instrument Flashcards
what are the instrument/gages that monitor the engine and systems?
- RPM
- Oil pressure and temperature
- Engine temperature
- Voltage
- Suction
- Fuel gauge
what are the 4 types of instruments?
1-Anemometric
2-gyroscopic
3-magnetic
4-radio electronics
Names anemometric instrument?
- vsi
- asi
- altimeter
Names gyroscopic instrument?
Turn n’ bank indicator
DG
Artificiel horizon
Names Magnetic instrument?
compass
RMI
Names Radio electronics instrument?
VOR,ADF
what instrument gives direction?
magnetic compass/gyroscopic compass
what instrument gives speed ?
IAS
what instrument gives altitude:
altimeter
what instrument gives Navigation?
ADF
DME
VOR
GPS
what are the three type of air pressure and explain them?
1-static air pressure : This is the weight of the air around the aircraft
2-Dynamic air pressure it is the pressure produced by the air velocity
3-total pressure: static air pressure + dynamic air pressure
What is connaected to the static pressure system ?
- IAS
- VSI
- Altimeter
The pitot tube is connected to which instrument ?
air speed indicator
how does work the altimeter ?
Altimeter works just like a barometer,It measures pressure variations
In straight and level flight (cruise flight) pressure does not change, Wafer volume remains constant, Indicated altitude remains constant
The wafer expension when it’s go higher in altitude and compress in low altitude
On an altimeter, the altitude remain constant, does it mean that true altitude is constant?
No, it mean that the wafer ins’t changing volume, the aircraft is flying at a constant pressure level.
When do you set and resettled your altimeter setting ?
before take-off and resettled at each local station and before landing.
where do you find your altimeter setting information
atis
fss
control tower
what is the maximum error of the altimeter?
+/- 50 ft if it’s more do not take off.
what happen to your altimeter near a mountain?
INDICATED ALTITUDE IS HIGHER THAN TRUE ALTITUDE
1-venturi effect
2-wind speed increases
3-pressure decrease
If the altimeter is set below the local altimeter setting WHAT HAPPEN?
Indicated altitude is lower than true altitude
If the altimeter is set above the local altimeter setting WHAT HAPPEN?
Indicated altitude is higher than true altitude
cold air density is -higher/lower- than warm air and is -lighter/heavier- than warm air.
higher/ heavier
What do air density with altitude?
it decrease with altitude and decreases faster in cold air than in warm air
what happen if some one keeps the warm air altimeter setting while flying to a cold air mass?
The true altitude in the cold air mass will be lower than indicated ( Flying from a high to a low: Watch out below )
If you fly to a high temperature region what happen to your altimeter?
Indicated altitude will be lower than true altitude
fly to a low temperature region what happen to your altimeter?
Indicated altitude will be higher than true altitude
what is indicated altitude?
it is the altitude as read on the altimeter.
what is pressure altitude ?
it is the pressure as read on the altimeter when set to 29.92hs(ISA) (flight pressure level)
what is the density altitude?
it is pressure altitude corrected for non-standard temperature (performance altitude)
what is the true altitude?
it is the real altitude above the mean sea level
what is the absolute altitude ?
it is the real altitude above the ground
what happen to the altimeter when the static port is block ?
the indicated altitude emains constant
what happen to the altimeter when the static port is partially blocked?
1- there will be a delay transfer of pressure information
2-under-estimates in a climb
3- over-estimates in a descent
what happen to the altimeter when the pitot tube is block ?
none
How does work the VSI?
The VSI measures the pressure difference measured between the wafer and the instrument compartment.
(when go up in altitude the wafer goes up and when goes down the wafer compress it self)
How long does it take to the VSI to get a stable lecture ?
6 to 9 sec
What happen to the VSI when the static port is block ?
The VSI freezes at zero.
What happen to the VSI when the static port is partially block ?
VSI will have a really slow response.
what is the maximum permissible error of the VSI?
200ft/min
What happen to the VSI when the pitot port is block ?
nothing
how does work the air speed indicator ?
The air speed indicator take the atmospheric pressure (static port the pressure around the wafer) + dynamic pressure (pitot tube air come inside the wafer) = total airpressure and give the IAS
What is the Vso and where it is on the air speed indicator?
the Vso is the full flaps power off stall speed and it’s the beginning of the white arc.
What is the Vfe and where it is on the air speed indicator?
The Vfe is maximum flaps extended speed and it is at the end of the white arc.
