B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 180; Flight Crew Total 21400; Flight Crew Type 1000
Situational Awareness
Aircraft Equipment Problem Less Severe
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem
On taxiout I recall that the First Officer was having difficulty making a PA for the flight attendants to prepare for takeoff. I tried to make the call with the handset; but I got a busy signal. Thinking that there must be a handset in the cabin that was not hung up and causing interference; the audio panel was used and successfully overrode the handset and got the prepare for takeoff call completed. After takeoff it became clear that there was indeed a problem with interphone communications between the cockpit and the cabin. Multiple remedies were attempted with no success. Text messages were sent to back and forth to Maintenance with descriptions of the failure and possible solutions that were unsuccessful. I attempted to use the SATCOM to contact Dispatch; but SATCOM voice had failed as well. I used my Captain's emergency authority to reset circuit breakers in the cockpit as I determined that the communications between the cockpit and the cabin were essential for a safe flight. Having exhausted all attempts to restore the system; Dispatch and Maintenance discussed if it was safe to continue the flight. I was asked if a system was in place to enable the cockpit and cabin crew to notify and communicate with one another. I replied that we had devised a system where the cockpit would make a 'Purser please' call on the PA to request a cockpit visit and if the Purser needed to get our attention she would simply buzz the cockpit. Dispatch determined that if I was comfortable with the operation we could continue the flight; which we did. Toward the end of the flight the interphone system regained some capability and we were able to regain communications between the cockpit and the cabin and within the cabin as well. Cabin to cockpit communications are essential and I will be vigilant to try to detect any degradation of the systems capability in the future before being committed to flight.
B777 Captain discovers possible cabin interphone problems prior to takeoff; but is able to make the takeoff PA. Once airborne it becomes apparent that the system is inoperative. A method of communication without the use of the interphone system is devised and the flight continues to destination.