INSTRUMENT GROUND SCHOOL HAZARDOUS WEATHER Authored By Lt Colonel Garrett L. Sager 30-Jan-2006...

INSTRUMENT GROUND SCHOOL

HAZARDOUS WEATHER

Authored By Lt Colonel Garrett L. Sager 30-Jan-2006

TX-129th Fort Worth Senior SquadronModified by Lt Colonel Fred BlundellTX-129 Fort Worth Senior Squadron

For Local Training Rev 5.0 02-Jan-2014

1

2

This Training Slide Show is a project undertaken by Lt Colonel Fred Blundell of the TX-129 Fort Worth Senior

Squadron, Fort Worth, TX for local use to assist those CAP Members interested in advancing their skills. The

information contained herein is for CAP Member’s personal use and is not intended to replace or be a substitute for any of the CAP National Training Programs. Users should review the presentation’s Revision Number at the end of each file name to ensure that they have the most current

publication.

Weather Hazards to Flight “Most Weather is Flyable” – Robert

Buck There a primarily 3 Weather Hazards

can really get you into trouble: Low Visibility / Ceilings Thunderstorms Ice

3

Instrument Ground School

Hazardous Weather

The #1 Rule to Dealing with Hazardous Weather is:

Always have a way out! That means knowing the weather around,

above & below. Know Yourself, and resist influence of

outside factors Passengers “Get-there-itis”

4


Hazardous Weather

Low Visibility Hazards

Mountain Obscuration Inability to Identify Runway

Environment Caused By

Fog Stable Air with Low Clouds Rain

5


Hazardous Weather

Fog Coastal areas

Large bodies of water, rivers

Upslope Fog Valleys Precipitation

Induced

6


Hazardous Weather

Low Visibility requires Precision! Maintain Altitude, Heading,

Navigation Track precisely! Follow Instrument Procedures

precisely Departure Enroute Arrival Approach

7


Hazardous Weather

Low Visibility on Departure: Takeoff Minimums and Obstacle

Departure Procedures SID’s

8


Hazardous Weather

Low Visibility Enroute & Arrival Know MEA, MOCA, MRA, etc. STARS Follow airways precisely, especially

in mountain areas

9


Hazardous Weather

Low Visibility on Approach: Don’t be committed to landing at an

airport that’s below minimums Have a good alternate, with plenty of

fuel to get there. Alternate Minimums

Never duck below minimums!

10


Hazardous Weather

Low Visibility Set Personal Minimums

Know weather trends, and have personal pre-departure destination minimums.

At the destination, set personal minimums for approach

11


Hazardous Weather

Low Visibility Know where VFR weather is

Especially handy during emergencies, like electrical / radio failure where IFR navigation capability is severely limited.

Have backup navigation & communication ability – handheld Nav/Com & GPS.

12


Hazardous Weather

Low Visibility – Resources AOPA ASF Online Course – Weather

Wise: Ceiling & Visibility Aviation Weather, Chap. 12.

13


Hazardous Weather

Thunderstorms Hazards

Severe or Extreme Turbulence

Hail Lightning

Causes & Types Airmass Frontal

14


Hazardous Weather

Thunderstorms Produced by cumulonimbus clouds,

and occur with Water Vapor Unstable Lapse Rate Lifting Action

15


Hazardous Weather

Thunderstorms Life Cycle Cumulus – the building stage.

Towering Cumulus, with

continuous updrafts Mature

Greatest Intensity, both updrafts & downdrafts

Dissipating Continuous downdrafts,

raining out.

16


Hazardous Weather

Thunderstorms

17


Hazardous Weather

Thunderstorms Lapse rate > 2C per 1000 ft, combined

with high humidity indicates an unstable atmosphere, and thunderstorms are likely.

Moist air is less stable than dry air, because it cools more slowly with altitude, so it must rise higher to cool.

18


Hazardous Weather

Thunderstorms K-Index measures moisture content of

the atmosphere High K-Index means Moist Air Low K-Index means Dry Air

19


Hazardous Weather

Thunderstorms Use Lifted Index to measure

atmospheric stability, i.e.. thunderstorm potential.

LI Value T-Storm PotentialPositive Unlikely

0 to -2 Possible, w/ good trigger

-3 to -5 Probable

< -5 Strong Probability

20


Hazardous Weather

Thunderstorms

21


Hazardous Weather

Thunderstorms Avoid ALL Thunderstorms, and especially

Strong Thunderstorms by 20 nm or more May cause turbulence and hail miles

from the storm. Remember that even a benign looking

cell can become a monster in minutes. Do Not Fly Under Thunderstorms, either. Fly well clear of area, or land and wait for

the storm to pass.

