ATSEP-BASIC-METEOROLGY (BAS-MET) Questions and Complete Solutions Graded A+

  Why is Meteorology important for aviation? - Answer: Meteorological service for safety, regularity and efficiency of international air navigation Does pressure increase or decrease when climbing ? - Answer: 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 ? - Answer: 1 kg Why does an aeronoid barometer have a vacuum in its vacuum chamber ? - Answer: Because air would underly changes in temperature and therefore cause inaccuracy What is the atmospheric standard pressure ? (ICAO) - Answer: 1013.25 hPa What is the atmospheric standard temperature according to ICAO ? - Answer: 15°C is the atmospheric standard humidity according to ICAO ? - Answer: 0% What is the atmospheric standard lapse rate for temperature according to ICAO? - Answer: 0.6°C per 100 m What is the atmospheric standard density according to ICAO ? - Answer: At MSL 1.225 kg/m³ Why is it necessary to set the subscale pressure for an altimeter ? - Answer: 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)? - Answer: 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 ? - Answer: Mean Sea Level How does temperature affect the air density and pressure ? - Answer: How does the true altitude change during a flight from high to low pressure when using a constant subscale setting ? - Answer: 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 ? - Answer: 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 ? - Answer: 30ft/1 hPa What is QNH ? - Answer: 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 ? - Answer: 120 ft - 1011 hPa - 1007 hPa = 4 hPa 30ft / 1hPa means 120 ft / 4hPa Why do we use QNH ? - Answer: We use it to be independent from ground pressure. Whats the indication on Runway (RWY) when you set the altimeter to QFE ? - Answer: 0 Fill in the table. - Answer: 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) - Answer: 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 ? - Answer: °C Unit of pressure ? - Answer: hPa Unit of Visibility ? - Answer: m or km Unit of cloud height ? - Answer: ft Unit of cloud amount ? - Answer: oktas Unit of wind speed - Answer: kt (knots) Unit of wind direction ? - Answer: ° (true north) Unit of relative humidity ? - Answer: % Instrument used for temperature ? - Answer: thermometer Instrument used for pressure ? - Answer: barometer Instrument used for visibility ? - Answer: transmissiometer Instrument used for cloud height ? - Answer: ceilometer Instrument used for cloud amount ? - Answer: visual / ceilometer Instrument used for wind speed ? - Answer: rotation anemometer Instrument used for wind direction ? - Answer: wind vane (wind sock) Instrument used for relative humidity ? - Answer: hygrometer What can we use to collect weather parameters ? - Answer: - weather station - registering balloon - weather observation on a ship - buoy - weather data collection via aircraft AMDAR - meteorological satellite What is wind ? - Answer: A vector of horizontal motion of the air relatively to the ground, characterised by wind speed and a wind direction. What is the measuring height of wind ? - Answer: 10 m above GND Why is the measuring height 10 m above the ground ? - Answer: to minimize ground effect and environmental friction Unit of Gusts ? - Answer: kt (knots) Unit of wind variation ? - Answer: degrees How many knots of windspeed per windsock section ? - Answer: 5 kt Where does the wind come from when the wind direction is 180° - Answer: South. The value always gives the direction where the wind is coming from. What is the optimal type of wind for departure or landing ? - Answer: headwind If you land on rwy 24 wind direction is 330°, which side will the wind hit your aircraft ? - Answer: right side What would be the best wind direction for landing on runway 24 ? - Answer: 240 ° headwind. Landing on runway 24 means the runway head torwards 240°. Wind direction 240° means the wind blows from 240° degrees and is therefore direct headwind which is optimal for landing or departure. You departure from rwy 17 and wind is blowing from 320°. What is the wind angle ? - Answer: 150° - |wind - runwayheading| How is gust defined ? - Answer: Max wind is 10 kt above the 10 minutes average wind What is a jetstream ? - Answer: It's "band" or stream of wind in one direction which can be used to save a lot of fuel if you're going in the right direction. What's a important factor of wind speed and wind direction on surface level ? - Answer: The surface roughness. Trees and mountains for instance influence the wind speed and wind direction. What happens to wind speed and direction on decend ? - Answer: Wind speed will degrees and wind will turn to left. What is the dew point ? - Answer: It's a temperature where air is fully saturated. It refers to a higher temperature. If you cool the air further water will condense and fog or clouds will occur. How do you call the delta between a temperature and its dew-point ? - Answer: Spread - A low spread indicated that there's a high chance of fog What types of views are defined ? - Answer: Which instrument is used to measure RVR ? - Answer: Scatterometer or Transmissiometer What is RVR ? - Answer: Runway Visual Range How is RVR defined ? - Answer: Distance at which a pilot on board of an aircraft located on the runway axis may see marks or lights bordering the runway or marking the axis. How is fog defined ? - Answer: Cloud on the ground visibility 1 km humidity = 100% Temperature equals dew point temperature Two types for cloud formations ? - Answer: thermal convection or forced lifting 2 types of clouds and how they're formed - Answer: thermal convection - cumuliform (local shower) , forced lifting - stratiform clouds (widespread continous rain) What is the wording for different octa values ? - Answer: 1 - 2 octa = few clouds 3-4 octa = scattered clouds 5-7 octa = broken clouds 8 octa = overcast What is a ceiling ? - Answer: 5-8 octa In which height to you place your thermometer for measuring ? - Answer: 2m above surface in dedicated shelter How should air density and temperature be for best aircraft performance ? - Answer: high density and cold temperature Name things air density affect when it comes to aircraft. - Answer: Fuel flow Range Landing distance Take-Off distance Rate of climb Engine performance Maximum possibe cruising altitude What is an Inversion or Inversion temperature ? - Answer: It describes the increase of temperature while climbing. Usually temperature drops when climbing. They are hazardous when situated near surface . If moist air is below the inversion in winter it causes icing. Name possible hazards for aircraft - Answer: Turbulence Windshear Icing Thunderstorm (micro burst, squall) Runway contamination Volcanic ash What is a turbulence ? - Answer: a 3-dimensional fluctuation in velocity and or direction of air current. They can be dangerours for aircraft structure. What are the effect of turbulence ? - Answer: - inconvenient for passengers - pancake sudden loss or gain in height - sudden loss or gain in speed - notable direction changes - metal fatigue (very dangerous) - resonance vibrations (very dangerous) What is light turbulence ? - Answer: it s noticable. No seatbelt signs no action necessary. What is moderate turbulence ? - Answer: moving is possible, loose objects move fasten seatbelt signs on counteracting on steering needed What is severe turbulence ? - Answer: moving not possible, shit's flying around A/C partly out of control What is extrem turbulence ? - Answer: serious injuries (too bad) A/C out of control things get really bad and disintegration starts What is wind shear ? - Answer: Changes in wind speed and direction. Aircraft performance is reduced extremely. When is wind shear hazardous ? - Answer: it occurs within the first few thousand ft above ground during take off or landing the true air speed changes by 10 to 20 kt within seconds Where does wind shear appear ? - Answer: Inversion Fronts Orographically induced Microburst Tornado When does structual icing occur ? - Answer: - a cold aircraft enters a humid airpsace ( clear of cloud: hoar frost) - supercooled water is in the atmosphere - an aircraft cools down during night within humid air resulting in hoar frost ( deposition) - hoar frost due to remaining cold fuel What is more endangered for icing : fast aircraft 400 kt or slow aircraft 160 kt ? - Answer: slow aircraft How do different icing itensities influence the course and sufficiency of anti icing ? - Answer: How does icing change the flight characteristics ? - Answer: lift decrease stall speed increase climb rate decrease How is a thunderstorm defined ? - Answer: cumulonimbus (cb) with thunder and lightning What types of microburst do you know ? - Answer: Wet and dry microburst Characteristics of Micro and Macrobursts - Answer: What types of runway contamination do you know ? - Answer: Where can volcanic ash appear ? - Answer: 80 000 ft diameter hundreds of miles spread around the whole globe Why is volcanic ash dangerous ? - Answer: silicate melting point = 1100°C turbine temp = 1400°C The silicate will made and glass will build on the outside of the plane, which is not good . - aircraft surfaces and cockpit windows will be sandblasted - damage to the jet engines -vibrations -engine flame-out -thrust loss on all engines (and as a result, increase in cabin altitude) -blocked pitot-tubes (resulting in false airspeed and altitude indications) -antennas and de-icing devices may be destroyed -contamination of the air-conditioning system -electrical, fuel and hydraulic systems affected -may generate false "cargo-fire" warnings Explain the impact of meteorological conditions and hazards on ATS operation - Answer: strong surface wind Do pilots have to inform theirselves about the latest official weather information before a flight ? - Answer: Yes it is legal requirement What does WX mean ? - Answer: Weather ... who came up with this What is METAR ? - Answer: Aerodrome weather report in written form. World wide availability. It shows the current weather situation ! It issued every half or full hour and valid for half or full hour. What is TAF? - Answer: area / Flight Information Region (FIR) weather forecast. How to get latest Met-Information ? - Answer: - internet - app's -radio (volmet or atis on certain VHF-Channels) -datalink (ACARS) -telephone Can't get them by morse code ... sad Wofür steht TAF ? - Answer: Terminal Aerodrome Forecast ? A routine weather forecast, valid for 9h 24 h or 30h Was ist ATIS ? - Answer: Automatic Terminal Information Services. Every 30 minutes includes METAR and is intended for departing and arriving traffic an airport. Can be printed via datalink. More common it's used as a loop audio recording on a certain radio frequency. What is VOLMET? - Answer: Weather broadcast via VHF-RADIO (it's looped) for inflight planning. every 30 minutes and it includes METARS What is SIGMET ? - Answer: SIGnificant METeorological Phenomena - describes conditions which can pose hazard to all aircraft in flight. Valid FIR or UIR How does weather affect ATC-Antennas ? - Answer: Radarantennas - windspeedlimits 130 km/h weatherradar antennas MET-Service - windspeed limits NDB,VOR - Thunderstorm Satellites ( COM,NAV) - solar storms What is significant weather ? - Answer: turbulence, thunderstorm Where to receive RVR - Answer: ATIS What is the common transition altitude in Germany ? - Answer: 5000ft