SF34 Saab 340 AOM Flashcards
Covers almost all AOM theory in regards to functions and numbers. (281 cards)
1
Q
Length?
A
19.73m
2
Q
Span w/out extended wingtips?
A
21.44m
3
Q
Span w/ extended wingtips?
A
22.75m
4
Q
Propeller Clearance?
A
0.51m
5
Q
Saab 340A Engine Type?
A
GE CT7-5A2
6
Q
Saab 340A Takeoff Power?
A
1735 shp / 1800 ehsp (@ sea level up to 34 degrees)
7
Q
Saab 340B Engine Type?
A
GE CT7-9B
8
Q
Saab 340B Takeoff Power?
A
1750 shp / 1870 shp (APR) / 1935 eshp (@ sea level up to 35 degrees)
9
Q
Wing tip sweep w/out extended wingtips?
A
32m
10
Q
Wing tip sweep with extended wingtips?
A
33.3m
11
Q
Flight maneuvering load factor limitations (clean configuration)?
A
+2.75g to -1.0g
12
Q
Flight maneuvering load factor limitations (flaps extended)?
A
+2.0g to 0g
13
Q
What is the purpose of the blowout panel on the cockpit door and if a blowout occurs, are the pilots still protected from the cabin?
A
The blowout panel with blowout if a rapid decompression occurs, equalising pressure between the cockpit and the passenger compartment.
On the cockpit side, the blowout panel is fitted with a cage to prevent entry, which includes bullet proof panels to protect aircrew from firearm discharge.
14
Q
Can the cabin be pressurised off one A/C pack?
A
Yes (certified up to 31,000ft however bleed air extraction requirements apply above 25,000ft).
15
Q
Temperature required to trip over-temperature switch in ACP compressor outlet duct?
A
225 degrees
16
Q
Temperature required to trip over-temperature switch in ACP outlet duct?
A
82 degrees
17
Q
An over-temperature in the compressor outlet, or ACP outlet duct will cause what from the WEU?
A
DUCT OV TEMP light on AIR COND panel and AIR COND master caution.
18
Q
Where does air from the left ACP get supplied to?
A
Cabin
19
Q
Where does air from the right ACP get supplied to?
A
1/3 cockpit, 2/3 cabin
20
Q
A small amount of bleed air from the left and right ACP is routed to where? Why?
A
Cabin Pressure Air Filter.
To prevent the filter from building up moisture.
AND
Tail Compartment.
Creates a slight over-pressure and supplies a stream of dry air to prevent moisture.
21
Q
If a bleed valve is closed, or after an engine failure, what is automatically shut off in terms of air supply?
A
The air supply to the tail compartment is shut off.
22
Q
At what speed will a L/R RECIRC light on the AIR COND panel come on?
A
80% of normal speed.
23
Q
When does the avionics fan operate and where does the air from the fan pull air in from, then dump the air?
A
The avionics fan is operated whenever any one of the three AVION switches are in the ON position.
The fan draws air from the cabin through a filter into the avionics rack, then dumped overboard through the outflow valves.
24
Q
When will the AVIONICS VENT master caution light come on?
A
If the avionics fan stops (fails).
25
If you only have one ACP serviceable, what needs to be done and why?
Ram air intake below the aircraft must be extended which will provide a backup intake if the second ACP fails.
ACP pressure will exceed the ram air pressure keeping the intake closed. If the remaining ACP fails, ram air pressure opens the check valve furnishing fresh air to the compartments.
26
What is the minimum speed required to maintain sufficient ram air pressure for the ram air ventilation intake?
210 KIAS
27
The dual temperature control system can automatically provide compartment temperature between what temperatures?
18 degrees - 29 degrees.
28
High and low temperature circuits keep duct temperatures in the ACP between what temperatures?
3 degrees - 75 degrees.
29
Will the high and low temperature circuits in the ACP operate in manual mode?
No. Only in automatic mode, therefore careful operation is required.
30
How many outflow valves are located in the empennage?
Two.
31
What type of outflow valve is the primary outflow valve?
Electro-pneumatic
32
What pressures are required for the relief valve to open in the pressurisation system (max and min)?
Positive differential pressure +7.6 psi
| Negative differential pressure -0.5 psi
33
When the emergency pressure dump switch is turned on, what happens?
Primary electro-pneumatic valve fully opens in the air.
| Both valves open if WOW on the ground.
34
Explain the 6 different pressurisation modes.
Ground Mode:
Valves are fully open.
Pre-Pressuristaion Mode:
When one power lever is moved above 64 PLA, the primary outflow valve is modulated towards its closed position permitting cabin pressuristaion at a rate of 300 fpm (at detent position), to 140 ft below actual cabin altitude.
If both power levers are retarded below the min. takeoff power position, the primary valve modulates a cabin uprate of 500 fpm, after 20 seconds, a timer gives a control command to full open the outflow valve.
Climb Mode:
Starts when WOW switches sense liftoff.
Primary outflow valve is regulated by the controller. The controller computes the barometric corrected selected LDG ALT and sensed aircraft altitude. These parameters are compared with the computed auto-schedule to establish a control point for cabin pressure regulation. Regulated at 500 fpm uprate. If takeoff altitude is less that the LDG ALT, the control point is initially set to the LDG ALT. The controller starts to uprate the cabin until it intercepts the auto-schedule when it changes control point and follows the auto-schedule. If takeoff ALT is greater than LDG ALT, takeoff altitude will be maintained until the auto-schedule exceeds the takeoff altitude.
