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CAA NZ CPL Meteorology study materials
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CAA NZ CPL Meteorology practice questions

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Question 1Aviation weather products

On a New Zealand MetService aviation forecast chart, what does the abbreviation 'SIGMET' specifically indicate?

  1. A short-term aerodrome forecast valid for nine hours
  2. Information issued for the safety of aircraft concerning hazardous en-route weather and other phenomena Correct answer.
  3. A routine forecast of upper winds and temperatures for a flight level
  4. A notice to airmen about aerodrome works in progress

Explanation

A SIGMET is issued to warn en-route aircraft of hazardous weather such as severe turbulence, icing, volcanic ash or severe convective activity. It is not a routine forecast product but a safety warning concerning phenomena that may affect a flight's safety.

Question 2Aviation weather products

In a New Zealand TAF, the group 'TEMPO' preceding a period indicates what?

  1. A forecast that has been cancelled and replaced
  2. A permanent change becoming the prevailing condition
  3. Conditions that will occur at least half of the stated period
  4. Temporary fluctuations expected to last less than one hour in total Correct answer.

Explanation

TEMPO denotes temporary fluctuations of conditions that are expected to last for less than one hour in each instance and, in total, for less than half of the indicated period. The prevailing conditions outside those fluctuations remain as previously forecast.

Question 3Aviation weather products

What does the term 'BECMG' signify when it appears in a TAF?

  1. An immediate and permanent change at a single stated time
  2. A temporary fluctuation lasting less than one hour
  3. A probability group indicating a 30 percent chance
  4. A gradual change during the stated period to new prevailing conditions Correct answer.

Explanation

BECMG indicates that conditions are expected to change gradually during the stated period and then become the new prevailing conditions. The change occurs over a transition period rather than at an instantaneous time.

Question 4Aviation weather products

On a New Zealand low-level significant weather chart, what does the term 'SFC VIS' refer to?

  1. The surface wind speed in knots
  2. The vertical visibility at the top of a cloud layer
  3. Surface visibility, the horizontal visibility at ground level Correct answer.
  4. The height of the surface above mean sea level

Explanation

SFC VIS denotes surface visibility, the horizontal distance at ground level that a pilot can see. It is distinct from vertical visibility, which describes how far one can see upward into a cloud or obscuration.

Question 5Aviation weather products

What is the primary purpose of a METAR issued for a New Zealand aerodrome?

  1. To report observed weather conditions at the time of observation Correct answer.
  2. To warn of volcanic ash along the route
  3. To provide upper wind and temperature data
  4. To forecast conditions for the next 24 hours

Explanation

A METAR is a routine aviation weather report of observed conditions at an aerodrome at the time of observation. It describes what the weather is doing now, not what is forecast.

Question 6Aviation weather products

In a METAR, the group '27015G30KT' indicates which wind condition?

  1. Wind to 270 degrees at 15 knots with a variation of 30 degrees
  2. Wind from 270 degrees varying between 15 and 30 knots
  3. Wind from 270 degrees at 15 knots with 30 knots of crosswind
  4. Wind from 270 degrees at 15 knots gusting to 30 knots Correct answer.

Explanation

The first three digits give the direction the wind is coming from in degrees true, the next two give the mean speed in knots, and the G group gives the gust speed. Thus 27015G30KT means wind from 270 degrees, 15 knots gusting 30 knots.

Question 7Aviation weather products

What does a 'QNH' value represent in an aviation weather report?

  1. The actual station pressure at the aerodrome reference point
  2. The aerodrome pressure reduced to mean sea level using the standard atmosphere Correct answer.
  3. The pressure setting used above the transition altitude
  4. The pressure at the transition level during climb

Explanation

QNH is the aerodrome pressure reduced to mean sea level assuming standard atmosphere conditions, and when set on the altimeter subscale it causes the altimeter to indicate aerodrome elevation on the ground. It is not the actual station pressure.

Question 8Aviation weather products

On an aviation forecast chart, what does the abbreviation 'ISOL' describe?

  1. A line of thunderstorms along a front
  2. A layer of stratiform cloud covering most of the area
  3. Isolated convective activity covering less than half the area Correct answer.
  4. Isolated embedded cumulonimbus within a broader cloud area

Explanation

ISOL is used to describe isolated convective activity, generally meaning coverage of less than about half of the forecast area. It is a coverage descriptor for phenomena such as thunderstorms or showers.

