Week 3: Pitot Static Instruments Flashcards
If you apply soapy water to a static port when the Altimeter is reading ASL, what happens?
It sucks in the water (destroys ALT)
What type of pressure goes into the altimeter and VSI?
Negative pressure
Should your altimeter be reading BSL or ASL before applying soapy water to it?
Below Sea Level
True or False, your static source is a vacuum?
True
What does the static port introduce?
Outside air at its normal atmospheric pressure (not moving)
The static port applies air to which instruments?
ASI, VSI, ALT
What is pitot pressure?
Generated by the fwd motion of the aircraft thru air
Pitot pressure is also know as what?
Impact, ram, total pressure
Which instrument uses pitot pressure?
ASI, Mach meter
Pitot tubes have what to keep them from icing?
Anti-icing
During leak checks what should you check?
Connections and junctions
Advanced pitot static systems have how many pitot tubes and static ports?
3 pitot, 6 static
What are the 2 modules in a Mach meter?
Airspeed and Altitude module
The mach meter/speed of sound depends on what?
Your altitude
What is the only instrument that normally points at 9oclock?
VSI
When is attenuated speed most important?
When landing
The ASI measures what?
Pitot and Static, differential pressure, speed of aircraft thru the air
What is indicated airspeed?
read directly from instrument
This type of airspeed is relative of the airmass you are moving through and compensates for pressure and temperature
True Airspeed
What is ground speed?
Speed of aircraft relative to the ground
When are ground speed and true airspeed the same?
no wind
If you set your altimeter to your current barometric pressure for that day, what should the ALT be reading?
0
How do you force your altimeter to read 0?
Decouple the baroset knob using the screw and then turn it to 0 then recouple it
The ALT is connected to what?
Static port
The ALT indicates what?
Height above sea level MSL/ASL
If the aircraft is flying below 18000ft what should the ALT be set to?
Local barometric pressure (Indicated Alt)
If the aircraft is flying above FL180 what will the ALT baro be set to?
29.92inHg
Indicated alt and pressure alt can be the same when?
On a standard day
What are the 5 types of Altimeters?
Sensitive, Encoding, Counter Drum, Servo, RadALT
What does the encoding altimeter encode the alt info for?
Txpr and ATC
The counter drum pointer range is what?
0-999
A servo alt has what?
A servo
How does the RAD ALT work and what does it measure?
Sends signal to ground and back then measures the time difference
When is the RAD ALT used and what is its range??
During approach and a range of FL25
How often do Altimeters require testing?
Every 24 months
In the ASI the case is vented to what? The diaphragm is vented to what?
Case vented to static port
Diaphragm to pitot port
The white arc on the ASI means what?
Flap operating range
The blue on the ASI is set by who?
Manufacturer
What does the mach meter show?
ratio of true airspeed to local speed of sound
As altitude increases what happens to the speed of sound?
Decreases
At what altitude does the speed of sound stop decreasing?
36000ft
Mach speed depends on what?
Altitude and temperature
How do you zero out a VSI that is not reading zero when on the ground?
Zeroing screw on bottom left side of instrument to adjust
What does the VSI indicate?
RATE of change of altitude in ft/min
The calibrated leak acts as a what?
A restrictor valve that prevents the case from getting instant pressure
In the VSI what gets the instant static pressure?
The diaphragm
If capsule has decreased pressure and case has higher pressure what does this mean?
Aircraft is climbing
Explain what happens in the VSI when the aircraft is descending
Capsule has higher pressure compared to case which has lower pressure
What does the IVSI have that makes it instant?
Accelerometers
The in class barfield tester does not have a what?
VSI