If the system fails to switch to flight mode, a backup feature will transfer the system to flight mode when aircraft altitude exceeds 15,000ft. In addition, the controller ensures the differential pressure never exceeds 7.1 psi.
On takeoff with both bleed valves closed, both outflow valves will be closed and the aircraft will automatically go into climb mode when the first bleed valve is opened.
Cruise Mode:
Reaches cruising level and altitude change is less than 200 fpm, system will transfer to cruise mode.
Downrate is revised from 0 to 300 fpm.
Cabin altitude is clamped at the control point, therefore cabin altitude will remain unchanged for flight disturbances not exceeding 100ft climb and 200ft descent.
A change in LDG ALT or barometric setting will cause a change in cabin altitude.
If an aircraft climbs more than 100ft or descends more than 200ft, the clamped altitude will be deleted and a new control point will be established when the altitude change again is less than 100 fpm.
Descent Mode:
When the aircraft descends 200ft in less than one minute, or descends more than 500 ft regardless of time, the system will go into descent mode. The cruise clamp is deleted and a new control point is established which is the higher of either the LDG ALT or the auto-scheduled altitude. The controller starts to downrate the cabin and maintains the new control point.
Landing Mode:
When WOW switches sense touchdown, and the aircraft altitude is less than 15,000 ft, the system will go into landing mode.
The primary valve will uprate at 500fpm for 20 seconds after which a timer will give a command driving the valve to the fully opened position.
35
How does manual pressurisation work?
Pressrisation can be manually controlled by a rotary knob on the pressure control panel.
Rotating the knob clockwise will increase and counterclowise will decrease the cabin altitude.
Primary valve remains closed.
36
Will the corresponding bleed valve automatically close with a L/R DUCT OV TEMP light?
Yes.
37
At what temperature will the RECIRC fans switch off due to over-temperature and when will they switch back on?
110 degrees. Will come back on when temperature decreases by 65%.
38
Should RECIRC fans be operated without an engine running?
No. RECIRC fans are cooled by airflow therefore an engine should be running.
39
When can you operate only one RECIRC fan on a B model aircraft?
27 pax or less.
40
When can you operate only one RECIRC fan on an A model aircraft?
25 pax or less.
41
What is the normal angle of bank for the Saab 340, and what does this get changed to with half bank ON?
27 degrees.
| Half Bank ON - 13.5 degrees.
42
What does EL, AIL or RUD on the EADI indicate?
Indicates difficulty in trimming the respective control forces (Elevator, Rudder, Aileron).
43
What does the Flight Director Comparator light look like, what does it mean, and how can it be reset?
Yellow "FD" in bottom left of EADI.
Differences of more than 5 degrees between the displayed pitch or roll steering commands.
Reset by the Master Caution button.
44
What is High Climb mode used for?
Normal climb in B model.
45
What is Medium Climb mode used for?
Normal climb in A model.
46
What is Low Climb mode used for?
Best rate of climb.
47
What does the white light on the overhead panel near the doors light indicate?
If a headphone is plugged in to the ground crew jack panel.
48
What temperature is required to cause a GEN OV TEMP light?
150 degrees.
49
What cools the starter/generator on the ground and in flight?
Integral fan on the ground and ram air in flight.
50
At what Ng is the starter motor, transferred to its generator function?
55% Ng
51
How many volts will be provided during a battery start and how is this possible?
48V.
| A series/parallel relay connects the batteries in series therefore adding both of their voltages.
52
What temperature does the NO BAT START light come on?
57 degrees.
53
At what temperature does the BAT HOT light come on and does anything else happen?
71 degrees. The battery will be disconnected from the GEN and START bus.
54
What does putting the battery switch into OVRD do?
With the battery switch in OVRD, the 71 degree switch will be overridden and the battery will be connected to the GEN BUS.
55
How are the battery compartments cooled on the ground and in flight?
Fan on the ground, ram air in flight.
56
What conditions must be met for the generator relay to close?
External power relay open, engine start complete, generator field current reset.
57
When will the external power over-voltage relay close (or not open)?
If the external power voltage exceeds 31V.
58
How is each respective PDU powered with the external power in and on?
Left PDU through the deactivated series/parallel relay.
| Right PDU subsequently through the closed bus tie relay.
59
When will the EXT PWR switch automatically be de-energised?
If the external power voltage drops below approximately 10V.
60
At what amperage will the over-current relay trip?
800A
61
What voltage and ampere-hour is the emergency battery?
24V/5Ah
62
When will the EMER PWR light on the overhead panel come on?
If the emergency battery voltage drops below 24V or if the EMERGENCY BUS is not powered.
63
At what frequency do the inverters run?
400Hz
64
When will the INVERTER light on the overhead panel come on?
If the DC supply to the selected operation inverter is interrupted or if the inverter fails.
65
Why is the 'wild' AC system called 'wild?
Because the frequency is variable between 460 - 600 Hz due to variations in propeller RPM.
66
If either AC Generator fails, will anything happen?
The AC GEN buses will automatically be tied together. This can be manually done by means of the L/R AC GEN switches on the overhead panel.
67
When will the L/R AC GEN light on the overhead panel come on?
If a generator fails or disconnects from the L.R A GEN BUS due to too low propeller rpm.
68
How much oxygen per minute does each outlet generally provide?
2L
69
When does the oxygen CWP light come on?
