Narrative:

In cruise flight my first officer needed to go to the bathroom and left the cockpit; 1:20 prior to landing. He closed the cockpit cabin siding pocket door behind him as he left for the rear lavatory of the airplane. Upon his return to reenter the cockpit he was unable to open the door and saw that the door had locked itself behind him when he left. He attempted to release the door using the lock override lever installed but was unable to unlock the door. He returned to the galley and had the flight attendant attempt to open the door without success. He called me from the galley on interphone and advised me of the situation. I asked him to try a third time as well as make an attempt to use the emergency access door commonly referred to as the 'doggy door'. Neither worked and he returned to the galley and called to informed me of the situation. Faced with a choice of leaving the first officer and flight attendant locked in the back or briefly leaving my seat to make one attempt to release the door from my side; I decided to leave my seat. In less than 10 seconds; I got out of my seat; released the door from the cockpit side and returned to my seat. During those 10 seconds; no one was at the flight controls nor had access to quick don oxygen. After landing; I wrote the door up for maintenance action and repair. Upon further examination maintenance found no discrepancies. The door operated normally and has not been problematic since. The first officer stated that the release mechanism did not seem to work and that the emergency entry door was also jammed. I have examined the door and find it operates normally. I believe insufficient training with reference to the operation and emergency operation of the door to be the primary culprit of the problem. A secondary issue is a bad design which allows the door to be closed in the locked position and allows the door to 'lock itself' when closed too firmly. The crewmembers then must use the lock override mechanism to open the door. I have recommended to the company that we provide additional training on the use of the lock override mechanism as well as daily preflight of the operation of the mechanism. Additionally; I have recommended all crewmember's be trained on the use of the 'doggy door' on the G-450 pocket door. I had considered having the first officer force the door but was concerned about further damage and jamming the door further. I considered leaving the crew in the cabin but decided that the risks associated with my being out of the seat for a moment 'to be less' than the risk associated with me flying the aircraft single pilot at night into an unfamiliar airfield. In the unlikely event of a depressurization; the 'auto emergency descent' function would have 'saved us' and the autopilot was on.

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Original NASA ASRS Text

Title: G-450 First Officer left the flight deck to use the lavatory and was unable to unlock the cockpit door upon return. Captain must leave his seat at FL410 in order to unlock the door from the inside.

Narrative: In cruise flight my first officer needed to go to the bathroom and left the cockpit; 1:20 prior to landing. He closed the cockpit cabin siding pocket door behind him as he left for the rear lavatory of the airplane. Upon his return to reenter the cockpit he was unable to open the door and saw that the door had locked itself behind him when he left. He attempted to release the door using the lock override lever installed but was unable to unlock the door. He returned to the galley and had the Flight Attendant attempt to open the door without success. He called me from the galley on interphone and advised me of the situation. I asked him to try a third time as well as make an attempt to use the emergency access door commonly referred to as the 'doggy door'. Neither worked and he returned to the galley and called to informed me of the situation. Faced with a choice of leaving the First Officer and Flight Attendant locked in the back or briefly leaving my seat to make one attempt to release the door from my side; I decided to leave my seat. In less than 10 seconds; I got out of my seat; released the door from the cockpit side and returned to my seat. During those 10 seconds; no one was at the flight controls nor had access to quick don oxygen. After landing; I wrote the door up for maintenance action and repair. Upon further examination maintenance found no discrepancies. The door operated normally and has not been problematic since. The First Officer stated that the release mechanism did not seem to work and that the emergency entry door was also jammed. I have examined the door and find it operates normally. I believe insufficient training with reference to the operation and emergency operation of the door to be the primary culprit of the problem. A secondary issue is a bad design which allows the door to be closed in the locked position and allows the door to 'lock itself' when closed too firmly. The crewmembers then must use the lock override mechanism to open the door. I have recommended to the company that we provide additional training on the use of the lock override mechanism as well as daily preflight of the operation of the mechanism. Additionally; I have recommended all crewmember's be trained on the use of the 'doggy door' on the G-450 pocket door. I had considered having the First Officer force the door but was concerned about further damage and jamming the door further. I considered leaving the crew in the cabin but decided that the risks associated with my being out of the seat for a moment 'to be less' than the risk associated with me flying the aircraft single pilot at night into an unfamiliar airfield. In the unlikely event of a depressurization; the 'auto emergency descent' function would have 'saved us' and the autopilot was on.

Data retrieved from NASA's ASRS site as of April 2012 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.