22


Hazardous Weather

Thunderstorms Embedded thunderstorms are storms that

are obscured by cloudy conditions, haze layers, etc. Visual “see & avoid” may be inadequate

“Spherics”, like Stormscope or Strikefinder, detect electrical discharge of lightning strikes Use Spherics to stay well clear of

thunderstorm areas Do NOT Use to pick your way between cells

23


Hazardous Weather

Thunderstorms Radar detects precipitation, not

instrument conditions. Learn to use and interpret radar

properly Without Radar or Spherics, avoid IMC

around thunderstorms.


Hazardous Weather24

Thunderstorm Penetration You’ve run out of options, got yourself

boxed into a corner, and penetration is inevitable. You’ve probably passed up numerous

opportunities to land, or go around, but kept saying, “this doesn’t look so bad”, and now you’re stuck.

Penetrate fronts or squall lines where the tops are the lowest Do NOT fly through areas of fuzzy white –

that’s probably hail Dark clouds mean rain

25


Hazardous Weather

Thunderstorm Penetration Fly straight ahead, Do not turn around

Turn increases load factor on airplane Straight through is often the shortest

route out of the storm. Maintain Attitude – Wings Level, Level

Pitch Do not try to maintain altitude Autopilot Altitude-Hold Off

26


Hazardous Weather

Thunderstorm Penetration Set power & trim for turbulence

penetration speed Pitot & Carb Heat ON Tighten Seatbelts Panel lights to maximum, seat at

lowest setting, and focus on the instruments Lightning flashes may cause

temporary blindness

27


Hazardous Weather

Thunderstorm Penetration You will probably be more scared than

you’ve ever been – Control Your Fear. It’s loud, turbulent, and very distracting

Never Stop Flying the Airplane Maintain attitude and airspeed Most T-storm related in-flight breakups

result from loss of control, and overspeed.

28


Hazardous Weather

Thunderstorms Resources Aviation Weather, Chap. 11 “Weather Flying” Chap. 14,

Robert Buck “Severe Weather Flying”,

Dennis Newton Weather Subject Area @

www.thecfi.com AOPA ASF Subject Reports

29


Hazardous Weather

http://www.thecfi.com/

Icing

30


Hazardous Weather

Icing – Effects Clear Ice & Rime Ice

31


Hazardous Weather

Icing – Effects Frost on the wings disrupts the flow over

the wings, and should be removed before flight. Tests indicate that frost, snow or ice

with texture similar to coarse sandpaper reduces lift by up to 30%, and increased drag by up to 40%.

32


Hazardous Weather

Icing - Effects Ice collects on any protuberance,

especially those with sharp leading edges. Wings & Stabilizers

Causes a loss of lift, increased drag Antennas

Ice may cause to flutter, and break

33


Hazardous Weather

Icing Ice collects on any protuberance, especially

those with sharp leading edges. Pitot Tubes

Ice obstructs pitot-tube, causing loss of airspeed indication

Engine Inlets Obstructs induction system

Propellers Unbalances propeller, causing severe

vibrations Causes loss of lift, and therefore loss of

thrust.

34


Hazardous Weather

Icing - Tail Stall Due to smaller leading edge, tail collects

ice faster than wing. Loss of tail down force causes nose-down

pitch. Flaps change the airflow over the tail.

35


Hazardous Weather

36


Hazardous Weather

Icing Requires 2 conditions

Visible Moisture Temperature at or below freezing

“Freezing Level” is the altitude where freezing temperatures exist. Can be determined using the average

lapse rate of 2C per 1000 ft. Not a precise indication, so leave some

margin.

37


Hazardous Weather

Icing Freezing rain results in the fastest and

greatest accumulation of ice. Indicates warmer temperatures above –

temperature inversion. Super-Cooled Liquid Droplets (SLD) are

liquid below freezing, large diameter, and freeze on impact.

38


Hazardous Weather

Icing

39


Hazardous Weather

Icing Freezing drizzle results in an

accumulation of ice similar to freezing rain. May form due to “collision-

coalescence”, and doesn’t necessarily indicate warmer temperatures above.

40


Hazardous Weather

Icing Ice pellets caused by rain freezing at

higher altitude Heavy, wet snow means temperature is

above freezing at your altitude. It formed above you, but is on the verge

of melting

41


Hazardous Weather

Icing In stratus clouds, 90% of ice occurs within

3000 feet altitude band. In cumulus clouds, icing can occur over

any altitude range Avoid individual clouds when conditions

are right for ice.

