What turbulence should be reported when it causes erratic changes in altitude and/or attitude one-third to two-thirds of the time?

The correct choice describes "Intermittent light turbulence," which is characterized by erratic changes in altitude and/or attitude happening one-third to two-thirds of the time. This level of turbulence indicates that while the aircraft may experience some fluctuations, these changes are not constant and are more sporadic in nature.

Understanding the classification of turbulence is crucial for flight safety and performance assessments. Intermittent light turbulence can warrant reporting because it can affect flight operational procedures and passenger comfort, even though it is not as severe as moderate or severe turbulence. Each classification serves a specific purpose in guiding pilots and dispatchers on how to respond or prepare for varying conditions during flight.

Other classifications mentioned, such as moderate or severe turbulence, depict significantly more drastic encounters with respect to aircraft control and passenger safety. Light chop refers to minor, generally inconsequential bumps that don’t significantly impact altitude or attitude. Recognizing this distinction helps in effectively communicating the type of turbulence encountered in flight operations.