国外航校私照飞行员地面课Lesson 12

1、Weather Hazards/ServicesLesson 12Weather HazardsWake Turbulence Three ingredients to a thunderstorm Lifting Action Unstable Air MoistureStages of a Thunderstorm Cumulus Mature DissipatingHow far away should pilots stay away from thunderstorms?Why should pilots remain that far from a thunderstorm?Wha

2、t other significant weather can be associated with thunderstorms?Types Radiation Fog Advection Fog Upslope Fog Precipitation Induced FogIngredients for Fog Temperature-Dew Point spread is less than 2 degrees Celsius and decreasingTypes of Ice Clear Rime Mixed Frost Ingredients for Ice Visible Moistu

3、re Temperature at or below freezing Can a VFR pilot fly into known icing conditions?If icing accumulates on your airplane what should you do?What types of features on an airplane prevent icing or de-ice the airplane in flight?Standard Pressure 29.92Standard Temperature 15 degrees CelsiusStandard Lap

4、se Rate 2 degrees Celsius Per 1,000 Feet Land Changes Temperature faster than WaterAs altitude increases temperature generally goes? Up Down Stays the sameWhy?Occurs when the temperature goes up with altitude.Acts as a lid for weather and pollutantsOver time can lead to low visibility due to fog, ha

5、ze, smoke and low clouds.Dew Point is the temperature at which the air would be saturated (100% Relative Humidity)If Temperature and DP are within 2 you will have visible moisture (clouds or precipitation)Amount of moisture in the air compared to the total amount that can be held at that temperature

6、Warmer air can hold more moistureTemperature and dewpoint converge at about 4.5 per 1,000 feetYou can estimate Cumulus cloud bases Temp 85 Dewpoint 67 18/4.5=4,000 Cloud bases should be 4,000 feet AGLDew forms when objects cool to below the dew point and water condensesFrost forms when objects cool

7、to the below the dew point and below freezing temperatures water vapor turns to frost via depositionTurbulence caused by thermalsThermals - Rising air heated by warm surface belowStable air forced over a mountain ridgeExpect it when winds are +25 knots perpendicular to mountain ridgesis the turbulen

8、t movement of air masses in the absence of any visual cues such as clouds, and is caused when bodies of air moving at widely different speeds meet.1Sudden drastic shift in wind speed and/or direction Can occur at any altitude and in any directionA microburst is a very localized column of sinking air

9、 caused by a small and intense downdraft.Gasses, dust and ash Highly abrasive Will pit the windshield and landing lights Clog Pitot-static system Clog air filters Shut down jet enginesCan look similar to cloudsWake turbulence is turbulence that forms behind an aircraft as it passes through the air.

10、This turbulence includes various components, the most important of which are wingtip vortices and jetwash.Heavy, clean, and slow aircraft create the most wake Turbulence. Jetwash refers simply to the rapidly moving gases expelled from a jet engine; it is extremely turbulent, but of short durationWin

11、gtip vortices are much more stable than jetwash and can remain in the air for up to three minutes after the passage of an aircraft.Wingtip vortices occur when a wing is generating lift. Air from below the wing is drawn around the wingtip into the region above the wing by the lower pressure above the wing, causing a vortex to trail from each wingtip.Taking off behind a large aircraft, rotate prior to the rotation point of the large aircraft and maint