42


Hazardous Weather

43


Hazardous Weather

Icing – The Appleman Line (IFR Magazine, Feb.06) Icing is most likely when temperatures

are between 0C & -22C 87% of reported icing (with >50%

humidity outside cloud) 71% of reported icing occurs with >65%

humidity, and temperatures between -2C & -15C.

44


Hazardous Weather

Icing – The Appleman Line (IFR Magazine, Feb.06) 95% Probability of Icing occurs under the

following conditions: OAT < 0C, and OAT is between dewpoint (T = Td) and

80% dewpoint (T = 0.8*Td)

45


Hazardous Weather

Icing

46


Hazardous Weather

Icing

47


Hazardous Weather

Icing Strategies In stratus clouds, with no freezing rain,

Climb In cumulus clouds, stay in clear air Approaching a warm front from behind

Climb along the front, the descend rapidly through it.

Turn Around

48


Hazardous Weather

Icing Case Study Field elevation around 600 feet,

Temp = 48F, DP = 37F

At what altitude would the cloud bases be, and would you expect to encounter ice in the clouds

If encountering ice, what would you do about it?

49


Hazardous Weather

Icing Case Study Cirrus SR22, N87HK, departed Birmingham AL

on 13 Jan 06 at 1601 CST headed for Orlando, ATP rated pilot. DUATS briefing

Forecast ice from 8000 to 10,000 feet. Pilot overlooked Airmet for ice from 3000

to 8000 feet. Pilot climbs at 120 kias, enters clouds at 5000

feet, encounters ice at 7000 feet. Stated he did not know MOCA where he

was.

50


Hazardous Weather

Icing Case Study Was cleared to climb to 9000 feet.

Stalled & spun at cloud tops, at 8000 feet, with a climb speed of 80 kias.

Unsuccessfully tried to recover from spin.

Pulled the “boy, I’m glad I bought a Cirrus so I can live through this” BRS handle. Stopped in trees, 4 feet above ground Pilot and 2 passengers exited safely.

51


Hazardous Weather

Icing Do’s – From IFR Magazine Dec. 05 Do Have a Plan A, and a Plan B Do take immediate action when you

encounter ice Do Climb when you encounter ice, unless

you KNOW you can get out of it by descending

52


Hazardous Weather

Icing Do’s – From IFR Magazine Dec. 05 Do use maximum power to climb If you must enter ice, Do use maximum

forward speed Do zoom climb through icing layer, if

possible Do tell ATC that you must take immediate

action Do ALWAYS FLY THE AIRPLANE!

53


Hazardous Weather

Icing Don’ts – From IFR Magazine Dec. 05 Don’t EVER Fly in Freezing Rain Don’t rely on boots to save you Don’t Climb at too slow an

airspeed Don’t climb in ice pellets

Freezing Rain is above you Don’t descend into colder air if

it’s raining Freezing Rain is below you.

54


Hazardous Weather

Icing Don’ts – From IFR Magazine Dec. 05 Don’t allow ATC to fly your airplane Don’t think the airplane will fall out of

the sky with a little ice Don’t stop flying the airplane Don’t use flaps on an ice-laden airplane Don’t get too slow in an ice-laden

airplane Don’t PANIC

55


Hazardous Weather

Icing Induction Icing

Use Carb Heat Alternate Induction Air Source

Pilot-Static Icing Use Pitot-Heat in the clouds, when

temperatures are near freezing.

56


Hazardous Weather

Icing Propeller Icing

Run at High-RPM Cycle RPM up & down Use prop-deice, if

equipped.

57


Hazardous Weather

Icing References IFR Magazine – wintertime issues “Weather Flying”, Robert Buck “In-Flight Icing”, Perkins & Rieke. AC 91-74, “Pilot Guide to Flight in

Icing Conditions) AOPA ASF Safety Advisor – Aircraft

Icing Icing Course – FAA, NASA, AOPA

58


Hazardous Weather

Questions?Always Think

Safety!

59


Hazardous Weather

INSTRUMENT GROUND SCHOOL HAZARDOUS WEATHER Authored By Lt Colonel Garrett L. Sager 30-Jan-2006...

Documents

Transcript of INSTRUMENT GROUND SCHOOL HAZARDOUS WEATHER Authored By Lt Colonel Garrett L. Sager 30-Jan-2006...