ATPL NAV AIDS EXAM QUESTIONS
AND ANSWERS
What is the only factor that affects the speed of sounds - Correct Answers -
Temperature: as it increases, so does the speed of sound
Formula for speed of sound - Correct Answers -38.94 * square root of the temperature
in kelvin
Errors from the machmeter - Correct Answers -Instrument, position and manoeuvre
induced errors
errors the mach-meter does not suffer from - Correct Answers -temp, density,
compressibility
how will instrument and position area effect the mach meter - Correct Answers -so that
it's always over reading
what is the purpose of the air data computer - Correct Answers -to supply digital air data
output to aircraft instruments and systems
what is the basic operating principle of the air data computer - Correct Answers -An
ADC converts the various analogue inputs to electric signals and transmits them via
data bus to the various flight instruments and systems
Two most basic essential inputs to the ADC - Correct Answers -pitot pressure and static
pressure
other two inputs to ADC - Correct Answers -total temperature and Angle of Attack
Outputs from an ADC (9) - Correct Answers -Altitude
Vertical Speed
IAS/CAS
TAS
Mach Number
Vmo/Mmo
Angle of Attack
TAT
SAT
,is there a provision for the manual input of data if there is a complete failure for both
ADCs - Correct Answers -no
How are errors associated with an electromechanical air data computer minimised -
Correct Answers -by employing correction cams
What is the indicated outside temperature - Correct Answers -The temperature that the
outside gauge reads
What is the static (true ambient) air temperature (SAT) - Correct Answers -is the true
temperature of the ambient air which is not affected by the passage of the aircraft
what is the total air temperature (TAT) - Correct Answers -SAT plus the maximum
possible ram rise in the prevailing conditions
what is the ram rise - Correct Answers -Frictional (kinetic) heating of the air in the
boundary layer and adiabatic heating effects of compressibility as the aircraft passes
through the air
what is the recovery factor - Correct Answers -is the proportion of the total air temp
which the sensing element is able to detect in the air passing it at any given time
Formula for SAT - Correct Answers -SAT = IOAT/(1+(0.2*k*M^2)
How does the Fly-By-Wire system work? - Correct Answers -by sending digital signals
from the flight controls or the autopilot via the flight control computer to the control
surfaces
what is the basic function of the AFDS and what does it stand for - Correct Answers -
What does the AFDS consist of - Correct Answers -3 AFDCs and the MCP
What do the AFDCs provide control of - Correct Answers -The Autopilot flight director
computers provides control of the flight directors and when engaged, the autopilot
where is the flight director information displayed - Correct Answers -PFD
What are the typical inputs to the flight director computer - Correct Answers -Mode
selection
pitch and roll system
irs
what inputs are not typically sent to the flight director computer - Correct Answers -
standby pitot static system
, what occurs if a flight director mode fails - Correct Answers -the respective steering bar
disappears
what is the normal method of disconnecting the auto pilot - Correct Answers -through
the control coloumn disconnect
What is the function of the FMA - Correct Answers -to display the current status of the
auto pilot flight director system
Where is the AFDS status annunciated - Correct Answers -below the FMA on the PFD
How are engaged or captured modes indicated on the FMA - Correct Answers -green
letters
What does alert height mean - Correct Answers -is a height above a runway which a
category 3 ILS must be discontinued and a missed approach carried out if a specified
failure occurs
what does fail operational mean - Correct Answers -means that the AFDS with land 3
annunciated can have a failure of a single system component after passing alert height
What does fail passive mean - Correct Answers -With Land 2 annunciated has a level of
redundancy that in the even of a failure there is no significant deviation of aircraft flight
path
what is the function of the gain programme in the approach mode - Correct Answers -is
ti expand the scale of the localised display in the later stages if an ils approach
What is the basic operating principle of the EFIS and what does EFIS stand for - Correct
Answers -Electronic Flight Instrument System is to graphically and alphanumerically
display flight and aircraft systems on one or more electronic screens.
