Transcript class #9 common ifr producers and flight procedures

CHAPTER 12
COMMON IFR PRODUCERS
St. Elmo’s Fire
AOPA VFR into IMC
 http://flash.aopa.org/asf/acs_vfrimc/
Scud running
http://www.youtube.com/watch?v=0g
WEi_TNKoI
IFR PROCEDURES
 Low
ceilings and non-instrument rated
pilots don’t mix.
 Attempting to fly visually under low cloud
decks can be tricky.
 Entering clouds or losing the horizon can
cause your senses to deceive even the most
experience instrument pilot; causing you to
lose your sense of direction and lose control
IFR PROCEDURES
 Usually
it takes a good scare to really
appreciate the illusions of IFR flight before
you change your thinking on IFR weather.
 Calgary-Regina-Grand Forks Trip
 Continued VFR into adverse weather is the
cause of about 25% of all fatal general
aviation accidents.
VFR/MVFR/IFR
What
is VFR weather?
Weather better than 1000 ft Ceiling;
Visibility better than 3 S.M.
What is MVFR?
From 1000 ft. - 3000 ft ceiling;
Visibility 3-5 S.M.
What is IFR
1000 ft ceiling or below, vis 3 S.M. or
below
CEILING
Ceiling
= the maximum height
from which a pilot can maintain
VFR in reference to the ground
Ceiling = as the lowest broken
(5/8-7/8) or overcast layer (8/8)
aloft or vertical visibility (VV) into
a surface-based obstruction.
IFR PRODUCERS
Fog,
low clouds, haze, smoke,
blowing obstructions to vision, and
precipitation.
Fog and low stratus restrict
navigation by visual reference
more often than all other weather
parameters.
FOG
 Temp/Dew
Point Temp spread is 2ºC (4 ºF) and
narrowing condensation/ fog/low clouds should
be expected. Your book says (5 ºF)
 Water vapor must condense for fog to form. If
there are no condensation nuclei present then
even with 100% relative humidity, fog will not
form.
 Salt, dust combustion by products, smoke are all
classified as condensation nuclei
FOG
Fog
is a surface based cloud composed of
either water droplets or ice crystals.
With the right conditions fog can form very
quickly (few minutes) VFR-IFR.
 http://www.youtube.com/watch?v=6EqQ9V1e5x
Q
Be
very cautious flying when the temp/
D.P.T. spread is close and getting closer.
FOG FORMATION
Fog
or a cloud may form by:
#1. cooling air to its dew point,
#2. by adding moisture to the air or
condensation nuclei.
FOG
 Radiation
Fog = Fog that forms on a clear
calm night or day break when the surface of
the earth is cooled by radiation until the
temperature of the air near the the surface is
below its initial dew point temp. Restricted
to land because water surfaces cool little
from nighttime radiation. Usually burns off
rapidly after sunrise.
wind
of 5 kts or less mix the air and
deepen the fog
FOG
Radiation
Fog =most conducive to
form on warm, moist air over low,
flatland areas on clear, calm nights
ADVECTION FOG
Moist
air moves over colder ground or
water
common along the coastal areas
deepens with winds up to 15 kts
depends on the wind to exist
More than 15 kts tends to lift it into
low stratus
Moves in rapidly with the wind day or
night and more persistent
FOG
 Advection
Fog = forms when moist air moves
over colder ground or water. Common along
coastal areas. At sea it is called sea fog.
