Narrative:

During climb thru approximately 15000 ft captain pm (pilot monitoring) took a call from flight attendant. All operations normal to this point. Lead flight attendant (flight attendant) informed captain that there was a very strong odor; a burning smell; what appeared to be smoke and acrid haze permeating the cabin; especially toward the back of the aircraft. She noted that the smell was very strong and haze was getting worse. Captain questioned if they could identify the location or source and they said no but were looking. Captain decided that best and safest course of action was to [advise ATC] and coordinate [a return to the departure airport]. First officer (first officer) remained flying pilot and worked with ATC to turn aircraft back to [the departure airport]. Captain ran smoke; fire or fumes checklist and spoke again with flight attendants. Passengers were then briefed. Further coordination with ATC; company and maintenance. Pm then returned to assist PF (pilot flying) in descent and arrival planning and briefing. Final call to fas pm was informed that smell and haze was dissipating and uneventful overweight landing weight was made. Arff met aircraft and no hotspots were noted on aircraft. Aircraft was then taxied to gate. No further abnormal events.

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Original NASA ASRS Text

Title: B737 Captain reported smoke in the cabin during climbout.

Narrative: During climb thru approximately 15000 ft Captain PM (Pilot Monitoring) took a call from flight attendant. All operations normal to this point. Lead FA (Flight Attendant) informed Captain that there was a very strong odor; a burning smell; what appeared to be smoke and acrid haze permeating the cabin; especially toward the back of the aircraft. She noted that the smell was very strong and haze was getting worse. Captain questioned if they could identify the location or source and they said no but were looking. Captain decided that best and safest course of action was to [advise ATC] and coordinate [a return to the departure airport]. FO (First Officer) remained flying pilot and worked with ATC to turn aircraft back to [the departure airport]. Captain ran smoke; fire or fumes checklist and spoke again with flight attendants. Passengers were then briefed. Further coordination with ATC; company and maintenance. PM then returned to assist PF (Pilot Flying) in descent and arrival planning and briefing. Final call to FAs PM was informed that smell and haze was dissipating and uneventful overweight landing weight was made. ARFF met aircraft and no hotspots were noted on aircraft. Aircraft was then taxied to gate. No further abnormal events.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.