Aviation Icing by Jamie Gudmestad

8/6/2019 Aviation Icing by Jamie Gudmestad

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SAWS Workshop IISAWS Workshop II

October 2008October 2008Jamie GudmestadJamie Gudmestad

-- Meteorologist InternMeteorologist Intern

WFO Midland, TXWFO Midland, TX-- Air Force ReserveAir Force Reserve

Weather ForecasterWeather Forecaster

Shaw AFB, SCShaw AFB, SC

AIRCRAFT ICINGAIRCRAFT ICING

Aviation Safety Foundation


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My employment

Full time Meteorologist

WFO Midland

Part time

Forecaster

for variousareas in the

Middle EastWikipedia


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Content of this presentation- Why icing is SO important to aviation

- Where and when icing commonly occurs

- The types of icing

- Type of aircraft most susceptible to icing

- TAFs and other products

- Future icing detection

- Where more information can be found


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The National Weather Service (NWS)

provides weather, hydrologic, and climate

forecasts and warnings for the United

States, its territories, adjacent waters and

ocean areas, for the protection of life and

property.


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www.airport-technology.com

"An estimated 819 people died in accidents

related to in-flight icing between 1982 and

2000."

Study by the National Transportation

Safety Board

Over 40 people/year


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Air Florida Flight 90

January 13, 1992

Washington DC

Aircraft was De-iced, then

sat on the runway

killed all 78 on board

Airdisaster.com


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A Cessna 208B Caravan

November 8, 2002

Parks, Arizona

Aircraft was in routefrom Las Vegas, NV on

its way to Midland, TX

Moderate mixed icing

aironline.com/wikipedia


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NormalNormal

IcedIced

Hanley Innovations:Airfoil Icing & Microtab Study

Airfoil


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Icing of other aircraft parts

AOPA Aviation Safety Foundation


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Icy Runways

Webshots.com


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Near Saturated environment

Favorable Atmospheric Conditions for Icing:

Temperature Dew point Depression Approx. RH

0 to -7C (32 to 18F) less than 2C (


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Winter

Map from the Air Safety Foundation (AOPA)


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-Icing is more likely & more severe in clouds located

near moisture sources & over mountainous regions

Mountains

University Corporation for Atmospheric Research (COMET)


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Fronts



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Fronts



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Clouds

HIGHHIGH 00 toto --2020C 0C 0 toto --1515C 0C 0 C & belowC & below

(32(32 toto --44F) (32F) (32 toto 55F) (32F) (32F & below)F & below)MEDMED --2020 toto --4040CC --1515 toto --3030CC

((--44 toto --4040F) (F) (--55 toto --2222F)F)

LOW


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Vertical Displacement increases Icing

AFWA TN 98-002


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Icing Severity definitions

Trace when the rate of ice accumulation is just slightlygreater than the rate of loss due to sublimation

Light the rate of ice accumulation may create a problem

if the aircraft remains in this environment for one hour

or more

Moderate when the rate of ice accumulation is so great

that even a short encounter can become hazardous

Severe whenever the rate of ice accumulation is such that

deicing or anti-icing equipment cannot control or reduce

the hazard



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Droplet Size

- Cloud droplets usually 40 microns or less

- Supercooled liquid droplets (SLD) are

40 200 microns; MOST SIGNIFICANT to

Aircraft Icing

- SLD most often includes freezing rain &

drizzle

University Corporation for Atmospheric Research (COMET) Fotosearch.com


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University Corporation for Atmospheric Research


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Type of aircraft

US Army Corps of Engineers; Wikipedia


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Temperature Type

32 to 18F Clear

18F to 15F Mixed

Less than 15F Rime

Type of Icing

AFWA TN 98-002


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TAFSN

WST

AF:CCCC TAF 011818 18020G28KT P6SM SCT030 BKN120

TEMPO 1822 BKN020

FM0400 16015KT P6SM BKN030 PROB30 0308 TSRA

BKN

030CBUSAF TAF:

CCCC TAF 011616 03008KT 0800 PRFG FEW000 BKN005

BKN012 WS015/12035KT QNH3001INS FG FEW002

TEMPO 1820 14012G18K

T3200

-SN

BLSN

FEW002OVC006 620065 SN FEW000

BECMG 2324 15012G20KT 3200 -SN BLSN FEW002

OVC004 620046 QNH2983INS TM01/19Z TM04/11Z

NWS Instruction 10-813 / AFMAN 15-124


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Reading the icing group

620065

6 The first digit icing group

2 The second digit type of icing006 The third, fourth & fifth digits height of icing

5 The last digit thickness of icing

AFMAN 15-124


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http://adds.aviationweahter.noaa.gov/icing


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Pirepshttp://adds.aviationweahter.noaa.gov/icing


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Research

- Supercooled

large droplet

- Heat transfer

- Anti-icing

protection

http://www.niar.wichita.edu/researchlabs/


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www.ucar.edu/communications

Technology improvements

More advanced

RADARs are

being tested byNational Center

for Atmospheric

Research


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Where you can learn more

http://www.meted.ucar.edu/

The Comet program

http://www.aopa.org/asf/

AOPA Air Safety Foundation


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Aircraft Icing

Thank you for your time!

Sources were cited on each slide

Questions???

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Aviation Icing by Jamie Gudmestad