AGK Flashcards
(278 cards)
1
Q
What do the seals around the piston do?
A
Prevent the loss of power around sides and the passage of oil to combustion chamber
2
Q
What does the inlet valve do?
A
Allows Fuel/Air mixture into cyclinder
3
Q
What is the four stroke cycle?
A
Induction
Compression
Power
Exhaust
4
Q
What happens in intake?
A
Fuel/air sucked into cylinder
Piston goes down
air flows through carburettor and onto cylinder via inlet valve and manifold
5
Q
What happens in compression?
A
Inlet valve closes
Piston moves up
Pressure of fuel/air mixture increases
temp increases
6
Q
When does the spark ignite the fuel/air mixture
A
Near completion of compression
7
Q
What happens during power stroke?
A
Piston driven down
exhaust valve opens just prior to completion
8
Q
What happens during exhaust stroke?
A
Piston goes up
Burned gases escape via exhaust manifold
9
Q
Why is some exhaust heat reclaimed?
A
For carby heat
Mixed with cold air for cabin air
10
Q
How many rotations do you get out of one complete stroke?
A
2 rotations
11
Q
What is the top dead centre
A
Piston top of stroke
12
Q
What does a higher compression do?
A
More power but need higher quantity of fuel and results in more cylinder wear
13
Q
What is the compression ratio?
A
Total Volume / Clearance Volume
14
Q
What controls the timing of the inlet and exhaust valve timing?
A
Camshaft that is gear driven by the crankshaft
15
Q
When does the inlet valve open?
A
Just prior to TDC, known as valve lead
16
Q
When does the inlet valve close?
A
Just prior to BDC, known as valve lag
17
Q
What is valve overlap?
A
When both valves are open together
18
Q
What does better valve timing do to the engine volume efficiency?
A
Increases engine volume efficiency
19
Q
What is the most effective crank angle between con rod and crank web?
A
90 degrees
20
Q
At what angle does ignition occur?
A
25 degrees before top dead centre
21
Q
At what angle does peak pressure occur?
A
30 degrees after top dead centre
22
Q
What is the power formula?
A
(Force x Distance) / Time
or thrust x velocity
23
Q
What does a higher compression do?
A
More power but need higher quantity of fuel and results in more cylinder wear
24
Q
What is volumetric efficiency?
A
Ratio of actual weight of mixture in cylinder after closure of valves TO weight of mixture present if no resistance to flow
Expressed as %
25
What controls the timing of the inlet and exhaust valve timing?
Camshaft that is gear driven by the crankshaft
26
When does the inlet valve open?
Just prior to TDC, known as valve lead
27
When does the inlet valve close?
Just prior to BDC, known as valve lag
28
What is valve overlap?
When both valves are open together
29
What does better valve timing do to the engine volume efficiency?
Increases engine volume efficiency
30
What is the most effective crank angle between con rod and crank web?
90 degrees
31
What happens after take off at approximately 300 ft and 2500rpm?
MP drops to approximately 25 in. Hg
32
At what angle does peak pressure occur?
30 degrees after top dead centre
33
What is the power formula?
(Force x Distance) / Time
or thrust x velocity
34
What does one horsepower equal?
33000 feet pounds/min
550 ft/s
0.746 kW
35
What happens to the engine output with a loss in oil temperature?
Cannot deliver full power
36
What is thermal efficiency?
Ratio of power actually produced by engine TP power theoretically available in fuel
37
What is the advantages of impulse coupling?
Higher volt to create stronger spark
Retard ignition timing at low RPM until TDC
Immediately after start allow timing of spark to return to normal (approx 25 degrees before TDC)
38
What are the max rpm drops for the magnetto check?
max 125 rpm drop with max 50 inbetween
39
As the throttle is increase to 1500 rpm, what happens to MP?
increases to roughly 15 in. Hg
40
At take off rpm of 2500-2650rpm, what happens to MP?
Increases to roughly 28 in. Hg
41
What happens after take off at approximately 300 ft and 2500rpm?
MP drops to approximately 25 in. Hg
42
What is the most important parameter for engine monitoring?
Oil Pressure
43
What happens if there is a large oil pressure drop?
Engine likely to fail
44
What happens to the oil temperature if the is a loss in pressure?
Temperature will rise
45
What happens to the engine output with a loss in oil temperature?
