Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 240; Flight Crew Total 12096; Flight Crew Type 3259
Fatigue
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR
General None Reported / Taken
Aircraft
I have reported this issue a number of times through logbook entries and/or ASAP reports each time I have flown this aircraft.This aircraft (as well as [another] aircraft) has a chronic noise issue; which violates FAR 117 with regard to providing the pilots a quiet rest facility. When in the Pilot Crew Rest Facility (Bunk) an intermittent; loud knocking noise is heard at varying intensities on irregular schedules. I have recorded this noise and provided it to the company. I recorded it again last night. It sounds as if someone kicks or raps loudly with a knuckle on the bunk wall right near the pilots' heads as they sleep. Last night it sounded like it was coming from below the bunk; through the aft wall. On other aircraft the location can vary. It is impossible to sleep through. First Officer stated to me that he distinctly heard the noise last night and it woke him up at least five times. It was so bad for me that I had to leave the bunk and tried to sleep in the crew rest seat. This was impossible due to coughing passengers and people walking up and down the aisle. I went back into the bunk. My break was almost six hours. Last night; this noise was so bad that I maybe slept an hour and a half. This was totally inadequate. I did not realize how fatigued I was until we after we landed.   We happened to have a representative from Boeing on the flight. I asked him afterward what he thought the knocking could be. He said that it is possible that 'oil-canning' between the E&E compartment and deck floor is what's happening; being caused by the differential in pressure and/or temperatures. The noise created by this problem is obstructive to the intent and application of FAR 117; and negatively impacts the safe conduct of our flights by interfering with the pilots' ability to achieve a restful break.  The insidious degradation of cognitive function which is not necessarily apparent to the pilot; and the fact one might not realize just how fatigued they are; should I encounter this situation again I will give strong consideration to new FAA guidance regarding inflight fatigue accumulation and need to reevaluate continuance of the flight so as to ensure fatigue level does not continue to increase.
B777 Captain reported the crew rest bunk area is subject to random noise intrusions in flight that make it difficult to get quality rest.