Review Meteorology and FARs

Meteorology/FAR and Review

• www.sal.ksu.edu/faculty/kingb

Weather Factors

• Atmospheric circulation– Weather changes are caused by uneven heating – Every process of weather is the result of or is

accompanied by a heat exchange– The sun is directly over the Tropic of Cancer

on June 21

Weather Factors

• Highs are usually associated with– Good visibility– Light winds– Few clouds– Good weather– Characterized by descending air

Weather Factors

– Lows are usually associated with• precipitation

• cloudiness

• poor visibility

• bad weather

• turbulence

• Wind

• characterized by rising air

• Example of lows are hurricanes and tornadoes

Weather Factors

• In the northern hemisphere– Air flows counterclockwise around a low

(cyclonic)– Air flows clockwise around a high

(anticyclonic)– If one were to fly directly to the center of a low,

the winds would come from the left and get stronger as one got closer

Weather Factors

• Relative Humidity– Measure of how much moisture is present for a

a parcel of air at a temperature.– If a parcel of air has a RH of 100%, it is

saturated. The temperature that it is at is called the dewpoint. If this parcel were cooled more, water vapor would clouds, fog, dew or frost

Thunderstorms

• Conditions– Unstable air– Lifting action– High moisture content

• Stages– Cumulus stage Mature stage– Dissipating stage

Hazards

• Embedded thunderstorms may be obscured by cloud layers

• Wind shear can be found on all sides as well as directly under it

• Greatest intensity during mature stage, which is signaled by precipitation at the surface

Frontal Turbulence

• Occurs in the narrow zone just ahead of a fast-moving cold front

Wingtip Vortices

• Tend to sink below the flight path of the generating aircraft

• Most hazardous during light, quartering tailwinds

• Land beyond where a large aircraft has touched down

Clear Air Turbulence

• Turbulence above 15,000 feet AGL not associated with cumuliform cloudiness is reported as CAT

• CAT is common in a upper trough on the polar side of the jet stream

Mountain Wave Turbulence

• Greatest turbulence occurs approaching the lee side of a mountain range in strong headwinds

• Standing lenticular and rotor clouds indicate the possibility of strong turbulence

Microbursts

• Intense, localized downdrafts seldom lasting longer than 15 minutes

• Downdrafts can be as strong as 6,000 feet per minute

• Performance changes drastically as an aircraft flies through a microburst

Fog

• Radiation Fog - ground fog - forms over fairly flat land on clear, calm nights

• Advection fog- forms near coastal areas when moist air moves over colder ground or water

Fog• Upslope fog forms when moist stable air is

forced up a sloping land mass

• Steam fog occurs as cool air moves over warmer water

• Precipitation-induced fog forms when warm rain falls through a layer of cooler air near the surface

Icing

• Freezing rain is most likely to have the highest rate of accumulation

• Ice, snow or frost having the thickness and roughness of sandpaper and reduce lift by 30% and increase drag by 40%

METAR

• Aviation routine weather reports

• METAR are routinely taken every hour at 50 past the hour. They are usually entered into the computer on the hour

• SPECI are special aviation weather report

Sky Condition

• Ceiling is defined as the height of the lowest layer of clouds or obscuring phenomena that is reported as broken or overcast

• If tops are know, your can find the thickness of clouds by adding the airport elevation to the height to the base of the clouds and subtract from the height of the cloud tops

Remarks Codes

• A02 - automated station with precipitation discriminator

• RAE42SNB42 - rain ended and snow began at 42 past the hour

• PRESFR - Pressure falling rapidly• SLP - Sea level pressure 1004.5 millibars• T00081016 - Temperature .8o C and dewpoint

is -1.6o C

TAF

• Terminal Aerodrome Forecast - valid for a 24 hour period and scheduled four times a day

• Primary source of destination weather

• AMD means and amended forecast

• COR means a corrected forecast

• RTD indicates a delayed forecast

Contractions

• VRB - wind direction is variable• 00000KT - calm wind• P6SM - prevailing visibility expected to be

greater than 6 statue miles• SKC - sky clear• PROB40 2102 +TSRA - 40% probability of

thunderstorms with heavy rain between 2100Z and 0200 Z

Area Forecast FA

• VFR Clouds and weather section summarizes sky condition, cloud heights, visibility, obstructions to vision, precipitation, and sustained surface winds of 20 knots or greater

• When winds are to be 20 knots or greater the categorical outlook includes the contraction WND

Wind and Temperature Aloft

• Usually given for nine level between 3,000 and 39,000 feet

• Winds are given in true direction and speed in knots

• Winds not forecast within 1,500 feet of station elevation

• Temperature not forecast for the 3,000-foot level or with 2,500 feet of the station elevation

Wind and Temperature Aloft

• Uses a four digit code for wind speed and direction, the first two digits are the wind direction in hundreds of degrees

• The second two digits indicate wind speed

• A two digit temperature code in degrees Celsius follows the wind speed and direction code

