APPENDIX D
HAZARDS
STUDENT HANDOUT
TERMINAL LEARNING OBJECTIVE (TLO): At the completion of this lesson, the student will:
ACTION: Plan a flight mission IFR or VFR in accordance with (IAW) weather conditions stated in FM 1-230 and AR 95-1.
CONDITION: In a classroom environment.
STANDARD: IAW FM 1-230.
SAFETY REQUIREMENTS: None.
RISK ASSESSMENT LEVEL: Low.
ENVIRONMENTAL CONSIDERATIONS: None.
A. ENABLING LEARNING OBJECTIVE (ELO) #1:
ACTION: The student will identify the conditions conducive to fog formation.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify conditions conducive to fog formation.
a. Definition of fog. Visible moisture with base below 50 feet and no visible downward motion.
(1) Surfaced based phenomena, visible moisture.
(2) Visible moisture with base at 50 feet or higher is a cloud (stratus type).
b. Factors conducive to fog formation.
(1) High moisture content (temperature and dew point within 2C or less).
(2) Condensation nuclei.
(3) Cooling action.
B. ENABLING LEARNING OBJECTIVE (ELO) #2:
ACTION: The student will identify factors affecting fog dissipation.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify factors affecting fog dissipation.
a. Heating.
b. Strong wind.
c. Greenhouse effect / overcast sky (slows dissipation).
C. ENABLING LEARNING OBJECTIVE (ELO) #3:
ACTION: Match the type of fog to the meteorological conditions associated with it.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to match the type of fog to the meteorological conditions.
a. Radiation fog.
(1) At night terrestrial radiation cools the surface of the earth. The surface cools lower layers of air to the dew point. This is the process called radiation cooling.
(2) Light winds (2 to 5 knots) deepen the cooling action.
(3) Usually localized.
(4) Tends to form between midnight and sunrise.
(5) Dissipates after sunrise (visible moisture changing to gas).
b. Advection fog.
(1) Warm, moist air flowing over a cool surface.
(2) Cool surface lowers temperatures of lower layers of air to near dew point.
(3) Results from surface cooling.
(4) May occur at any time the wind and temperature conditions are favorable.
(5) Wind speeds up to 15 knots.
(6) Deep moving, widespread.
(7) Persistent.
c. Upslope fog.
(1) Warm, moist air flowing up rising terrain.
(2) Cools adiabatically.
(3) May “cap” mountains (10-15k wind).
(4) Usually localized.
(5) May occur any time upslope adiabatic cooling occurs.
(6) Persistent.
d. Valley fog.
(1) Air on slopes cools rapidly at night, becomes more dense.
(2) Fills valley floor with cooler, more dense air which, if cooled to its dew point, can form fog.
(3) Gradually deepens.
e. Frontal fog (evaporation fog, adding moisture to air).
(1) Warm air forced aloft until precipitation falls.
(2) Falls through frontal inversion into colder air below, increasing dew point.
(a) Prefrontal--ahead of warm front (common).
(b) Postfrontal--behind cold front.
(3) Every front does not produce frontal fog.
f. Steam fog (evaporation fog).
(1) Cold, stable air over much warmer water.
(2) Water evaporates rapidly, increasing dew point.
(3) Common over lakes and rivers in fall.
(4) Can occur at any time conditions exist.
g. Ice fog. Any time fog forms in very cold temperature (-25C or colder) with abundant nuclei, tiny ice crystals are produced by sublimation.
D. ENABLING LEARNING OBJECTIVE (ELO) #4:
ACTION: The student will identify the best flight planning alternative when dealing with fog situations.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to determine alternate plans when dealing with fog situations.
a. Consider fog formation at destination to be--
(1) When temperature and dew point are to be within 2C.
(2) When field is near the coast or large bodies of water and large amounts of nuclei are present.
(3) If destination is near water with an onshore wind, select inland alternate behind ridge or range of mountains.
b. Check weather reports and forecasts for possibility of fog formation at destination.
c. Pick a good alternate.
d. Consult your forecaster.
E. ENABLING LEARNING OBJECTIVE (ELO) #5:
ACTION: Match the meteorological condition to the type of icing formed.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 - Provide instruction to determine condition for ice formation.
Types of icing and their characteristics.
a. Rime ice (0 to -20C).
(1) Small water droplets (supercooled).
(2) Stratiform clouds (0 to -20C), and upper cumuliform below -10 to -20C.
(3) Rough deposit.
(4) Builds to a point.
(5) Easy to break loose.
b. Clear ice (0 to -10C). Lower cumuliform clouds and in freezing rain.
(1) Large, supercooled water droplets.
(2) Clear, solid ice.
(3) Blunt shape.
(4) Hard to break loose.
c. Frost.
(1) Forms by sublimation of water vapor on cold (below 0C), clear nights.
(2) Tiny ice crystals.
(3) Should be removed from aircraft before takeoff.
F. ENABLING LEARNING OBJECTIVE (ELO) #6:
ACTION: The student will identify the conditions conducive to freezing rain.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 - Provide instruction to identify conditions conducive to freezing rain.
a. Freezing rain--visible moisture and below freezing temperatures.
(1) Rain falls from frontal inversion through wedge of polar air.
(2) Rain droplets freeze on aircraft as clear ice.
(3) Most common with warm fronts
G. ENABLING LEARNING OBJECTIVE (ELO) #7:
ACTION: The student will identify the hazards associated with icing.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 - Provide instruction to identify icing hazards.
a. Loss of autorotative capability.
b. Reduces lift.
c. Increases drag.
d. Increases weight.
e. Decreases stall speed (RW).
f. Reduces visibility when ice forms on windshield.
g. Reduces airflow to engines when ice forms on screens.
h. Pitot and/or static source icing results in instrument error.
i. Avoidance procedures.
