Metro-01
Review of Basic Meteorological Principles
PRESENTATION
I.
Meteorological definitions
A. Altitude
1. Indicated altitude: altitude read on an altimeter with current
barometric setting
2. Calibrated altitude: indicated altitude corrected for instrument
error
3. True altitude (QNH): height above mean sea level (MSL)
4. Absolute altitude: height above terrain (AGL)
5. Density altitude: pressure altitude corrected for temperature
NOTE: Density altitude is used to calculate takeoff roll, available
thrust, and power settings. To compensate for it, the pilot uses the
NATOPS performance charts by entering the chart with
temperature deviation and pressure altitude.
6. Pressure altitude (QNE): altitude read on an altimeter with a
barometric setting of 29.92
COMMON ERROR: Confusing pressure altitude with density
altitude.
B. Coriolis force: deflective force created by the difference in rotational
velocity between the equator and the poles of the earth
1. In the northern hemisphere, winds flow clockwise around areas of
high pressure and counterclockwise around areas of low pressure
2. In the southern hemisphere, winds flow counterclockwise around
areas of high pressure and clockwise around areas of low pressure
NOTE: In this lesson, descriptions are of weather phenomena
occurring in the northern hemisphere.
C. Frontal system: discontinuity formed between two contrasting
airmasses of different characteristics 1.1.1.2.4
1. Fronts affect ground speed, wind correction, and other planning
factors
2. Several associated weather hazards
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