Cannot deliver full power
46
What is the likely cause of the fuel pressure fluctuating?
Air is likely to be present
47
What are some symptoms of pre-ignition?
Rough running
Back firing
high CHT
48
What are the max rpm drops for the magnetto check?
max 125 rpm drop with max 50 inbetween
49
What does the accelerator pump do?
Adds extra squirt of fuel when throttle is pushed fully open
50
Why do we have an accelerator pump?
Airflow increases at a rate greater than the fuel flow, resulting in a weaker mixture
51
What will leaning to peak EGT do?
Best economy
52
What are the symptoms of icing?
Power loss
MP drop
loss in airspeed
rough running
53
What can an over rich mixture lead to?
Loss of power, higher fuel consumption, fouling of plugs and formation of carbon on piston heads and valves
54
What can over lean mixture do?
Detonation and high CHT
55
What is the cause of detonation?
Lower fuel grade
Over leaned mixture
Too high MP
over Heated engine
56
How do we cure detonation?
Mixture rich
Throttle back
increase airspeed
57
What are some symptoms of pre-ignition?
Rough running
Back firing
high CHT
58
When can carburettor ice occur?
Humidity above 50%
| OAT as high as 35 degrees celcius
59
What happens if you go higher than full throttle height?
Decrease in MP
| Power reduces as altitude increases
60
What is fuel ice/fuel vapour ice?
Downstream of jet where fuel introduced to carburettor airstream
61
What is throttle ice?
Fuel/air mixture of gases accelerate past throttle valve leading to decrease in static pressure and temp.
ice on throttle valve
62
What are the symptoms of icing?
Power loss
MP drop
loss in airspeed
rough running
63
What happens when you apply full carby heat?
Drop in RPM due to less dense hot air
| Mixture enrichens
64
What is used to supply intake manifold with more pressure?
Compressor
65
What does a increase pressure do from the compressor?
Increase mass of air
Additional fuel supplied
more power
66
What are the advantages of maintaining MP?
Maintaining MP maintains density of air fed into the engine so power output can remain constant with increasing altitude
67
What is the difference between internal supercharge and turbocharger?
Internal supercharge uses mechanically drive compressor
| Turbo charger uses exhaust gas from engine to turn turbine which turns compressor
68
What is the sequence for decreasing power?
Decrease MP, decrease RPM
69
What happens if you go higher than full throttle height?
Decrease in MP
| Power reduces as altitude increases
70
What happens to the MP as you climb in a supercharger engine?
MP maintained and power increases. The power increase is due to increase in volumetric efficiency
71
How is the exhaust gases brought from the engine to the turbine in a turbo charged engine?
Through the wast gate valve
72
What happens if there is a leak upstream from the waste gate valve?
Engine acts as through normally aspirated
73
What happens if there is a leak downstream from the waste gate valve?
No effect
74
What is a likely cause of manifold pressure fluctuations?
Sticky waste gate valve
75
What pitch should be selected at low speeds and high rpm?
fine pitch
76
What pitch should be selected at high speeds and low rpm?
Coarse pitch
77
What is the sequence for increasing power?
Mixture rich, increase RPM, increase MP
78
What is the sequence for decreasing power?
Decrease MP, decrease RPM
79
Which is larger, CTM or ATM?
CTM
80
What does CTM attempt to do?
move pitch to fine
81
What happens in a CSU if there is carby ice?
MP drops, RPM remains constant
82
What is windmilling?
When the prop drives the engine
83
When is windmilling likely to occur?
Steep dive
Power off
Engine failure
84
Why would we feather a prop?
to minimise drag following an engine failure
85
What pitch should be selected at low speeds?
fine pitch
86
What pitch should be selected at high speeds?
Coarse pitch
87
What does the McCauley system do?
through oil pressure, moves to coarse pitch and seeks fine pitch through springs
88
What does the Hartzell system do?
Through oil pressure moves to fine pitch, counter weight moves to coarse pitch
89
What happens if there is a loss in oil pressure in the McCauley system
Fine pitch stop
90
What happens is there is a loss in oil pressure in the Harzell system?
Coarse pitch stop
91
What is the formula for aspect ratio?
Span / chord
or
Span squared / blade area
92
What is feathering?
Aligning the chord line of prop with airflow
93
Why would we feather a prop?
to minimise drag following an engine failure
94
Dual ignition on an aircraft engine provides extra safety and what during flight?
