General Flashcards
What is the window on the altimeter which sets the atmospheric pressure called?
The Kollsman window
How many feet of altitude are increased by increasing the pressure setting by one inch Hg?
1000 feet
What is pressure altitude and how is it determined?
Pressure altitude is the height above the standard datum plane, and is determined by setting the altimeter to 29.92”
What pressure setting is used for all aircraft in the US and Canada above 18,000’?
29.92” Hg
What is Density Altitude and how is it determined?
Density Altitude is pressure altitude corrected for non-standard temperature and refers to the current density of air molecules at a given True Altitude, which can be used as an index to determine aircraft performance, not actual altitude. High density altitude means thinner air and less performance, whereas Low density altitude means thick air and better performance.
What is Indicated Altitude and how is it effected by colder than standard temperatures?
Indicated Altitude is the altitude as read from the altimeter with Kollsman window set to local pressure. In very cold conditions the altimeter will indicate lower than True Altitude, whereas higher temperatures will result in a higher than True altitude indication. Additionally, the Venturi effect of a howling wind in a mountain pass can cause the altimeter to indicate as much as 1000’ higher than True.
What is Absolute Altitude?
Absolute Altitude = AGL
What is Calibrated Altitude?
Calibrated Altitude is pressure altitude corrected for static pressure error, installation and instrument error.
What blade AOA is preferable for the propeller?
2-4 degrees
Why cycle the prop during run up in a constant speed prop system?
Proper operation of the governing system relies on warm engine oil, thus cycling the prop is necessary to expel cold oil and replaces it with warm.
Describe four ways to reduce engine temperature in flight. What are the associated negative impacts?
1) Reduce throttle (decreases airspeed and lift)
2) Cowl flaps (increases drag and thus slight decrease in airspeed)
3) Enrich mixture (Increase fuel consumption)
4) Emergency descent (drastic loss of altitude, unsustainable for continuous flight)
What is the formula for converting Celsius to Fahrenheit? Fahrenheit to Celsius?
C = 5/9(F-32)
F = 9/5C + 32
List the layers of Earth’s atmosphere from lowest to highest.
Troposphere
Stratosphere
Mesosphere
Thermosphere
What is the boundary between the troposphere and stratosphere called? What is the range of its height?
The Tropopause ranges from about 20K’ over the poles to approximately 65K’ over the equator, and is higher in summer than winter.
What is standard pressure in Hg”, millibars, lbs per square inch and mm? Why is mercury used to measure pressure?
29.92” Hg
1013.2 millibars
14.7 lbs/square inch
760 mm
Mercury is the heaviest substance which remains liquid at ordinary temperatures.
