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Problem:
What is the PAlt at an airport with a
field elevation of 5,900 feet and a 29 .75" Hg
altimeter setting?
Solution:
Press the key . Highlight the
Altitude line and tap enter . Enter IAlt:
and tap enter .
Enter the altimeter setting:
and tap enter .
The display will show PAlt equal to 6059 FT .
Density Altitude
In aviation calculations, air density is normally
specified by an altitude in a standard atmosphere,
instead of pounds per cubic foot . The altitude
corresponding to a given density is called the density
altitude (DAlt) . The Altitude function computes density
altitude (DAlt) based on pressure altitude (PAlt) and
the outside air temperature (OAT) .
Problem:
What is the DAlt at an airport with
a field elevation of 5,900, 29 .75" Hg altimeter
setting, and 75°F OAT?
Solution:
Press the key . Highlight the Altitude
line and tap enter . Enter IAlt:
and tap enter .
Scroll the curser to Baro and enter the altimeter
setting: and tap enter .
Scroll down to OAT and input , tap enter .
The display will show PAlt equal to 6059 FT and
DAlt equal to 8427 FT .
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CLOUD BASE
The Cloud Base function computes the altitude of the
cloud base above ground level (AGL) . The function
prompts for the dew point (Dewp) and outside air
temperature (OAT) at the airfield . If you want the
elevation of the cloud base above mean sea level
(MSL), you must add the elevation of the airfield to
the result from the Cloud Base function .
Problem:
At approximately what altitude above
the surface can the pilot expect the base
of cumuliform clouds to be if the surface air
temperature is 82°F and the dew point is 38°F?
Solution:
Press the key . Scroll to Cloud Base
and tap enter . You are prompted for the outside
air temperature (OAT) . Press:
and tap enter .
You are then prompted for dew point (Dewp) .
Press:
and tap enter .
The answer is 10,000 FT AGL .
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ALTITUDE
Pressure Altitude
In aviation calculations, air pressure is normally
specified by an altitude in a standard atmosphere,
instead of pounds per square inch or inches of
mercury . The altitude corresponding to a given
pressure is called the pressure altitude (PAlt) . An
aviation altimeter displays PAlt when the altimeter
setting window is adjusted to the standard
atmospheric pressure at sea level, 29 .92" Hg . PAlt is
required to calculate true airspeed (TAS) and density
altitude (DAlt) .
The Altitude function calculates pressure altitude
(PAlt), given the indicated altitude (IAlt) and altimeter
setting (Baro) obtained from the automated flight
service station (AFSS) or Air Traffic Control (ATC) .
An altimeter adjusted to this setting will indicate
the altitude of the airfield when the aircraft is on the
ground .
Problem:
You are planning to fly at 4,500 feet
IAlt and the current altimeter setting is 30 .15" Hg .
What PAlt should you use to calculate the TAS?
Solution:
Press the key . Highlight the
Altitude line and tap enter . Enter IAlt by pressing
and tap enter . Enter the altimeter
setting:
and tap enter .
The display will show PAlt equal to 4289 FT .
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E6-B
10:34
Altitude
Unit Conversions
Cloud Base
Ground Speed
To - From
Airspeed
Climb & Descent
Wind Correction
Holding Pattern
Fuel
Estimated Time Arrival
Wind Component
Rhumb Line
Standard Atmosphere
Glide
Compass Heading
