Here we go Flashcards
The air/ground data link system that allows text messages to be sent and received is called the?
Controller Pilot Data Link Communications (CPDLC)
The benefit of the CPDLC system is that?
There is reduced voice channel congestion
Which On-board Information System (OIS) domain controls the WLAN?
Cabin and communication
The MEL in a Network Storage System (NSS) can be accessed via which two domains?
Flight ops and avionics
The communication link which connects the avionics domain in a NSS and the avionics systems is a?
Two-way secure link
A ‘soft copy’ of the cabin crew operating manual can be accessed via the?
FAP
The three information areas found in a NSS are?
Maintenance, flight and cabin
To stop access to the avionics domain from the cabin and flight domains in a NSS, there is a?
Open world diode
Cabin lighting, temperature and passenger calls are controlled from the?
FAP
The ‘fasten seat belt’ and ‘no smoking’ signs on the passenger service units are controlled from which area of the aircraft?
The flight deck
The following cabin function can be carried out in flight?
The configuration of individual cabin zones
On a FAP, there is no need to input an access code when?
Loading software
A FAP can change its cabin layout configuration?
On the ground only
The configuration of passenger seats and their associated function is carried out via the?
CIDS
Passenger network services, such as telephone or email access, would use what avionic system for the transfer of data?
SATCOM
Passenger information between the aircraft and ground is transferred by the?
CIDS
The passenger database will be located in the?
Cabin network system
The 3 typical IMA system domains are?
Cockpit, cabin and utilities
The ARINC 664 Part 7 message frame which occupies the smallest bandwidth is?
Implicit message
A FBW system transmits and receives data on an ARINC 664 Part 7 at a maximum of?
10 Mbps
An advantage of an IMA system is that?
Modifications are normally made by software upgrade
The data payload in a AFDX message contains 14 bits of information, it requires how many pad bits?
3
In an AFDX system, the switch follows which protocol?
First-in-first-out
The Redundancy Manager (RM) in an AFDX system is located in an AFDX?
Platform
The Application Programming Interface (API) in an AFDX platform is defined by?
ARINC 653
In an AFDX system, an explicit message?
Has the decoding instructions contained in the message
The ARINC 664 Part 7 data payloads are?
Between 1 and 1471 bytes in length, with a minimum of 17 bytes
ARINC 664 Part 7 pertains to?
Ethernet network standards operating at transmission rates of 100 Mbps
In an AFDX system, the queuing port?
Is where buffering of the data takes place
AFDX is also known as?
ARINC 664 Part 7
A CVR?
Is an orange coloured LRU, and has a beacon that emits a sonic pulse at a frequency of 37.5 kHz
A passenger call button is pressed?
The CIDS director sends a signal via DEU A to illuminate the overhead light
In the event of a cabin decompression?
IFE is activated to display emergency information only
During an EVAC command initiation, the signal to disable the door opening with slide armed lever comes from?
CIDS director
An EVAC command can be initiated from the?
FAP and cockpit
When replacing the battery in an ULB?
Incorrect polarity will permanently damage the unit
The ULB, as fitted to the CVR, will supply a?
Pulsed 37.5 kHz acoustic signal for up to 90 days and is powered by an integral battery connected to a water sensitive switch
Cabin exit signs?
Must have an emergency power source
Flight deck announcements have priority over?
All audio sources
To allow radio communications during an AC power failure situation, one of the VHF radios will be connected to which power supply to allow its uninterrupted operation?
Essential busbar
CVRs are fitted with a ULB, these are powered by?
A battery which requires periodic replacement
A complex IFE may use which techniques to reduce the amount of cabling required?
Data compression and TDM
The three A/T control circuits are?
Speed, vertical speed and thrust
When the A/T is engaged, the selection mode will be shown on the?
PFD
The A/T disconnect message will not show when?
On the ground with thrust reverser application
Manual control of the ailerons will be aided by?
Lateral Central Control Actuator (LCCA)
In an AFCS, the localiser deviation distance and rate?
Signals are derived from localiser acceleration and cross runway acceleration
A typical aircraft’s autopilot pitch trim systems operation is based on?
