China Civil UAV Theory Questions — Questions 581–590
Unofficial study reference only. Not affiliated with or endorsed by any civil aviation authority — the official syllabus and regulations prevail.
UAV-Q0581. Hail that seriously endangers flight safety is usually associated with which cloud?
Explanation
Strong thunderstorm clouds (cumulonimbus) have strong updrafts that support ice crystal growth into hail.
UAV-Q0582. If wind direction is SE, the wind comes from
Explanation
Wind direction SE (southeast wind) means wind blows from the southeast.
UAV-Q0583. Northwest wind can be expressed as
Explanation
Northwest wind has a direction angle of 315°, abbreviated NW (North West).
UAV-Q0584. In weather forecast classification, which is INCORRECT?
Explanation
Basic weather forecast categories are synoptic forecasts (predicting weather system changes) and meteorological element forecasts (predicting temperature, wind, and other elements). “High wind and cooling forecasts” are specific weather phenomenon forecasts, not a basic category.
UAV-Q0585. In the standard atmosphere, sea-level temperature and pressure are:
Explanation
The standard atmosphere defines sea-level temperature at 15°C and pressure at 1013.25 hPa (760 mmHg).
UAV-Q0586. The force causing originally still air to move vertically is called:
Explanation
The force causing still air to move vertically is called convective lifting force, with thermal and dynamic causes.
UAV-Q0587. The same UAV flies two GPS-altitude 200-meter cruise flights at midday and in the evening on the same day, with the same ground reference pressure.
Explanation
At midday, higher temperature means lower air density, slower pressure decrease with height, and lower pressure altitude; in the evening, lower temperature means greater air density, faster pressure decrease, and higher pressure altitude.
UAV-Q0588. According to International Civil Aviation Organization rules, cloud amount for overcast skies is:
Explanation
The International Civil Aviation Organization uses the 8-point scale; overcast cloud amount is 8.
UAV-Q0589. Troposphere height in Earth's mid-latitudes is about
Explanation
Troposphere height: about 16 km at the equator, about 11 km at mid-latitudes, about 8 km at the poles.
UAV-Q0590. Which statement about airflow motion is correct?
Explanation
Study note: high pressure flows to low pressure. The horizontal pressure gradient force moves air from high-pressure to low-pressure regions, forming wind.