Instrument Q’s Flashcards
Liquid crystal displays
Are negatively affected by low temperatures
Deviation on N deviation on S / 2 is
Coefficient C
What is deviation
Error Inherent in a magnetic compass
An instantaneous VSI is connected to the
Static pressure only
As per eu ops 1.160 following an accident or incident the data pertaining to the event shall be recorded and rained for a period of
60 days for both
A +/. Symbol on a compass system indicates
Compass card and directional gyro are being synchronised
The DFDR is able to accept inputs directly from certain systems under what situations can the DFDR accept this data
System data must be in a format that is recon used by the DFDR
A single rate gyro can be used to sense attitude about
2 axis
The output of an E and I bar sensing device is
Phased sensed AC
Non magnetic proximity sensors should be checked
In the near condition
How is EPR measured
The ratio of compressor inlet pressure and the exhaust pressure
An artificial horizon gyro has
Three degrees of freedom and 2 gimbals
A boost gauge reads
Absolute pressure
A null indicator is a
Moving coil meter
An attitude gyro disturbed in pitch would apply a corrective force through the pitch motor acting between the
Outer gimbal and case
A category 2 approach has a decision height of 100ft and an RVR of
300m
A category 2 approach requires
A rad alt and an ILS coupled autopilot
For a rate gyro to detect roll movement its axis of spin must be
Athwartships
Vacuum systems can be used for
Instruments having an air driven gyro
A centralised warning panel process warnings, cautions and advisories/indications as follows
Red warnings
Amber cautions
Gren blue or white advisories/ indications
An AOA sensor is used for
Alpha protection
To leak test a vacuum system
Blank system inlets operate a vacuum pump stop the pump and check leak rate
A vertical gyro used as an artificial horizon has
1 gimbal with 2 axis of freedom
Temperature compensation in a servo altimeter is achieved by
Increasing the tension in the hair spring
A combined ASI indicates Mach
All the time airspeed is present
The dip angle at the equator is
0 degrees
An RMI would use for the displacement of the indicator needle
ADF & VOR
In order to check the turn indicator for correct operation dismount the indicator and check it against the
Horizontal axis
A compass has a residual deviation of + 1 degrees
To fly a heading of 180 degrees the pilot must steer
179 degrees
A vertical gyro senses disturbances in
2 axis
An OAT gauge when flying at a constant altitude if the airspeed was to increase the OAT indication would
Increase
A compass is made a periodic by
Using fluid
A compass shows 000 deviation is +2 after comprenant a is added heading is
358
A vacuum pump in an air driven I stringent system draws air
Through a filter into the instrument canes then into a pump where it is discharged overboard
A compass swing would be required after replacing a
Compass sensing unit
A compensatior capacitor in a capacitive fuel I dictation system is
To detect changes in dielectric constant due to temperature changes
A constant for e applied to the inner gimbal of a vertical gyro would cause
A continual precision roll
A direct reading compass fitted on an aircraft the safe distance for electrical cables carrying electrical current is
24”
A DC electrical cable must be postions
How far away from
A compass
24”
A densitometer in a capacitive fuel indication system measures
Density of the fuel by measuring the natural frequency of a vibrating spool
a desiccant used in the storage of instruments
is silica gel
a direct lift system using a floating magnet and reed switches measures
fluid volume
a direct reading bourdon gauge has a restriction in the inlet this to
dampen sudden pressure changes
a direct reading compass reads 000 degrees and after applying coefficient A if +2 degrees it should read
002 degrees
a FDAU transmits data to the flight data recorder by
ARINC 573/717 data bus
a FDR is activated when
the helicopter engines are started
a flux detector output is
AC voltage at twice the freq of the excitation voltage
a flux valve become permanently magnetised what will be the effect
more deviation
a force balance system using a capsule will produce an output which
is in opposition to capsule expansion
a fuel flow measurement system
cannot be adjusted
a fuel quantity test set consists of
capacitance bridge
a fuel system that corrects fuel SG is calibrated in
Lbs or KGS
a fuel system that ensures SG will be displayed in
Lbs or KGS
a gate valve is installed in a vacuum system to prevent
reverse flow fue to engine backfire
a garage pressure of 1 atmosphere is an absolute pressure of