Elevator out of neutral position
Aircraft with well-damped Dutch roll modes could experience a degradation in damping as?
Airspeed decreases and altitude increases
In an automatic pitch trim system there are usually 2 motors to drive the control surface, one operates at a fast speed, the other a slow speed. The?
Slow speed operation is used by the AP system
Stabiliser movement with no auto-trim command is also known as?
Unscheduled trim
In a typical engaged Auto-flight system, the CWS force transducer will?
Convert a mechanical force to an electrical steering signal
Operation of the force trim switch in a typical helicopter autopilot system?
Removes forces in the cyclic and pedals whilst they move to a new position
A typical secondary flight control system has moveable control surfaces such as?
Flaps and slats
In an AP system, aileron to rudder cross-feed is achieved by applying the?
Yaw gyro output signal to both rudder and aileron channels
A simple 3 axis autopilot system will?
Keep the wings level, hold a course, maintain an altitude and control yaw
WRT ILS GS capture, the gain programmer operates, in late model APs?
IAW information from the RA
A helicopter AFCS system, a CofG trim switch signal is connected in?
Parallel with the stick sensor and adds or subtracts so that their combined output cancels the vertical gyro input
One characteristic of a series actuator is that it?
Moves the control surfaces but not the cockpit controls
The Dutch roll filter used on yaw damper systems operates with a demodulator and modulator in series, between which is an electronic circuit, which is a?
Narrow band filter featuring a differentiated output
When in LNAV mode?
The FMC locks out any Mode Control Panel (MCP) commands
ILS localiser beam capture is normally dependent on a change of bank angle command based on?
Groundspeed, intercept angle and distance from the beam
A control wheel action in roll, with the AP engaged, operates a transducer which outputs a signal?
To cancel attitude hold allowing the pilot gradual and increasing bank angle
Engaging an AP to ‘command’ with the flight director on causes the AP to?
Engage to the existing flight director mode except if the flight director is in Go-Around, command mode is heading hold
In a LCCA, the pressure regulator is designed to?
Allow manual control inputs to override AP inputs
ARINC 664 Part 7 pertains to?
An ethernet network standard, normally operating at 100 Mbps
How long does a GPS satellite take to complete one orbit of the Earth?
Approximately 12 hours
The units for present position entry in INS are?
Latitude and longitude
TCAS RA displays?
Solid red square with an audio warning giving instructions such as ‘descend’ or ‘climb’
The DME measures which range to the ground beacon?
Slant
RA transmits on a frequency of?
4200 MHz to 4400 MHz
A Radar system where the received signal is a reflection of the original transmitted signal is called a?
Primary radar
On a weather radar display, the colour that shows the worst weather is?
Red
An INS contains?
3 accelerometers
INS/IRS is able to calculate distance by?
Integrating acceleration twice
NAVSTAR GPS uses a minimum of?
21 satellites
The frequency range used for speech in airborne radio communication is?
300 Hz to 3 kHz
Personnel should be kept clear of HF antennas whilst they are transmitting because?
There is a danger of radio frequency burns
The HF frequency band is from?
3 MHz to 30 MHz
The power output of a typical VHF communication system is?
25 Watts
At jet cruising altitudes, the range of VHF transmissions is in the region of?
250 nm
The VHF international aeronautical distress frequency is?
121.5 MHz
Aircraft VHF communication systems use the frequency range of?
118 MHz to 136.995 MHz
To receive a vertically polarised RF signal, the antenna is required to be?
Vertical
When transmitting a VHF band signal, the length of the antenna (aerial) will be?
Shorter than the antenna used for a LF band
In a simple AM receiver, the?
Detector removes the carrier, and keeps the original modulating signal
Micro Electro-Mechanical system (MEMS) sensor devices provide data for?
Structural health monitoring of the aircraft to sense damage such as fatigue cracks, impact damage and pitting
A yaw damper system will?
Minimise the instability caused by Dutch roll
If an AP is to be able to carry out automatic landings, it must be a?