More efficient combustion of charge during power stroke
95
If mixture is set to peak EGT, enrichening the mixture without adjusting the throttle will cause the power to?
Increase then decrease
96
How long should take off power be used?
To a limit of about three minutes
97
What is the purpose of a booster pump?
To guard against vapour lock
98
Application of carby heat when ice in present with a CSU will result in?
initial drop then increase in MP
| Constant RPM
99
If the engine is flooded, what is the correct way to start it again?
Mixture idle cut off
Throttle full open
crank and re-start
100
What is the main difference between CHT and EGT in regards to heat?
CHT responds more slowly to combustion temp change
101
Fluctuating fuel pressure indicates what?
Fuel vapourization
102
When is fuel vaporisation likely to occur?
Hot fuel and low atmospheric conditions
103
Dual ignition on an aircraft engine provides extra safety and what during flight?
More efficient combustion of charge during power stroke
104
Aircraft electric system operates at constant?
Voltage
105
If the alternator fails during flight, what will be shown on the centre zero ammeter?
discharge shown on CZA
106
Circuit breakers and fuses protect against?
Too many amps
107
Capacity of the battery is measure in?
Amp hours
108
A leak in the induction system of turbocharged engine with automatic boost control will be noticed when?
on climb to high level
109
What are bearings?
Ensure minimum wearing and friction
110
What is the formula for Brake Horse Power?
BHP = Indicated Horse Power - Frictional Horse Power
111
Describe radial engines
```
Used in older aircraft
Pistons radically around crankshaft
Excellent power to weight ratio
Good cooling
Large frontal area creates high drag and low visibility
```
112
What is the ideal stoichiometric ratio? What about rich and lean?
15 parts air to 1 part fuel (ideal)
8: 1 rich
20: 1 lean
113
What do you need to do in regards to the mixture if the density decrease?
Lean mixture
114
What are the symptoms of detonation?
High and increasing CHT
Significant power loss
Engine vibration
'Pinging' from engine
115
What are the symptoms of pre ignition?
Rough running
Back firing
Rise CHT
Engine damage
116
Where is heat in combustion removed?
half through exhaust gases
| rest through cylinder walls to cooling fins and via engine oil to cooler
117
When are cowl flaps opened and closed?
Open during take off and climb
| Closed during descent and cruise
118
What happens if cowl flaps left open during cruise?
Increase drag and reduce airspeed
119
What is the oil like if it has high viscosity
thick and sticky (cold)
120
What is the oil like if it has low viscosity?
Thin and runny (hot)
121
What does the pressure relief valve do?
Allows oil to return to inlet side of pump if oil pressure is too high
122
A scavenge pump and external oil tank are used in which oil system?
Dry sump
123
What does the antisurge and thermostatic bypass valve allow?
allows oil to bypass cooler when starting cold
| also allows to bypass cooler if bloked
124
What does a generator do?
Supplies DC by rotating magnetic field in vicinity of coiled conductor.
Magnetic field provided by permanent magnet's strength cant be changed
125
What happens when the RPM is low in a generator?
Generator volts too low so battery must assist
126
What happens the RPM is high in a generator?
Generator output can get too high and must be controlled by voltage regulator
127
What does an alternator do?
Magnetic field provided by electromagnet who's strength can be altered
128
What happens at low RPM in an alternator?
Power sent to electromagnet can be increased
129
What happens at high RPM in an alternator?
Power sent to electromagnet can be decreased
130
What does a left centre zero ammeter measure?
Alternator output
131
What does centre zero ammeter measure?
Current to and from battery
132
What does a position on CZA mean?
Current into battery a charge
133
What does a negative on CZA mean?
Battery dicharge
134
What does excessive negative on CZA mean?
Alternator has failed/battery is being drained
135
What does excessive positive on CZA mean?
Battery is not holding/accepting a charge
136
What does the voltmeter measure with alternator running?
Measure alternator output
137
What does a voltmeter measure prior to engine start up with master on?
Battery voltage
138
What do relays and solenoids do?
Remove dangerous high tension leads running into cockpit
139
What is a relay?
Allows pilot to switch light current on which is applied to solenoid?
140
What is a solenoid?
Metal bar placed inside a coil
| When light current applied, magnetic field pushes through coil and completes a heavy circuit
141
What does a rectifier do?
