boost pumps on?
2000 lbs
37
What does external power supply power to?
LH/RH AC bus, essential AC bus, and main AC bus which in turn powers the avionics buses and all four regulated TRs
38
What is the reset position for the APU generator?
OFF on the external/APU switch
39
When the External power/APU switch is placed to APU, what does it power?
connects the APU generator to the essential AC bus
40
What is powered if the APU is the only source of power?
essential and main AC buses
41
When does the start light on the APU go out?
until the APU compressor reaches 50 percent rpm
42
An ESS DC BUS OVERLOAD ACAWS message may appear during APU starts. No maintenance is required unless what?
unless a TR and/or other bus fail ACAWS message also appear
43
The APU has to warm up for how long without a bleed air load?
1 minute
44
What is the starter duty cycle?
1 minute ON, 4 minutes OFF
45
How long is the APU door operation?
9-18 seconds
46
How long from APU start light to on speed?
35 seconds
47
Normal APU rpm
98-105 percent
48
Max APU rpm
110 percent
49
Normal APU EGT
260-680 C
50
Max APU EGT and for how long?
710 C for 3 seconds maximum
51
Normal bleed air pressure
40-50 psi
52
Bleed air pressure check, 30 to 15 psi
Not less than 22 seconds
53
What occurs when the APU oil subsystem senses low oil pressure?
APU automatically shuts down
54
What type of prop is it?
| Describe some features of the propeller
Dowty R391 six blade, coarse seeking, counter-weight, variable pitch
controllable pitch in the ground operating range, constant speed in the flight and reverse ranges, full feathering
55
What are the propeller counterweights for?
they act as a safety device to drive the propeller blades towards feather if there is a loss of hydraulic pressure
56
What is the purpose of the propeller hub assembly?
provide an attachment point for the blades and a means of attaching the propeller to the PGB and to transmit engine HP to the blades
57
What is the purpose of the propeller pitch actuator? where is it located? what is it controlled by?
used to control fine and coarse blade angles
on the front hub
PCU
58
What is fine pitch? What direction is it driving the propeller?
refers to oil transferred, thru the beta tube, to the AFT side of the prop piston
Towards reverse position
59
What is coarse pitch? What direction is it driving the propeller?
refers to oil transferred, thru the beta tube, to the FORWARD side of the propeller piston
Towards feather position
60
What does the servo valve in the PCU do?
primary control device that changes blade angle in response to FADEC signals and operates in all modes except for manual feathering.
61
What does the auxiliary feather pump do?
provides backup oil pressure for full feathering when the FADEC-controlled feathering system is inoperative, when the high-pressure pump oil pressure is insufficient, and for ground maintenance purposes.
62
What is the purpose of the Magnetic Pulse Unit?
detects the passing of each blade and the propeller rotates and also provides backup NP sensing should the primary and secondary sensors fail.
63
Describe the three positions of the PROPELLER CONTROL switch and what they each do.
FEATHER - activates the aux feather pump and feathers the prop
NORMAL - shuts off the pump
UNFEATHER - commands prop to unfeather and drives it to full reverse unless the switch is released
64
How is propeller blade angle controlled?
by the PCU controlling the flow of oil to the pitch actuator in response to the FADEC signals. The FADEC controls engine fuel flow by providing signals to the FPMU
65
Positioning a power lever below FLT IDLE while airborne can cause what?
extreme propeller overspeed with damage to components, loss of electrical generators, and high drag levels.
66
Aux feather pump operating limit
80 seconds
67
Exceeding the 80 second aux feather pump operation limit could cause what to occur?
may cause oil to enter the compressor rotor. This creates a rotating imbalance when the engine is run and will likely result in severe engine damage.
68
Static propeller feathering is limited to how many cycles? When is a cycle counted?
2
| each time the aux feather pump is used to drive the prop from feather to reverse to feather
69
The prop counterweights will stabilize the blade angle at approx. how many degrees?
66
70
The prop will windmill on the counterweights at up to what percent NP?
40
71
At what percent does the propeller speed digital readout change to red?