Three axis system with A/T
In an AP system, the attitude reference device is typically?
A gyro
What colour of lamp illuminates when an ILS equipped aircraft flies over the ILS middle marker?
An amber light will illuminate
In most modern ILS, there are?
Three airborne receivers
In an AFCS, the yaw damper?
Counteracts the problem of Dutch roll
The speech frequency range used in airborne radio communications is?
300 Hz to 3 kHz
The DC tuning voltage in a frequency synthesizer is taken from the?
Frequency and phase comparator
WRT AM, a SSB signal compared with a DSB signal will?
Save power, and have a smaller bandwidth
If a superhet Rx is tuned to 8400 kHz, and the LO produces 7950 kHz, a second image channel frequency could be?
7500 kHz
WRT HF comms, the skip distance will be?
Greatest during the night
If the speed of the rotor in a turn and slip indicator is greater than normal, what would be the result?
It would overread
What is the order of the main parts of a compass swing?
Correcting swing, calibration swing and complete documentation
What are two reasons to carry out a compass swing?
When a new aircraft is received from the manufacturer and when certain components of the compass system have been replaced IAW the AMM
A compass base with a maximum of?
0.1° deviation is class 1
The voltage in the pick-off coil of each leg of a detector unit is due to?
The legs relative angle to the Earth’s magnetic field
In a leg of a flux valve, the overall voltage in the pick off coil will be zero when?
The aircraft is 90° to the Earth’s magnetic field
What is the purpose of the 3 crescent shaped slots in the detector unit?
To allow for adjustment of ‘A’ error
How is ‘B’ error removed in a detector unit?
By a potentiometer, increasing or decreasing the strength of electromagnets
How is ‘C’ error removed in a direct reading compass?
By corrector key adjusting permanent magnets
What is a cause of ‘A’ error in an aircraft’s compass system?
The detector unit not aligned with the aircraft’s longitudinal axis
‘A’ error in an aircraft’s compass system is?
The same when the aircraft is flying on all compass headings
When an aircraft is in a climb, what represents the angle of climb? The angle between?
Inner and outer gimbal
When an aircraft is in a roll, what represents the angle of roll? The angle between?
Outer gimbal and frame
What provides roll erection cut out in a vertical gyro?
2 electrolytic switches in series
A horizontal gyro at the North pole will drift at?
15° per hour
If nutation occurs 5 minutes after gyro start up, this indicates?
A fault
To avoid transport wander, a vertical gyro must?
Be earth-tied
How is gimbal lock of a vertical gyro prevented?
Stops are fitted between the inner and outer gimbals at 85°
When an aircraft does a loop, what happens to a vertical gyro?
Hit the stops and flips 180°
Speed control of AC powered electrical gyros is done by?
The constant frequency of the aircraft’s power supply
The ‘P’ component of the aircraft magnetic structure is known as?
‘B’ error and has maximum deviation when the aircraft is heading East or West
The ‘Q’ component of the aircraft magnetic structure is known as?
‘C’ error and has maximum deviation when the aircraft is heading North or South
In a servo-assisted altimeter, if the ‘warning flag’ appears, it means that?
There has been a power supply failure, or the servo mechanism has gone out of range
WRT direct reading compasses, during an aircraft turn, what mechanical error relates to causing the needle to try and follow the aircraft’s movement?
Liquid swirl
Which compass system uses a flux detector located at an extremity in the aircraft and an indicator?
Remote indicating compass
Radio waves bend around the curvature of the Earth due to what?
Diffraction
Where is the power supply for the no. 1 U/VHF transceiver taken from?
Battery busbar
What is the channel by which applications communicate in an IMA system called?
Logical
WRT a three-axis autopilot, ‘lateral cyclic pitch’ relates to which channel?
Roll channel
Which AFCS mode of operation enables the pilot to manoeuvre the aircraft in pitch and roll without fully disengaging the AFCS?
CWS mode
What does the yaw damper warning annunciator indicate?
The yaw damper system is not engaged in the operating mode
A nose-up biased mis-trim induced below 600 feet (rad alt) causing a pitch up effect if the AP is disengaged is known as what?