Question 9Aviation weather products

A pilot reads a TAF that includes a PROB30 group. What does this indicate?

  1. Conditions will definitely occur for 30 minutes
  2. A 30 percent probability that the associated conditions will occur Correct answer.
  3. Wind direction will vary by 30 degrees
  4. The forecast is only 30 percent reliable overall

Explanation

PROB30 indicates a 30 percent probability of the associated conditions occurring during the stated period. It is a probability qualifier attached to a change group, not a statement of forecast reliability or duration.

Question 10Aviation weather products

On a grid point wind and temperature chart, what do the plotted wind arrows and figures represent at a nominated flight level?

  1. Observed wind at the time the chart was issued
  2. Surface wind expected at the chart valid time
  3. Forecast wind direction and speed with temperature for that level Correct answer.
  4. Actual wind measured by the nearest radiosonde only

Explanation

Grid point wind and temperature charts present forecast wind direction and speed, along with temperature, for specified flight levels and valid times. They are forecast products for flight planning, not records of observed conditions.

Question 11Aviation weather products

What is the significance of the 'valid time' shown on an aviation forecast chart?

  1. The time by which the chart must be discarded
  2. The time of the most recent observation used
  3. The time at which the chart was issued to users
  4. The time for which the forecast conditions are expected to apply Correct answer.

Explanation

The valid time is the period for which the forecast conditions are expected to apply. Pilots must compare their planned flight time with the valid period to ensure they are using the chart for the correct period.

Question 12Aviation weather products

A SIGMET is issued for severe turbulence. What does 'severe turbulence' mean in this context?

  1. Turbulence causing large, abrupt changes in altitude or attitude with large variations in indicated airspeed Correct answer.
  2. Light chop felt only occasionally during cruise
  3. Turbulence occurring only within cloud
  4. Mechanical turbulence near buildings on the ground

Explanation

Severe turbulence produces large, abrupt changes in altitude or attitude and large variations in indicated airspeed, and may cause the aircraft to be momentarily out of control. It is a hazard level requiring a SIGMET warning.

Question 13Aviation weather products

A pilot planning a flight notices a SIGMET for volcanic ash on the route. What is the appropriate operational response?

  1. Continue as planned because SIGMETs are advisory only
  2. Avoid the affected area and plan a route clear of the ash cloud Correct answer.
  3. Reduce speed and proceed through the ash at low level
  4. Fly through at high level because ash is lighter than air

Explanation

Volcanic ash is a serious hazard to aircraft engines and airframes, and a SIGMET for ash requires avoidance of the affected area. The correct response is to plan around the ash cloud and remain clear of it.

Question 14Aviation weather products

In a TAF, the group 'FM1200' means what?

  1. The forecast becomes valid at 1200 UTC for the first time
  2. At 1200 UTC the forecast is cancelled
  3. Between 1200 and 1300 UTC, temporary conditions occur
  4. From 1200 UTC, conditions change to those following the group Correct answer.

Explanation

FM indicates a rapid, usually permanent change to new prevailing conditions beginning at the stated time. The conditions following FM1200 become the prevailing conditions from 1200 UTC onward.

Question 15Aviation weather products

How should a pilot interpret a METAR group showing 'BKN008'?

  1. Broken cloud with a base at 800 feet above aerodrome level Correct answer.
  2. Few cloud at 8,000 feet
  3. Sky obscured with vertical visibility of 800 feet
  4. Broken cloud with tops at 800 feet

Explanation

BKN denotes broken cloud cover, and the three-digit figure gives the height of the cloud base in hundreds of feet above aerodrome level. Thus BKN008 means a broken layer with base at 800 feet.

Question 16Aviation weather products

On a New Zealand significant weather chart, what does the abbreviation 'OCNL' indicate?

  1. Isolated activity covering less than half the area
  2. Continuous activity covering the entire area
  3. A single isolated thunderstorm
  4. Occasional convective activity, generally covering between half and three-quarters of the area Correct answer.

