Flight Instruments Flashcards
What 3 instruments are run on the pitot-static system?
Altimeter, vertical speed indicator, and airspeed indicator
The pitot- static system reads pressure from what ports?
The static ports reads atmospheric pressure for all 3 instruments. The pitot tube reads the impact pressure for the airspeed only.
Which instrument will become inoperative if the pitot tube becomes clogged?
Airspeed only
Which instrument(s) will become inoperative if the static vents become clogged?
Airspeed, altimeter, and vertical speed
What is indicated airspeed (IAS)?
The uncorrected reading obtained from the airspeed indicator
What is calibrated airspeed (CAS)?
The indicated airspeed corrected for installation and instrument error
What is true airspeed (TAS)?
Calibrated airspeed corrected for temperature and pressure variations
What is Vso?
Stall speed or minimum steady flight flight speed in the landing configuration - the lower limit of the white arc
What is Vfe?
Maximum flap extended speed - the upper limit of the white arc
What is defined by the white arc?
The flap operating range. Lower limit is Vso and upper limit is Vfe
What is Vs1?
The stall speed or minimum steady flight in a specified configuration- the lower limit of the green arc
What speeds are defined by the green arc?
Normal operating range. Vs1 is the lower and Vno is the upper
What is Vno?
The maximum structural cruising speed (the upper limit of the green arc and the lower limit of the yellow arc)
What is Vne?
The never exceed speed - upper limit of the yellow arc, marked in red
What does the yellow arc represent?
The caution range and should be avoided unless in smooth air. Vno at the lower and Vne at the upper
What is Vle?
The maximum landing gear extended speed
What is Va?
The design maneuvering speed. If rough air or sever turbulence is encountered, airspeed should be reduced to this or lower to minimize stress on the structure.
What is Vy?
The best rate-of-climb (the most altitude in a given period of time)
What is Vx?
The best angle-of-climb speed, the most altitude in a given distance
When do you use Vx vs Vy?
Use Vx immediately after takeoff to clear obstacles, then Vy to get to altitude
What is an altimeter?
Instrument used to measure height by responding to atmospheric pressure changes
Describe the 3 hands on the altimeter
The shortest measures altitude in tens of thousands, the intermediate in thousands, and the longest in hundreds
What is indicated altitude?
The altitude read on the altimeter after it is set to the current local altimeter setting
What is absolute altitude?
The height above the surface
What is true altitude?
The true height above mean sea level (MSL)
What is pressure altitude?
The altitude indicated with the Kohlsman window adjusted to 29.92. This is the standard datum plane: a theoretical level and it may be above, at, or below sea level.
What is density altitude?
The pressure altitude corrected for nonstandard temperature and/or pressure.
If a flight is made from an area of low pressure/low temperature to an area of high pressure/high temperature without adjusting the altimeter setting, will the altimeter indicate higher or lowers than the actual altitude?
Lower
If an altimeter setting is not available before flight, to which altitude should the pilot adjust the altimeter?
The elevation of the departing airport.
At which altitude shall the altimeter be set to 29.92?
18,000 feet MSL, class A airspace
Altimeter setting is the value to which the barometric pressure scale of the altimeter is set so the altimeter indicates what?
True altitude at field elevation
How do variations in temperature affect the altimeter?
Pressure levels are raised on warm days and the indicated altitude is lower than true altitude.
Under what condition will true altitude be lower than indicated altitude?
In colder than standard air temperature
When are pressure altitude, true altitude, indicated altitude, and density altitude all equal?
On a standard day (29.92 HG and 15 degrees Celsius) at sea level.
If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate
Lower than the actual altitude above sea level
A flight is made from an area of high pressure to an area of lower pressure without the altimeter setting being adjusted, the altimeter will indicate
Higher than the actual altitude above sea level
Which condition would cause the altimeter to indicate a lower altitude than true altitude?
Air temperature warmer than standard
What is the standard pressure lapse rate of the altimeter dial?
1 inch HG = 1000 ft in altitude
What 3 instruments rely on gyroscopes?
Attitude indicator, turn coordinator, and the heading coordinator
How do you read the attitude indicator?
The direction of bank is determined by the relationship of the miniature plane to the horizon bar.
Why must the heading indicator be periodically realigned?
It suffers from precession. Because of this it must be realigned with the magnetic compass during straight and level, I accelerated flight
A turn coordinator provides an indication of the
Movement of the aircraft about the yaw and roll axis
What is deviation?
Compass error caused by magnetic disturbances from electrical and metal components in the aircraft. The correction is displayed on a card.
What is variation?
The angular difference between the true, or geographic, poles and the magnetic poles at a given point.
What is magnetic dip?
The downward pointing tendency of the compass that can cause errors in compass indications
UNOS
Undershoot North, Overshoot South. The compass lags whenever turns are made to or from north. The compass leads whenever turns are made to or from south.
ANDS
Accelerate North, Decelerate South. Accelerating or decelerating while heading East or west will cause compass errors.
When are the indications on the compass most accurate?
During straight-and-level un accelerated flight
When accelerating or decelerating, what headings will the compass remain correct?
A north or south heading
