Fire Protection - Lavatories

Amendment: New notes regarding continuous cabin call chimes.

Continuous Cabin Chimes

Occasionally, a passenger call button will remain 'depressed' causing continuous cabin chimes which, after a very short time, become extremely annoying. If the offending button can be identified, the chimes can be stopped by tripping either the left or right (as applicable) PAX CALL/LAV SMOKE CB on the left side of the overhead panel.

However, as is indicated by the name of the CB, it has a dual role. Tripping the CB also disables the associated Left or Right Lavatory Smoke Detectors. If a Lavatory Smoke Detector is INOP, then the lavatory must be checked every 20 minutes for signs of fire.

Frequently, the fault is due to moisture in the button which may dry out after 20-30 minutes in the cruise, in which case the CB can be reset.

For despatch, MEL 26-26-3 applies (Note: there are both 'A' and 'C' entries).

Lavatory Fire Protection

Lavatory fire protection consists of these systems:

Lavatory Fire Detection

Lavatory Smoke Detector.

Each lavatory has a single smoke detector. If smoke is detected:

Note: The Lavatory Smoke Detector may not be triggered by cigarette smoke.

Note: The attendant call chime will sound continuously until the lavatory smoke detector is reset. If smoke is still present 60 seconds after the detector is reset, the attendant call chime will again sound until the interrupt switch is pushed.

Lavatory Smoke Warning The LAV SMOKE Light illuminates and the EICAS advisory message LAVATORY SMOKE displays when smoke is detected in any lavatory.

Lavatory Fire Extinguishing

Lavatory Fire Extinguishing.

Each lavatory has a fire extinguisher located in the waste container cabinet. Fire extinguisher operation is automatic. There is no flight deck indication.

Temperature Tape.

On the side of each waste bin, there is a temperature tape that indicates peak temperature range. The illustration shows a peak temperature greater than 180° F, but less than 200° F.

EICAS Messages