Explanation

OCNL describes occasional convective activity, generally meaning coverage of between about half and three-quarters of the forecast area. It sits between ISOL (less than half) and FRQ (widespread) on the coverage scale.

Question 17Aviation weather products

What information does an aerodrome forecast (TAF) provide that a METAR does not?

  1. The current aerodrome pressure setting
  2. Observed conditions at the time of issue
  3. The current runway in use
  4. Forecast conditions expected during a future validity period Correct answer.

Explanation

A TAF forecasts the expected conditions for a future validity period, whereas a METAR reports conditions observed at the time of issue. The two products serve complementary but distinct purposes.

Question 18Aviation weather products

A pilot sees a chart annotation of a 'trough' over the area. What weather is typically associated with a trough?

  1. Clear skies and descending air
  2. Steady high pressure with no change
  3. Unsettled weather with cloud and precipitation along the trough line Correct answer.
  4. Calm winds and no cloud

Explanation

A trough is an elongated area of relatively low pressure where air tends to converge and rise, producing cloud and precipitation along its axis. It is associated with unsettled weather rather than clear, descending conditions.

Question 19Aviation weather products

In a METAR, the group 'R24/0600' reports what?

  1. Runway 24 elevation of 600 feet
  2. Runway 24 braking action of 6
  3. Runway 24 visual range of 600 metres Correct answer.
  4. Runway 24 wind direction of 060 degrees

Explanation

The R group reports runway visual range, with the runway designator followed by the range in metres. R24/0600 therefore indicates a runway 24 visual range of 600 metres.

Question 20Aviation weather products

When a SIGMET is issued for severe icing, what does 'severe icing' mean?

  1. Icing that poses a serious hazard and may require immediate avoidance Correct answer.
  2. Ice accretion that has no effect on performance
  3. Light rime ice forming on the leading edge
  4. Frost forming on the ground before flight

Explanation

Severe icing is an icing intensity that constitutes a serious hazard to flight and may require immediate avoidance action. It is a SIGMET-worthy phenomenon because it can rapidly degrade aircraft performance.

Question 21Aviation weather products

A pilot compares a TAF with a METAR for the same aerodrome and finds the observed conditions differ markedly from the forecast. What is the most appropriate interpretation?

  1. The TAF is invalid and should be disregarded entirely
  2. The METAR should be used as a forecast for the next 9 hours
  3. The METAR must be in error because forecasts are always more accurate
  4. The forecast was for a different valid period, so the observed conditions may not match the forecast expectation Correct answer.

Explanation

A TAF forecasts conditions for a future validity period, so observed conditions at a given moment may differ from the forecast expectation. Discrepancies should prompt the pilot to reassess the current and expected conditions using the latest reports and forecasts.

Question 22Aviation weather products

On a significant weather chart, a forecast area is marked with 'EMBD'. What does this indicate?

  1. Widespread fog over the area
  2. A squall line along a front
  3. Convection embedded within a broader cloud layer and possibly obscured Correct answer.
  4. A single isolated thunderstorm

Explanation

EMBD indicates embedded convection, meaning convective cloud hidden within a larger cloud layer so that it may not be visible to the pilot. This is operationally significant because the hazard may not be apparent visually.

Question 23Aviation weather products

An AIRMET is issued for a phenomenon that does not meet SIGMET criteria. What is the operational significance of an AIRMET compared with a SIGMET?

  1. AIRMET and SIGMET are identical in scope and criteria
  2. AIRMET covers moderate hazards affecting low-level flights, while SIGMET covers severe hazards Correct answer.
  3. AIRMET covers severe hazards and SIGMET covers moderate ones
  4. AIRMET is only issued for volcanic ash

Explanation

An AIRMET warns of moderate hazards, such as moderate turbulence or icing, that may affect low-level flights, whereas a SIGMET is reserved for severe hazards. The distinction lies in the severity and the criteria for issuance.

Question 24Aviation weather products

A pilot reads a TAF with a validity period of 24 hours and a PROB40 TEMPO group. How should the pilot use this information?

  1. Expect the temporary conditions to last the entire period
  2. Treat the group as a permanent change to the stated conditions
  3. Expect a 40 percent chance of temporary fluctuations during the stated period and plan accordingly Correct answer.
  4. Disregard the group because probabilities are not operationally relevant

Explanation

PROB40 TEMPO indicates a 40 percent probability of temporary fluctuations during the stated period, which the pilot should consider as a possibility when planning. It does not mean the conditions will definitely occur or persist.