106
72
At what percentage are the propellers maintained thru fuel flow changes when the power levers are between FLT IDLE and reverse range?
99
73
At what percentage are the propellers maintained thru fuel flow changes when the power levers are above FLT IDLE?
100
74
At what percentage are the propellers maintained thru fuel flow changes when the power levers are in the reverse range?
101
75
What systems use bleed air?
```
engine starting
AC
cabin pressurization
leading edge ice protection
ABSLATS
```
76
Where does the cross ship manifold extend across?
the wing front beams btwn engines 1 and 4
77
A bleed air duct that extends along the right side of the fuselage delivers bleed air for what?
the cargo compartment refrigeration unit and floor heat
78
What do bleed air compensators do? Where are they installed?
allow for expansion and contraction of the ducts caused by heating and cooling.
in the longer sections of the bleed air ducts
79
If you close an isolation valve, are both refrigeration units lost?
No. the opposite pair of engines will drive both units.
80
Where are the isolation valves located?
on each wing just before the cross ship manifold enters the cargo compartment
81
If you close the divider valve, are both refrigeration units lost?
Allows at least one AC system to continue to operate.
82
Where is the divider valve located?
in the cross ship manifold between the two wing isolation valves.
83
What do the check valves in the bleed air system do?
Permit air flow in one direction only. Prevents air flow into an inoperative engine or the APU and loss of system pressure to the atmosphere
84
What do augmenter valves in the bleed air system do?
Regulate 14th-stage bleed air from the engine compressor
85
What does the BA/ECS do? What valves does it control?
regulates air temperature and pressure in the bleed air system
augmenter valves and nacelle SOVs
86
What type of material is used in the fabrication of the cross-ship manifold and why?
Inconel
| low thermal expansion property
87
What do the FLCVs require to open? What are they controlled by?
electrical power
| FMC
88
If the primary FMC fails followed by a failure of the secondary FMC, what is displayed?
the fuel tank quantity indicators on the flight station overhead FUEL MANAGEMENT panel will display dashes while the quantity indicators at the ACS FUEL MANAGEMENT panel will display the last valid values.
89
What type of tanks are the aux tanks?
Bladder type
90
Why are the external tanks compartmented with baffles?
to prevent surges between compartments that would affect CG
91
What does the main tank water removal system do?
provides continuous water removal from the tank low points during boost pump operation
maintains the fuel level around the boost pump when the aircraft is in a nose-down attitude with low fuel level in the tank
92
How much fuel can be dumped?
All usable except approx. 1520 lbs in each main tank
93
Dump rate with 4 transfer pumps
2000 lbs/min
94
Dump rate with 6 transfer pumps
2770 lbs/min
95
Dump rate with 8 transfer pumps
2950 lbs/min
96
Dump rate with 10 transfer pumps
3900 lbs/min
97
Dump rate with 2 AR pumps
5440 lbs/min
98
How is dumping prevented on the ground?
WOW system
99
How do you dump fuel if you're using a fuselage tank?
Fuselage tank fuel is dumped by the AR pumps, fuel from the other tanks may not be dumped directly overboard but may be transferred simultaneously into the fuselage tank.
100
In case of power failure, what do the crossfeed valves do?
hold last energized position
101
The fuel pressure indicator is located where on the FUEL MANAGEMENT panel?
right side of the cross ship manifold
102
How do you display fuel pressure from the left side of the cross ship manifold?
the cross ship valve OR both interconnect valves must be open
103
What is the general purpose of the APU?
supplies air for ground operation of the AC systems and for engine starting
provides shaft power to drive a 40-kVA AC generator
104
When is the APU fuel and ignition circuits energized?
when APU oil pressure rises above approx. 4 psi
105
When does the APU automatically shut down?
APU speed exceeds 110%
oil pressure is low
tachometer fails
106
How is the APU maintained at a constant speed of 100%?
the speed-sensing governor controls it by regulating fuel flow into the combustion chamber
107
What supplies APU starting control power?
isolated DC bus
108
What supplies power to the APU start motor?
the essential DC bus (if the essential DC bus is powered) and the utility battery
109
What should you do if the APU does not light off during ground start in extreme cold weather?
preheat the APU with an external source of heat prior to second start attempt
110
What does the Ground Beta Enable Valve do?
removes the hydraulic low pitch stop (13.0 +/-2 degrees) and isolates the OSG during ground beta operations to prevent it from reacting to overspeed transients.
