Authored by Rich Simerson Revised 01-Apr-2010 Modified by Lt Colonel Fred Blundell TX-129 Fort Worth Senior Squadron For Local Training Rev Jan

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.

Objectives  Discuss how convection currents affect aircraft glide path.  Discuss wind patterns around high and low-pressure areas.  Define “freezing level” and “lapse rate”  Discuss airframe icing and its affect on aircraft performance.  Discuss carburetor icing and its affect on aircraft performance. 3

Objectives (continued)  Discuss the characteristics of cold, unstable air masses and warm, stable air masses.  Concerning reduced visibility conditions, state the minimums for:  VFR visibility  Cloud bases when they cover one-half the sky  How far aircraft must remain below cloud cover  Discuss the dangers of wind shear.  Describe the ‘stages’ of a typical thunderstorm and discuss the dangers of flying too close. 4

Weather  The most important aspect of weather is its impact on flight conditions  Safety is paramount  Navigation — Visual verses Instruments  Effects on Search  Prevailing visibility  Search visibility  Search patterns and altitudes  Information — National Weather Service, Flight Service Stations, Flight Watch, PIREP’s 5

Flight Precautions  Each member of the aircrew must be vigilant during all phases of flight  Assign each an area to watch  Characterize visibility in the search area to establish the proper scanning range  May be different than assumed  Visibility conditions or turbulence may increase fatigue 6

Weather — Circulation 7

Weather — Circulation (Continued)  The earth rotates  Air moving north is pulled toward the east  This builds a high pressure belt about 30 degrees latitude  The northerly air flow cools and starts southward  These large circulations are responsible for mixing the air and most weather 8

Upward Convection Currents  Terrain which heats up creates updrafts  Updrafts tend to keep you from descending  Normally where there are updrafts there are also downdrafts 9 ROCKY TERRAIN PLOUGHED GROUND PAVED ROAD NORMAL GLIDE PATH EFFECT OF CONVECTION CURRENTS

Downward Convection Currents  Terrain which remains cool creates downdrafts  Downdrafts cause you to descend 10

Turbulence  Planning flight around high terrain requires special care  Wind currents on the downwind side can be very strong  Ridges and peaks should be cleared by at least 2000 feet 11 Wind Flight Path 2000 ft.

Circulation Around a High 12 H Air Sinks Moves Clockwise

Circulation Around a Low 13 L Air Rises Moves Counter Clockwise

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Lapse Rate  As altitude increases the temperature decreases at a fairly uniform rate of 3.6 degrees F per 1000 (2.0 degrees C per 1000) feet; this is known as lapse rate  Use this on hot days to determine how high you should climb to get to a comfortable temperature  At some altitude the air temperature reaches the freezing temperature of water; the freezing level 15

Icing  Frost  Snow  Icing  Airframe (lift & weight) (lift & weight)  Carburetor 16 Lift Thrust Decreases Weight Increases Decreases Drag Increases Rime ice is rougher Glaze ice is clearer

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The wing of a NASA Twin Otter after landing. This looks to be clear icing or perhaps mixed. Notice the runback well past the leading edge and on the underside of the wing. 18 Icing

The rectangular device on the windshield is the "hot plate", a plate of electrically heated glass which is mounted just ahead of the plastic windshield. When ice formation is especially bad, the only view forward is through the upper two- thirds of the plate, and the area around it becomes crusted with frozen runoff from the heated area. 19 Icing

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Carburetor Icing  Moisture in the air can condense, then freeze, blocking further flow of air and fuel to the engine.  Airplanes most vulnerable when operated in high humidity OR visible moisture with temperatures between 45F and 85F.  Most likely to form at low power settings such as in descents and approaches to landings.  Fuel injected engines are not vulnerable to carburetor icing. 21

Causes of Frontal Activity 22 DRY AIR COLD POLAR AIR TROPICAL MOIST AIR

Warm Front 23 St LouisIndianapolisColumbusPittsburgh Nimbostratus Altostratus Cirrostratus Cirrus WARM AIR COLD AIR dust/polutants

