The cloud base, reported in the METAR, is the height above

The troposphere

What values are used for the forecasted wind at higher levels?

What is the approximate composition of the dry air by volume in the troposphere ?

The wind direction in a METAR is measured relative to

Clear ice forms on an aircraft by the freezing of :

Under which conditions would you expect the heaviest clear ice accretion to occur in a CB?

The thickness of the

The troposphere is the

The tropopause is a height

Relative humidity depends on

The difference between temperature and dewpoint is greater in

Rime ice forms through aircraft surfaces of

How does a pilot react to heavy freezing rain at 2000 FT/AGL, when he is unable to deice, nor land?

Rising air cools because

In the mid-latitudes the stratosphere extends on an average from

The tropopause is lower

Relative humidity at a given temperature is the relation between

On the approach, the surface temperature is given as -5° C. The freezing level is at 3000 FT/AGL. At 4000 FT/AGL, there is a solid cloud layer from which rain is falling. According to the weather briefing, the clouds are due to an inversion caused by warm air sliding up and over an inclined front. W ould you expect icing? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

Atmospheric soundings give the following temperature profile : 3000 FT +15° C 6000 FT +8° C 10000 FT +1° C 14000 FT -6° C 18000 FT -14° C 24000 FT -26° C At which of the following flight levels is the risk for aircraft icing, in cloud, greatest?

At about what geographical latitude as average is assumed for the zone of prevailing westerlies?

What of the following is the most important constituent in the atmosphere from a weather stand-point ?

The average height of

The height and the tropopause are respectively in the order of

The type of icing that occurs in dense clouds with large supercooled drops that have a temperature of -5° C is most likely to be

Large supercooled water drops, which freeze on impact on an aircraft, form

Clear ice forms as a result of

An airmass is stable when weaker and disappears.

An airmass is unstable when

Hoar frost forms on an aircraft as a result of

Clear ice is dangerous because it

How does freezing rain develop?

Glaze or clear ice is formed when supercooled droplets are

A vertical temperature profile indicates the possibility of severe icing when the temperature profile

What flying conditions may be encountered when flying in cirrus clouds?

During the formation of rime ice in flight, water droplets freeze

Fallstreaks or virga are

When is the RVR reported at most airports? m.

In which layer is most of the atmospheric humidity concentrated ?

How does the height of

What is the type, intensity and seasonal variation of precipitation in the equatorial region ?

The reason for the fact, that the Icelandic low is normally deeper in winter than in summer is that

What, approximately, is the average height of the tropopause over the equator ?

A small supercooled cloud droplet that collides with an airfoil will most likely

W hile descending through a cloud cover at high level, a small amount of a white and rough powderlike contamination is detected along the leading edge of the wing. This contamination is called:

Two aircraft, one with a sharp wing profile (S), and the other with a thick profile (T), are flying through the same cloud with same true airspeed. The cloud consists of small supercooled droplets. Which of the following statements is most correct concerning ice accretion ?

Hoar frost is most likely to form when

Which of the following factors have the greatest effect on the formation of the various types of ice on an aircraft ?

Which one of the following statements concerning the formation of aircraft icing is most correct ?

A winter day in northern Europe with a thick layer of stratocumulus clouds and temperature close to zero degrees C at ground level, you can expect:

Which of the following cloud types are most likely to produce light to moderate icing when they are not subject to orographic lifting and consist of supercooled cloud droplets?

What is the meaning of the abbreviation "BKN"?

What process in an air mass leads to the creation of wide spread NS, AS and ST cloud coverage?

Which of the following cloud is classified as low level cloud ?

In which of the following conditions is moderate to severe airframe icing most likely to be encountered?

(For this question use annex 050-2065A) What is the classification of the airmass affecting position "Q" at 0600 UTC?

Which one of the following statements applies to the tropopause?

Where does polar continental air originate? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

Where is the source of summer?

In which air mass are extremely low temperatures encountered? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

What are the typical differences between the temperature and humidity between an air mass with its origin in the Azores and an air mass with its origin over northern Russia ? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

Which of the following clouds may extend into more than one layer?

Which form of precipitation from clouds containing only water is most likely to fall in mid-latitudes?

Which of the following is a cause of stratus forming over flat land?

Which of the following processes within a layer of air may lead to the building of CU and CB clouds?

What are the characteristics of cumuliform clouds?

Which of the following types of clouds are evidence of unstable air conditions?

Which of the following clouds are classified as medium level clouds in temperate regions ? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

(For this question use annex 050-1914A) Which one of the displayed cloud forms is representative of altocumulus castellanus?

A plain in Western elevation of 500 m (1600 FT) above sea level is covered with a uniform AC layer of cloud during the summer months. At what height above the ground is the base of this cloud to be expected?

What is the main

What is the relationship between meteorological visibility (met.vis.) and RVR in homogeneous fog?

