Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Less Severe
Aircraft Aircraft Damaged; Flight Crew Overcame Equipment Problem
Procedure; Aircraft
When stairs were brought up to the aircraft; I went aft to disarm the doors. After disarming the doors; I went to the lavatory and while in the lav I heard the 1L door begin to open. The door motor didn't sound as though it had run as long as a normal cycle (only for a second or less); and when exiting the lav I looked toward the 1L door to see that it was just slightly cracked open. The ground crew continued opening the door after a short delay. When the door resumed its upward motion a few moments later; it began to bind on the CRA [stowable Crew Rest Area] and the CRA moved noticeably aft as the binding got worse. The door stopped about 24 inches open and was clearly binding on the CRA. Maintenance boarded and began to examine the problem; stairs were positioned at the 1R door; and deplaning was accomplished without incident. A maintenance writeup was made regarding the problem. Preflight in ZZZZ had been normal; the CRA was secured with latch in the 'LOCKED' position. I did note a prodigious amount of bedding present in the CRA (full to the ceiling) and removed/replaced the bedding during preflight. During postflight (following the incident); I was able to see into the bunks with the CRA deployed several inches and they were packed with a large amount of bedding material as well. Maintenance noted as they entered the CRA (and cleared out the bedding material) that the latch was still secured in the 'LOCKED' position even though the CRA was deployed several inches. Likewise; the handle used to bypass the electric deployment motor and manually deploy the unit was fully in (stowed). The 1L door operation was normal and door arming was accomplished without incident or note of abnormality. There was never any visual indication in flight that the CRA had deployed; nor was there any EICAS indication. Upon arrival in ZZZZ1; the CRA was stowed at the time of door disarming. (The design of the plastic around the arming handle is such that it is fairly apparent if the CRA is not stowed). I later learned that a maintenance review showed a writeup a day prior to the incident describing damage to the 1L door plastic caused by the CRA. It appears this may have happened more than once. My best guess is that the bedding constrained within the bunks when the CRA was closed exerted some pressure upon the locking mechanism. Motion of the 1L door as it opened created just enough movement in the structure for it to spring free a small amount. I don't know if the lock pin itself was broken; as we departed the aircraft before maintenance had started troubleshooting.-If initial opening of the door upon block-in was accomplished by the operating crew; it would be readily apparent if something inside the aircraft was obstructing the door's travel. -During preflight; the CRA is stowed and the bunks are not accessible for inspection. Additionally; since the bunk shrinks as the CRA is stowed any materials inside have the potential to be compressed upon CRA stowing. As such; materials other than the bunk cushions should not be stowed in the bunks themselves. -Crews have become accustomed to difficulty closing the CRA. The electric motor seldom works and sometimes it takes two crewmembers working together to successfully stow the unit. [Consequently]; the forces created by compressing bunk contents (not necessarily additional materials; but potentially a binding or compression of the cushions themselves) may not have been deemed unreasonable upon closure. Design improvements to the CRA such that the standard deployment and stowage mechanisms are used would allow for better crew recognition of an abnormal condition. -Spare/used bedding accumulates in some aircraft to the point that there is little additional space to stow it. This creates issues and often leads to creative solutions; none of which are ideal. (Such as stowing bedding within the bunks themselves).
When ground crew attempted to open the 1L door of the reporter's cargo configured MD11 the door bound up on a partially deployed flight crew rest module.