Weather Theory for Pilots Exam

ADVANCE FLYING ACADEMY

Weather Theory for Pilots Exam

The Weather Theory for Pilots Exam evaluates your understanding of meteorological principles, weather phenomena, and their effects on flight. This knowledge is essential for safe flight planning and in-flight decision-making. Below is a detailed study guide.

Key Topics to Study

1. The Atmosphere

Composition:
- 78% Nitrogen, 21% Oxygen, 1% trace gases.
Layers:
- Troposphere: Most weather occurs here; temperature decreases with altitude.
- Stratosphere: Stable; contains the ozone layer.
- Mesosphere, Thermosphere, Exosphere: Less relevant to flight operations.
Standard Atmosphere:
- Sea level temperature: 15°C (59°F).
- Pressure: 29.92 inHg or 1013.2 hPa.

2. Temperature and Pressure

Temperature Lapse Rate:
- Standard rate: -2°C per 1,000 feet.
Pressure Lapse Rate:
- Decreases approximately 1 inHg per 1,000 feet.
Isobars:
- Lines of equal pressure; closer spacing indicates stronger winds.
High and Low Pressure Systems:
- High: Stable weather, sinking air.
- Low: Unstable weather, rising air.

3. Moisture and Clouds

Relative Humidity:
- Percentage of moisture in the air compared to its capacity.
Dew Point:
- Temperature at which air becomes saturated and condensation occurs.
Cloud Types:
- Low Clouds: Stratus, stratocumulus, nimbostratus (rain-producing).
- Middle Clouds: Altostratus, altocumulus.
- High Clouds: Cirrus, cirrostratus, cirrocumulus.
- Vertical Development: Cumulus, cumulonimbus (associated with thunderstorms).

4. Weather Phenomena

Fronts:
- Cold Front: Fast-moving, unstable air, thunderstorms likely.
- Warm Front: Slower-moving, stable air, widespread precipitation.
- Stationary Front: Little movement; prolonged precipitation.
- Occluded Front: Cold air overtakes warm air; complex weather.
Wind Shear:
- Sudden changes in wind speed or direction, hazardous during takeoff and landing.
Turbulence:
- Caused by thermal activity, mechanical obstructions, or jet streams.
Fog Types:
- Radiation Fog: Forms on clear, calm nights.
- Advection Fog: Warm, moist air moves over a cool surface.
- Upslope Fog: Air is forced to rise and cool.
- Precipitation Fog: Evaporation saturates cooler air.
Icing:
- Rime Ice: Opaque, forms quickly.
- Clear Ice: Transparent, forms slowly and adheres strongly.
- Mixed Ice: Combination of rime and clear.

5. Thunderstorms

Stages:
- Cumulus: Updrafts dominate.
- Mature: Updrafts and downdrafts; precipitation begins.
- Dissipating: Downdrafts dominate; storm weakens.
Hazards:
- Turbulence, lightning, hail, microbursts, and wind shear.
Avoidance:
- Maintain at least 20 nautical miles distance from severe storms.

6. Winds and Currents

Coriolis Effect:
- Causes winds to deflect right in the Northern Hemisphere and left in the Southern Hemisphere.
Jet Streams:
- High-speed winds at high altitudes, influence flight time and turbulence.
Mountain Waves:
- Occur on the leeward side of mountain ranges; can cause severe turbulence.

7. Weather Reporting and Forecasting

METAR:
- Current weather observations; issued hourly.
- Format includes temperature, wind speed/direction, visibility, and sky conditions.
TAF (Terminal Aerodrome Forecast):
- Forecasts for airports, valid for 24–30 hours.
SIGMET:
- Advisories for severe weather like turbulence, icing, and volcanic ash.
PIREPs (Pilot Reports):
- Reports from pilots on actual weather conditions.

8. Flight Hazards

Microbursts:
- Small, intense downdrafts with high wind speeds; hazardous during approach and departure.
Lightning:
- Can damage electronics and temporarily blind pilots.
Volcanic Ash:
- Extremely dangerous; causes engine damage and abrasion.

Sample Questions

Multiple Choice:
What type of fog forms when moist air moves over a cooler surface?
- A. Radiation Fog
- B. Advection Fog
- C. Upslope Fog
- D. Precipitation Fog
(Correct Answer: B - Advection Fog)
True/False:
Thunderstorm avoidance requires a minimum distance of 5 nautical miles.
(Correct Answer: False – Minimum recommended distance is 20 nautical miles.)
Scenario Question:
You are approaching an airport with a reported METAR indicating wind shear. What precautions should you take during approach and landing?
Fill-in-the-Blank:
The __________ is a boundary between two air masses of different temperatures and humidity.
(Correct Answer: Front)
Practical Problem:
While cruising at 30,000 feet, you encounter significant turbulence caused by a nearby jet stream. What actions should you take to maintain safety and comfort for passengers?

Study Tips

Understand Weather Patterns:
- Study common weather systems and how they affect flight operations.
Learn to Interpret Weather Reports:
- Practice decoding METARs, TAFs, and SIGMETs.
Familiarize with Hazards:
- Focus on conditions like wind shear, turbulence, and icing that directly impact flight safety.
Use Resources:
- Study aviation weather handbooks, online simulators, or training videos to visualize concepts.
Review Real-World Cases:
- Analyze incidents involving weather-related challenges for practical insights.