What is the Vs1 and where it is on the air speed indicator?
the Vs1 is the power off stall speed no flaps and it’s at the beginning of the green arc.
What is the Vno and where it is on the air speed indicator?
The Vno is the maximum normal operation speed and it’s at the end of the green arc.
What is the yellow arc on the air speed indicator?
caution airspeed, if no tuburlence
What is the Vne (redline) and where it is on the air speed indicator?
The Vne is the never exceed speed (redline)
when The air speed indicator give the true airspeed?
only under the ISA conditions ( oat: 15°C-29.92 hg in)
Flying at _____True Airspeed indicated airspeed_______.
constant/decrease
Flying at ______indicated Airspeed true airspeed ______.
constant/increase
As altitude_______, true airspeed _________
Because density ________.
increases/increases/decreases
As altitude increases, indicated stall speed ___________ But, true stall speed ______.
remains the same/ increases
What happen On aircraft were the static port is to the left when the pilot perform A sideslip to the left?
A sideslip to the left produces a static over-pressure
The speed is under-estimated (there is a risk of spiral)
What happen On aircraft were the static port is to the left when the pilot perform A sideslip to the right?
A sideslip to the right produces a static under-pressure
The speed is over-estimated (there is a risk of stall and spin)
Side slip to the left WHAT HAPPEN TO ASI?
RELATIVE WIND COME FROM THE LEFT
static port is on the left and pitot tube on the right
Static pressure increases
Indicated airspeed decreases
THE AIRSPEED INDICATOR UNDER-ESTIMATES
Side slip to the right WHAT HAPPEN TO ASI?
RELATIVE WIND COME FROM THE RIGHT
static port is on the left and pitot tube on the right
Static pressure decreases
Indicated airspeed increases
AIRSPEED INDICATOR OVER ESTIMATES
WHAT HAPPEN TO ASI WHEN THE PITOT TUBE IS BLOCKED:
- in constant speed
- in climbing
- in descending
- in constant speed it will act as altimeter
- it will overestimate in climb (wafer expand)
- it will underestimate in descend (wafer contract)
WHAT HAPPEN TO ASI WHEN THE STATIC PORT IS BLOCKED:
- in constant speed
- in climbing
- in descending
- static pressure stay constant so the reading will be wrong
- Airspeed indicator under-estimates (Wafer contracts and Indicated airspeed decreases)
- Airspeed indicator over-estimates(Wafer expands and Indicated airspeed increases)
Earth’s magnetic field It is the magnetic field that extends from the Earth’s inner core Joining the north and south poles. It is tilted at an angle of _______with respect to the rotational axis (True north)
11.5 degrees
What is the difference between the true north and the magnetic north ?
magnetic variation
What is the magnetic dip ?
The magnet of the compass lines up with magnetic lines. They are parallel to the surface at the equator
They are 90° to the surface at the pole.
Causing a downward tilt of the Needle as it comes closer to the north pole.
what are isogonic lines ?
Isogonic lines are lines on the Earth’s surface along which the declination has the same constant value, and lines along which the declination is zero are called agonic lines.
what is agonic line?
an imaginary line on the surface of the earth connecting all points at which the declination of the magnetic field of the earth is zero.
How many magnetised bars have a compass ?
usually 2 magnets
What can we do to reduce magnetic dip ?
The center of gravity of the aircraft Compass
Is lowered Vertical force causing the DIP
Applied on the normal compass
If the same force is applied on an aircraft compass
The center of gravity is displaced rearward
what happen when the aircraft is heading to the north and turning ?
the vertical force due to dip, WILL PRODUCE A ROTATION OF THE COMPASS FIRST, IN THE OPOSITE DIRECTION OF THE TURN
THEN IN THE SAME DIRECTION BUT SLOWLIER
This is called: compass lag
S.A.N.D.
what happen when the aircraft is heading to the south and turning ?
the vertical force due to dip, WILL PRODUCE A ROTATION OF THE COMPASS IN THE SAME DIRECTION THAN THE TURN
BUT FASTER
This is called: compass lead
S.A.N.D.
When the aircraft accelerate with a heading east or west what happen to the compass ?
The card tips forward The DIP moves the needle downward And rotates the card CCW
Showing a turn to the north
A.N.D.S.
When the aircraft decelerate with a heading east or west what happen to the compass ?
The card tips rearward
The DIP moves the needle downward And rotates the card CW Showing a turn to the south
A.N.D.S.