111
What does the feather valve do?
allows the auxiliary feather pump to override the PCU servo valve to fx the prop. This override function protects against system failures in which the primary system is incapable of feathering the prop.
112
What happens if the high pressure oil pump loses pressure completely?
The counterweights will move the blade angles toward 66 degrees and will stabilize NP at less than 40 percent. Drag in this configuration is very low.
113
What are the 3 primary sources of electrical power?
AC, DC, external power
114
Which MCBs are on the pilot side circuit breaker panel? Copilots?
Essential DC bus MCBs
Main and avionics DC bus MCBs
115
How many ECBUs are there? How many AC and DC ECBs are in each unit?
14
24 DC / 15 AC
116
What is the AC power system comprised of? What is it powered by?
6 AC buses and 2 AC inverters
powered by an external power supply, engine generators, and/or APU generator
117
What powers the main avionics AC inverter and what does the inverter power in return?
Avionics DC bus
Main avionics AC bus
118
What powers the essential avionics AC inverter and what does the inverter power in return?
Isolated DC bus
essential avionics AC bus
119
What does the external power supply?
all 12 AC and DC buses
120
What are the engine generators rated at? How are they cooled?
115V
3 phase
oil-cooled
121
What is the APU generator rated at? How is it cooled?
115V
3 phase
air-cooled
122
What is the DC power system comprised of?
6 DC buses
4 transformer rectifiers
bus-tie relay
2 batteries
123
What do the transformer rectifiers do?
convert AC power to DC power
124
What does the bus-tie relay do?
separates the isolated DC and avionics DC buses from each other when the APU is not online
125
What are the two batteries? What do they supply power to?
Utility battery - utility battery bus and isolated dc bus
Avionics battery - avionics battery bus and avionics dc bus
126
What are the batteries rated at?
lead-acid
| 24 Vdc, 35 amp/hour
127
Are the batteries interchangeable?
Yes, they are identical and interchangable
128
What are the 6 AC buses?
LH, RH, essential, main, essential avionics, main avionics
129
Which buses are powered by any of the engine-driven generators?
Both the essential ac bus and the main ac bus
130
What buses are powered by the APU if the APU is the only source of power?
essential ac and main ac
131
What bus is ALWAYS powered by the APU?
essential ac
132
If one generator is failed, which generator picks up the load? If both are failed on the same wing?
generator on the same wing
symmetrical generator on opposite wing
133
What are the inverters rated at?
115 Vac
134
The inverters supply how much power?
26 Vac
135
Can the APU and external power supply power at the same time?
No. Interlocks allow either or to supply power
136
During ground operations, do not attempt to start the APU if the battery voltage is less than what? In-flight? What happens if you do, both on the ground and in-flight?
22 Vdc, may cause the battery to overheat
23 Vdc, a voltage transient may cause an unrecoverable loss of essential equipment including MC, displays, and other mission critical battery powered systems.
137
If a differential fault has occurred, the generator cannot be reset until when?
DC power has been removed from the GCU
generator has stopped rotating
generator control circuit breaker is pulled and reset
138
What does the Generator Control Unit do?
monitors the generator frequency and voltage and regulates the power output to the bus
139
A GCU can fail without generating an ACAWS. When should you suspect a latent GCU failure?
when 115 Vac is indicated on all phases with the % LOAD indicating zero when the generator should be providing power to the electrical system
140
What TRs does the essential ac bus power?
1 and 2
141
What TRs does the main ac bus power?
3 and 4
142
Which TRs power the essential DC bus?
1 and 3
143
Which TRs power the main DC bus?
2 and 4
144
What are the 6 DC buses?
essential, main, isolated, avionics, utility battery bus, avionics battery bus
145
The TRs convert AC power into how much DC power?