Question 25Aviation weather products

Why are METAR observations at New Zealand aerodromes typically issued at half-hourly or hourly intervals?

  1. To provide long-term climate records
  2. To satisfy international requirements for daily weather summaries
  3. To replace the need for aerodrome forecasts
  4. To provide frequent updates of current conditions for operational decision-making Correct answer.

Explanation

Routine METARs are issued at frequent intervals so pilots and operators have up-to-date observations of current conditions for take-off and landing decisions. The frequency supports operational decision-making rather than climate record-keeping.

Question 26Aviation weather products

A METAR contains 'QNH 1013'. What does this value represent?

  1. The pressure altitude of the aerodrome at the time of observation
  2. The aerodrome pressure reduced to mean sea level using the standard atmosphere
  3. The altimeter setting that would read aerodrome elevation on the ground Correct answer.
  4. The actual station pressure at the aerodrome reference point

Explanation

QNH is the altimeter subscale setting that makes the altimeter indicate aerodrome elevation when the aircraft is on the ground. It is sea-level pressure derived from station pressure using the ISA temperature profile, not the raw station pressure.

Question 27Aviation weather products

On an aviation forecast chart, the abbreviation 'ISOL' describes which expected coverage of a phenomenon?

  1. Scattered coverage of 50 to 75 percent of the area
  2. Isolated cells covering less than about 50 percent of the area Correct answer.
  3. Widespread coverage over more than 75 percent of the area
  4. Occasional occurrence with no defined spatial coverage

Explanation

ISOL denotes isolated activity, conventionally less than about half of the forecast area affected. It is a spatial coverage term, distinct from OCNL, which describes frequency in time rather than area.

Question 28Aviation weather products

A TAF includes the group 'PROB30'. How should the pilot interpret this?

  1. The conditions will persist for 30 minutes within the validity period
  2. There is a 30 percent probability the stated conditions will occur during the group's time window Correct answer.
  3. The forecast has a 30 percent chance of being issued incorrectly
  4. Thirty percent of the forecast area will experience the conditions

Explanation

PROB30 is a probability group meaning a 30 percent likelihood of the associated conditions occurring within the stated period. It is not a duration, an area fraction, or a measure of forecast accuracy.

Question 29Aviation weather products

On a New Zealand significant weather chart, the abbreviation 'OCNL' indicates which characteristic of the depicted activity?

  1. Occasional occurrence, meaning the phenomenon is frequent but not continuous Correct answer.
  2. Overcast cloud covering the entire area
  3. Orographic cloud forming on the ranges
  4. Occluded front crossing the area

Explanation

OCNL means occasional, describing activity that occurs frequently but not continuously in time. It is a frequency descriptor and should not be confused with cloud-cover or frontal abbreviations.

Question 30Aviation weather products

In a TAF, the change group 'FM1200' means what?

  1. From 1200 UTC a new set of conditions replaces the previous ones Correct answer.
  2. The forecast becomes valid at 1200 UTC and expires at 1200 UTC the next day
  3. At 1200 UTC the previous conditions will cease with no replacement
  4. Between 1200 and 1300 UTC conditions will be temporarily as stated

Explanation

FM marks a rapid, persistent change: from the stated time onward the new conditions apply until superseded. It differs from TEMPO and BECMG, which describe temporary or gradual changes within the existing forecast.

Question 31Aviation weather products

A METAR reports 'BKN008'. How should the pilot interpret this?

  1. Broken cloud at 8,000 ft above aerodrome level
  2. Broken cloud with a top of 800 ft above mean sea level
  3. Broken cloud with a base of 800 ft above aerodrome level Correct answer.
  4. Broken cloud with bases at 800 m above mean sea level

Explanation

Cloud heights in METAR are coded in hundreds of feet above aerodrome level, so BKN008 is a broken layer based at 800 ft. The three-digit group is always hundreds of feet and is referenced to the aerodrome, not mean sea level.

Question 32Aviation weather products

A pilot compares a TAF with a METAR for the same aerodrome and finds the observed conditions differ markedly from the forecast. What is the correct interpretation?

