Ice Accretion

Question 1

Hoar frost occurs on airframe in clear air when the temperature of airframe is

Answer 1

> (a) below the frost point
(b) frost point
(c) just above the frost point

Question 2

In clouds at temperatures below 0°C an aircraft may encounter icing of the type

Answer 2

(a) only Glazed
(b) only Rime
>(c) intermediate between these two

Question 3

Opaque Rime ice is

Answer 3

> (a) Light porous
(b) Solid
(c) Mixture of porous and solid

Question 4

Rime is formed by freezing of ………. supercooled water droplets on airframe when aircraft is flying through clouds

Answer 4

> (a) Small
(b) Large
(c) Medium

Question 5

Glazed ice is formed by freezing of ……… supercooled water droplets on airframe when aircraft is flying through clouds

Answer 5

(a) Small
>(b) Large
(c) Medium

Question 6

The ………. ice poses serious aviation hazard

Answer 6

(a) Rime
(b) Hoar Frost
>(c) Glazed

Question 7

Airframe icing occurs below 0°C. Its probability of occurrence decreases progressively below -20°C, as at lower temperatures the proportion of super-cooled water drops in a cloud

Answer 7

(a) Increases
>(b) Decreases
(c) Does not change

Question 8

CI, CS and CC clouds consist mostly ice crystals. Icing hazard is therefore

Answer 8

(a) Maximum
(b) Medium
>(c) Negligible

Question 9

AS, NS consist of supercooled water drops and ice crystals in varying proportion ……. icing is possible

Answer 9

(a) Maximum
?(b) Light or moderate
(c) Negligible

Question 10

In AC clouds …….. icing is possible in mountainous areas

Answer 10

(a) Light
(b) Moderate
>(c)Severe

Question 11

In TCU icing may range from light to severe type at least up to ……. level.

Answer 11

(a) -40°C level
(b) 30°C level
>(c)-20°C level

Question 12

In CB icing may range from light to severe type up to -20° C level. Below this temperature severe icing is

Answer 12

> (a) not significant
(b) significant
(c) maximum

Question 13

Liquid water content is an important factor in icing As the maximum water concentration is around ……… maximum ice formation in clouds may also be expected around that level.

Answer 13

(a) -25°C level
(b) -20°C level
>(c) -15°C level

Question 14

carburetor icing occurs when air from intake passes through a venturi (choke) and causes expansional cooling and vaporization of fuel. Serious icing can occur at extreme temperatures

Answer 14

(a)13°C
>(b) 30°C to -10°C
(c) 20°C

Question 15

…….. occurs in a moist cloudless air on an aircraft surface having temp. below 0°C , due to sublimation of water vapour onto feathery ice crystals.

Answer 15

(a) Rime
(b) Glazed
>(c) Hoar Frost

Question 16

……… occurs in St, Sc, Ac, Cu, NS at temperature -10 to -40°C and in Cb at temperature -20 to -40C

Answer 16

(a) Rime
(b) Glazed
>(c) Hoar Frost

Question 17

In clouds ……… occurs when a wide range of water drop sizes are present at temperatures between 0°C and -40°C

Answer 17

(a) Rime
(b) Glazed
>(c) Mixture of rime and clear ice

Question 18

………… occurs in AS, NS, AC and towering CU or CB between 00 C and —200 C, in warm front below 00 C, especially if the aircraft has rapidly descended from a colder region.
(a) Glazed
(b) Rime
(c) Mixture of Rime and Clear ice

Answer 18

(a) Glazed
(b) Rime
>(c) Mixture of Rime and Clear ice

Question 19

When fog freezes on parked aircraft it produces ………..

Answer 19

> (a) Hoar Frost
(b) Rime
(c) Clear ice

Question 20

Icing ……… the stalling speed appreciably

Answer 20

(a) Decreases
>(b) Increases
(c) Does not increase/decrease