28 Vdc
146
When should you pull MCBs?
only during emergencies or maintenance
147
What does the utility hydraulic system power?
```
Wing flaps
Main landing gear
Nose landing gear
Normal brakes
Nosewheel steering
Aerial refueling reels
Half of the aileron, rudder, and elevator control boost
```
148
What does the booster hydraulic system power?
Half of the flight control boost system
149
What does the auxiliary hydraulic system power?
ramp and cargo door
emergency brakes
emergency nose landing gear extension
(AR system in case of utility failure)
150
How is the auxiliary system connected to the utility system on the ground?
ground test valve
151
Utility system reservoir
5.5 gallons
152
Booster system reservoir
3.1 gallons
153
Describe the utility/booster system reservoirs
non-pressurized
| gravity-fed
154
Suction boost pump pressures
0-20 gallons/min
| 70-90 psi
155
What are the engine-driven hydraulic pumps rated at?
3000 psi
156
The flow capacity of each engine-driven hydraulic pump depends on what?
engine RPM
157
When do the pressure relief valves open in the hydraulic system?
3450 psi and reset at 3100 psi
they bypass 23 gallons/min when fully open
158
Where is the hydraulic ground test valve located?
aft of the left main landing gear wheelwell
159
What is the hydraulic ground test valve used for?
allows the aux hyd system to be tied to the utility hyd system
ground maintenance and operational checkout of the utility hydraulic system
160
Why are the suction boost pumps turn on prior to starting engines?
To prevent cavitation
161
What utility hydraulic system pressure triggers the ACAWS caution UTIL SYS PRESS HI?
3450 psi
162
When the FIRE handle is pulled, which valves in the hydraulic systems are shut off?
the suction line shutoff valve
the pressure line shutoff valve
163
Auxiliary hydraulic reservoir
5.3 gallons
164
How is the auxiliary hydraulic pump driven?
electrically-driven
165
Where can we read auxiliary hydraulic pressure at all times?
direct-reading pressure indicator
166
What is the benefit of the ground test valve in the hydraulic system?
eliminates the need for engine operation normally required to supply utility hydraulic system pressure
167
How are the flight control surfaces moved?
by hydraulic booster assemblies connected through a series of cables, pulleys, and torque tubes.
168
What does the aileron diverter valve do?
provides improved handling qualities at speeds below 270 kts when the autopilot is not engaged
directs either low limit or high limit booster and utility hyd pressure to the aileron booster assembly
169
What is the difference between the left and right aileron trim tabs?
left - moved by an electrical actuator
right - fixed in place and only adjustable while the a/c is on the ground
170
What system controls the elevator auto trim system?
the flap system
171
What physically moves the elevator trim tabs?
mechanical jackscrews (which in turn are connected to an electric motor via a flex drive cable)
172
ADV system
What happens to pressure once airspeed increases beyond 270 kts?
reduced until airspeed is once again less than 265 kts
173
What are the conditions that allow the MCs to activate the Aileron Diverter Valve?
lateral autopilot disengaged
airspeed less than 270
hyd system px is within limits
aileron system px transducers have not failed
prop speed of two cross-side engines is greater than 80 percent
174
When you move the aileron trim tab to the left, what direction does the trim tab move?
moves the left hand trim tab DOWN which forces the left aileron up and lowers the left wing
175
When you move the aileron trim tab to the right, what direction does the trim tab move?
moves the left hand trim tab UP which forces the left aileron down and lowers the right wing
176
When you move the rudder trim tab to the left, what direction does the trim tab move?
to the right - this forces the rudder to the left
177
When you move the elevator trim tab to NOSE DOWN, what direction does the trim tab move?
up - forcing the elevators down and pitching the nose down
178
Describe the flaps
Fowler high-lift type (4 flaps total)
flap motion is a combination of an aft movement to increase wing area and a downward tilting movement to alter the airfoil section to increase lift and drag
179
What mechanically raises and lowers the flaps?
8 jackscrews (2 in each flap)
180
What holds the flaps in the selected position and prevents movements by aerodynamic loads?
a spring-loaded flap brake
181
How does hydraulic pressure raise and lower the flaps?
