Met

Question 1

effects of icing

Answer 1

aerodynamic
weight
flying controls
vision
vibration
blocked instruments
undercarriage
engine ice

For ALM main consideration is struts and general risks associated with ice

Question 2

what are the six types of icing

Answer 2

clear (slow forming, forging horns on leading edges and is very adhesive)

Rime (brittle so breaks off so no real problem)

packed snow

rain ice

hoar frost

engine ice (+5 danger zone, air pressure drops to around 0 degrees)

Question 3

effects of icing on an aircraft

Answer 3

aerodynamics
increased weight
control surfaces stick or jammed
pitot tubes blocked
undercarriage extension retraction problems
engine intakes blocked
communication is affected
vision reduced
possible vibrations due to uneven loading

Delays departures due to time it takes to de-ice.
On A400M it’s difficult to clear from tailplane due to its height.

Question 4

How does temperature affect Aircraft Operations?

Answer 4

# Engine performance (including WAT limits).
# Icing

Question 5

how does wind direction affect Aircraft Operations

Answer 5

deciding factor for which runway to use (aircraft take off and land into wind)

cross wind limitations

limitations operating aircraft ramp, door and stabilisers struts

Question 6

factors affecting severity of ice

Answer 6

droplet size
aircraft speed
aerofoil shape
temperature just Below Zero

Question 7

how is fog / mist created

Answer 7

as air cools below saturation point it creates mist and can be dispersed by heat or wind
(radiation or advection)

Question 8

What are the 2 most common types of fog in the U.K.?

Answer 8

Radiation fog

Advection fog

Question 9

what is radiation fog

Answer 9

very common type of fog, it is most prevalent during the autumn and winter

Forms overnight as the air near the ground cools and reaches saturation point

This type of fog requires clear skies and high humidity, with little or no wind.

Can be dispersed by the sun, wind or dry air

Question 10

what is advection fog

Answer 10

Forms when warm and moist air is blown across a cooler surface (land or water)

dispersed only when dry air replaces the humid air.

Examples of advection fog include San Francisco

Question 11

What is a METAR?

Answer 11

An hourly or half hourly observed weather conditions report and can include a trend

Question 12

what is a TAF

Answer 12

is a forecast valid for 9 hours updated every 3 hours

Question 13

in weather collection what is a SPECM and SPECB

Answer 13

SPECM Manky

SPECB Better

Question 14

what is a warm front

Answer 14

usually between 300-600 miles wide

slow moving and rises above cold front causing cloud development (due to frontal lifting)

Question 14

What are the trigger actions for clouds?

Answer 14

convection
orographic uplift
mass ascent / descent
mechanical turbulence -

Question 15

what is dew point

Answer 15

the temperature at which air would become saturated

Question 16

what is buy ballots law

Answer 16

if the wind is in your back then low pressure is on your left

Question 17

ice general information

Answer 17

ice needs a nucleus for water molecules to form

range for icing is + 52 - 20 degrees centigrade

freezing rain falls as water but as it hits an air frame forms ice

Question 19

what is an occluded front

Answer 19

cold front advancing through warm front until it reaches the next cold front

this forces the warm front to rise, this causes a triple point and is associated with heavy rain

as the warm front is lifted the occluded front slowly loses its energy and peters out

Question 20

what is a cold front

Answer 20

usually between 50-100 miles wide

fast moving and advances underneath the warmer front

this causes warm air to rise and thus cloud development

Question 21

what is a temperature inversion

Answer 21

a layer of warm air trapped between cooler layers

trapped pollutants can cause haze

flying above can give problems with horizontal visibility

flying below can cause ducting which causes trapping of radar waves and increasing their range

Question 22

How can you get a negative dew point?

Answer 22

Anegative dew pointsimply means the air is dry enough that it would havetobe cooledtothat very low temperature, in ordertocause moisturetobegintocondense out as ice crystals or supercooled water droplets.