If the oxygen pressure drops to 800 +/- 35psi
70
Which oxygen bottles do the quick-donning masks use if connected to a portable oxygen bottle?
310L
71
What are the flow rates on the 310L oxygen bottle?
2L/min
72
What are the flow rates on the 120L oxygen bottle?
4L/min or 2L/min
73
Minimum duration of the 310L oxygen bottle?
One outlet - 80 min
| Two outlets - 50 min
74
Minimum duration of the 120L oxygen bottle?
HI - 20 min
| LOW - 30 min
75
What BUS do the 'jetpacks' charge off?
R ESS BUS
76
When will the emergency lights come on automatically?
If electrical power is lost on R MAIN START BUS (with system in the armed position).
77
What does the EMER LIGHT UNARMED cwp indicate?
EMER LIGHT switch is in the off position.
78
What type of fire extinguisher is used in the aircraft (handheld)?
Halon 1211.
79
ELT duration?
50* (52) hours.
| AOM
*Tech course and ACE Manual
80
When will the ELT activate?
5-7G impact, manual activation on switch, manual activation on ELT unit.
81
What type of fire detection is on the Saab 340?
Single continuous loop detection circuit.
82
How does the fire detection detect a fire?
Measures the resistance of the circuit. If a preset resistance value is reached, it will indicate a fire.
If there is too quick of a resistance change then a fire warning will not be given, and a detector fail indication will be given.
83
What will pulling a fire handle result in?
Engine fuel shutoff valve closed.
Engine bleed air pressure regulator valve is closed.
Start-Gen field relay open.
Fire bell silenced
Master warning is reset.
Both main and reserve extinguisher squibs for the engine are armed.
84
What fire extinguishing agent is used in the engine compartments?
Halon 1301.
85
What type of tail pipe overheat detectors are on the Saab 340?
Three over-temperature detectors wired in parallel so that an overheat signal from one of them will set the overheat warning off.
86
Where are the three smoke detectors?
Avionics, lavatory and cargo compartments.
87
What type of fire extinguishing agent is used in the cargo compartment?
Halon 1301
88
How does the cargo fire extinguisher work?
Dual wall type extinguisher.
Outer volume rapidly floods the compartment with agent to extinguish the fire.
The inner volume slowly leaks a regulated flow of the agent through a restrictor maintaining a specified concentration level high enough to prevent re-ignition.
89
What temperature in the tail pipe will trigger a tail pipe hot warning?
235 degrees.
90
What BUS is the smoke detection on?
L/R BAT BUSES
91
When does the CARGO EXTG light come on?
When pressure inside the bottle has decreased to 310 - 260 psi. (Outer volume discharged)
92
At what temperature does the lavatory bin extinguisher fire, and what agent is used?
75 degrees. Halon 1211.
93
What is the centering spring in the aileron system used for?
To improve the lateral stability at extreme sideslip angles.
| Also compensates the aerodynamic upfloat in case of a disconnection during flight.
94
The stick pusher movement is not available when which elevator channel is jammed?
Left.
95
What is the elevator downspring in the elevator system used for?
To improve stick-force variation with speed at low speed.
96
Which side is the elevator autopilot servo linked to?
Left side.
97
Which side is the aileron autopilot servo linked to?
Right side.
98
What restrictions does the rudder limiting system provide?
Below 150 knots, full range of rudder movement.
Between 150 and 200 knots, 15 degree limit.
Above 200 knots, 6.3 degree limit.
99
When will the RUDDER LIMIT light come on (what could cause it)?
A malfunction of the Rudder Limit System.
Could be caused by power loss, limiting mechanism fails to enter proper position for corresponding airspeed, a failure in the speed sensors or excessive rudder command for corresponding airspeed due to mechanical failure.
100
Can the Rudder Limiter be overriden? If so, how and will the CWP light go out?
Yes. By setting the RUDDER LIMIT switch to the OVRD position.
The light will remain on until the speed is below 140 KIAS at which point the actual rudder position will correspond with the limiting mechanism.
101
What does the left flap position sensor supply signals for?
```
Left flap position indicator pointer in cockpit.
Position feedback for flap operation.
Takeoff configuration warning (CONFIG).
Flight recorder.
Left stall warning channel.
```
102
What does the right flap position sensor supply signals for?
Right flap position indicator pointer in cockpit.
Landing configuration warning (CONFIG).
Right stall warning channel.
103
When will the FLAPS light on the CWP illuminate?
If there is a malfunction in the flap electrical control system.
104
How are the aileron, elevator and rudder locked with the GUST LOCK?
Aileron and elevator are locked mechanically.
| Rudder is locked electrically.
105
When will the GUST LOCK CWP illuminate?
If the gust lock handle is in the off position but the rudder gust lock remains engaged.
106
When will the PITCH TRIM CWP illuminate?
If there is a discrepancy between the left and right trim tabs.
107
What is required to not get a CONFIG warning on takeoff?
Flaps 0 - 15.
Condition levers max.
Pitch trim in green band.
108
When the fuel quantity indicators are tested, what quantity will be shown?
455 +/- 23kg
109
How long does it take to refuel to mid-level?
Approximately 8 minutes
110
How long does it take to refuel to full?
Approximately 15 minutes.
111
What are the standby fuel pumps used for?
To takeover if the main pump fails.
| To supply the engine with fuel during engine start until the main pump can provide sufficient pressure.
112
Below what fuel quantity can the magnetic dipstick measure fuel?
