Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
|
What are the first two layers of the atmosphere?
|
Troposphere and Stratosphere
|
|
|
What is the average height of the troposphere over the US?
|
36,000 feet MSL
|
|
|
What is the boundary between the troposphere and the stratosphere?
|
Tropopause
|
|
|
What are the temperature characteristics of each atmospheric layer?
|
Troposphere - decreasing; Tropopause - isothermal; Stratosphere - Inversion
|
|
|
What are characteristics of the tropopause?
|
Isothermal, jet stream just below, contrails, moderate to severe turbulence (wind shear from jet stream)
|
|
|
What are three ways to identify the tropopause?
|
average height (36,000), anvil tops of thunderstorms, haze layer with definite top
|
|
|
What are the characteristics of the stratosphere?
|
Temperature inversion due to gas ozone, smooth, excellent visibility
|
|
|
What is the composition of dry air?
|
78% nitrogen, 21% oxygen, 1% other, 0-5% by volume of water vapor
|
|
|
What are condensation nuclei and what do they do?
|
Dust and salt particles, pollen, etc --- appear as haze and reduce visibility
|
|
|
What is the environmental lapse rate / existing lapse rate (ELR)?
|
Standard: 2 degrees C / 1,000 feet
|
|
|
What is a shallow lapse rate?
|
1.5-3.0 degrees C / 1,000 feet
|
|
|
What is a steep lapse rate?
|
>3.0 degrees C / 1,000 feet
|
|
|
What is a characteristic of a temperature inversion?
|
Stable conditions, few hundred to a few thousand feet thick
|
|
|
What is the altimeter / temperature error rate?
|
11 degrees C variation from standard = 4% altimeter error
|
|
|
How does aircraft altitude vary with the altimeter readings for non-standard temperature variations?
|
Colder than standard = aircraft lower than indicated; Warmer than standard = aircraft higher than indicated
|
|
|
What is the altimeter rule for flying through temperature variations?
|
High to Low - look out below; Low to High - plenty of sky
|
|
|
What is atmospheric pressure?
|
Pressure exerted on a surface by the atmosphere due to weight of air directly above that surface
|
|
|
What is standard pressure?
|
14.7 lbs / square inch
|
|
|
How does pressure change with altitude?
|
Always decreases, more rapidly at higher altitude
|
|
|
What two units are used in the U.S. to measure atmospheric pressure?
|
Inches of mercury and millibars
|
|
|
What are the standard day pressure and temperature lapse rates?
|
1 in-Hg / 1,000' and 2degC / 1,000'
|
|
|
What pressure is used for the altimeter?
|
Sea Level Pressure (SLP) or Station Pressure (SP)
|
|
|
What is the formula for Sea Level Pressure (SLP)?
|
SLP = SP + Terrain correction (1 in-Hg/1000 feet)
|
|
|
What causes pressure changes on the earth's surface?
|
Movements of high and low pressure systems, temperature and moisture content
|
|
|
What are isobars?
|
Lines of equal barometric pressure
|
|
|
What are the standard types of pressure distribution patterns?
|
High, Low, Ridge, Trough
|
|
|
What type of weather is generally associated with fronts and squall lines?
|
Poor weather
|
|
|
What type of weather is generally associated with highs and ridges?
|
Good weather
|
|
|
What are the features of the altimeter?
|
Barometric altimeter, aneroid barometer, feet, Kollsman window w/ reference pressure (altimeter setting)
|
|
|
What type of altitude does 29.92 set in the altimeter show?
|
Pressure Altitude
|
|
|
What is necessary for the indicated altitude to be useful?
|
Correct reference setting - 29.92 or local altimeter setting in the Kollsman window
|
|
|
What is the insturment error allowance for IFR flight?
|
+/- 75 feet
|
|
|
What is true altitude?
|
Actual heigh above MSL; calibrated altitude corrected for nonstandard temperature deviations
|
|
|
When does true altitude equal calibrated altitude?
|
On a standard day
|
|
|
What altitudes are airfields, hazards, and terrain elevations given in?
|
Feet MSL
|
|
|
What is absolute altitude?
|
AGL - height above terrain
|
|
|
What is pressure altitude?
|
Height above the standard datum plane
|
|
|
When is pressure altitude (29.92) required to be used?
|
When above 18,000 feet MSL
|
|
|
What is density altitude?
|
Pressure altitude corrected for non-standard temperature
|
|
|
What is density altitude used for?
|
Indication of aircraft/engine performance.
|
|
|
What is the relative density altitude on a hot day?
|
High
|
|
|
What is the relative density altitude on a cold day?
|
Low
|
|
|
How does moisture affect aircraft performance?
|
Similary as temperature, to a lesser degree
|
|
|
What is the relative actual altitude after flying to a lower MSL pressure area?
|
Low
|
|
|
What is the relative actual altitude after flying to a higher MSL pressure area?
|
High
|
|
|
What is the altitude rule for flying through pressure changes?
|
High to Low - look out below; Low to High - plenty of sky
|
|
|
Which has greater affect on altimeter error, pressure or temperature?
|
Pressure
|
