China Civil UAV Theory Questions — Questions 511–520
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UAV-Q0511. Aircraft icing is ice accumulating on certain parts of the airframe surface. Aircraft icing is mainly divided into three major types:
Explanation
Aircraft icing is mainly divided into three major categories — ice, rime, and frost — and ice is further divided into clear ice, rime ice, and white ice.
UAV-Q0512. At night, temperatures drop and low-level inversions often occur, which causes:
Explanation
A nighttime low-level inversion is stable, so pollutants and water vapor do not disperse easily, readily forming fog and haze.
UAV-Q0513. The properties of an air mass are
Explanation
An air mass has large horizontal and vertical extent and small horizontal temperature gradients (uniform elements).
UAV-Q0514. An air mass is a large air mass whose meteorological elements (mainly temperature, humidity, and hydrostatic stability) are relatively uniform in horizontal distribution. Which of the following is INCORRECT?
Explanation
An air mass has a small horizontal temperature gradient (uniformly distributed elements), so option C is incorrect.
UAV-Q0515. When flying in descending airflow on a mountain's leeward slope, besides losing altitude, the serious hazard is caused by:
Explanation
In descending airflow on a mountain's leeward slope, the pressure altimeter is based on a standard atmosphere model while the actual atmosphere differs, so readings are higher than actual altitude, creating danger.
UAV-Q0516. Which physical quantity reflects how humid the atmosphere is? ( )
Explanation
Relative humidity is the percentage of water vapor pressure to saturation vapor pressure in the air, reflecting how humid the atmosphere is.
UAV-Q0517. What is the main cause of low-level wind shear?
Explanation
Low-level wind shear is mainly formed by severe convective weather (such as thunderstorms), frontal activity, radiation-inversion low-level jets, and similar conditions, which cause violent airflow changes.
UAV-Q0518. The atmosphere's heat comes mainly from absorbing solar radiation. Which statement is correct?
Explanation
Study note: atmosphere 78/21/1; for radiation, look for 24. See the solar radiation distribution chart: the atmosphere absorbs 24%.
UAV-Q0519. A hand-launched electric fixed-wing civil UAV generally has difficulty flying autonomously above which wind force?
Explanation
Hand-launched electric fixed-wing UAVs have weak wind resistance; autonomous flight becomes difficult above force 4 winds (refer to common UAV wind resistance standards).
UAV-Q0520. Which statement about fog is INCORRECT?
Explanation
Fog mainly affects visibility, interfering with manual takeoff and landing and aerial photography equipment results; heading autonomous flight mainly relies on sensors and is less affected by fog.