Subchapter 9.7 – PIREPs and Flight Condition Reports
PIREP stands for Pilot Report. A PIREP is an observation about weather, turbulence, icing, wind, or other flight conditions that you transmit to ATC en route. PIREPs are not requests; they are contributions to aviation safety. Every pilot depends on PIREPs from other pilots to avoid hazards.
ATC actively solicits PIREPs, especially when there are reports of: