Narrative:

On approach; base leg on a visual at 3;000 MSL; intercom rang once. Flight attendant reported 'smell of something burning'; sounding concerned. I directed him to keep us posted and told him we had 4 minutes to landing. We were number one with good weather and already with a clearance for a visual; so we flew an expeditious approach. No need for priority handling. After landing; flight attendant reported all clear. We had a gate hold; then taxi in. We had an additional maintenance issue; unrelated; which we had to address; but once at the gate; I asked the flight attendant for more information to make as accurate and complete logbook entry as possible. It was at that point I learned the full story. Fas identified the source of smoke smell as coming from the power port system. They turned it off; and the smoke dissipated. What bothered me is that they said the power port system had dropped offline twice (or so) and they reset it after each failure until the smoke/smell occurred. Not knowing how the system works; I'm speculating that the system shut itself down possibly as a protective function; like a circuit breaker. Could resetting the system have had the same effect of repeatedly resetting a circuit breaker; i.e. Possibly removing a layer of protection? Please pass this on to engineering and maintenance. Should we have a policy or procedure not to repeatedly reset this system or reset it at all? Should there be a limit to resets and/or notification to the cockpit crew if accomplished?it's hard to blame the fas; but it would have been nice to have had the information included in the intercom call that the power ports had dropped off and been reset repeatedly. This crew got it right by recognizing the link; assuming the power port system truly was at fault; but some crews are more capable than others; as we all know. Without knowledge of the prior resets; we pilots would not and did not have any idea what the likely source of the smell was; nor could we offer any advice or commands to turn off the power port system. I'm not comfortable being behind my fas about the likely source of smoke. Fas got the action right; but the communication of the likely source was lacking. If smoke and/or burning smells were related to the repeated power port resets; I recommend a reset policy similar to other cabin circuit breaker resets. Further; this system should be reviewed to ensure a protection system is in place which would prevent whatever overheated in this event. I was very happy this happened so close to landing; daylight; good weather; etc.

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Original NASA ASRS Text

Title: B737-800 Captain reported the flight attendants notified the cockpit of a burning smell related to power ports in the cabin shortly before landing.

Narrative: On approach; base leg on a visual at 3;000 MSL; intercom rang once. FA reported 'smell of something burning'; sounding concerned. I directed him to keep us posted and told him we had 4 minutes to landing. We were number one with good weather and already with a clearance for a visual; so we flew an expeditious approach. No need for priority handling. After landing; FA reported all clear. We had a gate hold; then taxi in. We had an additional maintenance issue; unrelated; which we had to address; but once at the gate; I asked the FA for more information to make as accurate and complete logbook entry as possible. It was at that point I learned the full story. FAs identified the source of smoke smell as coming from the power port system. They turned it off; and the smoke dissipated. What bothered me is that they said the power port system had dropped offline twice (or so) and they reset it after each failure until the smoke/smell occurred. Not knowing how the system works; I'm speculating that the system shut itself down possibly as a protective function; like a circuit breaker. Could resetting the system have had the same effect of repeatedly resetting a circuit breaker; i.e. possibly removing a layer of protection? Please pass this on to engineering and maintenance. Should we have a policy or procedure not to repeatedly reset this system or reset it at all? Should there be a limit to resets and/or notification to the cockpit crew if accomplished?It's hard to blame the FAs; but it would have been nice to have had the information included in the intercom call that the power ports had dropped off and been reset repeatedly. This crew got it right by recognizing the link; assuming the power port system truly was at fault; but some crews are more capable than others; as we all know. Without knowledge of the prior resets; we pilots would not and did not have any idea what the likely source of the smell was; nor could we offer any advice or commands to turn off the power port system. I'm not comfortable being behind my FAs about the likely source of smoke. FAs got the action right; but the communication of the likely source was lacking. If smoke and/or burning smells were related to the repeated power port resets; I recommend a reset policy similar to other cabin circuit breaker resets. Further; this system should be reviewed to ensure a protection system is in place which would prevent whatever overheated in this event. I was very happy this happened so close to landing; daylight; good weather; etc.

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.