Narrative:

Captain on break, relief pilot was PF on left seat. Flight attendant brought a meal up, and I used the opportunity to use the lav. When I exited the lav, I saw that no one was guarding the cart. I called the cockpit to ask the flight attendant if she had anyone available to man the cart. As soon as I dialed the cockpit, a flight attendant showed up to guard the cart, so I hung up the phone. I was surprised to then see the cockpit door open (I had not signaled the cockpit via the door lock control). The flight attendant came out of the cockpit and the door closed behind her. I called the cockpit and suggested that I use a key to get in. I tried the key, but I apparently just manually locked the door, and it didn't open. I called the cockpit again and the relief pilot suggested I use the emergency code. (We both forgot about the normal unlock switch in the cockpit since we never use it.) of course, that didn't work, since the door was now manually locked. As I was returning to the interphone, the door was opened from inside the cockpit. I returned to my duty station, and the flight continued normally. Supplemental information from acn 590091: he tried repeatedly to push on the door for entry while I was using the electronic unlock and the door would not open. At this time I was concerned about all the attention being focused on trying to get the cockpit door open and I wanted him in the cockpit. I therefore removed my oxygen mask and opened the door from inside.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B777 PF HAS TO LEAVE HIS STATION TO LET THE OTHER PLT BACK INTO THE COCKPIT WHEN UNABLE TO OPEN THE DOOR. THERE IS ALSO CONCERN THAT NO FLT ATTENDANT WAS GUARDING THE CART WHEN THE PLT USED THE LAV.

Narrative: CAPT ON BREAK, RELIEF PLT WAS PF ON L SEAT. FLT ATTENDANT BROUGHT A MEAL UP, AND I USED THE OPPORTUNITY TO USE THE LAV. WHEN I EXITED THE LAV, I SAW THAT NO ONE WAS GUARDING THE CART. I CALLED THE COCKPIT TO ASK THE FLT ATTENDANT IF SHE HAD ANYONE AVAILABLE TO MAN THE CART. AS SOON AS I DIALED THE COCKPIT, A FLT ATTENDANT SHOWED UP TO GUARD THE CART, SO I HUNG UP THE PHONE. I WAS SURPRISED TO THEN SEE THE COCKPIT DOOR OPEN (I HAD NOT SIGNALED THE COCKPIT VIA THE DOOR LOCK CTL). THE FLT ATTENDANT CAME OUT OF THE COCKPIT AND THE DOOR CLOSED BEHIND HER. I CALLED THE COCKPIT AND SUGGESTED THAT I USE A KEY TO GET IN. I TRIED THE KEY, BUT I APPARENTLY JUST MANUALLY LOCKED THE DOOR, AND IT DIDN'T OPEN. I CALLED THE COCKPIT AGAIN AND THE RELIEF PLT SUGGESTED I USE THE EMERGENCY CODE. (WE BOTH FORGOT ABOUT THE NORMAL UNLOCK SWITCH IN THE COCKPIT SINCE WE NEVER USE IT.) OF COURSE, THAT DIDN'T WORK, SINCE THE DOOR WAS NOW MANUALLY LOCKED. AS I WAS RETURNING TO THE INTERPHONE, THE DOOR WAS OPENED FROM INSIDE THE COCKPIT. I RETURNED TO MY DUTY STATION, AND THE FLT CONTINUED NORMALLY. SUPPLEMENTAL INFO FROM ACN 590091: HE TRIED REPEATEDLY TO PUSH ON THE DOOR FOR ENTRY WHILE I WAS USING THE ELECTRONIC UNLOCK AND THE DOOR WOULD NOT OPEN. AT THIS TIME I WAS CONCERNED ABOUT ALL THE ATTENTION BEING FOCUSED ON TRYING TO GET THE COCKPIT DOOR OPEN AND I WANTED HIM IN THE COCKPIT. I THEREFORE REMOVED MY OXYGEN MASK AND OPENED THE DOOR FROM INSIDE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.