Task C. Weather

Question 1

What are the different approved sources of Weather data?

Answer 1

National Weather Service
Flight Service Station
Aviation Weather Center

Question 2

What are the acceptable weather products that can be used for preflight planning?

Answer 2

Surface aviation weather observations (METARs)
Upper Air Observations (PIREPs, AMDAR, MDCRS)
Radar Observations (four different types)
Service Outlets (FSS, TIBS, HIWAS)

Question 3

What are the different types of weather briefing?

Answer 3

Standard
Abbreviated
Outlook

Question 4

What is the composition of the atmosphere?

Answer 4

78 percent nitrogen
21 percent oxygen
1 percent other gases such as argon or helium

Question 5

What is the importance of atmospheric stability?

Answer 5

Because it determines whether or not air will rise and cause storms, sink and cause clear skies, essentially do nothing. Stability is dependent upon the Dry and Saturated Adiabatic Lapse Rates and the Environmental Lapse Rate.

Question 6

What is the definition of wind shear?

Answer 6

Wind shear is a change in wind speed and direction over a short distance. It can occur either horizontally or vertically and is most often associated with strong temperature inversions or density gradients. Windshear can occur at high or low altitudes.

Question 7

What are the different sources of wind shear?

Answer 7

Frontal activity, thunderstorms, temperature inversions, surface obstructions

Question 8

How can you avoid mountain waves?

Answer 8

Turbulence caused by extreme mountain waves can extend into all altitudes that you might use, but dangerous turbulence can usually be avoided by clearing the mountains at least half again as high as the height of the mountain.

Question 9

What is the standard atmosphere at sea level?

Answer 9

59 degrees F (15 degrees C)
29.92 Hg (1013.2 mb)

Question 10

What is the standard lapse rate in temperature and pressure?

Answer 10

Standard temp lapse rate 3.5 degrees F (or 2 degrees C) per 1,000 feet altitude gain up to 36,000 (then constant)

Standard pressure lapse rate 1 inch Hg per 1,000 feet altitude gain up

Question 11

What are the different types of precipitation?

Answer 11

Rain (RA), Drizzle (DR), Snow (SN), Hail (GR), Ice Pellets (PL), Thunderstorms (TS), Ice crystals (IC)

Question 12

What are fronts?

Answer 12

Fronts are the boundary layer between air masses (where weather happens)

Question 13

Explain the different types of fronts.

Answer 13

Cold fronts: A cold front is when a mass of cold air moves to displace warm air,

Warm Fronts: When warm air overtakes and replaces cooler air.

Stationary Front: No apparent movement because the opposing forces of the two air masses are relatively balanced.

Occluded Front: Occurs when a fast-moving cold front catches up to a slow-moving warm front.

Question 14

What are the requirements for cloud formation?

Answer 14

Formation requires Moisture to be lifted, where it condenses at its dew point into visual Moisture.

Question 15

What causes turbulence?

Answer 15

Turbulence is caused by the relative movement of disturbed air through which an aircraft is flying. Its origin may be thermal or mechanical, and it may occur either within or clear of cloud.

Question 16

What are the severity types of turbulence?

Answer 16

Light

Moderate

Severe

Extreme

Question 17

What is light turbulence?

Answer 17

Light turbulence momentarily causes slight changes in altitude and/or attitude or a slight bumpiness. Occupants of the airplane may feel a slight strain against their seat belts.

Question 18

What is Moderate turbulence?

Answer 18

Moderate turbulence is similar to light turbulence but somewhat more intense. There is, however, no loss of control of the airplane. Occupants will feel a definite strain against their seat belts and unsecured objects will be dislodged.

Question 19

What is severe turbulence?

Answer 19

Severe turbulence causes large and abrupt changes in altitude and/or attitude and, usually, large variations in indicated airspeed. The airplane may momentarily be out of control. Occupants of the aircraft will be forced violently against their seat belts.

Question 20

What is extreme turbulence?

Answer 20

The airplane is tossed violently about and is impossible to control. It may cause structural damage.

Question 21

What is required for a thunderstorm to form?

Answer 21

Moisture

Instability

Lifting mechanism

Question 22

What is a microburst?

Answer 22

It all starts with the development of a thunderstorm and the water droplets/hailstones being suspended within the updraft. Sometimes an updraft is so strong it suspends large amounts of these droplets and hailstones in the upper portions of the thunderstorm.

Question 23

What are the different types of icing?

Answer 23

Mixed Ice

Clear Ice

Rime Ice

Question 24

When can we expect frost in our aircraft?

Answer 24

Normally occurs on clear, calm wind nights when air temperature and dew point are below freezing. May occur when descending from a zone of freezing temperatures into high humidity.

Question 25

What is fog and how can it form?

Answer 25

Fog is a surface-based cloud composed of either water droplets or ice crystals. A small temperature-dew point spread is essential for the fog to form. Therefore, fog is prevalent in coastal areas where Moisture is abundant. However, fog can occur anywhere.

Question 26

What are the different types of obstruction to vision that we can encounter while flying?

Answer 26

Obstructions to vision are listed in the Manual of Surface Observations (WBAN), Circular N, as follows: fog, ground fog, blowing snow, blowing sand, blowing dust, ice fog, haze, smoke, dust, and blowing spray.

Question 27

What is the importance of a flight assessment tool?

Answer 27

Because every flight has some level of risk, it is critical that pilots are able to differentiate, in advance, between a low-risk flight and a high-risk flight and then establish a review process and develop risk mitigation strategies. A FRAT enables proactive hazard identification, is easy to use, and can visually depict risk. It is an invaluable tool in helping pilots make better go/no-go decisions and should be a part of every flight.