PT2 CHP8 Performance and Limitations Flashcards
What are the different types of altitudes?
Indicated, True, Absolute, Pressure and Density
What is indicated altitude?
Read directly from the altimeter
What is true altitude?
Vertical distance of the aircraft above sea level (expressed as feet above Mean Sea Level) MSL
What is absolute altitude?
Vertical distance of the aircraft above an obstacle (expressed as feet Above Ground Level) AGL
What is pressure altitude?
The altitude corrected for non-standard pressure
What is density altitude?
The pressure altitude corrected for non-standard temperature
The pressure altitude corrected for non-standard temperature is known as what?
Density altitude
The pressure altitude corrected for non-standard temperature is known as what?
Pressure altitude
What is the vertical distance of the aircraft above an obstacle (expressed as feet Above Ground Level) AGL known as?
Absolute altitude
What is the vertical distance of the aircraft above sea level (expressed as feet above Mean Sea Level) MSL is known as?
True altitude
What is the altitude read directly from the altimeter known as?
Indicated altitude
How many ways can pressure altitude be calculated and what is/are that/those method/s?
Set the altimeter to 29.92” Hg, apply a correction factor to the indicated altitude, using a formula
What are the steps for determining pressure altitude for an airport? (3)
- Determine the current altimeter setting
- Read the altitude correction factor
- Apply the correction factor to the field elevation
How do you determine the pressure altitude for an airport located at 6,757 ft when the altimeter setting is 30.20” Hg?
- Determine the correction factor by looking at the table, which is (-257)
- Apply the correction factor to the field elevation (6,757-257 = 6,500)
-This signifies the airplane feels like it’s at 6,500 feet MSL
If the altitude corrected for non-standard pressure is lower than true altitude, what does this signify?
The aircraft feels like it’s flying at a lower altitude, which is better for performance
If the altitude corrected for non-standard pressure is higher than true altitude, what does this signify?
The aircraft feels like it’s flying at a higher altitude, which is worse for performance
What is the formula for determining pressure altitude?
PA = [(29.92 – current pressure) x 1,000] + airport elevation
How you determine what the outside pressure is to properly set the altimeter?
Listen to the ATIS and/or read the METAR
In addition to pressure, what changes with altitude?
Temperature
What is the temperature at sea level on a standard day?
15˚C (59˚F)
If the temperature at sea level is not 15˚C (59˚F), what must be done?
Adjust the pressure altitude into density altitude
What is the rate temperature decrease as the aircraft climbs?
Rate of -2˚C per 1,000 ft
What is the density altitude formula?
DA= [(local temperature (at that time)) – standard temperature)] x 120 + pressure altitude
When looking at a density altitude chart, how do you determine density altitude?
- Find the point on the horizontal axis based on the given outside air temperature, then draw a vertical line
- Find the point in the chart based on the pressure altitude given, then draw a horizontal line (will be an angled line)
- Draw a horizontal line to find the point on the vertical axis and determine the approximate density altitude in thousands of feet.