B757 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Total 5559; Flight Crew Type 380
Time Pressure; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Other / Unknown; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Overcame Equipment Problem
Aircraft; Human Factors
About an hour into the flight; during cruise at FL340; had an EICAS lavatory smoke indication. I asked the copilot to get WX/ATIS for the nearest airport and be ready to don the o2 mask. I then transferred aircraft control to him and called the forward cabin inter phone to establish communication with the cabin. The Flight Attendant in the aft galley answered. I started to ask about the situation and the Flight Attendant cut me off and said 'I'm working it!!! I'll call you back' and hung up.I [checked] the clock and quickly reviewed the emergency descent and smoke; fire; or fumes Quick Reference Checklist with the copilot. At 45 seconds elapsed time; I called the forward cabin again to establish communication (if I couldn't; I would assume that the crew was fighting a fire and I would initiate the descent). This time; the Purser and aft galley Flight Attendant answered. The aft Flight Attendant kept talking over the Purser and said that if was a false detection. I thoroughly debriefed them both on crew communication protocol and how very close we came to going to [an alternate].
B757 Captain reported communication breakdown between flight and cabin crew as a result of false lavatory smoke alarm.