What are advantages of LCD displayed over CRT and what does LCD stand for -
Correct Answers -Lighter, Less volume, more efficient, more reliable and more legible
what displays are not normally included on and EADI or PFD - Correct Answers -
Weather
Terrain
TFC
Wind
What is the function of the symbol generators in an EFIS - Correct Answers -Provide
video signals to the ND and PFD LCDs
on EFIS displays what colour is used to denote command information - Correct Answers
-Magenta
AND ANSWERS
What is the only factor that affects the speed of sounds - Correct Answers -
Temperature: as it increases, so does the speed of sound
Formula for speed of sound - Correct Answers -38.94 * square root of the temperature
in kelvin
Errors from the machmeter - Correct Answers -Instrument, position and manoeuvre
induced errors
errors the mach-meter does not suffer from - Correct Answers -temp, density,
compressibility
how will instrument and position area effect the mach meter - Correct Answers -so that
it's always over reading
what is the purpose of the air data computer - Correct Answers -to supply digital air data
output to aircraft instruments and systems
what is the basic operating principle of the air data computer - Correct Answers -An
ADC converts the various analogue inputs to electric signals and transmits them via
data bus to the various flight instruments and systems
Two most basic essential inputs to the ADC - Correct Answers -pitot pressure and static
pressure
other two inputs to ADC - Correct Answers -total temperature and Angle of Attack
Outputs from an ADC (9) - Correct Answers -Altitude
Vertical Speed
IAS/CAS
TAS
Mach Number
Vmo/Mmo
Angle of Attack
TAT
SAT
,is there a provision for the manual input of data if there is a complete failure for both
ADCs - Correct Answers -no
How are errors associated with an electromechanical air data computer minimised -
Correct Answers -by employing correction cams
What is the indicated outside temperature - Correct Answers -The temperature that the
outside gauge reads
What is the static (true ambient) air temperature (SAT) - Correct Answers -is the true
temperature of the ambient air which is not affected by the passage of the aircraft
what is the total air temperature (TAT) - Correct Answers -SAT plus the maximum
possible ram rise in the prevailing conditions
what is the ram rise - Correct Answers -Frictional (kinetic) heating of the air in the
boundary layer and adiabatic heating effects of compressibility as the aircraft passes
through the air
what is the recovery factor - Correct Answers -is the proportion of the total air temp
which the sensing element is able to detect in the air passing it at any given time
Formula for SAT - Correct Answers -SAT = IOAT/(1+(0.2*k*M^2)
How does the Fly-By-Wire system work? - Correct Answers -by sending digital signals
from the flight controls or the autopilot via the flight control computer to the control
surfaces
what is the basic function of the AFDS and what does it stand for - Correct Answers -
What does the AFDS consist of - Correct Answers -3 AFDCs and the MCP
What do the AFDCs provide control of - Correct Answers -The Autopilot flight director
computers provides control of the flight directors and when engaged, the autopilot
where is the flight director information displayed - Correct Answers -PFD
What are the typical inputs to the flight director computer - Correct Answers -Mode
selection
pitch and roll system
irs
what inputs are not typically sent to the flight director computer - Correct Answers -
standby pitot static system
, what occurs if a flight director mode fails - Correct Answers -the respective steering bar
disappears
what is the normal method of disconnecting the auto pilot - Correct Answers -through
the control coloumn disconnect
What is the function of the FMA - Correct Answers -to display the current status of the
auto pilot flight director system
Where is the AFDS status annunciated - Correct Answers -below the FMA on the PFD
How are engaged or captured modes indicated on the FMA - Correct Answers -green
letters
What does alert height mean - Correct Answers -is a height above a runway which a
category 3 ILS must be discontinued and a missed approach carried out if a specified
failure occurs
what does fail operational mean - Correct Answers -means that the AFDS with land 3
annunciated can have a failure of a single system component after passing alert height
What does fail passive mean - Correct Answers -With Land 2 annunciated has a level of
redundancy that in the even of a failure there is no significant deviation of aircraft flight
path
what is the function of the gain programme in the approach mode - Correct Answers -is
ti expand the scale of the localised display in the later stages if an ils approach
What is the basic operating principle of the EFIS and what does EFIS stand for - Correct
Answers -Electronic Flight Instrument System is to graphically and alphanumerically
display flight and aircraft systems on one or more electronic screens.
What are advantages of LCD displayed over CRT and what does LCD stand for -
Correct Answers -Lighter, Less volume, more efficient, more reliable and more legible
what displays are not normally included on and EADI or PFD - Correct Answers -
Weather
Terrain
TFC
Wind
What is the function of the symbol generators in an EFIS - Correct Answers -Provide
video signals to the ND and PFD LCDs
on EFIS displays what colour is used to denote command information - Correct Answers
-Magenta
