Altimetry Flashcards
What is a barometer used to measure?
Atmospheric Pressure
What is an altimeter used to measure?
Altitude
A Dyne is equal to 00001 newtons, and a hectopascal is equal to how many dynes?
1000 per square cm
Pressure and Altitude are inversely proportional at least in the Troposphere, what does this mean?
As altitude increases, pressure decreases
What is a wet bulb thermometer and how does it work?
It is a thermometer wrapped in wet cloth. the evaporation of water creates a cooling effect on the thermometer, and when all of the water is evaporated, the atmospheric saturation, or, relative humidity can be calculated
Outline the parameters of the International Standard Atmosphere (ISA)?
Standard atmospheric pressure: 1013.25hPa or 29.2 inches of mercury at MSL.
Temp at MSL: 15 degrees celcius
ELR of -1.98 degrees celcius per 1000ft.
Define height?
Vertical distance of a point measured from a specified datum.
Define altitude?
Vertical distance of a point measured from MSL
Define elevation?
Vertical distance of a point or level on the surface of the earth measured from MSL.
What is QFE?
Query Field Elevation. Atmospheric pressure corrected to a specific elevation.
Aerodrome elevation
The elevation of the highest point of the landing area..
What is QNH?
Query Nautical Height. Atmospheric pressure corrected to MSL.
Define level?
A generic term relating to the vertical position of an aircraft in flight and meaning variously: height, altitude or flight level.
Define flight level?
A surface of constant atmospheric pressure, which is related to a specific pressure datum, 1013.25hPa, and is separated from other such surfaces by specific pressure intervals (ICAO 4444)
FL intervals can vary below and above FL200. How so?
500ft intervals allowed below FL200, 1000ft intervals only above FL200.