Hydraulic pressure goes to the flap drive motor
Flap drive motor provides torque to the flap drive gearbox
182
What component prevents movement of the flaps when an asymmetric flap condition is sensed?
emergency flap brake
183
Which component drives the flap travel through both hydraulic and mechanical action?
flap drive gearbox
184
When will the landing gear warning audio go off?
When flap lever is set to 70 percent or more with refueling pods NOT attached
When flap lever is set to 80 percent or more with refueling pods attached
and with landing gear not down and locked
185
When will the defensive system pylon chaff dispensers be disabled?
When flaps are extended greater than 15 percent
186
Describe how the flaps move.
Flap lever -> moves control cables -> sets switch plate which sends an electrical signal to wing flap selector valve -> directs hyd pressure to flap motor
flap motor drives flap drive gearbox which spins the torque tubes -> torque tubes spin the 90 degree gearboxes which turn the jackscrews
187
What are the two basic reasons that we could have a flap failure?
electrically and hydraulically
188
What may result from pressing the manual reset on the emergency flap brake valve while the aircraft is in flight?
asymmetrical condition
189
What do the brake fuses do?
prevent excessive hydraulic fluid from escaping the brake system in the even of a brake line failure
190
How much brake fluid can escape the system before the brake fuse closes?
approx. 10 cubic inches
191
If emergency brakes are selected, what system is inoperative?
anti-skid system
192
What type of wheel brakes are installed on the aircraft?
hydraulically operated multiple disk
193
How is the anti-skid system activated?
anti-skid system provides touchdown protection, preventing brake application, until a wheel spin-up or WOW signal from either landing gear is sensed
194
What prevents the MLG from moving in the event of a hydraulic pressure loss?
an uplock brake
195
What serve as downlocks and prevent the MLG from retracting?
friction washers
196
What is the purpose of the nose landing gear pin when its installed?
prevents the release of the internal downlock and accidental retraction of the NLG
197
When the landing gear is NOT in the down and locked postion, when will the landing gear aural warning sound?
when power levers are within 5 degrees of FLT IDLE and the aircraft is below 1500 ft AGL (can be hushed)
when extending the flaps more than 70 percent without refueling pods or 80 percent with refueling pods (cannot be hushed)
198
Normal pressurization can be maintained with one AC, provided what else is on?
cargo underfloor heat
199
What does the outflow valve do in flight? on the ground?
in flight - exhausts air from the cabin at a controlled rate to maintain the desired level of pressurization
on ground - allows avionics cooling discharge air to escape overboard
200
Where is the outflow valve located?
aft right hand corner of the flight station, behind the ACS.
201
What does the safety valve do?
relieves excessive positive or negative pressure to prevent damage to the aircraft or injury to personnel
202
What does the MANUAL VALVE CONTROL ROCKER SWITCH do?
controls the electric actuator of the outflow valve. Functional only when the pressurization mode select switch is in MAN
203
AUTO RATE SELECTOR
What does NORM do?
MIN?
MAX?
NORM - provides a nominal climb rate of 500 fpm and a nominal descent rate of 300 fpm
MIN - zero fpm rate
MAX - 3000 fpm rate
204
What does NO PRESS do?
opens the outflow and safety valves and depressurizes the cabin at the rate set by the AUTO RATE selector
205
What does AUX VENT do?
opens the AUX VENT valves and closes the AC flow control valves and floor heat shutoff valves
206
What does the LDG/CONST ALT selector do?
sets the altitude of the selected landing field or the desired altitude when in the CONST ALT mode
207
What does the DIF PRESS indicator display?
the cabin-to-atmosphere differential pressure in inches of mercury
208
What does the EMER DEPRESSURE handle release?
releases the emergency depressurization door in the center overhead escape hatch
209
Which cabin pressurization system switch controls the electric actuator of the outflow valve when the pressurization mode switch is in the MAN position?