2 atmospheres
a glass cockpit system on a modern aircraft primarily consists of
a PFD & multifunction display (or nav display)
a gyroscope having one plane of freedom at right angles to the plane of rotation and its gimbal restrained either electrically or by a spring is known as
a rate gyro
a gyroscope with a vertical spin axis has the roll torque motor located about the gyroscopes
lateral axis
a gyroscopic body has its rigidity increase by
increasing the rotor speed
a laser ring gyro gives
rate of angular displacment
a leak in the static line in a pressurised part of an aircraft can cause the mach indication to
decrease
a mach meter
compensates for square law
a mach meter is
compensated with square law screws and an arm
a mach meter reads the correct value
at any altitude
a mach meter transduces
airspeed and altitude
a mach meter
has adjustment screws for the purpose of square law calibration
a mach meter works
always
a master warning is issued when
overspeed and excessive cabin pressure altitude occurs
a pendulous vane type erection system fitted to a gyro horizon works on the principle of
increase reaction of the air from a fully open port
a pito static leak check is carried out
whenever the pitot static systems are disturbed
a pneumatic indicator takes its indications from
reservoir
a positive coefficient A adjustment of a compass will give a heading
increase on all headings
a pressure gauge such a a hydraulic break pressure gauge indicates 1000psi in terms of absolute pressure this represents
1014.7 psi
a pressure of on atmosphere is equal to
14.7 psi
a radio altimeter system can be self tested
on the ground only
a rate gyro has
a calibrated spring between inner gimbal and case
a rate gyro has how many degrees of freedome
1
a rate two turn is
360 degrees per minute
a radiometer uses
current input and output
a remote compass compensator unit is replaced which of following us correct
a comopass swing must be performed
a sensitive altimeter reading 100ft when the millibar scale is set to the atmospheric pressure at airfield level (QFE)
indicates that the instrument is unserviceable
a silica gel desiccant is require to be replaced w
when all pink
a standby ADI use
a vertical gyro
a small constant leak in the case of VSI fitted in a pressurised aircraft would during level flight cause the instrument to indicate
a rate of climb
a standby air supply for gyro operation could be obtained from
a venturi
a standby artificial horizon uses a
earth gyro
a standby compass has a pair of magnets for adjustment they are initially placed
parallel with each other
a tacho generator has
its own independent electric system
a tacho generator pointer is moved by
a drag cup coupling
a temperature bulbs resistance is
directly proportional to temperature
a temp of 59F is equivalent to
15C
a thermo couple
cannot be shortened
a turn and slip needle points to the left when the aircraft is
turning left
a turn and slip needle/pointer moves to the left what is the aircraft doing
turning left
a typical radiometer indicating system would use
single phase AC for indicator and transmitter
a unit with two springs and a mass pick off is
an accelerometer
a VSI is connected to
static pressure
a vacuum mercury gauge reads 5 in this pressure is
below ambient pressure
a vertical gyro used for autostabilisition the roll attitude will be limited in
heading and localiser mode
a VSI metering unit consist of
both an orifice and a capillary
a drag cup type of tacho generator system used for indicating the rev/min of a turbine engine has
an indépendant electrical system
above 2500ft the Rad alt
pointer is hidden behind a ask with off flag out of view
absolute pressure of 25psi is
10.3psi
acceleration error produces
a false indication of climb
adding 3ft of cable to both TX & RX aerials on a rad alt would give you
9 feet error
after correction of the north south heading reading on a compass swing the resultant correction is known as
residual deviation
after disconnecting the supply to an electrically operated gyro instrument it is recommended that to allow the gyro rotor to stop before moving the instrument
15 mins should elapse
after replacing an instrument of the pitot static group it is neccassry to
carry out a leak test on the appropriate systems
after the compass has been corrected for Coefficient A, B & C the remaining error is known as
Residual Deviation
after using a pitot static test set the pressure in the aircraft static system should be released to the atmosphere by
venting the static system via an internal bleed in the test set
agonic lines link places of
zero variation
air density compensation requires
altitude and OAT
