Appendix A A-1 APPENDIX A. DEFINITION OF COMMON TERMS USED IN EN ROUTE
FORECASTS AND ADVISORIES Table A-1. Definition of Common Terms Used in En Route Forecasts and Advisories (FA, SIGMET, AIRMET, TCA, VAA, ROFOR) Contraction Translation Definition EMBD Embedded Thunderstorms or Cumulonimbus Thunderstorms or cumulonimbus (CB) clouds that are embedded in cloud layers or concealed by haze.
EXTREME TURB Extreme Turbulence Turbulence in which aircraft is violently tossed about and is practically impossible to control. It may cause structural damage.
FIR Flight Information Region An airspace of defined dimensions within which flight information service and alerting service are provided.
FL Flight Level A surface of constant atmospheric pressure which is related to a specific pressure datum, 1013.2 hectopascals (hPA), and is separated from other such surfaces by specific pressure intervals.
FRQ Frequent Thunderstorms or Cumulonimbus Consisting of elements with little or no separation between adjacent thunderstorms with a maximum spatial coverage greater than 75 percent of the area affected by the phenomena at a fixed time or during the period of validity.
IMC Instrument Meteorological Conditions Ceiling greater than or equal to 500 feet to less than 1,000 feet and/or visibility greater than or equal to 1 to less than 3 miles. LIMC is a sub-category of IMC, thus, IMC conditions are ceiling less than 1,000 feet and/or visibility less than 3 miles.
ISOL Isolated Thunderstorms or Cumulonimbus Consisting of individual features affecting an area with a maximum spatial coverage less than 50 percent of the area affected by the phenomena at a fixed time or during the period of validity.
LINE TS Line (of Thunderstorms) A line of thunderstorms being at least 60 miles long with thunderstorms affecting at least 40 percent of its length.
LIMC Low Instrument Meteorological Conditions Ceiling less than 500 feet and/or visibility less than 1 SM. LIMC is a sub-category of Instrument Meteorological Conditions.
Appendix A A-2 Contraction Translation Definition MVMC Marginal Visual Meteorological Conditions Ceiling greater than or equal to 1,000 feet to less than or equal to 3,000 feet and/or visibility greater than or equal to 3 to less than or equal to 5 miles.
MOD ICE Moderate Icing The rate of accumulation is such that even short encounters become potentially hazardous and use of deicing/anti-icing equipment or diversion is necessary.
MOD TURB Moderate Turbulence Turbulence that causes changes in attitude (pitch, roll, yaw) and/or altitude, but the aircraft remains in positive control at all times. It usually causes variations in indicated airspeed.
MT OBSC Mountain Obscuration Conditions over significant portions of mountainous geographical areas are such that pilots in-flight should not expect to maintain visual meteorological conditions or visual contact with mountains or mountain ridges near their route of flight.
OBSC Obscured Thunderstorm or Cumulonimbus Obscured by haze, smoke, or cloud or cannot be readily seen due to darkness.
OCNL Occasional Thunderstorms or Cumulonimbus An area with a maximum spatial coverage between 50 and 75 percent of the area affected by the phenomena at a fixed time of during the period of validity.
SCT Scattered 25 to 50 percent of area affected.
SEV ICE Severe Icing The rate of accumulation is such that normal deicing/anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary.
SEV TURB Severe Turbulence Turbulence that causes large, abrupt changes in altitude and/or attitude. It usually causes large variations in indicated airspeed. Aircraft may be momentarily out of control.
VMC Visual Meteorological Conditions Ceiling greater than 3,000 feet and visibility greater than 5 miles.
Appendix A A-3 Contraction Translation Definition
VOLCANIC
ERUPTION Volcanic Eruption A volcano eruption has occurred when an eruption report is received from a volcano observatory. A volcanic eruption is also considered to have occurred regardless of volcano observatory notification if reported by PIREP, or ground observer, or if remote sensing data indicates that an eruption has occurred based on satellite imagery or WSR-88D radar data or any other reliable sources are identified.
VOLCANIC ASH Volcanic Ash Any ash that can be seen by any one or more of the following: satellite imagery (visible, IR, multi-channel or TOMS), PIREPs, ground observations, radar and VAFTAD (In the event volcanic ash is entrained in clouds, the volcanic ash will be treated as visible using the VAFTAD as guidance).
WDLY SCT Widely Scattered Less than 25 percent of area affected.
WDSPR Widespread 50 percent or greater of the area affected.
