Chapter 16 - Visibility

Question 1

What is the visibility for Fog

Answer 1

less than 1000m

Question 2

What is the visibility for Mist

Answer 2

1000m or more

Question 3

What is the visibility for Haze

Answer 3

0 - 5000m

Question 4

Radiation Fog has 3 requirements and expected to develop at

Answer 4

All the heat radiates away over night because of clear skies.
Humidity High
2-8 knots of light winds

ground to 500ft
often isothermal fog layer

Question 5

Valley Fog is created

Answer 5

Is when the cold air katabtically drops into moist valley.

Question 6

Orographic Fog

Answer 6

Is cloud develop on top of hills but in contact with the surface

Question 7

Frontal Fog

Answer 7

Ahead of a warm front - after rain and surface is wet causing lots of evaporation

Question 8

Ice Fog

Answer 8

High latitude, dry air, ice crystals

Question 9

Ice Fog

Answer 9

High latitude, dry air, ice crystals

Question 10

Haze is from

Answer 10

Solid Particles

Question 11

Smog is from

Answer 11

Smoke and Fog

Question 12

Main visibility is measured how

Answer 12

Look out at objects with certain distances in a 360 degree process. has to be over 50% all round to give figure

Question 13

Secondary Visibility is

Answer 13

Less than 50% distance

Question 14

If up to 800m its reported in

Answer 14

50m steps

Question 15

If up to 800-5000m its reported in

Answer 15

100m steps

Question 16

If up to 10km its reported in

Answer 16

1 km steps

Question 17

9999 =

Answer 17

10km or more

Question 18

Runway Visual Range =

Answer 18

Surface visibility in direction of landing

Question 19

How and where is RVR measured

Answer 19

By a transmissometer (7 and a half feet up), situated at threshold (300m) , mid point (1000-1500m) and stop end.(300m) - done every 60 seconds

Question 20

How often are updates of RVR for ATC and METARS

Answer 20

ATC - averaged over 1 min

METAR - average over 10 mins

Question 21

If the Visibility has a U,D and N next to it what does it mean

Answer 21

Increasing Visibility = U
Decreasing Visibility = D
No change = N

Question 22

Vertical Visibility - is measured 100’s feet how is it presented for 200 feet

Answer 22

VV002

Question 23

To what is the difference between fog and mist compared to haze

Answer 23

humidity has to be high for fog and mist