Converts AC to DC current
142
What does a inverter do?
Converts DC to AC
143
What does a fuse protect from?
Protects from too high current (amps)
144
What does the condenser do?
Prevents unwanted sparks across breaker points. Stores current when circuit is broken
145
During you magneto check, there is an excessive RPM drop with the engine running smoothly, what could this be?
Magnetto timing is incorrect
146
During your magneto check, there is excessive RPM drop and rough running, what could this be?
Spark plugs fouled/faulty
147
During your magneto check, there is no RPM drop and engine runs smoothly, what could this be?
Fault in the switch or wiring
| Magnetos remain live
148
When is spark fouling likely to occur?
During prolonged descents with low power
149
With regards to RPM, what happens if engine torque is equal to prop torque?
RPM is constant
150
With regards to RPM, what happens if engine torque is greater than prop torque?
RPM will increase
151
With regards to RPM, what happens if engine torque is less than prop torque?
RPM will decrease
152
What pitch should you select for climbs?
Fine pitch
153
Define fine pitch?
Climb prop
used for low airspeeds
Small blade angle
Small geometric pitch
154
What pitch should you use during the cruise?
Coarse pitch
155
Define coarse pitch
Cruise prop
Used for High speeds
Large blade angle
Large geometric pitch
156
What is geometric pitch?
How far the prop would theoretically movie forward in one rev
157
What is aerodynamic twisting moment?
Attempting to twist blade to coarse pitch
158
What is centrifugal twisting moment?
Attempting to twist blade to fine pitch
159
Which is stronger, ctm or atm?
CTM
160
Where is the blade angle greater, hub or tip?
Hub
161
What happens if the speeder spring fails?
fly weigh fling outwards
governor senses overspeed
blades coarsen
large rpm
162
How do you lean for best power?
slightly rich of peak EGT
163
How do you lean for best economy?
slightly lean of EGT
164
What does the fuel vent do?
Allows air to flow into fuel tank to replace fuel
165
What would happen if there was no fuel vent?
Fuel would be unable to enter lines
166
What happens in the carburettor?
fuel/air is mixed in correct proportion for engine
167
Where is the throttle valve in relation to venturi?
downstream
168
What is 'idling jet?'
at low engine speeds, uses low pressure at throttle butterfly lop to deliver fuel
169
What is impact ice?
Super cooled dropletts freeze on impact with cold surface
170
Where is impact likely to occur?
Air filter, manifold walls, throttle butterfly
171
When is carby ice likely to occur?
Low power during long descent
172
What can be done if the air filter is blocked?
Carby heat can be used as alternate air supply
173
What does a fluctuating fuel pressure indicator likely to mean?
Fuel vapour is present
174
What should you do if the fuel pressure indicator is fluctuating?
Use the boost pump
175
What is cavitation?
Low and high pressure producing bubbles of vapour in fuel pump
176
What does applying carby heat do in a fixed prop?
Causes RPM drop
177
What does applying carby heat do in a variable pitch prop?
Drop in MP
178
Where is manifold pressure measured?
At the inlet valve
179
How does the compressor work?
Speeds the flow of air up
1. Air enters at centre of impeller
2. Centrifugal forces accelerates air outwards resulting in increased energy
3. Air is slowed by diffuser, increasing pressure
4. This compresses air and makes it more dense, which is then introduced through induction
180
Why is a compressor used?
Compensates for lack of air with increasing altitude.
| Pumps air into inlet manifold allowing power to be maintained with increasing altitude
181
What is ground boosting?
Occurs when engine can achieve more power at sea level through use of compressor
MP can be increased above normal seal level value of 30in HG to approx 35 in Hg.
182
Where is the supercharger linked to?
Linked to crankshaft via gears or belt driven
183
With internal supercharger, where is the compressor located?
Between carburettor and inlet valve
184
Where is the compressor located with an external supercharger?
Before carburettor
185
Explain how gear driven supercharger gets air?
Crankshaft connected to gears allowing impeller to spin approx 10 times faster. This increases the MP
186
What happens if the impeller spins too fast?
There could be too much pressure, leading to over boosting and detonation
187
What is 'rated boost'?
Recommended limitation of MP for supercharged engine
188
What happens if you go over the rated boost?
Increasing the MP above the rated boost will result in detonation
189
Explain how the turbo charge system works?
