Remote Pilot – Small Unmanned Aircraft Systems › III. Weather › Task B. Effects of Weather on Performance

UA.III.B.K1h

Knowledge

Weather factors and their effects on performance.

Hail

Study note

Get a short, cited explanation of this element written from the FAA handbooks: the core idea, the numbers that matter, common test traps, and a quick self-check.

From the FAA library

Pilot's Handbook of Aeronautical Knowledge p. 12-24
Chapter 12: Weather Theory › Air Masses › Hail
icing conditions. Pilots should be alert for icing anytime the temperature approaches 0 °C and visible moisture is present. Hail Hail competes with turbulence as the greatest thunderstorm hazard to aircraft. Supercooled drops above the freezing level begin to freeze ... other drops latch on and freeze to it, so the hailstone grows—sometimes into a huge ice ball. Large hail occurs with severe thunderstorms with strong updrafts that have built to great heights. Eventually, the hailstones fall, possibly some distance…
Pilot's Handbook of Aeronautical Knowledge p. 12-17
Chapter 12: Weather Theory › Atmospheric Stability › Precipitation
support them. It can occur in several forms as it falls toward the Earth, including drizzle, rain, ice pellets, hail, snow, and ice. Drizzle is classified as very small water droplets, smaller than 0.02 inches in diameter. Drizzle usually accompanies ... indication of a temperature inversion and that freezing rain exists at a higher altitude. In the case of hail, freezing water droplets are carried up and down by drafts inside cumulonimbus clouds, growing larger in size as they come…
Pilot's Handbook of Aeronautical Knowledge p. 12-22
Chapter 12: Weather Theory › Flight Toward an Approaching Cold Front › Thunderstorms
heavy for the cloud to support and begin falling in the form of rain or hail. This creates a downward motion of the air. Warm, rising air; cool, precipitation-induced descending air; and violent turbulence all exist within and near ... heights of 50,000 to 60,000 feet depending on latitude. Flying under thunderstorms can subject aircraft to rain, hail, damaging lightning, and violent turbulence. A good rule of thumb is to circumnavigate thunderstorms identified as severe or giving…
Aeronautical Information Manual p. 7-1-40
Chapter 7. Safety of Flight › Section 1. Meteorology › 7-1-12. ATC Inflight Weather Avoidance Assistance
radar antenna when it strikes an object or moisture which may be in the form of rain drops, hail, or snow. The larger the object is, or the more dense its reflective surface, the stronger the return will be presented ... systems can often determine the intensity of a precipitation area, but the specific character of that area (snow, rain, hail, VIRGA, etc.) cannot be determined. For this reason, ATC refers to all weather areas displayed on ATC radar scopes…
Pilot's Handbook of Aeronautical Knowledge p. 13-21
Chapter 13: Aviation Weather Services › Electronic Flight Displays (EFD) /Multi-Function Display (MFD) Weather › NEXRAD Limitations
reflectivity does not provide adequate information from which to determine cloud layers or type of precipitation with respect to hail versus rain. Therefore, a pilot may mistake rain for hail. In addition, the base reflectivity is sampled at the minimum…
Pilot's Handbook of Aeronautical Knowledge p. 13-12
Chapter 13: Aviation Weather Services › Aviation Forecasts › Convective Significant Meteorological Information (WST)
safety of every flight. Convective SIGMETs are issued for severe thunderstorms with surface winds greater than 50 knots, hail at the surface greater than or equal to ¾ inch in diameter, or tornadoes. They are also issued to advise pilots ... INTSFYG AREA SEV TS MOVG FROM 24045KT. TOPS ABV FL450. WIND GUSTS TO 60KTS RPRTD. TORNADOES…HAIL TO 2 IN… WIND GUSTS TO 65KTS POSS…