Flight Instruments Flashcards
Define static pressure
Ambient pressure
Define dynamic pressure
Pressure due to motion
Explain how the airspeed indicator works
Dynamic pressure from the pitot tube is linked to the wafer. This expands and contracts depending on the ambient pressure from the static pressure
Explain how the altimeter works
A sealed aneroid wafer expands and contracts depending on the surrounding static pressure
Explain how the VSI works
Static pressure is connected to a sealed wafer. The wafer is surrounded by air that is static as well but is linked through a calibrated leak.
How will a blocked static port affect the altimeter?
Freezes it
How will a blocked static port affect the VSI?
Constant zero
What will the airspeed indicator read when only the RAM air input is blocked? And Why?
Zero
The dynamic pressure inside the airspeed indicator releases through the drain valve. As a result, the casing is filled with only static pressure.
What will the airspeed indicator read when the RAM air input and drain valve are blocked? And Why?
Acts as an altimeter
Climb: Airspeed increases
Descent: Airspeed decreases
The dynamic pressure is trapped inside the wafers. In a climb, the pressure decreases. As a result, the pressure difference between the wafers and casing becomes greater and indicates an increase in airspeed.
What are the gyroscopic instruments?
Attitude, heading, turn coordinator
What are the pitot/static instruments
Airspeed, altimeter, VSI
What gyroscopic instrument(s) are electrically powered?
Turn coordinator
What gyroscopic instruments are vacuum powered?
Attitude and heading
What are the two principles of gyroscopes?
Rigidity in space and precession
What is precession?
A force applied to a gyroscope is felt 90 degrees in the direction of rotation
What is rigidity in space?
A gyroscope will resist any force applied to it
What gyroscopic principles does the heading indicator use?
Rigidity in space
What gyroscopic principles does the attitude indicator use?
Rigidity in space and gyroscopic precession
How is the attitude indicator mounted?
Horizontally
How is the heading indicator mounted?
Vertically
What gyroscopic principles does the turn and slip indicator use?
Gyroscopic precession
What gyroscopic principles does the turn coordinator use?
Gyroscopic precession
The turn coordinator shows
Rate of turn and rate of roll
The turn and slip indicator shows
Rate of turn
Explain the compass oscillation error
The compass bouncing around due to turbulence
Explain the compass deviation error
Electronic interference without the aircraft interferes with the compass’ readings
Explain the compass dip error
The farther north you are the lines of magnetic field dip vertically downwards. The compass turns downwards
Explain the compass turning error
“UNOS”
Turning from the north the compass will want to stay on the northerly heading so it lags
Turning from the south the compass will want to align itself with the north so it leads your turn
Explain the compass acceleration error
“ANDS”
On an easterly or westerly heading and under acceleration the compass will indicate a turn towards north
Under decceleration, the compass will indicate a turn towards to south
What will the airspeed indicator read when the static port is blocked?
Erroneous readings
What does the ADC provide us with?
Pitot static
OAT
TAS
Wind
What does the AHRS provide us with?
Attitude and heading