UPSLOPE FOG
Moist stable air cooled
adiabatically as it moves up
sloping terrain
depends on wind to exist
very dense and can exist at high
altitudes along the upsloping
terrain
PRECIPITATION INDUCED
FOG
Warm
rain or drizzle falling through
cool air
evaporation from the precip saturates
the cool air and “poof” fog
associated with warm fronts mostly
may also form along cold fronts and
stationary fronts
little or no wind
FRONTAL INDUCED FOG
Usually
a result of saturation due to
evaporation or precipitation
Either adding the moisture or cooling
the air to saturation
ICE FOG
occurs
when temp is below
freezing and the vapor sublimates
directly into ice crystals
conditions are similar for
formation of radiation fog
-25º F or colder so usually found in
arctic region or colder winter spots
STEAM FOG
Air is blown from a cold
surface over warmer water
Low stratus clouds
hard to predict bases
scud running not advisable
FOG
Fog
on a METAR is used to indicate
visibility of less than 5/8 of a SM
FOG
HAZE AND SMOKE
Haze
- salt or dry particles not
classified as dust or something else
occurs in stable air
Smoke forest fires, industrial areas
Both can be bad under a temp
inversion
Can cause visual illusions
HAZE AND SMOKE
Usually
only a few thousand feet
thick, but sometimes may extend as
high as 15,000 feet.
Usually have well defined tops with
visibility above great.
Downward visibility from a haze
layer is usually very poor, especially
at a slant. Worse if faced into the sun
HAZE AND SMOKE
Smoke
concentrations form primarily
in industrial areas when air is stable.
It is most prevalent at night or early
morning under a temperature
inversion but can persist throughout
the day.
Clears a lot slower than fog
Must be dispersed by air movement.
HAZE AND SMOKE
Needs
to be blown away or
Convection which allows mixing and
spreading out of the smoke or haze to
a higher altitude.
BLOWING PHENOMENA
Dust,
sand
Precip- drizzle, rain , snow
White out conditions
Very common to have 0, 0
weather
BLOWING PHENOMENA
Can blow particles as high as
15,000 feet.
Visibility is restricted at the
surface and aloft.
Once dust becomes airborne
may take several hours for
visibilities to improve
BLOWING PHENOMENA
PRECIPITATION
 Drizzle
and snow restrict visibility to a
greater degree than rain.
 Drizzle falls in stable air and is usually
associated with fog (poor vis)
 Heavy snow and rain associated with a
severe thunderstorm can result in 0 vis.
 With heavy rain visibilities seldom below a
mile and usually for a short period of time.
PRECIPITATION
Freezing
precipitation - freezing to
the windshield lowers visibility to
a few inches.
OBSCURATION
surface
based phenomena
classified in 10ths
VV
ceiling may be noted but once
below it horizontal vis may be
severely restricted
OBSCURATION
An
obscured ceiling differs from a
cloud ceiling. With a cloud ceiling
you normally can see the ground
and runway onced you descend
below the cloud base. With an
obscured ceiling, it restricts
visibility between your altitude and
the ground
OBSCURATION
VISIBILITY
Ground
level, air-to-ground and air-toair visibilities are all important when
flying.
Ground Level - done by weather
observer uses a prominent object
viewed against the horizon for
estimating daytime visibility.
VISIBILITY
Prevailing
Visibility - is provided for
aviation by the weather service. It is
the maximum visibility common to
sectors comprising one half or more of
the horizon circle as viewed from the
observing site at eye level. It is
provided in statute miles.
RVR RUNWAY VISUAL RANGE
For
landing and take-off under
instrument flight conditions, the
prevailing visibility is not of as much
importance as the visibility within the
runway environment itself.
Requirements is that of the runway
lights rather than ground feature.
Measured by an instrument called a
transmissometer
RVR RUNWAY VISUAL RANGE
RVR
is measured in feet in North
America.
Values are measured by
transmissometer mounted on 14 foot
towers along the runway 250 feet apart
typically.
1,600=1/4
2,400=1/2
3,200= 5/8 5,000=1mile
RVR RUNWAY VISUAL RANGE
Air
to ground visibility - prevailing and
rvr are horizontal visibilities near the
surface.
Air to ground is forward visibility,
typically lower then the above two
SVR slant visual range - slant visual
distance used for the choice to continue
to land or not.
