Chapter 16: Visibility

Question 1

Obscurity

What Reduces Visibility (3)

Answer 1

Water droplets (clouds, fog, mist, spray, rain)
Ice
Particles (inversion, storm)

Question 2

Types of Obscurity (3)

Visibility, Altitude, Composition?

Answer 2

Fog < 1000 m @ GL
Mist 5000 < vis < 1001 m @GL
Haze 0 - 5000 m of solid particles

Question 3

Fog Types (7)

Answer 3

Radiation
Orographic
Frontal
Advection
Evaporation / Artic Sea Smoke / Steam Fog
Freezing Fog
Ice Fog

Question 4

Radiation Fog

Requirements (4), How High, Disperse Mechanism

Answer 4

Katabatic or Ground Inversion
Clear Skies (ground cools quickly)
High humidity
Light winds ( 2 - 8 kn)
500', up to 1000 - 1500' and disperse with heat

Question 5

Frontal Fog

Which Front, Where in Front

Answer 5

Warm front -> humid air from Ns falls in cold temperature -> fog ahead of front

Question 6

Advection and Evaporation Fog

Requirements

Answer 6

Advection: Warm moist air over cold surface
10 - 15 kn winds
Evaporation Fog: cold stable air over warm sea -> evaporation

Question 7

Freezing and Ice Fog

Answer 7

Freezing: SCWD fog

Ice Fog: Ice crystals

Question 8

Particle Obscurities (3)

Answer 8

Haze - particles
Smog - pollution
Dust Storm

Question 9

Dust Storm

Visibility? Wind Speed?

Answer 9

Heavy dust storm < 200 m
Moderate dust storm 200 - 600 m
Wind speed = 15 - 20 kn

Question 10

Last Obscurity (non precipitation related)

Answer 10

Sun Glare: sun glare, cloud reflection

Question 11

Air to Ground Visibility

How affected?

Answer 11

Slant visibility goes down as altitude goes down

i.e. better visibility from up top

Question 12

Visibility Reporting

What Visibility Reported? Steps of?

Answer 12

> 50% vis reported
and in case of low visibility for remaining 50%:
half of main vis or vis < 1500 m

0 - 800m -> steps 50 m
800 - 5000 -> steps 100 m
< 10 km -> steps 1 km

Question 13

RVR

What is? When Need RVR? How to Report Vis < 50m, Vis > 1500? Steps Of?

Answer 13

Runway Visual Range
when vis < 1500 m
M0050 = vis < 50 m
P1500 = vis > 1500 m

0 - 400 m -> steps 25
400 - 800 m -> steps 50
800+ -> steps 100

Question 14

RVR Measurement

Measurement Device? Where Positioned? How High? Update Frequency? Letters Attached to Report (3)?

Answer 14

Transmissometer
120 m parallel to RW
7.5'' above ground level
Updated 1 min, Metar avg 10 min
U = increasing, D = decreasing, N = no change

Question 15

CAT I

Min, DH, RVR, Gnd Vis?

Answer 15

Min: 200’
DH: 200’
RVR: 550 m
Gnd vis: 800 m

Question 16

Vertical Visibility

How to Report 200’ Vertical Visibility? Bad Vertical Visibility?

Answer 16

VV002 = 200’ vertical visibility

VV///