Cold Front 24 St LouisIndianapolisColumbusPittsburgh COLD AIR WARM AIR Cumulonimbus

Occluded Front 25 St LouisIndianapolisColumbusPittsburgh COLD AIR WARM AIR COLD AIR Cumulonimbus Nimbostratus Altostratus Cirrostratus Cirrus

Clouds 26 Altocumulus

Lenticular 27 Clouds

Lenticular 28 Clouds

Towering Cumulus 29 Clouds

Mushroom 30 Clouds

Reduced Visibility  Under almost all circumstances, VFR daytime flight requires:  At least three miles visibility  When clouds cover more than one-half the sky, cloud bases must be no lower than 1,000 ft. AGL  Search aircraft must usually remain at least 500 ft. below the cloud deck 31

Reduced Visibility (CONTINUED)  Fog  Haze  Snow  White out  Blowing dust  Affected by sun angle and direction  Aircrew must increase vigilance during these conditions 32

Wind Shear  Thunderstorms  Fronts - wind shear may advance as far as 15 nm  Air flow around obstacles 33 Windward

Wind Shear  Two potentially hazardous situations, dangerous mainly during landing:  Tailwind turns calm or to a headwind  Headwind turns calm or to a tailwind  Critical conditions for potential low-level wind shear:  Cold Front: After front passes If moving 30kts or more, may exist below 5000 ft for up to 3 hours  Warm front: Before front passes May exist below 5000 ft. for up to 6 hours Danger passes once front passes airport  Pilot must adjust quickly 34

Weather Thunderstorms 35 Cumulus StageMature StageDissipating Stage

Lightning In-Cloud (IC) 36

Cloud-to-Cloud (CC) 37

Flight Planning WX Sources Telephone National Weather Service –WX Brief ( ) Standard Briefing –METARS (updated as significant change has occurred) –Terminal Area Forecast (i.e. IND) Good for 12 hoursGood for 12 hours 3 x per day3 x per day –Area Forecast (entire state or area you designate) Every 12 hoursEvery 12 hours Route of FlightRoute of Flight

Flight Planning WX Sources Telephone National Weather Service Winds Aloft All altitudes All altitudes Notams Notams Current Airmets Convective Sigmets Cloud Tops (reported) Pilot Reports (PIREPS) High/Low Pressure Areas Fronts 39

Flight Planning Computer WX Sources  AOPA.org  Weather  Satellite Images  Radar Imagery  Surface Wx Imagery  Upper Air Imagery  Textural WX 40

Flight Planning Computer WX Sources (Continued)  Weatherunderground.com  Temperature  Heat Index  Wind Chill  Radar  Dew point  Visibility 41

Flight Planning Computer WX Sources (Continued)  Intellicast.com  Radar  Severe Weather  Satellite  Surface Analysis  Hurricane Watch  More Spam 42

Flight Planning Computer WX Sources (Continued)  NOAA’s National Weather Center (adds.aviationweather.noaa.gov)  Turbulence  Convection  Winds/Temps  Prog Charts  Metars  Tafs  Pireps 43

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45 Plain Language Interpretation of METAR

46 JOT Time 1240Z C-172 at Fl Level Reported sky cover was overcast from ft. Occasional light chop. Scattered Virga Observed

47 JOT reported at the same time 1245Z showed surface weather winds from 190 at 4knots, visibility was 10sm and CLEAR! Temperature was 23C and dew point 19C

Radio Services  Flight Service Station (FSS)  Flight Watch (122.0)  Automatic Terminal Information Service(ATIS)  Transcribed weather broadcasts (TWEB)  Scheduled weather broadcasts  Fifteen minutes after the hour  Alerts, hourly weather, Advisory, Pilot Reports, Radar  Pilot Weather Reports (PIREP) 48

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Questions? 50 Always Think Safety!