Below 500kg.
113
What is the capacity of the hopper tank?
90kg.
114
How are mid-level and full-level sensed when refueling and what happens if this fails?
Optical sensors.
| Overfill float switch in each cell will interrupt the power and turn on the corresponding OVERFULL light.
115
With the engine shutdown, will the standby fuel pump start due to the main pump stopping?
No. A condition lever actuated switch will inhibit the automatically start of the standby pump.
116
If the main pump has failed, and then the standby pump fails, will the engine be starved of fuel?
Not necessarily, the standby pump on the opposite side can be switches on to supply fuel through the crossfeed.
117
If the fire handle is pulled, what happens to fuel supply to the engine?
An electrical shutoff valve at each engine nacelle will shut off the fuel supply to the engine.
The L/R VALVE CLOSED light on the overhead fuel panel indicates the condition.
118
What does the L/R Fuel Filter light indicate?
Comes on if the fuel filter becomes clogged and the fuel is bypassing the filter.
119
What does the fuel flow indicator show when being tested?
345 +/- 16 kg/h
120
The fuel is heated before it reaches the HMU. What heats the fuel?
PGB Oil.
121
When does the FUEL FILTER light come on, and when does fuel actually start bypassing the filter?
9 psid.
| Bypass at 18 psid.
122
What is hydraulic power used to operate?
Flaps, landing gear, brakes, nose wheel steering.
123
What are the four hydraulic accumulators and what are they used for?
Main accumulator - supplies flaps, landing gear, nose wheel steering.
Emergency accumulator - landing gear uplock release.
Two accumulators - Brake system, one for outboard brakes and one for inboard brakes.
124
Capacity of the main hydraulic reservoir?
310 cu inches (5L)
125
Capacity of the hand pump reservoir?
150 cu inches (2.5L)
126
When will the hydraulic pump operate?
When the main accumulator hydraulic pressure drops below 2100 psi and until 2900 psi.
Landing gear is selected down and until left gear is locked down.
Landing gear is selected up and until both main gears are locked up.
127
With HYD PUMP switch in override, what pressure will be supplied?
3000 psi.
128
What is the pressure of the hydrogen pre-charge in the hydarulic accumulators?
1650 psi.
129
When will the HYDR master caution come on?
To indicate low hydraulic pressure in any of the hydraulic accumulators (Below 1800 psi) or high temperature of the fluid in the main reservoir (Over 116 degrees).
130
What type of CB/Fuse protects the hydraulic pump?
200 AMP Fuse.
131
When will the hydraulic filter 'pop' and when will it bypass?
'Pop' at differential pressure of 70 psi.
| Bypass between 90 - 150 psi.
132
What are the different components of the ice and rain protection system?
```
Wing and stabiliser (boot) de-icing.
Engine anti-icing.
Propeller de-icing.
Windshield heating.
Windshield wipers.
Pitot tubes, OAT and AOA sensor heating.
```
133
What supplies most of the power for the ice and rain protection systems?
115 VAC wild power.
134
What is bleed air used for in the ice and rain protection system?
Wing and stabliser boots, engine split lip and inlet guide vanes.
135
Where are ice and rain protection systems controlled from? Are there any that don't have controls?
On the overhead panel.
| Main pitot tubes, temperature probe and AOA sensor are automatically powered as soon as one AC generator is online.
136
When will the DE-ICE OV TEMP light come on?
If the temperature reaches 150 degrees.
137
What pressure does the regulator maintain in the bleed air icing system?
18 psi with a relief valve if the pressure exceeds 25 psi.
138
How does the Saab prevent the boots from inflating when not pressurised?
In each distribution valve to the boots, a an air ejector is installed which passes a small flow of regulated air overboard to create enough suction to prevent the boots from inflating.
139
What is the order of the de-icing boots sequence?
Stabiliser, Outboard wing, Inboard wing, Stabiliser.
140
When in CONT mode for de-icing boots, how often is the inflation cycle completed?
Once every three minutes.
141
When will a timer light come on?
No pressure sensed downstream of the valve sequenced for opening within 4 seconds.
The activated timer gives no inflation signal.
The boots are not cycling.
Pressure remains on in the stabiliser boot zones (CONT).
Pressure remains on in the stabiliser boot zones when next cycle is activated (ONE CYCLE).
Pressure remains on in left and right inboard wing or left and right outboard wing boot zones after more than 8 seconds.
142
What sections of the engine have anti-ice, and how are they respectively heated?
Inlet lip, intake ducts and inlet protection device with exhaust nozzle which are electrically heated.
Splitter lip and inlet guide vanes are heated with bleed air.
143
How do you switch on the electric and bleed air components of the engine anti-ice system?
The L/R ENGINE anti-ice switches will control both the electric and bleed air components.
144
Where is bleed air bled from to increase the engine stall margin in low power operation, and how does the system work?
5th compressor stage.
The bleed air is via the HMU 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 the sleeve is fully closed.
145
If the right engine 115 VAC generator fails, can the right engine still operate its engine anti-icing?
No. No crossfeed function available for the engine anti-ice.
146
What RPM is required for the AC Generator relay to close?
1000 rpm.
147
When will the L/R INTAKE light illuminate?
If over-temperature sensor senses a temperature exceeding 125 degrees.
If the under-temperature sensor senses a temperature below 10 degrees (inhibited for 25 seconds when switch first turned on).
Loss of power in one or more phases in the three-phase power supply.
