Narrative:

Climbing through FL220 the EICAS annunciated lavatory smoke. Flight attendants reported hearing the right aft lavatory smoke detector alarm. Flight attendants did not observe smoke or smell smoke in the lavatories. ATC [was advised] and the flight diverted to [the departure airport].

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Original NASA ASRS Text

Title: B757-200 flight crew reported returning to the departure airport after receiving a lavatory smoke alarm.

Narrative: Climbing through FL220 the EICAS annunciated LAVATORY SMOKE. Flight attendants reported hearing the right aft lavatory smoke detector alarm. Flight attendants did not observe smoke or smell smoke in the lavatories. ATC [was advised] and the flight diverted to [the departure airport].

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.