Progress Test 8 Flashcards
(46 cards)
What is the difference between Flight visibility and Reported meteorological visibility?
Flight visibility is the visibility from the cockpit to clouds and haze.
Reported Meteorological visibility is what’s reported seen from the ground.
Haze is a build up of dust and smoke particles, what pressure system does this occur in?
A High pressure system.
Haze is particularly bad beneath the inversion layer, what effect does haze have on the pilots distance perspective?
Objects are actually closure than what is thought.
Areas below the haze are particularly dark, what effect can flying lower have on visibility?
Flying the lower can increases the visibility but also increase the risk.
True or False? Flying above the haze layers allows pilots to see through the haze, and allows clearer identification of airfields.
True.
Why does mist and fog effect visibility?
Because the suspended condensed water droplets reflect and refract light making vision through difficult, especially during sunrise.
What distance of visibility does mist occur?
Between 1000m and 5000m.
What distance of visibility does fog occur?
when the visibility is less than 1000m.
What is advection fog?
Caused when moist air moves over cooler surfaces causing the air temperature to drop leading to 100% relative humidity.
Where is advection fog normally found?
When moist air is being cooled by the sea and forms fog (sea fog), rivers and bodies of water are susceptible to fog.
Sea fog is present in quite strong winds, what effect does this have inland?
coastal areas can be effected for a few miles inland before the fog disperses into low cloud due to turbulent mixing.
what is radiation fog?
Radiation fog forms over land at night due to surface cooling, this is difficult to forecast accurately.
Radiation fog is air with higher moisture content and is likely to cool at it’s dew point, what is required for this to happen?
Clear and cloudless night, clouds create a thermal blanket and requires winds from 2-8kts. Less than 2kts dew is more likely and more than 1kts low cloud is more likely.
what is the cloud base for 8kts, 9kts and 10kts wind in radiation fog?
8kts = 800ft
9kts = 900ft
10kts = 1000ft
Katabatic winds can assist radiation fog, when is radiation fog most likely to occur?
Name Four ways.
Most likely to occur at dawn
Most likely to occur during the Autumn.
-Where the diurnal temperature variation is the greatest
More likely to occur in high pressure systems
Or when temperature or dew point is less than 2 degrees.
What is Frontal Fog?
Caused by warm or occluded frontal weather systems and occurs just ahead.
How is frontal fog formed?
Rain ahead of the frontal fog falls and saturates the air beneath it causing fog to form. Distinction between cloud and fog can be difficult and an indistinct cloud base.
What is hill fog?
Cloud covering a hill.
What are the effects on visibility in the rain?
Name 3 effects.
-Visibility is reduced
-Lights at night can reflect light making vision difficult
-Effects distance judgment
What is the effects on visibility of drizzle?
-Results in visibility of 3000m or less
-Can dramatically reduce visibility as stationary droplets can effect vision on the windshield.
What is the effect on visibility of snow?
-Can result in no visibility
-can build up on the airframe and windshield
-can freeze controls
How can hail effect flight?
-Very noisy
-can cause severe airframe damage
How can flight into sunlight effect visibility?
Flying into the sun can effect visibility
-Objects can reflect into the pilots eyes
How can the moonlight effect visibility?
Visibility can be increased when heading into the moonlight. Makes objects stand out more.