air driven gyros compared to electric gyros generally rotate
slower
aircraft certified before 1997 with RVSM maximum tolerance for the system is
+- 300ft system & +- 50ft for instrument error
aircraft heading HDG is
the angle between true north and the longinutdal axis of the aircraft
aircraft instruments are classified into three categories
flight instruments engine instruments navigation instruments
all fly to information in an EFIS system is displayed in
magenta
alpha angle relates to which system
angle of attack system
alpha vane signal could be fed to _ _ when close to stall
thrust levers
an absolute pressure gauge measures
the applied pressure referred to a perfect vacuum
an aircraft ASI has
pitot to the capsule and static to the outside of the capsule
an aircraft in climb maintains the same IAS what it its true airspeed
higher than its IAS
an aircraft increases in altitude the ASI indication remains constant what will happen to the true airspeed value
increase
an aircraft landing on QFE the altimeter will
read zero on touchdown
an aircraft magnetic compass is swung to update the compass correction card when
equipment is added that could effect compass deviation
an aircraft that is being rectified for RVSM will require
a flight test verification
an aircraft with mach warning will warn
when Mcrit is reached
an airspeed indicator responds to changes in
dynamic pressure
an altimeter consists of
a barometric scale adjustment
an altimeter in a pressurised aircraft at altitude has a case leak the altimeter will
under read
an altimeter is operated
by the static system
an altimeter on ground check reads slightly outside permitted tolerance
an in situ adjustment can be carried out
an articial horizon has
the inner gimbal pivoted laterally
an artificial horizon uses
a vertical gyro
an artificial horizon will have a corrective torque applied
at 90 degrees before the axis in which the correction is required
an ASI compressibility error correction will be negative
negative
an ECAm system is tested under the following conditions
aircraft on the ground with parking brake set/on
an electrical gyro has usually a speed of
20,000 rpm
an electrically operated standby artificial horizon
requires an emergency power supply
an engine vibration indicator system uses
2 filters in the indicator
a letter H displaying on the EHSI indicates
DME hold
an HSI provides what information
VOR, PLAN, ILS, MAP, RADAR
an ILS indicator is
across filters
an important air data used with the IRS is
TAS
an increase in forward speed at a constant throttle will result in EPR
Decreasing
an instantaneous VSI indicates instant values of VS by
using a plunger to correct any lagging of the indicator
an instrument used for measuring negative pressures
has anti clockwise pointer movement if bourdon tube operated
an open circuit in the temperature bulb as used in the DC radiometer would cause
the pointer to read full scale
an RMI has inputs from VOR and
azimuth gyro
an RMI requires the following inputs
heading and radio deviation
an uncorrected ADI is affected by
roll
aneroid capsule measure pressure with respect to
a vacuum
AOA alarm is sounding to close to stall rectification is to
move probe up
angular momentum of a gyro rotor depends on
moment of inertia and angular velocity of the rotor
apparent drift of a vertical gyro is a function of
COS of latitude
apparent drift on directional gyro its corrected by
an adjustment nut on inner ring
as part of the checks on the DFDR system you are required to carry out a check using the self test switch on the AIDS printer actuation of the switch causes the printer to print in
forty column mode
at the lowest point of each vent line you would normally find a
self draining non return valve
at what height does the rising runway appear
200ft
at which two points on a gas turbine engine is EPR measured
compressor inlet and jet pipe
Bourdon tube have
oval cross section
brake temperature readings provide
coloured indications on a CRT display
capacitance fuel quantity indication test set is connected
by replacing capacitance probes
capacitors in a capacitance fuel contents indication system are wired in
parallel
Coefficient A correction is carried out
after B and After C
Coefficient A is adjusted
on any heading
compared to air driven gyros the electric gyro runs faster
faster
compase base classification class 2 is periodically re-surveyed every
2 years
compass compensator units have greatest effect when the magnets are
90 degree apart
Compass error Q corrections correct
C Error
Compass error remaining after all the corrections which is used for entry on the deviation card should not exceed
3 degrees