A Cat 3 trim up bias (for Cat 3 autoland systems)
In the event of a system failure, what will the autoland system operate as?
Fail-passive system
Which mode of AFCS operation is necessary to permit an engagement of the channel without any violent manoeuvres of the aircraft?
Synchronisation mode
What is the maximum elevation of the localiser signal?
7°
The purpose of squelch is to?
Ensure that no background noise is heard under weak or no signal conditions
Signal absorption by the ionosphere is greatest?
During the day
In a 3 beam janus system, the beams are arranged such that?
The front left and rear beams give ground speed and the front left and front right beams give the aircraft’s drift from the centre line
Most airborne Doppler radars transmit beams at angles of?
60° to 70°
WRT radar receivers, if its reception bandwidth is narrowed?
The sensitivity will increase
During an autopilot signal sent from the flight control computer to the elevator servo actuator, what will happen at the control column?
It will move in relation to the movement of the elevators
When is VNav available for selection?
From take-off and may end at ILS approach
When A/T is coupled to FLCH, when will it hold the N1 limit?
In the climb
What supplies the feedback signal in the yaw damper to cancel the yaw rate gyro signal?
LVDT
During localiser capture, if the estimated bank angle is less than 10 degrees, what will the outcome be?
Delayed 1 turn
After G/S capture, what will the G/S deviation be attenuated by when the aircraft is approximately at 50 feet above the runway?
100%
Engine pressure ratio feedback to the FMC in the A/T thrust management function occurs through which units?
EIUs
How long will it take to capture the mode control panel altitude in FLCH mode?
125 seconds
The control wheel is moved in roll with the AP engaged, this operates the transducer which outputs a signal to do what?
To cancel attitude hold allowing the pilot the gradual and increasing bank angle
What is the purpose of the lag circuit, which is connected in series with the stick position sensor, in a helicopter’s AFCS roll channel?
Match the lag in the roll gyro output signal
What are the three A/T control circuits?
Speed, vertical speed and thrust
What is ‘dead space’?
Limit of ground wave reception and the first returning skywave
What is the altimeter commonly set to below the transition height to allow the aircraft altitude to be easily compared with the height of the ground?
Local QNH
What is meant by true altitude?
Actual height in feet of the aircraft AMSL
What is meant by absolute altitude?
Actual height in feet of the aircraft AGL
What does a computer use to calculate density altitude?
Pressure and temperature
What are two benefits of the servo altimeter?
- Accurate at lower altitudes
- Can follow rates of climb and descent up to 6,000 ft per minute without any appreciable time lag
WRT groundwaves, which type of frequency will be most affected by penetrations of the underlying terrain?
High frequency signals
When will an RF wave become an escape ray?
If the RF wave passes over half way through an ionised layer before it is bent back (parallel) to the layer
What is the typical efficiency of an aerial transmitting at high frequencies?
90%
How far behind a directional aerial array will the reflector be placed?
A quarter wavelength behind the dipole
Which type of transmission cable is most suitable to carry frequencies up to 1000 MHz
Coaxial cable
What frequency range does a NDB cover?
190 kHz to 2 MHz
What is antenna effect in an ADF system?
If the vertical limbs of a loop aerial are not balanced to earth, produces two minimum readings which are not true null points
What is the modulation of the reference signal in VOR?
FM
What is the spacing in VOR?
0.05 MHz
Describe Cat A VOR?
- 120 channels
- 112 - 117.95 MHz
- Normal en route navigation
- 200 nm
- 200 W
What is the general allowance of error in VOR?
± 2°
What is the purpose of ADS-B?
Surveillance technology which determines its position via satellite navigation and periodically broadcasts it, enabling it to be tracked
What will extended squitter allow?
49 individual parameters to be sent
Which type of navigation takes navigational reference data from aircraft systems and uses this information to fly along direct pre-programmed routes?
RNAV
What is the accuracy of P-RNAV and what is it used for?
Terminal approaches
± 1nm for 95% of the time
At what flight level are spoken messages inhibited in TCAS?