ILLUSIONS IN FLIGHT
 AIM
8-1-5
 The leans - An abrupt correction of a banked
attitude, which has been entered too slowly to
stimulate the motion sensing system in the inner
ear, can create the illusion of banking in the
opposite direction. The disoriented pilot will
roll the aircraft back into its original dangerous
attitude, or if level flight is maintained, will feel
compelled to lean in the perceived vertical
plane until this illusion subsides
ILLUSIONS IN FLIGHT
 AIM
8-1-5
 Coriolis illusion - An abrupt head movement in
a prolonged constant-rate turn that has ceased
stimulating the motion sensing system can
create the illusion of rotation or movement in
an entirely different axis. The disoriented pilot
will maneuver the aircraft into a dangerous
attitude in an attempt to stop rotation. This
most overwhelming of all illusions may be
prevented by not making sudden, extreme head
movements (especially while turning)
ILLUSIONS IN FLIGHT
False
Horizon - Sloping cloud formations,
an obscured horizon, a dark scene spread
with ground lights and stars, and certain
geometric patterns of ground light can
create illusions of not being aligned
correctly with the actual horizon. The
disoriented pilot will place the aircraft in a
dangerous attitude
ILLUSIONS IN FLIGHT
Graveyard
spin - A proper recover from a spin
that has ceased stimulating the motion sensing
system can create the illusion of spinning in
the opposite direction. The disoriented pilot
will return the aircraft to the original spin.
Graveyard spiral - Constant rate turn
descending can cease to stimulate your senses,
so that you believe your wings are level.
Pulling back on the controls tightens the spiral
even more
ILLUSIONS IN FLIGHT
Atmospheric
illusions - Rain on the
windscreen can create the illusion of greater
height, and atmospheric haze the illusion of
being at a greater distance fro mthe runway.
The pilot who does not recognize these
illusions will fly a lower approach.
Penetration of fog can create the illusion of
pitching up. The pilot who does not recognize
this illusion will steepen the approach, often
quite abruptly.
ILLUSIONS IN FLIGHT
TRUST
YOUR INSTRUMENT
READ 8-1-5 IN YOU AIM IF
YOU GET A CHANCE
IFR
 If
you can go IFR, get a clearance before
you lose your horizon or enter clouds.
 If VFR make a 180. Any pilot knows how
to make a 180; a good pilot knows
when!!!!!
 Don’t get “get to your destination itis”
 Wait until the weather is good for VFR
QUESTIONS
Where
can you encounter wind
shear?
Any altitude, can be both in the
horizontal and vertical direction.
QUESTIONS
When
is it more likely to have
radiation fog form?
Over land clear calm nights
QUESTIONS
When
is it more likely to have
advection fog form?
Along coastal areas
QUESTIONS
When
is it more likely to have
steam fog form?
Over a water surface
QUESTIONS
What
types of fog depend on wind
in order to exist?
 Advection fog and upslope fog
QUESTIONS
In
industrial areas low clouds and
fog are common why?
Increase in cloud condensation
nuclei.
FMH-1 CHAPTER 12
 METAR
KMWH 092052Z 22003KT 10SM
SCT009 02/M02 A2981 RMK AO2
SLP105 6//// T00171022 55000 PNO $
 6=3 and 6 hour precip amount
 ////=indeterminable amount of precip
 If 2.17 inches of precip occurred would be
coded 60217
METAR KMWH 092052Z 22003KT 10SM
SCT009 02/M02 A2981 RMK AO2 SLP105 6////
T00171022 55000 PNO $
 5=3 hour pressure tendency
 Next digit need to reference table 5 on the table =
atmospheric pressure now lower than 3 hours ago
decreasing then increasing
 000 = amount of pressure change in tens of
hectopascals
 52032 = steady increase of 3.2 hectopascals in the
past three hours

 METAR
KMWH 092052Z 22003KT 10SM
SCT009 02/M02 A2981 RMK AO2
SLP105 6//// T00171022 55000 PNO $
 PNO = when automatic stations are
equipped with a tipping bucket rain gauge
and that sensor is not operating PNO shall
be coded
 $ = maintenance is needed on the system