FAA Aircraft Dispatcher (ADX)MeteorologyMedium
A pilot report describes turbulence that causes definite strains against the seat belt or shoulder harness, unsecured objects are dislodged, and occupants feel a definite variation in altitude and/or attitude, but the aircraft remains in positive control at all times. How should this turbulence be classified according to standard PIREP reporting criteria?
- ASevere turbulence
- BLight turbulence
- CModerate turbulence
- DExtreme turbulence
Show answer & explanationAnswer & explanation
Correct answer: C. Moderate turbulence
Moderate turbulence is characterized by definite strains against seat belts/harnesses, dislodging of unsecured objects, and noticeable variations in altitude/attitude, while the pilot maintains positive control of the aircraft at all times. Severe turbulence, by contrast, involves large abrupt changes in altitude/attitude and may cause momentary loss of control.
Why the other options are wrong
- A. Severe turbulence involves large, abrupt changes and possible momentary loss of control, which is not described here.
- B. Light turbulence causes only slight, erratic changes with occupants feeling a slight strain, not definite strains or dislodged objects.
- D. Extreme turbulence is violent, tosses the aircraft about, and may cause structural damage—far beyond what is described.
Turbulence Intensity Reporting Criteria
Standardized PIREP categories (light, moderate, severe, extreme) describe turbulence based on effects on occupants and aircraft control.
- Light: slight, erratic changes in altitude/attitude, slight strain felt
- Moderate: definite strains, dislodged objects, aircraft remains in control
- Severe: large abrupt changes, possible momentary loss of control
- Extreme: violent tossing, aircraft may be impossible to control, structural damage possible
Memory trick: Light shakes, Moderate strains, Severe throws, Extreme breaks.