148
At what temperatures will the under and over temperature sensors "cut in" and "cut out" the inlet heat controller at?
60 degrees "cut in"
| 80 degrees "cut out"
149
What do the L/R ENG ANTI-ICE lights represent?
That the switch has been turned on or off.
| No representation on whether the system is actually working
150
When does the L or R AIR light come on?
If the electronic solenoid valve does not close when engine anti-ice is switched off.
If the electronic solenoid valve does not open when engine anti-ice is switched on.
151
Where are the prop de-icing boots powered from?
115 VAC wild bus.
152
What does the L/R PROP DE-ICE indicate?
If the system is working and will go out with system failure.
153
When will the L/R PROP lights on the overhead panel come on?
AC or DC power failure.
Timer not cycling or remaining permanently on.
Over or Undercurrent to propeller boots.
Cycling interval periods are off by more than +/- 0.5%.
154
If the AC generator fails, can the other AC gen power the L/R prop de-icing boots?
Yes.
155
What powers the prop de-icing timer?
28 VDC.
156
In NORM power position, how long does the prop de-ice cycle go for?
11 seconds on.
| 79 seconds off.
157
In the MAX power position, how long does the prop de-ice cycle go for?
90 seconds on.
| 90 seconds off.
158
When should each mode of propeller de-icing be turned on?
OFF > -5 degrees
NORM -5 to -12 degrees
MAX < -12 degrees
159
Why should NORM and MAX not be used at temperatures higher than recommended?
Due to the risk of ice to melt and 'run back' and re-freeze behind the boots.
Run back ice can cause reduction in propeller thrust up to 30%.
160
Can MAX be used at any time outside its recommended range?
MAX can be used between -10 to -12 degrees if unacceptable propeller vibrations are experienced.
Can use briefly at temperatures warmer than -10 degrees if unacceptable vibrations are experienced, however be mindful of run back ice and only use until vibrations stop.
161
How are the front windshields and forward part of the side windshields heated?
From the 115 VAC system.
162
How is fogging prevented on the windshields?
Air from the air conditioning system is directed to the inside of the windshields to prevent fogging as soon as the air conditioning system is working.
163
How many controllers regulate the heating of the windshields and which controller heats which windshields?
2 controllers.
Left controller powers left front and right side windshields.
Right controller powers right front and left side windshields.
164
If a controller detects an overheat sensor circuit failure or a complete controller fault in the windshield heating system, what will happen?
It will shut off power to the affected windshield and illuminate the respective windshield light (L/R SIDE or L/R FRONT light).
165
If only the normal temperature circuit fails and the over-temperature sensor circuit takes over in the windshield heating system, what will happen?
The caution light will illuminate but the windshield will still be heated.
166
If an aircraft has both NORM and HIGH modes for side windshield heating, what are the two modes used for, and are there any restrictions on their use?
NORM is for defogging. MAX is for de-icing.
| NORM must be used for at least 7 minutes prior to selecting HIGH in order to reduce thermal stresses.
167
What modes are available on the windscreen wipers?
PARK, OFF, LOW, HIGH
168
How are the pitot tubes, OAT gauge and AOA sensors heated?
All except the standby pitot tube are supplied with 115 VAC wild frequency. The standby pitot tube is supplied with 28 VDC.
169
When is the heating for the pitot tubes and sensors which use 115 VAC turned on?
Whenever the 115 VAC buses are powered.
| OAT is only turned on in the air (WOW switch)
170
Where is the 115 VAC generator mounted?
On the propeller gear box.
171
How does the boot de-ice cycle work on CONTINUOUS?
6 seconds on, 4 cycles, 24 seconds total.
| 156 second dwell.
172
When AISBV is turned on at high power, what engine indications will be received?
Increase in ITT, decrease in TRQ.
173
When AISBV is turned on at low power, what engine indications will be received?
Little or no change.
174
Where does the ADC receive pitot pressure from?
Left pitot tube.
175
Where do the pneumatic instrument receive pitot pressure from?
Right pitot tube.
176
What does the standby pitot/static tube provide pressure for?
Standby instruments and airspeed sensor.
177
How are pressure differences between pitot tubes attempted to be eliminated?
Each static chamber is interconnected with the other in order to try and eliminate any differences.
178
What does the airspeed sensor do?
Converts pressures from the standby pitot/static tube to electrical IAS signals which it provides to the AHRS and Rudder Limiter systems. The Rudder Limiter system uses this IAS as an accuracy check of the ADC provided IAS signal.
179
On the Fast-Slow indicator on the EADI on some aircraft, one dot indicates how many knots away from bugged speed?
5 knots.
180
When does the Flight Recorder system become powered and start to operate?
When one engine is running and one generator is online.
181
How many hours of flight data does the Digital Flight Data Recorder hold?
Approximately 25 hours.
182
The Cockpit Voice Recorder records the last how many minutes of cockpit communications?
30 minutes.
183
Which way do the gear retract?
Forward.
184
How are gears retained in the up or down position?
With locks.
185
When the gear is extended, what is the position of the gear doors?
Nose wheel door fully open.
| Main gear doors are partly closed.
186
When gear is selected up, what happens?
An electrically operated control valve ports hydraulic pressure to release the down-locks and pressurise the hydraulic actuators.
When the gear is up, an up-lock hook will engage a roller on the gears and retain them in the retracted position.
187
When the gear is selected down, what happens?