MANUAL VALVE CONTROL switch
210
Basically, how is pressurization achieved?
with air supplied from the bleed air system and ducted through the air conditioning system
211
What event would have to occur to force the safety valve to work?
combination of the cabin pressure controller and outflow valve fails to regulate the cabin pressure within structural limits
212
At what differential pressures does the safety valve open?
14.96 in Hg or -0.76 in Hg
213
What are the 6 sub modes within the AUTO mode of the cabin pressurization system?
GROUND - provides an unpressurized cabin by opening the outflow and safety valves
PREPRESSURIZATION - as power levers are advanced above FLT IDLE for takeoff, cabin altitude begins a descent to 300 ft below field elevation
CLIMB - occurs at liftoff. Either with WOW or gear is retracted and IAS is greater than 100 kts
CRUISE - cabin altitude will increase to the auto schedule value and hold that value after the aircraft altitude remains constant within 200 feet for 10 minutes
DESCENT - initiated when aircraft altitude decreases 1,000 ft or more from the highest altitude achieved during flight
LANDING - WOW or landing gear extended and IAS is less than 60 kts
214
When will you get the CAB PRESSURIZED ACAWS?
differential pressure exceeds 0.2 in Hg with WOW and power levers below FLT IDLE
215
What is the duty cycle of the outflow valve manual control motor?
3 mins on, 17 mins off
216
When will you get the CAB ALT HIGH ACAWS?
when cabin altitude is greater than 10,000 ft
217
The constant altitude pressurization mode uses what as an altitude reference?
pilot barometric setting
218
What is the rate of depressurization when the EMER DEPRESS switch is in the DUMP position?
an uncontrolled rate independent of cabin altitude
219
What 3 valves close when the EMER DEPRESS switch is in the DUMP position?
floor heat shutoff valve
flight station AC control valve
cargo compartment AC control valve
220
How long does it take to gain control of the outflow valve in manual pressurization mode?
40 seconds
221
What does the cross flow valve in the AC system do?
connects the flight station and cargo compartment distribution ducts so that one system can provide AC to both the flight station and cargo compartment
222
What are the two stages of the refrigeration unit in the AC system?
air-to-air heat exchanger
cooling turbine
223
Under what conditions might the ECS produce small chunks of ice and expel them at high speed from the air conditioning outlets?
high humidity
224
How much water is removed from the refrigerated air by the water separators?
70-85 percent
225
In which position is the pressurization mode select switch placed when using an external air conditioning unit?
AUX VENT
226
What are the 3 major assemblies of the engine?
PGB
torquemeter
power section
227
What does the PGB do?
transmits shaft power from the torquemeter, reduces shaft rpm to run the propeller, and provides shaft power to the GMAD
228
What does the GMAD provide drive pads for?
```
AC generator
Hydraulic pump
PGB oil supply and scavenge pump
PCU
Prop high px oil pump
OSG
```
229
Where is the GMAD located?
rear of the propeller gearbox
230
What does the torquemeter do?
transmits engine output power to the PGB and supplies torque reference to the FADECs
231
What are the major components of the power section of the engine?
variable flow 14 stage compressor
2 stage gas generator turbine
2 stage free power turbine
232
What does the PUAD provide drive pads for?
FPMU
PMA
Oil px and scavenge pumps
Air turbine starter
233
Where is the PUAD located?
lower forward portion of the engine power section
234
What does the NIU do?
provides conditioning and processing of engine monitoring system sensor data signals
provides engine, nacelle, and propeller sensor signal conditioning and nacelle component control
235
What does the FPMU do?
delivers filtered, metered fuel necessary for engine operation, and pressurized fuel for the CVG hydraulic actuator
236
What does the CVG do?
changes the angle of the compressor stator blades to assist with engine power control
237
What does the FCOC do?
cools engine return oil and heats the fuel to minimize engine fuel system icing
238
How big is the oil tank?
20 gallons
12 gallons of oil, 8 gallons of air
239
How big is the oil reservoir for the emergency feather pump oil supply?
0.66 gallon
240
What does the air oil cooler use on the ground to cool the engine oil? In flight?
Ground - propeller air flow
In flight - ram air