  1. The forecast has verified poorly and the observation should be treated as current reality Correct answer.
  2. The difference is due to the TAF being in local time and the METAR in UTC
  3. The TAF must be reissued before the flight can depart
  4. The METAR is invalid and the TAF should be used for planning

Explanation

A METAR reports actual observed conditions, while a TAF is a forecast that can be wrong. The pilot should plan on the observation for current conditions and treat the forecast as guidance for later.

Question 33Aviation weather products

On a significant weather chart, a forecast area is marked 'EMBD'. What does this indicate?

  1. The hazard is embedded within cloud and not visible to the eye Correct answer.
  2. The hazard is embedded only over mountainous terrain
  3. The hazard is embedded in a frontal zone
  4. The hazard is expected to dissipate within the validity period

Explanation

EMBD means embedded: the phenomenon, typically cumulonimbus or turbulence, is hidden within other cloud and cannot be seen visually. This matters because the hazard may not be detectable by eye and requires other avoidance strategies.

Question 34Aviation weather products

An AIRMET is issued for a phenomenon that does not meet SIGMET criteria. What is the operational significance of an AIRMET?

  1. It warns of conditions that may affect low-level or light aircraft but are not severe enough for a SIGMET Correct answer.
  2. It cancels all SIGMETs for the same area
  3. It is issued only for volcanic ash and tropical cyclones
  4. It is advisory information with no operational relevance

Explanation

An AIRMET advises of weather that may be significant to light or low-level operations but below SIGMET thresholds. It remains operationally relevant even though it is not a SIGMET.

Question 35Aviation weather products

A pilot reads a TAF with a 24-hour validity and a PROB40 TEMPO group. How should the pilot use this information?

  1. Assume the temporary conditions will occur at some point during the 24 hours
  2. Plan for a 40 percent chance of temporary conditions within the group's stated period Correct answer.
  3. Ignore the group because probabilities are not operationally useful
  4. Treat the temporary conditions as the prevailing forecast for the whole period

Explanation

PROB40 TEMPO combines a 40 percent probability with a temporary fluctuation, so the pilot plans for a chance of brief deterioration within the stated window. It does not mean the conditions will certainly occur, nor that they prevail for the full validity.

Question 36Aviation weather products

A pilot is planning a night flight and the TAF shows 'TEMPO 2000 BR' during the flight window. What does this indicate?

  1. Temporary temperature of plus 2 degrees Celsius
  2. Temporary cloud base of 2,000 ft with rain
  3. Temporary wind of 200 degrees at 2,000 kt
  4. Temporary visibility of 2,000 m in mist Correct answer.

Explanation

In a TAF, a four-digit group such as 2000 followed by BR denotes visibility in metres with mist. BR is the code for mist, and the figure is a visibility, not a cloud base or wind value.

Question 37Aviation weather products

A pilot notes that a SIGMET for a tropical cyclone has been issued for the region. What information does the SIGMET provide that a routine TAF does not?

  1. The QNH at the destination at the forecast time
  2. The position, intensity and movement of the cyclone as a hazard to flight Correct answer.
  3. The expected aerodrome cloud base during the cyclone
  4. The runway in use at the destination aerodrome

Explanation

A SIGMET warns of significant en-route hazards such as tropical cyclones, giving position, intensity and movement. Aerodrome-specific forecast details like cloud base, runway and QNH are TAF or aerodrome forecast content.

Question 38Aviation weather products

On a significant weather chart, an area is marked with a hatched region and the label 'CB'. What does this depict?

  1. Areas of clear air with no cloud
  2. Areas of stratocumulus with light drizzle
  3. Areas of cumulonimbus cloud with associated hazards such as icing and turbulence Correct answer.
  4. Areas of cirrus with no operational significance

Explanation

CB marks cumulonimbus, and significant weather charts highlight associated hazards including icing, turbulence and hail. Stratocumulus, clear air and cirrus are not depicted as CB areas.

Question 39Aviation weather products

A pilot notices that a TAF for the destination has a validity period ending before the planned arrival time. What is the correct action?

  1. Obtain a more current forecast covering the arrival time Correct answer.
  2. Use the METAR at departure as the arrival forecast
  3. Assume conditions will remain unchanged after the TAF expires
  4. Use the TAF as valid for arrival since it is the latest available

Explanation

A TAF applies only within its stated validity, so arrival after expiry requires a more current forecast. Extrapolating beyond validity or using a departure observation as an arrival forecast is not sound planning.

Question 40Aviation weather products

A pilot must decide between two alternate aerodromes, one with a SIGMET for severe icing and one with an AIRMET for moderate turbulence. Which statement best reflects the operational priority?

  1. The AIRMET aerodrome is more hazardous because AIRMETs are issued more frequently
  2. Both products have equal hazard weight, so either alternate is equally suitable
  3. The SIGMET aerodrome presents the greater hazard because SIGMET criteria denote severe conditions Correct answer.
  4. Neither product affects alternate selection since both are advisory only

Explanation

SIGMETs are issued for severe hazards such as severe icing, while AIRMETs cover less severe phenomena. The severe icing SIGMET therefore represents the greater threat and should weigh more heavily in alternate selection.

Question 41Aviation weather products

A pilot reads a METAR with 'WS RWY24' appended. What does this indicate?

  1. Wind shear has been reported on runway 24 Correct answer.
  2. Runway 24 is closed due to works
  3. Runway 24 surface wind is 24 kt
  4. Windsock at runway 24 is serviceable

Explanation

The WS group with a runway designator reports wind shear on that runway, a significant hazard for approach and departure. It is not a closure, a surface wind speed or a serviceability note.

Question 42Aviation weather products

A pilot is analysing a forecast chart where a cold front is expected to cross the route during the flight. Which weather sequence is most consistent with the passage of the front?

  1. Steady drizzle with rising temperature and no wind change
  2. Persistent fog with rising pressure and light winds
  3. A wind shift with squally showers, then clearing and a temperature fall Correct answer.
  4. Gradual clearing with falling temperature and no wind change

Explanation

A cold front typically brings a marked wind shift, squally showers or thunderstorms, followed by clearing and a fall in temperature as colder air arrives. Steady drizzle with rising temperature is more typical of a warm front.

Question 43Aviation weather products

A pilot is reviewing a TAF that includes both a BECMG group and a TEMPO group for the same period. How should these be interpreted together?

  1. Both groups describe the same conditions and are redundant
  2. The BECMG conditions will gradually become established, while the TEMPO conditions are brief fluctuations within that period Correct answer.
  3. The BECMG group cancels the TEMPO group once the change is complete
  4. The TEMPO group overrides the BECMG group entirely

Explanation

BECMG describes a gradual, permanent change to new prevailing conditions, while TEMPO describes temporary fluctuations that may occur within the period. They are complementary, not mutually cancelling, and both must be considered.

Question 44Aviation weather products

A New Zealand METAR includes the remark 'RMK RF00.0/000.0'. What does this report tell the pilot?

  1. Rainfall recorded since the previous observation and since 0900 local time Correct answer.
  2. The runway friction coefficient measured on the main runway
  3. The rate of fuel burn reported by the last departing aircraft
  4. The relative humidity and dew point depression at the aerodrome

Explanation

New Zealand METARs carry supplementary rainfall data in the RMK section, expressed as rainfall in millimetres over two periods: since the last observation and since 0900 local time. The two figures are separated by a slash, so RF00.0/000.0 means no measurable rain in either period. This is climatological supplementary information and has no bearing on runway condition or aircraft performance.

Question 45Aviation weather products

A pilot wants the most frequent routine weather report available for a New Zealand aerodrome during a busy operational period. Which product should be consulted?

  1. The aerodrome METAR, issued at half-hourly or hourly intervals Correct answer.
  2. The area forecast, issued twice daily
  3. The SIGMET, issued when phenomena reach the required threshold
  4. The aerodrome TAF, issued four times daily

Explanation

The METAR is the routine aerodrome observation and is issued at half-hourly or hourly intervals at New Zealand aerodromes, so it gives the most frequent and most current picture of actual conditions. A TAF is a forecast, not an observation, and is issued far less often. Area forecasts and SIGMETs cover wider areas or specific hazardous phenomena rather than frequent single-aerodrome observations.