Hydraulic pressure is ported to the up-locks and hydraulic actuators.
As soon as the gears are fully extended, the downlocks will engage.
188
When the emergency gear extension handle is pulled, what happens?
The gear actuator hydraulic pressure lines will be connected to the return lines to prevent hydraulic lock.
Emergency accumulator pressure will then release the up-locks and the gear will extend and lock by gravity and aerodynamic forces. The gear door mechanism is disconnected from the gear, leaving the doors in fully open position. The disconnection is made by an explosive separation bolt that is electrically activated by the emergency extension handle.
189
How does "touchdown protection" help and how does it work?
It prevents braking whilst in flight to avoid landing with braked wheels and consequent damage to the tyres.
In order to brake with anti-skid protection, the following is required:
Anti-skid switch ON and appropriate power lever below flight idle plus 3 second delay; OR
Appropriate left or right weight on wheel switch activated to ground position plus 3 second delay; OR
Average wheel speed over 50 kts
190
If a wheel locks, what protection is available and what does it do?
Locked wheel protection dumps the brake pressure in a brake circuit should the wheel speeds in the circuit differ by more than 50%.
191
At what speed does anti-skid cut out?
20 kts
192
When will the A-SKID INOP light come on?
If any parameter in the anti-skid control box circuits and the wheel speed transducers exceed their established limit.
Also comes on if the anti-skid switch is OFF when the gear is extended before landing.
193
What is the maximum steering deflection left or right?
60 degrees.
194
When will the landing gear configuration warning sound?
Gear up with radio altitude less than 500 ft and one power lever retarded below minimum takeoff power (62 PLA).
If flaps 20 or more is selected and landing gear is not extended and locked down, or flaps are below 22 degrees and PL above 62 or flaps below 18 degrees.
195
Main tyre pressure?
115 +/- 4 psi.
196
Nose tyre pressure?
55 +/- 4 psi
197
Maximum tyre speed?
165 KIAS
198
At what temperature will the thermal relief plugs in the tyres deflate the tyre?
180 degrees
199
What brake pressures will the PARK BRK cwp come on at?
| Why might this be an issue?
On at 1700 psi, off at 950 psi.
Park brake can be set ON between 950 and 1500 psi so park brake may be on without a CWP.
200
If there is a failure of the normal instrument lighting power source, what instruments will be lit by the emergency power supply unit?
```
Standby attitude indicator.
Standby airspeed indicator.
Standby altimeter.
Standby compass.
Standby VOR/ILS indicator.
Cabin pressure indicator.
```
201
What does the DPU do?
Executes the orders from the DCP by generating the necessary signals to display the required information.
202
If the data from one EFIS side fails, what can be done?
XSIDE DATA will transfer data from one side to the other.
203
If either the EADI or EHSI fails, what can be done?
ADI REV/HSI REV can transfer the information onto the other screen to provide a composite display.
204
If the DPU on one side fails, what can be done?
DRIVE XFR will allow the opposite side DPU to provide drive signals for the failed side.
205
If using ADI REV/HSI REV, do you move the switch towards the failed screen, or operating display?
Move the switch towards the operating display.
206
What aircraft systems are operated by pneumatic power?
Air conditioning.
Pressurisation.
Boot De-cing
207
Where is low pressure bleed air bled off?
5th stage compressor.
208
Where is high pressure bleed air bled off and how much greater is the pressure than that of the low pressure bleed air?
6th stage compressor (radial).
| 3 times greater the pressure.
209
When is high pressure bleed air supplied?
If the gas generator speed drops below approximately 80 percent Ng. (76 psi)
210
How is the high pressure bleed air cooled in flight and on the ground?
In flight, ram air. On the ground, a jet pump creates an under-pressure behind the pre-cooler which sucks air through the cooler.
211
When does the high pressure bleed air valve close?
If bleed air temperature after the precooler exceeds 288 degrees.
If the fire handle is pulled.
If the HP VALVE switch is set to OFF.
212
When will a HP HIGH light come on?
If the HP valve fails to close after a 'close signal'.
213
How is the HP valve actuated?
Pneumatically, requiring a bleed pressure of minimum 10 psi.
214
If there is a loss of electrical control power to the HP valve, will it fail open or closed?
Closed.
215
When will the low pressure bleed air valve close?
If bleed air temperature exceeds 288 degrees.
If the fire handle is pulled.
If the regulated pressure exceeds 43.5 psi.
If the air conditioning pack compressor discharge temperature exceeds 225 degrees.
If the distribution duct temperature exceeds 82 degrees.
If the BLD VALVE switch is set to OFF.
216
When will the BLD CLOSED light come on?
If the low pressure bleed air valve is closed.
217
When will the BLD FAULT light come on?
If the low pressure bleed valve fails to close after a close signal has been received.
If the temperature is too high, or if the regulated pressure is too high.
218
How is the low pressure bleed valve actuated?
Pneumatically, requiring a minimum pressure of 10 psi.
219
In case of loss of electrical power, will the low pressure bled valve fail open or closed?
Open.
220
Can the bleed systems be interconnected? If so, how are they connected and when can they be connected?
Yes.
| There is an interconnect valve which can only be operated on the ground.
221
What does the X VALVE OPEN light indicate?
That the X VALVE is confirmed open.
222
How is the XVALVE operated and if there is a loss of electrical control power will the valve fail open or closed?
Pneumatically requiring 10 psi. Will fail closed.
223
How is a leak of bleed air detected?