When readingthe compass
Heading Northor South what should you do ?
Make sure The wings are level
When readingthe compass Heading Eastor West what should you do ?
Make sure The airspeed is constant
what is the compass swing ?
Aircraft are made of metal and use electricity and radio waves. These will affect the magnetism field around the aircraft. The compass indication is deviated by this field. To correct the deviation, the compass is adjusted on each aircraft. The compass reading is compared
to a master compass outside the aircraft every 30 degrees and the deviation is recorded.
where can you find the compass correction card and how many time per year need to be corrected ?
in the journey log and in the plane
and it’s one time per year
How many axis does work a gyroscope ?
3 axis
what are the two principle of an gyroscope ?
1- rigidity in space (gyroscopic inertia)
2-precession
what is the rigidity in space ?
Due to inertia, a rotating body will resist any forces applied to modify its axis of rotation.Once rotation is established…It keep the same position
what is precession ?
Once rotation is established…
A force applied to modify the axis of rotation
will be felt at 90°awayfromthe point where it is applied
In the direction of the rotation
what is the apparent precession ?
Once set, the directional gyro will maintain a specific direction.
But, the aircraft moves over a rotating earth.
This will oblige the pilot to readjust the gyro for more precision 15° per hour
what is the deviation gyro ?
The friction between rotating parts will cause an error.
3° to 4°every 15 minutes
what are the power sources of the gyroscope ?
1- vaccum system
2-electricity
what are the instrument using a gyroscope?
- attitude indicator
- directional gyro
- turn n bank indicator
- turn coordinator
The rotor of the attitude indicator is mounted __________
and turns around the ____________
horizontally / vertical axis
the attitude indicator Utilise the____________ principle
rigidity in space
The attitude indicator is working on________.
two axis (vertical and horizontal)
the attitude indicator will :
Following an acceleration, it will show a ________
Following a deceleration, it will show _________
climb/descend
the attitude indicator will :
Following an ________, it will show a climb
Following a _________, it will show descend
acceleration/deceleration
On which principle the DG works ?
rigidity in space
how The rotor of the DG is mounted and turning around which axis ? and need to be readjust every ?
mounted vertically and turning around the horizontal axis
-15min
what is apparent precession on the DG ?
Gyroscopic inertia keeps the gyro fixed in space so that, it does not move.
But the earth rotating underneath it gives it an apparent motion.
This causes an apparent drift or precession which varies with latitude
It is 15° per hourat the north pole and almost 0° at the equator
what is deviation on the DG ?
Frictional forces in the gyro system cause a precession too. This precession causes a drift of the card,
Of 3° to 4° every 15 minutes
On the DG, AS WE APPROACH THE _________, THE MERIDIANS BECOME MORE PARALLEL AND
THE APPARENT PRECESSION IS ________.
EQUATOR / REDUCED
What are the instrument need’s vaccuum
1- directional gyro
2-attitude indicator ( artificial horizon)
How does works a turn and bank indicator ?
1 -A turn indicator using the precession property of gyroscopes
2 -An Iron ball in a liquid filled tube influenced by gravity and the centrifugal force in a turn.
(turn and bank ind.)How is mounted the rotor and on what axis the rotation is ?
Rotor mounted vertically and
Rotation axis is perpendicular to aircraft’s longitudinal axis(horizontal axis)
The turn and bank reacts to the _____________ deflects the needle in the direction of yaw
yaw Precession
note: only the yaw causes a turn indication
what is called when : Precession deflects the aircraft model in the direction of yaw
(When aircraft is rolling: Precession deflects aircraft model in the direction of roll)
Both Roll and Yaw causes a turn indication
yaw motion
What is a slipping turn ?
Ball is influenced by:
Gravity And Centrifugal force If the gravity is greater
Than the centrifugal force Ball moves inside the turn
Aircraft is slipping inside ( right turn and the ball goes to the right)
what is a skidding turn ?
Ball is influenced by:
Gravity And Centrifugal force If the gravity is less
than Centrifugal force Ball moves outside the turn
Aircraft is skidding outside ( right turn the ball goes to the left)
what is a rate turn one ?
360°in 2 minutes
180°in 1 minute
3°per second
how do you calculate the rate one turn angle in KTS and MPH ?
10% of TAS + 7 if speed is in kts
10% of TAS + 5 if speed is in mph
how are driven The turn and bank And The turn coordinator?
the are electrically driven.