(1) Flight planning.
(2) Avoid known or forecasted icing conditions.
H. ENABLING LEARNING OBJECTIVE (ELO) #8:
ACTION: The student will identify conditions conducive to the development of thunderstorms.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction conducive to thunderstorm development.
a. Unstable or conditionally unstable air.
b. High moisture content (high dew point).
c. Lifting action – thermal convection, orographic mechanical, frontal.
I. ENABLING LEARNING OBJECTIVE (ELO) #9:
ACTION: The student will identify the types of thunderstorms.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify the types of thunderstorms.
a. Air mass.
(1) Thermal convection.
(2) Orographic (mechanical).
b. Frontal.
(1) Cold front.
(2) Squall line.
(3) Warm front.
J. ENABLING LEARNING OBJECTIVE (ELO) #10:
ACTION: Match the stage of the thunderstorm to the meteorological conditions described.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to determine stages of a thunderstorm.
a. Cumulus stage.
(1) Vertical currents--all upward.
(2) Temperature distribution--warmer in cloud than outside.
(3) Turbulence--light to moderate.
(4) Surface winds--gusty and variable.
(5) Precipitation--none outside of cloud.
b. Mature stage begins when precipitation starts.
(1) Vertical currents--possible 6,000 F.P.M. up and 4,000 F.P.M. down.
(2) Temperature distribution--warmer in updraft areas and colder in downdraft areas.
(3) Turbulence (most severe in mid-altitude levels).
(4) Surface winds--strong and gusty.
(5) Precipitation--heavy rain showers.
c. Dissipating or anvil stage.
(1) Vertical currents--all downward.
(2) Temperature distribution--colder in cloud than outside.
(3) Turbulence--moderate to severe.
(4) Surface winds--strong and gusty.
(5) Precipitation--heavy rain showers decreasing to light to none.
K. ENABLING LEARNING OBJECTIVE (ELO) #11:
ACTION: Given the meteorological conditions of a microburst, determine its classification.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to determine a microburst classification.
a. Microburst – a short-lived, powerful downburst of air associated with convective activity with diameters up to ½ mile, lasting 5 – 15 minutes.
(1) Wet microburst – A typical wet-microburst is produced from a low base cumulus cloud with heavy rain. A descending wet microburst may first appear as a darkened mass of rain descending through light rain.
(2) Dry – A typical dry microburst is produced from a high based cumulus cloud with little or no surface rain. In extremely dry situation, the storm will normally produce virga. The dry-microburst may have a ring of dust under the base of the cloud, indicating the surface position.
L. ENABLING LEARNING OBJECTIVE (ELO) #12:
ACTION: The student will identify the recommended flight procedure for a thunderstorm situation.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify flight procedures for thunderstorms.
a. Air mass thunderstorms -- Circumnavigate by at least 20 miles.
b. Frontal thunderstorms --land.
c. Do not intentionally fly into a thunderstorm.
d. Inadvertent thunderstorm penetration.
(1) Attitude of aircraft--use attitude indicator to establish attitude for maximum endurance airspeed.
(2) Select altitude and heading (4,000’ to 6,000’ AGL is the area with the least turbulence).
(3) Cockpit lights--bright.
(4) Airspeed--maximum endurance airspeed (do not rely on airspeed indicator).
(5) Radio equipment (turn volume down).
(6) Do not turn back.
M. ENABLING LEARNING OBJECTIVE (ELO) #13:
ACTION: Identify the meteorological conditions associated with mountain wave activity.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify conditions associated with wave activity.
a. Mountain Wave – needs stable air with winds in excess of 25 knots blowing across a mountain range. (Sometimes referred to as MWT – mountain wave turbulence in METAR.)
b. Turbulence
(1) Usually most dangerous feature.
(2) Most found on lee side of mountain.
(3) May extend downwind for several miles.
(4) Drafts may range from slight bumpiness to 6,000 feet/minute.
(5) Helicopters, due to close proximity to surface, are especially susceptible.
c. Clouds.
(1) Cap cloud.
(a) “Caps” the mountain range (found mostly to windward).
(b) Stationary.
(2) Lenticular.
(a) Most familiar sign of wave conditions.
(b) Forms on crest of wave.
(c) Known as altocumulus standing lenticular (ACSL).
(d) Stationary and forming in layers with altitude.
(3) Rotor.
(a) Very dark, ominous cloud.
(b) Rolling appearance.
(c) Generally forms at height of mountain ridge.
(d) Generally stationary.
N. ENABLING LEARNING OBJECTIVE (ELO) #14:
ACTION: Identify the correct mountain wave crossing procedure.
CONDITION: In a classroom environment and given a student handout.
STANDARD: IAW FM 1-230.
Learning Step/Activity 1 – Provide instruction to identify mountain wave crossing procedure.
a. If practicable, avoid completely (don’t go).
b. Avoid ragged, lenticular clouds.
c. Avoid cap cloud.
d. Stay clear of rotor cloud.
e. Approach mountain range at a 45 angle and at an altitude that is as high as practical (remain clear of clouds VFR).
f. Be suspicious of altimeter readings (may indicate more than 1,000 feet higher than actual).
g. When flying into wind, use updrafts to help gain safe altitude for crossing mountains.
h. Climb to crossing altitude early, and avoid downdrafts.
D-1