AIM ¶ 7-1-21 — Turbulence PIREPs
AIM 7-1-21: How to report turbulence PIREPs to ATC, including intensity classifications (light, moderate, severe, extreme) and required report elements.
When you hit turbulence, ATC and other pilots need to know — fast. AIM 7-1-21 urges pilots to report turbulence as soon as practicable so controllers can warn following traffic and forecasters can refine their products. This is a recommended practice, not an FAR mandate, but it's a core airmanship expectation.
A proper turbulence PIREP includes:
- Aircraft location
- Time of occurrence (UTC)
- Turbulence intensity (light, moderate, severe, extreme)
- Whether it occurred in or near clouds
- Altitude or flight level
- Type of aircraft
- Duration of the turbulence
Intensity is classified per Table 7-1-11 based on aircraft reaction and reaction inside the cabin:
- Light — slight, erratic changes; occupants feel slight strain
- Moderate — greater intensity but aircraft remains in positive control; unsecured objects dislodged
- Severe — large, abrupt changes; aircraft momentarily out of control
- Extreme — aircraft violently tossed; possible structural damage
Use occasional (<1/3 of the time), intermittent (1/3–2/3), or continuous (>2/3) to describe duration. Above 15,000 ft and not associated with cumuliform clouds, report as CAT (clear air turbulence) with the appropriate intensity, or as light/moderate chop.
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What is the direct cause of all wind?