There is a temperature variable resistance continuous loop hot air leak detector system installed which is routed alongside the bleed ducting between the engine nacelle and the cross valve on each side of the aircraft. If the control unit senses a temperature of 205 degrees, the affected sides BLD AIR LEAK light will come on with a master caution.
224
When can HP bleed valves be opened on the ground to increase cooling air to the cabin?
If the ambient temperature is greater than 21 degrees.
| ITT below 800 degrees.
225
In flight, what pressure will cause the ENG OIL PRESS cwp to come on?
25 psi.
226
On the ground, what pressure will cause the ENG OIL PRESS cwp to come on?
7 psi.
227
What is the compression ratio of the engine?
17:1
228
What in the engine is 'variable'?
Inlet guide vanes, stator vanes for the 1st and 2nd stage.
229
With what ratio does the propeller gear box drive the propeller?
15.9:1
230
What three functions does the propeller gear box oil system provide?
Lubricates the gear box. However also used for propeller pitch control and fuel heating.
231
When will the L/R FUEL LOW TEMP light come on?
If the fuel temperature is too low (0-3 degrees).
232
What does HMU stand for and what does it do?
Hydromechanical Unit.
Provides high pressure metered fuel for combustion. Schedules fuel to meet the various engine operating conditions and demands. Also controls the variable geometry system (IGV and stage 1 and 2 stator vanes) and the start and anti-ice bleed valve to provide for efficient and smooth engine operation throughout the entire speed range.
233
At what engine speed does the HMU flame out the engine as overspeed protection?
110% Ng.
234
What does the torque motor do?
Increases fuel beyond PL position with two functions:
Meters engine fuel, by signals from the DECU bottoming governor circuit, in order to achieve a pre-set variable minimum PROP RPM on ground (1040/1200).
To meter engine fuel, by signals from the DECU constant torque and APR circuit, in order to achieve a selected torque (CTOT-function) or torque push (APR-function).
235
What should the fuel used indicator show on a lamps test?
8880.
236
What does the overspeed and drain valve do?
During normal operation, the overspeed and drain valve allows metered fuel to pass from the HMU to the fuel injectors.
If an Np overspeed is sensed by the DECU, the fuel flow is shut off to the fuel injectors and bypassed back to the inlet of the HMU high pressure pump, causing a momentary engine flameout.
At engine shutdown, the overspeed and drain valve allows fuel upstream of the valve to be purged back through the fuel injector manifold and lines to an environmental container located just forward of the wheel well.
237
What is Ng and how is it measured?
Ng is the engine rpm which is the speed of the gas generator. The signal is taken from the engine electrical power alternator which is driven by the accessory gear box.
238
What are the Ng signals used for?
ENG rpm indication.
DECU flame out protection system (autoignition).
Autocoarsen system.
239
Where is the Forward Np sensor located, how does it work, and what is the signal used for?
Located at the forward end of the propeller drive shaft housing between the gas generator and the PGB.
Used to measure power turbine speed.
Sensor contains a permanent magnet and wire coil and produces a pulse of current each time a timing notch on the shaft passes. The signals are used for PRPM indication (via the DECU) and BG function.
240
Where is the Aft TRQ/Np sensor located, how does it work, and what is the signal used for?
Located in the exhaust frame. Np is picked up the same way as in the forward Np sensor.
Torque is picked up by an electronic measurement of twist applied to the Np rotor shaft. The rotor shaft is hollow and a coaxial reference shaft is pinned to the rotor shaft at the forward end and is free at the aft end.
The rotor shaft and the reference shaft have four teeth at the aft end, 180 degrees apart and offset 90 degrees from the teeth on the rotor shaft.
A dual-function monopole sensor is installed and senses the rotary motion and relative position of the teeth. In a no-load condition, the teeth pulses are equal to the reference shaft teeth pulses. When power is applied, a measurable twist occurs on the rotor shaft which is directly proportionate to the applied power. The reference shaft will not twist since it is free at its aft end; therefore the phase relationship of the torque shaft and reference shaft teeth changes, and the phase shift between the induced pulses is a measurement of twist (torque) applied to the propeller through the reduction gear.
The signals are used by the DECU for TRQ indication, Autocoarsen system, CTOT/APR system, Np overspeed protection and back up Np signals to the BG function should the forward Np fail.
241
What does DECU stand for and where is it mounted?
Digital Electronic Control Unit.
| Mounted below the compressor casing.
242
How is the DECU powered?
The DECU is powered by the engine electrical power alternator.
243
What does the DECU do?
```
The DECU accepts signals and provides functions as below:
Np overspeed protection;
Flameout protection (autoignition);
Bottoming governor (BG) function;
CTOT system with APR function;
TRQ/PROPR RPM indication;
ITT indication.
```
244
At what RPM does the power turbine overspeed protection activate and what does it do?
25,000 rpm.
DECU activates the overspeed solenoid on the overspeed drain valve which shuts off fuel and turns on ignition.
When the rpm has dropped below 1573, the DECU signal is removed causing the fuel flow to return. The ignition is on for at least 7 seconds after the overspeed has passed.
245
How does autoignition work and when does it activate?
The DECU compares actual gas generator speed rate of change to a predetermined flameout schedule to detect an engine flameout. When such a condition is detected, the auto-ignition system will be triggered for at least 7 seconds. Should Ng decrease below 62%, ignition will be shut off to prevent sub-idle relight.
246
What is the purpose of the bottoming governor?