Compensator magnets in a standby compass exert greatest influence at
90 degree to each other
Coefficient C is
(DEV on N - Dev on S)/2
Componenet P affects
Coefficient B
Compressibility error in a pitot head is caused by
compression of air in the tube at high speed
corrections to a mechanical ASI are for
square law error and temperature
cyclic shift of the gator connections in a torque sychro results in
output datum advanced 240 degree
Damping on a rate gyro can be either
viscous eddy current or air dash pot
data collected by FDAU can be divided into two categories
mandatory and ACMS
Deviation from the HSI lubber line is known as
apparent A
DFDAU received aircraft parameters are of analogue, discrete or binary digit from the
aircraft systems
digital weather radar is on map mode what happens
antenna tilts down
during a change to a Lower altitude the piston unit in an IVSI will creat for an instant
more pressure to the capsule only
during compass swing using a data compass the error permitted in aligning the aircraft is
5 degree
during a coordinated turn a pendulous suspended flux detector will assume the angle of
dynamic vertical
during climb the pressure in the VSI capsule will be
lower than the pressure in the case
EFIS display SG1 + SG2 are for the captain and FO displays what is the purpose of SG3
Back up for SG1 & 2
EGPWS mode 2 announces
whoop whoop pull up
EICAS indicates
engine performance and aircraft status
EICAS provides the following
engine parameters and system warnings
EICAS EFIS ECAM are all terminologies applicable to
Glass cockpit instrumentation
electrical driven gyros are
rotated faster than air driven gyros
Elimination of vibration in the instrument panel is by use of
shock mounts
EICAS displays alert messages on the
Primary EICAS display unit
Engine vibration signals are
filtered to remove unwanted frequencies
Equivalent airspeed is
calibrated airspeed corrected for compressibility
FDR data is stored on
semiconductor memory
Flight director bares move up in slow increments what controls their rate/speed
rate feedback
Flight director command bars indicate
direction in which aircraft is to be manoeuvred
Flight director incompatible modes are
VOR & glideslope
following replacement of a seperetly mounted compass corrector box a compass calibration swing will be required
without exception
for a given IAS with an increase in altitude TAS will
increase
for a particular IAS as the density decrease with altitude the TAS
increases
for a vertical gyro which is moved in pitch which gimbal would be moved to correct the pitch movement
longnitudanal
for aircraft certified after 1997 and with RVSM the maximum tolerance for the system would be
+- 200ft plus +- 50ft for instrument error
Fo ran EGPWS to indicate predictive wind shear it needs an input from
weather radar
Fuel tank units (capacitcane) are connected
paralell connection
Gauge pressure as indicated on a direct reading bourdon tube pressure gauge is equal to
absolute pressure minus atmospheric pressure
gimbal lock in a displacement gyro occurs when
spin axis becomes coincident with any of the axis of freedom
GPS runs on which band
L band
GPWS inop light comes on engineer would initially
do a level 2 self test to determine the source of the fault
GPWS is
C Band
GPWS mode 1 is excessive
rate of decent
GPWS mode 7 provides what warning
windshear
GPWS mode 7 wincher is activated at
1500ft rad alt for take off and for landing
graphics generators
are fitted to aircraft that have CRT/Flat screen displays
Gyro precessional force is
directly proportional to applied force
Gyro rigidity is proportional to
mass speed and radius of mass from spin axis
How are direct reading compasses calibrated
mechanical magnetic compensator assembly is adjusted to counter stray magnetic field influence
how do you detect and locate a leak in a pitot static system
pressurise the system and use the soap bubble detection method
how does a Machmeter work
TAS and speed of sound
how is a direct reading compass made to be aperiodic
the compass bowl is filled with fluid
how is leading edge flap position indicated in the cockpit
Torque sychro
how is temperature compensation achieved in the fluid of a compass
bellows and diaphragm
how is the gyro aligned in a rate of turn indicator
it has a horizontal spin axis aligned laterally
how is the information on a directional gyro outer gimbal taken off
by a flux take off device
how may the basic principle of the rad alt be described
as a measure of the time between a RF pulse transmission and the reception of its echo from the ground directly below the aircraft
How should an operating gyro be caged
by pulling the caging knob with a steady action
