Weather

Question 1

What are the standard pressure and temperature values for sea level?

Answer 1

Pressure: 29.92 inHg (or 1013.25 hPa).

Temperature: 15°C (59°F).

These values are used as a baseline for calculating pressure and density altitude, ensuring consistent aviation performance standards.

Ref: PHAK Chapter 11

Question 2

What is the standard temperature lapse rate?

Answer 2

2°C per 1,000 feet of altitude gain.

This assumes stable atmospheric conditions and is critical for calculating density altitude and understanding temperature changes with altitude.

Ref: PHAK Chapter 11

Question 3

What is the standard pressure lapse rate?

Answer 3

1 inHg per 1,000 feet of altitude gain.

Understanding this helps in calibrating altimeters and calculating altitude adjustments.

Ref: PHAK Chapter 11

Question 4

Discuss surface analysis charts.

Answer 4

Surface analysis charts provide a snapshot of pressure systems, fronts, isobars, and weather conditions at the surface.

Key features include high/low-pressure systems, fronts, and wind patterns.

Ref: Aviation Weather Services (AWS), Chapter 4

Question 5

What does it mean when isobars are close together?

Answer 5

Stronger pressure gradient and higher winds.
Pilots should expect turbulent conditions and potentially hazardous weather.

Ref: AWS, Chapter 4

Question 6

What are the characteristics of a stable air mass?

Answer 6

Smooth air.

Poor visibility (due to haze or fog).

Continuous precipitation.

Stratiform clouds.

Ref: PHAK Chapter 12

Question 7

What are the characteristics of an unstable air mass?

Answer 7

Turbulent air.

Good visibility (due to vertical mixing).

Showery precipitation.

Cumuliform clouds.

Ref: PHAK Chapter 12

Question 8

What must be present in order for a thunderstorm to form?

Answer 8

Moisture.

Unstable air.

Lifting action (e.g., frontal lifting, convection, orographic lifting).

Ref: PHAK Chapter 12

Question 9

What are the three stages of a thunderstorm?

Answer 9

Cumulus Stage: Updrafts dominate, forming cumulus clouds.

Mature Stage: Updrafts and downdrafts coexist; precipitation begins.

Dissipating Stage: Downdrafts dominate, weakening the storm.

Ref: PHAK Chapter 12

Question 10

How far away should you remain from a thunderstorm?

Answer 10

At least 20 NM to avoid turbulence, hail, and lightning.

Ref: PHAK Chapter 12

Question 11

What are the different types of fog?

Answer 11

Radiation Fog: Forms on calm, clear nights as heat radiates away.

Advection Fog: Warm, moist air moves over a cooler surface.

Upslope Fog: Air is lifted along terrain and cools.
Steam Fog: Cold air moves over warm water.

Ice Fog: Forms in extremely cold temperatures.

Ref: PHAK Chapter 12

Question 12

What are the different types of ice?

Answer 12

Clear Ice: Smooth and hard, forms in cumulus clouds or freezing rain.

Rime Ice: Rough and opaque, forms in stratiform clouds.

Mixed Ice: A combination of clear and rime ice.

Ref: PHAK Chapter 10

Question 13

In what cloud types will you encounter the various types of ice?

Answer 13

Clear Ice: Cumuliform clouds.

Rime Ice: Stratiform clouds.

Mixed Ice: Embedded thunderstorms or towering cumulus.

Ref: PHAK Chapter 10

Question 14

How was the weather for today’s flight gathered?

Answer 14

Sources include METARs, TAFs, Area Forecasts, AIRMETs, SIGMETs, and weather charts.

Services like ForeFlight, AviationWeather.gov, and Flight Service Stations provide this data.

Ref: AWS Chapter 5

Question 15

What is Flight Service?

Answer 15

Flight Service provides preflight weather briefings, in-flight updates, and assistance for route changes or emergencies. Pilots can contact them via 1-800-WX-BRIEF.

Ref: AIM 4-1-1

Question 16

What is a METAR?

Answer 16

Meteorological Aerodrome Report, providing current weather at an airport, including wind, visibility, sky conditions, and altimeter setting.

Ref: AIM 7-1-30

Question 17

What are the different types of METARs and what are the valid times?

Answer 17

Routine METAR: Issued hourly.

SPECI: Special METAR for significant weather changes, issued anytime.

Ref: AIM 7-1-30

Question 18

How are the temperatures above FL240 identified?

Answer 18

Temperatures above FL240 are always negative and are preceded by a minus sign only when they are below -50°C. Temperatures between -1°C and -49°C omit the minus sign.

Ref: AIM 7-1-5

Question 19

What does 710556 mean on a winds aloft forecast at FL300?

Answer 19

71: Wind direction is 210° (subtract 50 from the first two digits for altitudes above FL240).
05: Wind speed is 5 knots.
56: Temperature is -56°C.

Ref: AIM 7-1-5

Question 20

What are the different types of Significant Weather Prognostic Charts?

Answer 20

Low-Level (Surface to FL240): Depicts areas of turbulence, freezing levels, and IFR/MVFR weather.

High-Level (FL250 to FL630): Shows jet streams, clear air turbulence (CAT), and thunderstorm activity.

Mid-Level (10,000 to FL450): Used for identifying features like volcanic ash and turbulence in this range.

Ref: AIM 7-1-6

Question 21

What are the valid times for a Significant Weather Prognostic Chart?

Answer 21

Issued four times daily.

Valid times include 12 and 24-hour forecasts for low-level charts, and 24 and 48-hour forecasts for high-level charts.

Ref: AIM 7-1-6

Question 22

What is a PIREP?

Answer 22

Pilot Report (PIREP) is a report provided by pilots regarding actual weather conditions encountered during flight.

Ref: AIM 7-1-20

Question 23

Is a PIREP in AGL or MSL?

Answer 23

Cloud bases are reported in AGL, while tops, turbulence, and icing levels are reported in MSL.

Ref: AIM 7-1-20

Question 24

What are the different levels of turbulence?

Answer 24

Light: Slight, erratic changes in altitude/attitude.

Moderate: Changes are more noticeable, and control remains with difficulty.

Severe: Large, abrupt changes; momentary control loss may occur.

Extreme: Aircraft may be out of control, with structural damage possible.

Ref: AIM 7-1-23