To automatically provide a minimum prop rpm during ground operation only.
247
What rpm is maintained during normal ground operation?
1040 rpm.
248
What rpm is maintained during full reverse thrust operation?
1200 rpm.
249
What are the several functions which affect BG enabling/disabling and thereby torque motor operation?
CL quadrant switch. Provides BG enabling with CL in MIN - MAX range.
DECU function which enables the BG above 830 PRPM and disables the BG below 280 PRPM. The upper limit is to prevent overswing and the bottom limit is to prevent ng acceleration in the event of Np sensing signal system failure.
PL quadrant switches which together with a WoW switch function will disable the BG with PL in the range FLT IDLE to 64 PLA, when airborne. This is to prevent asymmetric power should one torque motor inadvertantly be activated during the approach/landing phase of flight. On ground, the BG is enabled regarless of PL position, provided CL is in MIN - MAX range.
250
Where is the ITT measured from?
Between the gas generator turbine and the power turbine.
251
How many thermocouples measure the ITT by displaying an average temperature?
7.
252
What are the three functions of the alternator driven from the accessory gear box?
Ignition power, DECU power, Ng RPM signal.
253
What type of engine oil system does the Saab 340 have?
Self-contained, recirculating, dry sump system.
254
Capacity of the engine oil tank?
7.3 quarts (7L)
255
How many quarts may be added to the engine when the oil reaches the 'add' level?
2 quarts.
256
Can you over-service the engine oil?
No.
257
How many scavange pumps in the engine oil system?
6.
258
When will the L/R ENG OIL PRESS cwp light come on?
If the oil pressure is below 30 psi.
259
What indications would be seen before a loss of oil pressure?
Fluctuating oil pressure and then a drop in oil pressure.
Oil temperature will hold steady or start to decrease slightly due to air beginning to mix with the supply line and the oil aerating.
260
When will the L/R CHIP DETECT light come on?
If metal particles are present in the oil system.
261
What is the capacity of the PGB oil reservoir?
5 quarts (4.7L) of which 1 quart constitutes a reserve for emergency propeller feathering.
262
Is it possible to over-service the PGB oil?
Yes.
263
Will the counterweights on the propeller tend to move the blades towards coarse or fine pitch?
Coarse.
264
How does the propeller overspeed governor work and when will it operate?
Flyweight operated unit similar to the CSU. If the propeller reaches an overspeed condition (1453 rpm or more) when in governing mode (PL at FLT IDLE or above), the overspeed governor shuts off the oil supply to teh CSU, causing the propeller blades to move towards coarse pitch by counterweight action and thereby reducing RPM.
265
How many modes of operation does the autocoarsen system have and what are they?
AUTOCOARS LOW and AUTOCOARS HIGH
266
When will the autocoarsen system be in AUTOCOARS LOW mode?
PLA < 64 degrees (one or both PL)
Ng > 55% (both engines)
Ne > 60% (both engines)
267
When will autocoarsen occur in AUTOCOARS LOW mode?
Ng < 55% (failed engine)
Ne < 60% (failed engine)
Ng > 55% (good engine)
268
When will the autocaorsen system be in AUTOCOARS HIGH mode?
PLA > 64 degrees (both PL)
TRQ > 50% (both engines)
P3 > 120 psi (both engines)
269
When will autocoarsen occur in AUTOCOARS HIGH mode?
```
PLA > 64 degrees (both PL's)
TRQ > 50% (good engine)
TRQ < 50% (failed engine)
TRQ differential > 25% (between engines)
P3 < 120 psi (failed engine)
```
270
What does propeller synchrophasing do and how does it work?
Reduces propeller noise and vibration.
To be able to synchrophase, RPM must be within 10 RPM of each other. PCU governors will keep the propellers in the same relative position and thereby also the same RPM.
271
Which propeller is the master propeller in the Dowty propellers?
Neither. Drives the slower RPM to the high RPM.
272
Which propeller is the master propeller in the Hamilton propellers?
L/H is the master.
273
When will the Flight Idle Stop logic not allow the power lever through the flight idle gate?
Stop Closed - Aircraft in Flight
L and R LDG retracted; OR
L and R LDG extended and L and R not weight on wheels and L and R inboard and outboard wheel speed < 9 kts
274
When will the Flight Idle Stop logic allow the power lever through the flight idle gate?
Stop Open - Aircraft on Ground
L or R LDG extended and L or R inboard or outboard wheel speed > 25 kts; OR
L or R weight on wheels
275
What is the Takeoff Inhibit button used for?
To inhibit nonessential warnings not needed during the takeoff phases.
276
What is the Ground Ops button used for?
To minimise the nuisance effect of various cautionary alerts for ground handling and prior to takeoff.
277
What does the BITE light indicate?
A fault detected by the BITE equipment.
| Indicates a detected failure which has caused loss of system redundancy.
278
When will the overspeed warning sound?
If Vmo is exceeded by 1.5 - 6 knots.
279
What are the 5 distinct warnings the stall warning system provides for an impending stall?
```
Stick shaker.
Aural Warning.
Autopilot disengage.
Stick Pusher
Visual warning - 3 amber lights and 2 pusher lamps
```
280
At what 'G' will the stick pusher disengage so as to stop forcing the aircraft into an unacceptable nose down maneuver?
< 0.5g
281
How much lower than the normal AoA does the ice speed compute its angle of attack?
Approximately 6 degrees lower.
