PPL PPL Aviation Weather Services and Meteorology 2 — Questions and Answers
Question 1: What hazardous weather does a SIGMET warn about?
- Routine light turbulence along airways
- Conditions hazardous to all aircraft such as severe turbulence, severe icing, or volcanic ash (Correct answer)
- Minor weather changes requiring alternate route planning
- Minimums below VFR at destination airports
Correct answer: Conditions hazardous to all aircraft such as severe turbulence, severe icing, or volcanic ash
SIGMETs are issued for meteorological conditions significant to all aircraft including severe turbulence, extreme icing, dust storms, and volcanic ash clouds.
Question 2: How are Winds Aloft forecasts (FB) used in flight planning?
- To determine which runway will be in use at the destination
- To plan fuel burn, flight time, and favorable cruise altitudes based on forecast winds at various levels (Correct answer)
- To identify icing levels along the route
- To determine turbulence severity for passenger comfort
Correct answer: To plan fuel burn, flight time, and favorable cruise altitudes based on forecast winds at various levels
Winds Aloft forecasts provide predicted wind direction, speed, and temperature at various altitudes, enabling pilots to optimize route altitude for tailwinds, fuel efficiency, and flight time.
Question 3: What cloud types and conditions characterize a stable atmosphere?
- Towering cumulonimbus clouds with severe turbulence
- Stratiform (layered) clouds, smooth flight conditions, and reduced visibility in haze (Correct answer)
- Rapid vertical development of cumulus clouds
- Clear skies with unlimited visibility and smooth air
Correct answer: Stratiform (layered) clouds, smooth flight conditions, and reduced visibility in haze
A stable atmosphere resists vertical mixing, producing flat stratus clouds, steady precipitation, haze, and smooth but often instrument-weather conditions.
Question 4: Why are thunderstorms particularly dangerous to light aircraft?
- They create high ceilings that prevent VFR flight
- They generate severe turbulence, lightning, large hail, wind shear, and microbursts that can exceed aircraft structural limits (Correct answer)
- They cause icing only at high altitudes above the freezing level
- They reduce engine performance due to elevated temperatures
Correct answer: They generate severe turbulence, lightning, large hail, wind shear, and microbursts that can exceed aircraft structural limits
Thunderstorms can produce turbulence capable of structural failure, wind shear that overwhelms aircraft performance, large hail that destroys windshields, and lightning that disables avionics.
Question 5: What does 'VFR NOT RECOMMENDED' in a weather briefing mean?
- VFR flight is legally prohibited in the briefing area
- The briefer advises that conditions are not suitable for VFR flight, though the pilot retains final authority (Correct answer)
- IMC conditions exist at the destination and alternate airports
- ATC has temporarily restricted VFR flight in the region
Correct answer: The briefer advises that conditions are not suitable for VFR flight, though the pilot retains final authority
'VFR Not Recommended' is the briefer's professional advisory opinion that conditions are hazardous for VFR flight; however, the pilot in command makes the final go/no-go decision.
Question 6: What is a microburst and why is it hazardous during takeoff and landing?
- A light, refreshing downdraft common in mountain areas
- An intense localized downdraft that creates dangerous wind shear with a sudden headwind followed by a severe tailwind (Correct answer)
- A small area of localized ground fog that reduces RVR
- Clear air turbulence associated with the upper-level jet stream
Correct answer: An intense localized downdraft that creates dangerous wind shear with a sudden headwind followed by a severe tailwind
A microburst is a powerful downdraft that diverges outward on impact with the ground, first producing a headwind then a sudden tailwind, causing rapid and potentially unrecoverable airspeed and altitude loss.
PPL PPL Aviation Weather Services and Meteorology 2
What hazardous weather does a SIGMET warn about?