Atmospheric Stucture 3.1 Flashcards
Describe the characteristics of the. Troposphere.
Layer adjacent to the Earth’s surface.
Varies from 55,000 over the Equator and 28,000 over the Poles; USA - 36,000 ft MSL. Due to heating height extends in summer than in winter. Temp Decrease with increase in Alt. Large amount of Moisture and condensation Nuclei are found causing nearly ALL WEATHER to occur within. Winds +200Kts occur at Top of layer.
Describe the characteristics of the Tropopause.
Boundary Layer between Troposphere and Stratosphere.
Temp is Constant with Alt; Strongest Winds (Jet Stream just below layer); Contrails Formed at lower level coldest area; Anvil Top of T/S Penentrate.
USA - 36,000 ft MSL.
Haze Layer with Definite top frequently exist.
Describe the characteristics of the Stratosphere.
Increasing Temp wit Increasing Alt due to gas Ozone.
Smooth with Excellent Visibility
Thin air results in little resistance to the A/C
Lacks weather equals outstanding flying.
36,000 - 60,000ft
Describe the flight conditions associated with the Troposphere.
Nearly all Weather occurs; ATM becomes less dense w/ALT. 1/2 of it Lies below 18,000 and 90% w/in 53,000 ft.
Wind speeds over 200KTS at top of Layer.
Describe the flight conditions associated with the Tropopause.
Anvil tops of T/S penetrate layer.
Strongest winds and Jet Streams happen just below the Pause. Mod to Severe turbulence associated with wind shear due to jet stream
Describe the flight condition associated with the Stratosphere.
Generally Smooth with excellent visibility,
Air is thin and offer little resistance to A/C
Lack of Weather makes Outstanding Flying.
Define Lapse Rate.
Decrease in ATM Temp with Increasing Altitude.
State the Average Lapse Rate in Celsius.
2 degrees Celsius per 1000 Ft.
3.5 Fahrenheit
Define Atmospheric Pressure.
Pressure is Force per Unit Area.
The Pressure exerted on a surface by the ATM due to the Weight of the column of air directly above that surface.
State the Standard Units of Pressure Measurement.
Inches of Mercury- (in-Hg) measures of the height of a column of mercury that can be supported by ATM Pressure.
Millibars (mb) a direct representation of pressure which is defined as force per unit area.
Define the Standard Atmosphere.
Standard Day at Sea Level.
- 92 in-Hg and 15 degrees Celsius
- 2 mb and 59 degrees Fahrenheit
* *1000 ft increase = pressure decrease 1 in-hg(34mb) and Temp decrease 2 Celsius (3.5 F)
Differentiate between Sea Level Pressure and Station Pressure.
Station Pressure - The ATM pressure measured directly at an airfield or other weather station.
Sea Level Pressure - the pressure that would be measured from the existing weather if the station were at MSL. Can be measured directly at Sea Level or calculated if station not at sea using STD Press Lapse Rate.
Define the types of Altitudes.
Indicated Alt. - read directly from. Altimeter.
Calibrated Alt. - Indicated Corrected for Instrument Error.
MSL/True Alt - actual HT above MSL, Cal Alt corrected for (T) deviations
AGL/Absolute - HT above the terrain directly below the A/C.
Pressure Alt. - HT above the Standard Datum Plane.
Density Alt. - PressAlt corrected for NON Std Day (T) deviations
Define Indicated Altitude.
Altitude read directly from the Altimeter.
Must have the correct reference in the Kollsman Window. Thus to equal either MSL or Press Alt.
Describe the Effects of Pressure changes on Aircraft Altimeters.
Change of .10in-HG = 100 ft on Alt.
- *H-L = A/C lower than Indicated. // MSL = Ass.Alt(-) Alt Error // AGL = MSL(-) Field Elev. // IndonDeck = Field (+) Alt Error
- *L-H = A/C higher than Indicated. // MSL = Ass. Alt (+) Alt. Error // AGL = MSL (-) Field Elevation // IndonDeck = Field Elev.(-) Alt Err