Uses exhaust gas to spin turbine which is connected to compressor before inlet of engine
190
What happens if the waste gate is open?
Exhaust gases go overboard
191
What happens if was gate is closed?
Exhaust gases diverted to turbine
192
Why must the throttle be partly closed with a fixed waste gate?
To prevent overboosting
193
How does the 'throttle open wastegate' work?
As butterfly valve begins to open, waste gate remains open. When b.v. fully open waste gate begins to rotate to closed position
194
How does the automatic waste gate work?
Uses density and differential pressure to control and monitor waste gate
195
What is the critical altitude?
With throttle fully open and waste gate closed, height above which engine power drops and aircraft climbs
196
What is full throttle height?
Altitude where certain MP for full throttle not available
197
What happens if there is a leak upstream of waste gate?
Engine will behave as though normally aspirated
198
What happens if there is a leak downstream of wastegate?
No effect on turbo system
199
What does fluctuations of manifold pressure indicate?
A sticky wastegate
200
What is the main cause of turbine failure?
Turbine spinning at high RPM in very hot exhaust, leads to deformation of turbine blades
201
How would you recognise turbine failure?
Smoke as oil from turbines is exposed to hot exhaust
202
What is turbo lag?
Apparent lag in MP increase prior to closure of wastegate. Once waste gate begins to close MP increase at a greater rate.
203
What is the main risk of turbo lag?
Risk of overboosting the engine
204
Why is there turbo lag?
Compressor wont spin until the waste gate starts to close and airflow is directed over the turbine
205
Why is the hydraulics reservoir vented?
To prevent vacuum forming as fluid is removed
206
What is the purpose of the hydraulics reservoir?
To store fluid.
| Feeds main power pump via standpipe
207
How does the variable displacement hydraulic pump work?
Changes the volume of flow to meet demands of the system. Can be electric or engine drive
208
How does the constant displacement hydraulic pump work?
Maintains constant volume of hydraulic fluid
209
What is a pressure regulator and what pump is it used in?
Used in constant displacement pump
| Spring loaded to relieve pressure when it reads a preset value. This allows oil to flow back to reservoir
210
What does the accumulator do?
Stores oil pressure and assists pump to maintain pressure
211
Why do we not use vegetable based hydraulic fluids?
They can't be mixed
| Form sludge and cause corrosion
212
When can you use synthetic hydraulic fluids?
Only in systems designed for it
213
What happens if there is air in the hydraulic system?
Lead to system over heating due to inadequate lubrication and cooling
214
What happens if there is a leak in the hydraulic system?
Piston may slip back again after fluid begins to escape.
| i.e. if 30 degrees flaps selected, the flaps may be begin to come back up again
215
What happens if there is low accumulator pressure?
The pump must do more work which leads to slower operation. The operations will be noisier without surge protection
216
Explain how the toe brakes work?
As pedal on rudder is depressed, this applies pressure to piston in master cylinder which is transmitted through brake line to slave cylinder. The slave cylinder presses brake pads on the brake discs.
217
What happens if there is air in the brake system?
They feel spongy and brake effectiveness is reduced
218
How do you fix air in the brake system?
Air must be bled of all air
219
What will happen if there is a leak in the brake system?
Initially the system will feel normal but will be noticed as fluid levels decrease
220
If the CoG is behind the main wheels, do we have a nose or tail wheel?
Tail wheel
221
If the CoG is ahead of the main wheels, do we have a nose or tail wheel?
Nose
222
What is stronger, tail + nose wheels or main wheels?
Main wheels. Nose/tail wheels cannot withstand as high a loads
223
What is a spring steel strut?
Absorbs shocks by bending under load and then returning to original shape when load removed
224
What is a 'bungee'?
Elastic bands which absorb shocks by stretching under load
225
How do oleo pneumatic struts work?
Piston acting against compressed gas (nitrogen) and oil in cylinder. The gas absorbs shocks and oil smooths out operations and prevents bouncing
226
What are torque links?
In oleo fitted systems, prevents wheel turning on own accord
227
What does the shimmy damper prevent?
Lateral vibration
228
What does retracting the undercarriage reduce?
Parasite drag
229
What is the retractable undercarriage powered by?
Electrical pump
230
How do down locks work?
