HAZARDS TO FLIGHT Flashcards
List some problems caused by flying through ash cloud
- engine flame out
- Erosion of blades/engine parts
- blockage of pitot tubes
- poor radio reception
- Poor visibility
- St Elmo’s fire
What are the 5 types of warnings issued wrt volcanic activity in NZ
- The volcanic alert level system
- The ICAO colour code system
- Volcanic ash advisory message
- SIGMETs
- NOTAMs
What are the current active volcanoes in NZ?
White Island
Mt Ruapehu
If a volcano is at alert level 1 in NZ, what is the danger zone coverage
radius of 3nm and 3000ft centered on the vent.
What is the issue of volcanic ash & dust vs. weather radars?
Dry, wx radars will not receive a return from volcanic ash & dust. Nothing will display.
What to do in the case of inadvertent flight into ash
- reduce power to idle
- exit ASAP: 180 deg descending turn as terrain allows. (do not attempt to climb out
- Turn on all anti ice systems, conditioning packs, APU, continuous ignition.
- restart engine if rqd.
Define blowing snow
A blizzard which consists of snow particles that are raised from a snow covered SFC by wind.
What does threshold wind speed for blizzard depend on?
-temps
-size & shape of snow particles
-age of snow
Wind threshold for new vs. old snow?
New: 10kts
Old: up to 40kts
How high can a blizzard reach?
VIs?
up to 100ft AGL (due to how stable the environment is in cold places).
Vis down to 0m
Where in NZ would you expect to see a blizzard?
North island: central ranges.
South island: Alps
What environments are dust storms associated with?
What does this have to do with the characteristics of dust storms? Accentuated by?
Hot & dry, therefore unstable.
Unstable environment, therefore DS can reach up to several thousand feet.
Aggravated by cold fronts forcing the dust up & over advancing wedge of cold air.
Where would we expect dust storms in NZ?
Very rare, can get weak ones on eastern side of the ranges in a gusty NW flow. E.g. canterbury plains.
Issues to aviation in duststorms?
Reduced vis & loss of horizon
When does whiteout occur
In uniformly overcast condxns over a snow covered SFC.
What does whiteout cause & why
Lack of SFC and horizon definition due to diffuse, shadowless illumination.
How does whiteout affect our senses?
Causes spatial disorientation & impaired distance judgement;
- lack of distance perception
- Reduced or false horizon definition
- lack of shadows/contrast
- Vertigo
What is diffuse illumination
Light that comes from all directions with equal intensity, due to scattering of suns rays by an overcast layer.
