Crucial because "severe" turbulence for a small Cessna might only be "light" for a large Airbus A380 .
Aircraft is tossed violently; practically impossible to control. Potential for structural damage to the airframe. Reports must also specify how often the bumps occur: Occasional: Less than 1/3 of the time. Intermittent: 1/3 to 2/3 of the time. Continuous: More than 2/3 of the time. 4. Common Types of Turbulence
A standard pilot report ( PIREP ) for turbulence must include several critical data points to ensure air traffic control (ATC) and other aircraft have a clear picture of the conditions:
Understanding the cause helps in formulating an accurate report and choosing an avoidance strategy: Chapter 8. FAA Weather Services
Turbulence is officially categorized into four intensity levels based on its effect on the aircraft and occupants: Aircraft Reaction Occupant/Cabin Effect Slight, erratic changes in altitude or attitude. Slight strain against seat belts; liquids may splash. Moderate More intense changes; aircraft remains in positive control. Definite strain against belts; unsecured objects dislodge. Severe Large, abrupt changes; momentary loss of control.
Whether the turbulence occurred in clouds or clear air (CAT). 2. Intensity Classifications
The specific coordinates or waypoint where the event occurred and the time in UTC.
Occupants forced violently against belts; walking is impossible.