• All temperature above 24,000 feet are negative

Surface Analysis Chart

• Surface Analysis chart is a good source for general information over a large area. Shows position of fronts, temperature, dewpoint, wind at valid time of the chart

• When solid lines, called isobars, are close together the pressure gradient is greater and the winds are stronger

• A dashed line indicates a weak pressure gradient

Weather Depiction Chart

• Information on the chart is derived from the METAR reports

• Provides an overview of favorable and adverse weather

• Prepared every three hours

• A bracket symbol ] to the right of a station circle means it is an automated location

RADAR Summary Chart

• Only chart which shows lines and cell of thunderstorms

• You can determine the tops and bases of the echoes, the intensity of the precipitation and direction of movement

• Most effective when used in combination with other charts, reports, and forecasts

Graphic Forecasts

• Low-level Significant Weather Prognostic Chart is valid up to 400 millibars of pressure or about 24,000 feet

• Issued four time a day with a valid time printed on the lower margin of each panel

• Shows areas of IFR, MVFR, VFR and moderate or greater turbulence

Graphic Forecasts

• Severe Weather Outlook Chart is used for advance planning and provides 48-hour outlook for general and severe thunderstorm activity

• Crosshatched areas generally indicate severe weather and are labeled SVR

Types of Briefings

• Standard is the most complete briefing and assumes no familiarity with the weather picture

• Abbreviated is used to update weather information when you need only one or two specific items

• Outlook is used if you departure is six or more hours away. You should update with a standard or abbreviated briefing closer to flight time

In-Flight Weather Sources

• Airmets - WA - Airmans meteorological information are forecasts for a maximum of a six hour period

• Sierra for IFR conditions

• Tango for turbulence

• Zulu for icing and freezing levels

SIGMETs

• Significant meteorological information - WS - – Severe Icing– Severe and extreme turbulence– Volcanic eruptions– Duststorms, sandstorms or volcanic ash

lowering visibility to less than three miles

Convective SIGMETs

• Imply severe or greater turbulence, severe icing and low level wind shear

• Contain either an observation and a forecast or just a forecast for tornadoes, significant thunderstorm activity or hail 3/4 inch or greater in diameter

Enroute Flight Advisory Service

• Flight Watch is available daily from 6 AM to 10 PM when flying between 5,000 AGL and 17,500 MSL any where in the US

• Contact on 122.0 with your aircraft ID, ARTCC facility identification and name of the nearest VOR

FAR 1Definitions & Abbreviations

• Flight Visibility - average horizontal forward distance from the cockpit.

• Ground Visibility - prevailing horizontal visibility near surface as reported by US NWS or an accredited observer.

• IFR conditions - not VFR below 1000 and 3

FAR 61

• 61.57 (C) - To act PIC under IFR, within preceding 6 calendar months:– Logged 6 approaches– Holding procedures– Intercepting and tracking courses through use

of nav systems

– Note: A Sim or FTD may be used.

Part 91

• 91.3 - PIC is PIC

• 91.21 - use of electronic devices that may cause interference with nav systems is prohibited.(cell phones, stepping motors etc.)

• 91.103 - Latest info required, alternatives available, known traffic delays.

Part 91

• 91.167- Enough fuel to fly to first airport, then if an alternate is required, fly to alternate airport, then fly for 45 min after at normal cruising speed. An alternate is not required if 1 hr of ETA, 2000’ ceiling, 3 miles visibility.

Part 91

• 91.169 - To be an alternate, unless denoted by A in triangle on NOS charts– Precision approach - 2 mi., 600’

– Non precision approach - 2 mi., 800’

– No approach - allow descent from MEA to approach and landing under VFR

Part 91

• 91.185 - Comm Failure– If IFR

• Route– Last assigned– Radar vectored, direct to fix, route or

airway specified in vector clearance.– EFC– Filed

Part 91

• 91.185 - Comm Failure– If IFR

• Altitude - Highest of – Last assigned– MEA– EFC

• Time– Commence approach as close as possible to

EFC or filed.

Part 91

• 91.205 Instrument and Equipment Readiness– For IFR flight, navigation equipment must be

appropriate to ground facilities– Above 24,000, DME required if using VOR

navigational equipment– Need attitude indicator, heading indicator and

turn coordinator for IFR

Part 91

• 91.211 Supplemental Oxygen– Above 15,000, each passenger must be

provided supplemental oxygen– Above 14,000, required crew must use– Between 12,500 and 14,000, oxygen must be

provided for time in excess of 30 minutes

Part 91

• 91.215 ATC Transponder and Altitude Reporting Equipment and use– Must use Mode C– Within Class B– Within 30 NM of primary Class B airport– Within and above Class C– Above 10,000 ft MSL except below 2,500 AGL

and in Class A airspace

Part 91

• 91.411 Altimeter System and Altitude Reporting Equipment Test and Inspections– Each static pressure system and altimeter

instrument must be tested by the end of the 24th month

NTSB 830

• Accidents, incidents, overdue AC, and preservation of wreckage