Pitot Static Flashcards
What are the two most critical factors of the atmosphere?
Temperature and pressure
Temperature is the most critical everything in the atmosphere chases it
What is atmospheric pressure?
The force exerted by the weight of a column of air
What is standard sea level pressure in inches of mercury?
29.92
What is standard sea level temperature in degrees Celsius?
15 degrees
What is standard temperature lapse rate with altitude?
2 degrees/ 1,000 feet
A change in 1 inch of mercury pressure is approximately ___________ feet of altitude.
1,000
Define impact pressure.
Static pressure plus dynamic pressure
Define static pressure
Ambient pressure
Which instruments depend on static pressure only?
VSI and Altimeter
Which instrument depends on both impact and static pressure?
Airspeed indicator
What pressures affect the pitot static system?
Dynamic and static
Three types of airspeed
Indicated, calibrated, and true
Indicated airspeed
Read from the dial on the face of the instrument
Calibrated airspeed
IAS corrected for instrument and installation error
True airspeed
CAS corrected for density error
Three errors in airspeed indicator
Installation, density, and instrument
Installation error
Caused by misalignment of the pitot tube with the relative wind and position of the static vents
Density error
Caused by pressure and temperature changes, air less dense as altitude increases
Instrument error
Caused by friction in the instrument
Is the VSI a pressure differential measuring instruments?
yes
Pressure used in the diaphragm of the VSI
Static
Pressure used in the case of the VSI
restricted static
How much time lag does the VSI have when leveling off from a climb or descent?
a few seconds
The altimeter is a ____ with a Kollsman window to adjust for atmospheric pressure changes.
Aneroid barometer
What does the setting knob on the altimeter change when it is turned?
Kollsman setting and position of the needles
How would the altimeter react to a pressure increase while on the ramp and again in flight?
It would indicate a lower altitude on the ramp; the change would not be apparent in flight.
How would the Kollsman window react to a pressure increase while on the ramp and again in flight?
No change in either
A change of .15 inch of mercury pressure is equal to
150 feet
Indicated altitude
Altimeter indication
True altitude
Altitude above MSL
Pressure Altitude
Altitude above the standard datum plane (29.92”Hg)
Absolute altitude
Altitude above the terrain
Altimeter setting
station pressure corrected to MSL
Why is an altimeter setting necessary?
To correct for pressure changes
Maximum allowable error in the altimeter
75’ (FAA), aviators should check operator or maintenance manual to confirm accurate limit for their aircraft.
When flying into an area of lower pressure without resetting the altimeter, would your true altitude be higher or lower than your indicated altitude?
lower
If you depart a base with an altimeter setting of 29.82 and an hour later receive a new altimeter setting of 30.22, how much higher or lower than true altitude would the altimeter indicate prior to adjusting the altimeter to the new setting?
400’ lower than true altitude
At the last reporting point, you corrected the altimeter by setting the Kollsman scale on 29.92.” Hg. Prior to landing, you received a new setting of 29.80. What is your true altitude in relation to indicated altitude (before you reset the altimeter)?
120’ lower than indicated altitude
When flying into an area of higher pressure without resetting the altimeter, would your altimeter indicate higher or lower than your true altitude?
lower
When flying into an area of colder than standard temperature, would the indicated altitude will be more or less than true altitude?
more
What instrument stops functioning properly due to pitot icing?
airspeed indicator
What is the recommended corrective action when the static system is clogged
switch to an alternate source or break the glass on the VSI
(true or false) High DA and low air density mean nearly the same thing
true
What causes density error?
Nonstandard pressure and temperature
True airspeed
CAS corrected for density error