Below 400 ft AGL
What is the typical corrective vertical speed an aircraft is given as an RA?
1500 feet per minute
What might be experienced where the transmission frequency is too close to the MUF?
Skip fading
The end of an open circuit line in a transmission line is seen as what kind of circuit?
Parallel tuned circuit
What is the formula for SWR?
SWR = Vmax/Vmin
What does the max power density radiated by an aerial divided by the power density radiated by an isotropic aerial at the same distance equate to?
Gain of an aerial
What is the beamwidth of an aerial defined as?
The angle between the half power points
What are some of the losses common in aerials?
- Dielectric
- Brush discharge
- Copper
- Eddy current
What is the efficiency of practical aerials?
15% at low frequencies to 90% at high frequencies
When might you use a folded dipole?
In cases where it is necessary to use a transmission line of high characteristic impedance (of the order of 300Ω) to feed a centre fed half wave dipole, to make matching easier
What does the annunciator of the remote indicating compass show?
Constant indicating of synchronism between the gyro and the flux detector
During a banked turn, if the attitude indicator did not have a roll erection cut out system, what would happen?
An error in roll would become an error in pitch
What is the tolerance of a VSI?
10% of the maximum reading
The four modules in an ADC are?
- Altitude
- Computed airspeed
- True airspeed
- Mach
The versine signal is used in the?
Pitch channel only for lift loss compensation
What happens to the F2 layer between winter and summer?
It is further away in the summer
Why are groundwaves usually vertically polarised?
Horizontally polarised signals are heavily attenuated in groundwaves
What are the five types of fading?
- Selective
- Interference
- Polarisation
- Skip
- Absorption
The yaw damper rate gyro filter consists of a demodulator, amplifier and washout network. Filtering accomplished in these circuits eliminates?
Steady state signals and unwanted high frequency signals
What are the criteria for glideslope capture in AP?
- Aircraft must be flying toward the G/S
- The difference between runway track and ground track must be less than 80°
A FIFO buffer would be located in what part of the AFDX system?
Switch
In an Onboard Maintenance System (OBMS), the CMC should be capable of providing a common point for display of information. In what format should this information be displayed?
Plain english
A typical data loader in an OBMS will operate IAW which ARINC standard?
ARINC 615
What are the g forces associated with the flight recorder accelerometers?
Simply
A modern VHF communications system using phase locked loops and a voltage controlled master oscillator should produce a frequency accurate to how many decimal places?
4 decimal places
WRT power amplification, what type of amplification is used for HF SSB?
Class AB linear amplification
How is a SSB transmitter’s power rated?
Peak Envelope Power
Which ARINC specification does the HF comms transceiver conform to?
719
How long does it take for the MECH or ATT call lights to automatically extinguish if not cancelled by a reset key?
1 minute
What are the four types of aerial coupling?
- Stagger tuned
- Transformer
- Auto transformer
- Capacitive
Which type of aerial coupling gives the best selectivity?
Transformer
Which type of aerial coupling will give the best and widest bandwidth?
Stagger tuned
What are the examples of external noise?
- Man made
- Atmospheric
- Cosmic
What is the typical power output of a HF radio system?
400 W
What are the stages in a Super Het receiver?
RF Amp - Mix (above LO) - IF Amp - Demod - AF Amp
What are the problems of VHF and UHF?
- Skin effect
- Stray capacitance
- Lead inductance
- Stray resonances
- Parasitic oscillation
To calculate the wavelength of an EM wave, we could use?
Wavelength = velocity / frequency
What type of noise can be caused by semiconductors?
Shot or flicker noise
In an AM transmitter, when will the modulator only have to provide a small amount of amplification?
When using low level modulation
What might be the class of amplifier used in all of the stages leading up to the RF power amplifier stage where high level modulation is used?
C
What type of transistors is a buffer amplifier most likely to use?
FETs
What name is given to a technique that controls the stability and accuracy of an oscillator, whilst enabling the variability of its tuning?
Frequency Synthesis
What frequencies will a crystal oscillator in overtone mode use?
Harmonics of the fundamental frequency