The wind indicator for a weather observation receives the measured value from an anemometer. Where is this instrument placed?

Which of the following cloud types can project up into the stratosphere?

Runway Visual Range (RVR) is

Freezing fog exists if fog droplets

What does dewpoint mean? which a mass of air which ice melts. (danger of icing). which the relative

What is the boundary layer between troposphere and stratosphere called?

Which of the following is the definition of relative humidity ?

The relative humidity of a sample air mass is 50%. How is the relative humidity of this air mass influenced by changes of the amount of water vapour in it?

How, if at all, is the relative humidity of an unsaturated airmass influenced by temperature changes?

How does relative humidity and the dewpoint in an unsaturated air mass change with varying temperature?

When a given mass of effect will it have on relative humidity? afternoon an air temperature of +12° C and a dew point of +5° C were measured. What temperature change must occur during the night in order to induce saturation?

Clouds, classified as

The presence of altocumulus lenticularis is an indication of the

The presence of altocumulus castellanus indicates

What type of cloud is being described ? A generally grey cloud layer with fairly uniform base and uniform appearance, which may give drizzle or snow grains. When the sun is visible through the cloud, the outline is clearly discernible. Sometimes it appears in the form of ragged patches.

Cumulus clouds are an indication for

Which of the following are medium level clouds ?

Strongly developed cumulus clouds are an indication of

A cumulonimbus cloud at moderate latitudes in summer contains

Altostratus clouds are classified as

Convective clouds are formed

The maximum amount of water vapour that the air can contain depends on the

In an unstable layer there are cumuliform clouds. The vertical extent of these clouds depends on the

Dew point is defined as

Considering the North Atlantic region between 30° N and 65°N together with the adjacent land areas during winter, the normal disposition of the main anticyclones at the surface is

Considering the North Atlantic region between 30° N and 65° N and the adjacent land areas during mid-summer, the predominant pressure systems are

Select the answer which you consider will complete correctly the following statement in relation to the main pressure systems affecting the North Atlantic region between 30° N and 65°N. During winter the predominant mean low pressure system at the surface is usually centred over

In which of the following areas do surface high pressure systems usually predominate over the North Atlantic region between 30° N and 65° N and the adjoining land areas during the northern summer?

(For this question use of the route indicated from 30° E to 50° E, the upper winds in January above FL 300 are most likely to be

Which layer of the atmosphere contains more than 90 per cent of all water vapour?

What are the images of satellites provided daily by the Service used for?

When will the surface wind in a METAR record a gust factor ?

At what degree of icing can ICAO"s "No change of course and altitude necessary" recommendation be followed?

At what degree of icing should ICAO"s "Change course and/or altitude immediately" instruction be followed?

At what degree of icing should ICAO"s "Change of course and/or altitude desirable" recommendation be followed? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

(For this question use annex 050-4314A) Continuous freezing rain is observed at an airfield. Which of the four diagrams is most likely to reflect temperatures above the airfield concerned? 1 SWITZERL Which of the following PE +FZRA GR SHSN 0 -1 0 0 conditions is most likely to cause airframe icing ? 1 SWITZERL In which of these cloud NS CS AS SC 0 -1 0 0 types can icing be virtually ruled out? 1 SWITZERL In which of these cloud CU CI SC NS 0 -1 0 0 types can icing be virtually ruled out?

In which of these temperature bands is ice most likely to form on the aircraft"s surface?

You have been flying for some time in dense layered cloud. The outside air temperature is -25° C. Which of the following statements is true? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

Which of the following causes echoes on meteorological radar screens?

Going from the equator to the north pole, the altitude of the tropopause

What is the approximate speed of a 40-knot wind, expressed in m/sec?

What is the approximate speed of a 90 km/h wind, expressed in knots?

What is the approximate speed of a 25-knot wind, expressed in kilometres per hour? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

An airborne weather radar installation makes it possible to detect the location of hail

W hile approaching your target aerodrome you receive the following message: RVR runway 23: 400m This information indicates the

Which of the following cloud types is a medium level cloud ?

Which of the following cloud types is found at high levels? subject/sec aragraph wording Domanda rispostaA rispostaB rispostaC rispostaD ck1 ck2 ck3 ck4

A plain in Western Europe with an average height of 500 m (1600 FT) above sea level is covered with a uniform CC layer of cloud during the summer months. At what height above the ground is the base of this cloud to be expected?

A plain in Western Europe with an average height of 500 m (1600 FT) above sea level is covered with a uniform SC layer of cloud during the summer months. At what height above the ground is the base of this cloud to be expected?

Which of the following types of cloud can extend over the low, medium and high cloud levels ?

Which types of clouds are typical evidence of stable air conditions?

Which of the following statements is true of the dew point of an air mass?

In which environment is aircraft structural ice most likely to have the highest rate of accretion ?