Locks the landing gear down with mechanical latches at end of extension cycle
231
What is the squat switch?
Prevents system from activating when weight on wheels
232
Why are there uplocks used?
Allows hydraulic system/electrical system to shut down after cycle
233
What does a dry powder system do to extinguish fire?
When heated releases CO2 which doesnt support combustion
234
Why should dry powder not be used in engine fires?
Residue is a corrosive
235
What is the most effective fire extinguisher system?
Halogenerated hydrocarbon agents
236
How are fire protection systems operated?
by the electrical system
237
How do fire detectors work?
Switches turn on when certain temp is reached. Circuit closes
238
What does a single axis autopilot control?
Longitudinal axis (roll)
239
What is a single axis autopilot made up of?
Turn coordinator, computer amplifier and actuator
240
What does a two axis autopilot control?
Roll and pitch
241
What are the factors affecting rigidity?
Weight (more heavy = more rigid)
Speed (faster spin = more rigid)
Radius of mass from axis (further away = more rigid)
242
What is precession?
Tendency to resist force applied at point with displacement at 90 degrees in direction of rotation.
243
If you apply a force on gyro, where does it move?
90 degrees from applied force (in direction of rotation)
244
What does a gimbal do?
Supports but allows gyro to move freely
245
How is a vacuum driven gyro rotated?
Shaft at rear of engine. Air against buckets cut into rim of gyro
246
What are the disadvantage of vacuum gyro?
Ineffective at high altitude
Cant be contained within sealed case
Dust and moisture affect life
Can't be run until engine started
247
Under IFR what are the conditions for gyro instruments?
Can't all be from one source
248
Which instruments are generally vacuum and which are generally electric?
AH and DG vacuum
| TC electric
249
What is the degrees limitation in pitch?
85 degrees
250
What are acceleration errors in gyros?
AH.
| Causes false right bank indication
251
Which is more serious, acceleration or turn errors?
Acceleration
252
What direction does DG indicate?
Magnetic north
253
What are the errors with the DG
Doesn't know where north actually is
| Needs to reset with reference to compass (usually every 15 mins)
254
What does the turn coordinator use to indicate turn?
Precession. It responds to yaw with roll
255
What does the pitot and static measure?
Change in atmospheric pressure
256
What happens if the pitot tube is blocked on climb?
ASI will over read on climb
257
What happens if the pitot tube is blocked on descent?
ASI will under read on descent
258
What happens if the static tube is blocked on climb?
ASI will under read on climb
VSI will read 0
ALT will be read alt that it became blocked at and hence under read
259
What happens if the static tube is blocked on descent?
ASI will over read on descent
VSI will read 0
ALT will read alt that is became blocked and hence overread
260
If QNH is set at 1005 but actual QNH is 1017, what will your actual height be when altimeter reads 3500?
1017 - 1005 = 12
12 x 30 = 360
360 + 3500 = 3860 feet
261
What is the difference between true north and magnetic north called?
Magnetic variation
262
What is compass deviation caused by?
Metals and electrics in the aircraft
263
Where is magnetic dip the greatest?
Maximum at the poles
264
Where is magnetic dip the least?
At the equator
265
If you are on an easterly course, and start to accelerate, what will the compass show?
Apparent turn to south
266
If you are on a northerly course and accelerate what will the compass show?
No deviation
267
If you are on a westerly course and start to decelerate, what will the compass show?
Apparent turn to the north
268
If you are on a southerly course and start to decelerate, what will the compass show?
No deviation
269
If you are turning onto a northerly heading, what will happen?
Overshoot north by approximately 30 degrees
270
If you are turning onto a southerly heading, what will happen?
Undershoot south by approximately 30 degrees
271
When will detonation occur?
After ignition spark
272
What is the purpose of a fuel control unit in fuel injection system?
To supply metered fuel to fuel manifold unit
273
When operating an engine fitted with a supercharger, the use of carby heat should be regulated by reference to what?
CAT
| carburetor air temp gauge
274
Angle of attack of prop blade =?
Angle between relative airflow and face of blade
275
Blade angle =?
Angle between chorine of prop and plane of rotation
276
Angle between resultant velocity of prop blade and plane of rotation is?
Helix angle
277
Resistance to motion in plane of rotation is?
Prop torque
278
To be coupled to an ILS, an autopilot must be capable of operating in how a minimum of how many axes?
2