Appendix B APPENDIX B. STANDARD CONVERSION CHART Figure B-1. Standard Conversion Chart Speed - Distance Temperature Pressure - Altitude Altimeter Setting M/H KTS KM/H ° F °C INS. MBS./hPas.
100- 180 120 50 INS. MBS./hPas. 100 5 FT* 28.5 965 110 12 400 230 970 90 -170 110 40 13 • 220 210 100 160 100 14 -200 - 190 980 80 150 90 15 500 180 29.0 90 30 - 170 140 80 16 - 160 • 990 80 70 130 17 - 150 120 70 20 18 600 - 140 - 130 29.5 - 1000 60 70 60 10 19 • 120 50 10 20 - 110 100 • 1010 60 700 - 100 90 40 21 90 30.0 22 50 80 30 80 - 1020 23 70 70 20 800 24 60
•- 10 • 1030 10 25 50 30.5 50 26 40
• 1040 40 -20 27 - 900 30 20 -10 30 28 20 -20 31.0 -1050 10 10 20 -30 29 10
- 1000 10 -30 30
- 1060 -40 -40 31 - 1050 •- 10 M/H KTS KM/H ° F ° C INS. MBS./hPas. * Standard Atmosphere 100'S FT* 31.5 INS. MBS./hPas. - 1065 B-1
Appendix C APPENDIX C. DENSITY ALTITUDE CALCULATION To determine density altitude:
1. Set the aircraft's altimeter to 29.92 inches of Mercury. The altimeter will indicate pressure altitude.
2. Read the outside air temperature.
3. Mark the intersection of pressure altitude (horizontal) and temperature (vertical) lines on the chart.
4. Read the density altitude from the diagonal lines.
Figure C-1. Density Altitude Computation Chart 20,000 + + +
STANDARD ATMOSPHERE + + + + + +
DENSITY ALTITUDE 15,000 + 15,000 10,000 + + 10,000 5,000 ‡ 5,000 + + + + + - 5,000 + + + _+ + + -5,000 -50 -40 -30 -20 -10 Temperature °C 0°C 10 20 30 40 50 -50 -40 20 Q°F 2° Temperature °F 40 60 80 100 120 C-1
Appendix D D-1 APPENDIX D. INTERNET LINKS Table D-1. Selected National Weather Service (NWS) Links
NWS WEBSITE LINKS National Weather Service (NWS) Aviation Digital Data Service (ADDS) Aviation Weather Center (AWC) Storm Prediction Center (SPC) Alaska Aviation Weather Unit (AAWU) Center Weather Service Units (CWSU) Weather Forecast Office (WFO) Weather Forecast Office (WFO) Honolulu, HI –Aviation Products Table D-2. Selected Federal Aviation Administration (FAA) Links
FAA WEBSITE LINKS Federal Aviation Administration (FAA) Air Traffic Control System Command Center (ATCSCC) Flight Service Operations
Appendix E APPENDIX E. WSR-88D WEATHER RADAR NETWORK Figure E-1. WSR-88D Weather Radar Network Sites KATE KCBW КОІХ KMSK KGGW *KMBX OKMVX KDLH
OKIFX OKBIS GIX KELX KABR O KCRB d KRIW KUDX KFSDO KARY КИКУ :ĆỂR KEUF © KBGM- EBE KLŘX KNIX KCYS KLYX KOAX O KLOT KCLEO «кссх / OKRGK KFTGO ÖKUEX IL O 1) KISX| KIND OKILN KRLX
• KMUX O KCLD ÖKEAX OKAKQ © KHNK KEIR KI CE KPUX O KDDCO OKIC Ö KSGF KRAX" KVBX O KEYXO O KVTX KABX KVNE KINS OKSEX KNQI *коНі OKLIX © KNKX KYUX KIWA KF SX кніх KFDX СКАМА ÖKLBB OKFDR OKTLX KLZK KCWKO КВИХ KMXX O КЕРС RJCx • ОКСАЕ OKCLX КЕМХ SKEPZ KMAF • KDYXO OKFWS OKSHV КРОЕ KJAN KEOXO O EVAI
RICH LPLA кАлт KGRK * кихСя КМОВ OKMLE
KOPX KEWX KHGX KTBWO O KAMX
PAECO PAPD OKCRP O KBRO PAHC - О РИКУ PINO KBYX T CER RKSGIO PAIH PHKM O
POTA (O RKIK E-1
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