Ground school, on live data

Weather Information

CA.I.C · PA.I.C · FI.III.C

Sources, reports, forecasts and hazards — and how to tell what a real one is saying when it does not look like the example in the book.

• The atmosphere and stability

  Layers, the standard atmosphere, lapse rates and inversions — and the one question stability actually answers.

• Wind

  Pressure gradient, Coriolis and friction, and why the surface wind differs from the wind a few thousand feet up.

• Moisture and precipitation

  The two growth processes, and how the vertical temperature profile decides rain, snow, ice pellets or freezing rain.

• Air masses and frontsInteractive

  Why a cold front gives you a narrow violent band and a warm front hours of layer cloud — with the fronts on the current surface analysis.

• Clouds

  Cloud as the visible record of rising air, the four sources of lift, and reading shape as a report on stability.

• Fog, mist and obstructions to visibilityInteractive

  The seven mechanisms and whether the sun will clear each one, with the stations closest to their dewpoint right now.

• ThunderstormsInteractive

  Three ingredients, three stages, seven hazards, and the microburst sequence — with the convective SIGMETs in force.

• Structural icing and the freezing levelInteractive

  Why droplet size decides clear or rime, and what freezing rain says about air you cannot see. AIRMET Zulu live.

• Turbulence, shear and mountain wavesInteractive

  The atmosphere as a fluid over an obstruction, and why a lee-side downdraft can out-climb a light aircraft. AIRMET Tango live.

• How to read a METARInteractive

  Every group in order, then a report a US station is sending right now to call before you reveal the answers.

• How to read a TAF

  Forecast periods, change groups, and how far each one can be trusted.

• VFR, MVFR, IFR and LIFR

  Where the thresholds come from, and why the worse of the two always wins.

• PIREPs, AIRMETs, SIGMETs and TFRs

  Who issues them, what they cover, and which are advisory against regulatory.

• Sources, products and the go/no-go decision

  What each product is for, what MOS is not allowed to forecast, and why the decision continues after departure.

That covers every element of the ACS weather task: composition and stability, wind, temperature, moisture and precipitation, weather system formation, clouds, turbulence, thunderstorms, frost and icing, fog and mist, obstructions to visibility, the briefing, the sources, the reports and charts, in-flight advisories, and the go/no-go decision.

Navigation and cross-country planning

CA.I.D · FI.II.I

• Building a nav log, step by step

  Course, heading, groundspeed and time, in the order you actually work them out.

• How to read an approach plate

  Every section of the chart, and what each minimum is telling you.

Being built next

• Fuel planning and reserves
• Altitude selection: hemispheric rule, terrain, winds and oxygen
• Preferred routes and CDRs — what ATC will actually clear you for
• Obstacles, terrain and minimum safe altitudes

National airspace system Planned

CA.I.E · FI.II.G

Classes A through G against real airspace rings, special use airspace with its current activity, the Mode C veil, and military training routes — each shown on the chart it is drawn on.

Performance and limitations Planned

CA.I.F · FI.II.F

Density altitude at a real field right now, takeoff and landing distance, crosswind components against real runway alignments and the live wind. The fifteen calculators already do the arithmetic; these lessons explain what the answer means.