Aeronautical Information Manual (AIM), page 542

Index   541 -- Page 542 -- 543

AIM      CHG 2                                                                                             3/15/07

As with mountain wave turbulence or clear air               The best available information on this phenomenon
turbulence, an invisible plume may be encountered           must come from pilots via the PIREP reporting
unexpectedly. Cooling towers, power plant stacks,           procedures. All pilots encountering hazardous
exhaust fans, and other similar structures are depicted     plume conditions are urgently requested to report
in FIG 7-5-2.                                               time, location, and intensity (light, moderate, severe,
Pilots are encouraged to exercise caution when flying       or extreme) of the element to the FAA facility with
in the vicinity of exhaust plumes. Pilots are also          which they are maintaining radio contact. If time and
encouraged to reference the Chart Supplement U.S.           conditions permit, elements should be reported
where amplifying notes may caution pilots and               according to the standards for other PIREPs and
identify the location of structure(s) emitting exhaust      position reports (AIM Paragraph 7-1-22, PIREPS
plumes.                                                     Relating to Turbulence).

FIG 7-5-2 Plumes 7-5-14 Potential Flight Hazards

Page 542 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   541 -- Page 542 -- 543