Question 46Aviation weather products

A TAF for a New Zealand aerodrome contains the group 'BECMG 1418/1420 3000 SHRA BKN012'. How should the pilot interpret this?

  1. There is a 30 percent probability of 3000 m visibility in rain showers between 1800 and 2000
  2. Conditions will persist at 3000 m visibility in rain showers for the whole period from 1400 to 2000
  3. Conditions are expected to become 3000 m visibility in rain showers with broken cloud at 1200 ft, with the change occurring gradually within the two-hour window Correct answer.
  4. Conditions will temporarily reach 3000 m visibility in rain showers between 1800 and 2000, then revert

Explanation

BECMG indicates a gradual, permanent change to the new conditions, and the time group 1418/1420 gives the window within which that change is expected to occur. The elements after the time group are the conditions that will prevail once the change is complete. Unlike TEMPO, the new conditions are not expected to revert to the previous ones.

Question 47Aviation weather products

A pilot is checking a SIGMET for a route and sees that it covers embedded cumulonimbus with tops above FL300. Which operational conclusion follows most directly?

  1. The pilot may treat the SIGMET as advisory only, since SIGMETs are not binding
  2. The pilot should expect the cumulonimbus to remain below FL200 and dissipate within the hour
  3. The pilot should plan to avoid the area vertically or laterally, because the hazard exceeds the capability of the aircraft to overtop it Correct answer.
  4. The pilot may plan to overfly the area provided the aircraft can reach FL310

Explanation

A SIGMET advises of hazardous en-route weather that may affect flight safety, and embedded cumulonimbus is one of the phenomena for which it is issued. If the tops are forecast above FL300, overtopping is impractical for most light aircraft, so avoidance in the lateral or vertical plane is the sensible planning outcome. The report is information to be acted on, not a clearance or an advisory that can be ignored.

Question 48Aviation weather products

A pilot is reviewing a low-level significant weather chart and sees an area annotated 'TURB MOD'. How should this be read?

  1. Occasional moderate turbulence is expected within the delineated area Correct answer.
  2. Turbulence is expected to be limited to the surface layer
  3. Moderate turbulence is reported as occurring at the time of the chart
  4. Moderate turbulence is expected only above the chart's upper level

Explanation

On significant weather charts, intensity descriptors such as MOD describe the expected severity, and the label applies to the delineated area for the validity period of the chart. The chart is a forecast product, so the annotation describes expected turbulence rather than an observation. Coverage qualifiers such as ISOL, OCNL and FRQ describe how much of the area is affected.

Question 49Aviation weather products

A pilot receives a METAR showing '12005KT 090V150' and a separate remark of 'WS TKOF RWY09'. How should these two items be used together during the take-off briefing?

  1. The wind is light but variable in direction, and windshear has been reported on take-off for runway 09, so the pilot should expect possible shear despite the light mean wind Correct answer.
  2. The wind is gusting to 15 kt and the shear remark refers to the landing direction only
  3. The variable direction range means the wind is calm and the shear remark can be disregarded
  4. The wind is from 120 degrees at 5 kt and the shear remark confirms that runway 09 is closed

Explanation

The group 090V150 gives the range of direction variation, while 12005KT shows a light mean wind, so the pilot knows the direction is varying but the speed is low. The WS TKOF RWY09 remark is a report of windshear affecting take-off on runway 09, which is operationally significant even with a light mean wind. The two items must be considered together in the take-off briefing.

Question 50Aviation weather products

A pilot is planning a flight and finds that the only available forecast for the destination is a TAF whose validity period ends two hours before the planned arrival. What is the most appropriate course of action?

  1. Assume the last forecast conditions in the TAF will persist unchanged until arrival
  2. Extend the TAF validity period by adding the planned flight time to the end of the period
  3. Use the TAF as issued, since a forecast remains valid until a new one replaces it
  4. Obtain a more recent TAF or an amended forecast covering the arrival time, or plan on the basis that the forecast does not cover the arrival period Correct answer.

Explanation

A TAF is only a forecast for the period it states, and beyond that period it provides no forecast information at all. The pilot must therefore seek updated or amended guidance covering the arrival time, or accept that the arrival weather is not forecast by that product. Assuming persistence beyond the validity period is not supported by the product.