DGCA Meteorology: Ice Accretion Questions
62 exam-style Ice Accretion questions for the DGCA Meteorologypaper (CPL & ATPL). The first 12 are free below with answers and explanations — sign up free to practise all of them with progress tracking.
- Q1
Rime is formed by freezing of ____ supercooled water droplets on airframe when air is flying through clouds
- ASmall
- BLarge
- CMedium
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Correct answer: A. Small
Rime forms when small supercooled droplets freeze almost instantly on impact, trapping air between the frozen droplets and giving a rough, opaque, brittle deposit; large droplets spread before freezing and produce clear ice instead.
- Q2
Airframe icing typically:
- AIncreases stalling speed
- BDecreases stalling speed
- CNo effect on speed
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Correct answer: A. Increases stalling speed
Ice on wings messes with lift, so the plane stalls at a higher speed.
- Q3
In which of these cloud types can icing be virtually ruled out?
- ACU
- BCI
- CSC
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Correct answer: B. CI
Cirrus consists almost entirely of ice crystals, which bounce off the airframe rather than adhering, so airframe icing can be virtually ruled out; icing requires supercooled liquid water such as found in cumulus or stratocumulus.
- Q4
Opaque Rime ice is
- ALight porous
- BSolid
- CMixture of porous and solid
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Correct answer: A. Light porous
Opaque rime is light and porous because the small supercooled droplets freeze instantly on impact, trapping air pockets between them; solid, dense deposits are characteristic of clear ice from large droplets.
- Q5
Airframe icing is most likely at temperatures:
- AAbove +10°C
- B0°C to -10°C
- CBelow -40°C
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Correct answer: B. 0°C to -10°C
Icing happens most in 0°C to -10°C, where supercooled droplets freeze on impact.
- Q6
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?
- AStratocumulus and cirrostratus
- BStratus and cumulonimbus
- CAltocumulus and altostratus.
Show answer
Correct answer: C. Altocumulus and altostratus.
Altocumulus and altostratus are mid-level layer clouds frequently composed of supercooled droplets, typically giving light to moderate icing. Cirrostratus is ice crystal cloud with negligible icing, while cumulonimbus produces severe rather than light icing.
- Q7
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?
- AStratocumulus and cirrostratus
- BStratus and cumulonimbus
- CAltocumulus and altostratus.
Show answer
Correct answer: C. Altocumulus and altostratus.
Altocumulus and altostratus containing supercooled droplets typically give light to moderate icing; cirrostratus is composed of ice crystals with little icing risk, and cumulonimbus gives severe icing rather than light to moderate.
- Q8
Heavy icing is possible in
- ACI
- BCB
- CCS
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Correct answer: B. CB
Cumulonimbus carries the risk of heavy icing, since its strong updraughts hold large concentrations of big supercooled droplets that form clear ice rapidly; cirrus and cirrostratus are ice-crystal clouds with little icing.
- Q9
Large supercooled water drops, which freeze on impact on an aircraft, form
- Arime ice
- Bhoar frost
- Ccloudy ice
- Dclear ice
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Correct answer: D. clear ice
This Explanation is Coming Soon
- Q10
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?
- AAircraft T experiences more icing than S
- BAircraft S and T experience the same amount of icing
- CNeither of the aircraft accumulate ice due to the small size of droplets
- DAircraft S experiences more icing than T
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Correct answer: D. Aircraft S experiences more icing than T
This Explanation is Coming Soon
- Q11
Supercooled droplets can be encountered
- Aonly in winter above 10000 FT
- Bonly in winter at high altitude
- Cat any time of the year
- Din winter only in high clouds
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Correct answer: C. at any time of the year
This Explanation is Coming Soon
- Q12
Freezing precipitation occurs
- Aonly in the precipitation of a cold front
- Bonly in the precipitation of a warm front
- Cmainly in the form of freezing hail or freezing snow
- Dmainly in the form of freezing rain or freezing drizzle
Show answer
Correct answer: D. mainly in the form of freezing rain or freezing drizzle
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