Flight Crew Last 90 Days 200; Flight Crew Total 15865; Flight Crew Type 1272
Confusion; Situational Awareness; Workload; Communication Breakdown
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Human Factors; Procedure
Climb from FL390 to FL410 possible altitude deviation.I was on lavatory break returning to the cockpit thus not on the flight deck as the aircraft left FL390 for FL410. When I initially called for re-entry to the cockpit while awaiting the flight attendant to set up the cart for 'blocking' via interphone. My First Officer asked if I wanted to climb to the FMC recommended FL410; it was my leg. I said yes it was smooth. It took a minute or two to set up the door 'block'. As I entered at approximately 38;900 feet ATC asked 'who cleared you to 410?' He then cleared us to FL 410 in the same transmission there was no traffic conflict that we were aware of I noted the time as approximately XA:27.I inquired with ATC if we needed to contact anybody about 'this' since I was clear the 41;000 feet was in the 'ALT' window and did not think my First Officer would have put it there without a 'clearance' to do so. Controller stated that they were researching the tapes and querying the Controller about a possible Controller Pilot Data Link Communication (CPDLC) clearance being issued they might not be aware of. It was curious that the Controller knew and stated we were going to 41;000 verses 'why are you in a climb' or 'say altitude'. My thought at the time is he may not be sure if he or did or didn't already clear us. I realize the Automatic Detective Surveillance (ADS) lets him see the 'ALT' window.
A B787 Captain left the flight station for short break and upon return noted the aircraft climbing to FL410 from FL390. Uncertain about the clearance; he inquired and was then cleared to FL410.