ATSEP-BASIC-METEOROLGY (BAS-MET)

ATSEP-BASIC-METEOROLGY (BAS-MET) Why is Meteorology important for aviation? Meteorological service for safety, regularity and efficiency of international air navigation Does pressure increase or decrease when climbing ? It decreases because more atmosphere is below us when we climb up. At sea level: How much weight does 1 cubic metre of air have ? 1 kg Why does an aeronoid barometer have a vacuum in its vacuum chamber ? Because air would underly changes in temperature and therefore cause inaccuracy What is the atmospheric standard pressure ? (ICAO) 1013.25 hPa What is the atmospheric standard temperature according to ICAO ? 15°C is the atmospheric standard humidity according to ICAO ? 0% What is the atmospheric standard lapse rate for temperature according to ICAO? 0.6°C per 100 m What is the atmospheric standard density according to ICAO ? At MSL 1.225 kg/m³ Why is it necessary to set the subscale pressure for an altimeter ? Because the altimeter indicates the vertical distance between measured and the subscale pressure (pressure differs depending where you are) value. Therefore you have to set it for your location in order to get the correct height in your area. Does the altimeter show the height relative to the Mean Sea Level (MSL)? It depends whether you set it to the pressure on MSL. If you don't it will show the height relative to the pressure you've set it. What does MSL mean ? Mean Sea Level How does temperature affect the air density and pressure ? How does the true altitude change during a flight from high to low pressure when using a constant subscale setting ? Altitude will decrease. There's a saying that goes like: From high to low look out below. If you don't adjust your altimeter you might just hit a mountain. What is QFE ? It s the Pressure at Field Elevation (ELEV). If you set your altimeter to QFE it will show 0 ft if you're standing on the field. What is the barometric lapse rate at sea level with ISA-conditions ? 30ft/1 hPa What is QNH ? It's the estimated sea level pressure based on the measured QFE with 30ft/1hPa under ISA-Conditions If QNH = 1011 hPa and QFE = 1007 hPa how high is the elevation difference between both locations under ISA-Conditions ? 120 ft - 1011 hPa - 1007 hPa = 4 hPa 30ft / 1hPa means 120 ft / 4hPa Why do we use QNH ? We use it to be independent from ground pressure. Whats the indication on Runway (RWY) when you set the altimeter to QFE ? 0 Fill in the table. Solution: Subscalesetting, Indication on RWY, Indication on flight QFE,0,HGT QNH,ELEV,ALT 1013 hPa,QNE,FL/PL/Press.Alt. Why do we use FlightLevel if there are different pressure values in different areas and we don't get the correct altitude by dialing in one fixed value (flightLevel 1013.25 hPa is set) Because everybody has the same margin of error therefore it's good enough for seperation and aircraft won't crash, which is a good thing to be honest. Unit of temperature ? °C Unit of pressure ? hPa Unit of Visibility ? m or km Unit of cloud height ? ft Unit of cloud amount ? oktas Unit of wind speed kt (knots) Unit of wind direction ? ° (true north) Unit of relative humidity ? % Instrument used for temperature ? thermometer Instrument used for pressure ? barometer Instrument used for visibility ? transmissiometer Instrument used for cloud height ? ceilometer Instrument used for cloud amount ? visual / ceilometer Instrument used for wind speed ? rotation anemometer Instrument used for wind direction ? wind vane (wind sock) Instrument used for relative humidity ? hygrometer What can we use to collect weather parameters ?