Narrative:

Made logbook write-up for a B737-800 aircraft [due to] forward entry door will not close properly from inside aircraft unless significant force is applied to door. The aft latches failed to engage. This is a significant safety issue on this aircraft since the door light is out in this condition. Maintenance checked the forward entry door and found no defects. They lubed the lock rollers and door hinges per our maintenance manual (M/M) chapter 52-11-00. I am extremely concerned about this malfunction since our air carrier has had numerous in-flight interrupts; in the form of failure to pressurize; due to improper forward entry door closure. Here is what I observed: [since] this was a ferry flight; the flight crew operated the forward entry door. I noticed a definite looseness upon opening the forward entry door. Upon further investigation; I noticed that when the door is brought to the most inner position; when the door is actually inside the aircraft; and the next step is to rotate the door handle 180-degrees clockwise; the door was noticeably further 'inside' the cabin than normal. At this point; when the handle was rotated; it was obvious the door was not closing properly due a noticeable lack of resistance on the handle. I then observed on the aft; vertical edge of the door; a noticeable gap along the entire aft edge of the door. I opened and closed the door several times and each time the door rollers failed to latch onto any of the door's aft latching [cam tracks]. Upon further investigation; I observed the following: the door can only be latched closed properly from the inside by exerting at least 30-40 pounds of outward force on the door as it is closed. If one closes the door from the outside; the door can be closed and latched properly if the 'bat wing' [external] handle is pulled significantly. If the outer 'bat wing' handle is only pulled sufficiently to engage the locking mechanism the door is able to be latched closed improperly. At this point about a 7/8' of an inch gap can be seen along the aft edge of the door from the outside.if one allows the door to close rapidly; allowing the momentum of the door to 'bounce' off the inner hinge stop; and bounce back to the outer/closed position...(this is how I have observed most [customer service] agents close the B-737 forward entry door)...then the door 'bounces' outboard sufficiently to allow the door to latch properly. This particular aircraft is not modified with the extra rear latch micro [proximity] switch as the newer aircraft are. Therefore; when this aircraft door is closed and the rear [latching] rollers failed to engage inside the latch [cams]; the door warning light is extinguished; indicating a 'closed' door. It was not closed properly at all though. Note: the micro [proximity] switch; indicating door closure; is in the upper forward latch [cam track]; and always latches with the door closed. It is this pilot's opinion; that one of two things is happening on this aircraft and very possibly numerous company aircraft:1) the [door] hinge assemblies are bent; cracked or loose.2) the [fuselage] structure where the hinges are attached is damaged or cracked. 3) the hinge attachment point on the door is damaged or bent; due the numerous emergencies our air carrier has experienced with the aft rollers not engaging and the fact this is a known issue; reference the additional aft [proximity] switch installations on the forward doors on our newer aircraft. I request an immediate inspection of this aircraft by knowledgeable maintenance personnel educated or experienced in this B-737 door issue. The sign-off of this aircraft regarding my pilot report is not a satisfactory one in my opinion.

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Original NASA ASRS Text

Title: A B737-800 Line Captain reported numerous air turnbacks due to failure to pressurize the cabin. Improper forward entry door closures at the aft upper latching roller and the lack of a door warning proximity switch for the aft upper latching roller were cited. The door forward upper roller cam track does have a proximity switch to alert the flight crews.

Narrative: Made logbook write-up for a B737-800 aircraft [due to] forward entry door will not close properly from inside aircraft unless significant force is applied to door. The aft latches failed to engage. This is a significant safety issue on this aircraft since the door light is out in this condition. Maintenance checked the forward entry door and found no defects. They lubed the lock rollers and door hinges per our Maintenance Manual (M/M) Chapter 52-11-00. I am extremely concerned about this malfunction since our air carrier has had numerous in-flight interrupts; in the form of failure to pressurize; due to improper forward entry door closure. Here is what I observed: [since] this was a ferry flight; the flight crew operated the forward entry door. I noticed a definite looseness upon opening the forward entry door. Upon further investigation; I noticed that when the door is brought to the most inner position; when the door is actually inside the aircraft; and the next step is to rotate the door handle 180-degrees clockwise; the door was noticeably further 'inside' the cabin than normal. At this point; when the handle was rotated; it was obvious the door was not closing properly due a noticeable lack of resistance on the handle. I then observed on the aft; vertical edge of the door; a noticeable gap along the entire aft edge of the door. I opened and closed the door several times and each time the door rollers failed to latch onto any of the door's aft latching [cam tracks]. Upon further investigation; I observed the following: The door can ONLY be latched closed properly from the inside by exerting at least 30-40 LBS of outward force on the door as it is closed. If one closes the door from the outside; the door can be closed and latched properly if the 'bat wing' [external] handle is pulled significantly. If the outer 'bat wing' handle is only pulled sufficiently to engage the locking mechanism the door is able to be latched closed improperly. At this point about a 7/8' of an inch gap can be seen along the aft edge of the door from the outside.If one allows the door to close rapidly; allowing the momentum of the door to 'bounce' off the inner hinge stop; and bounce back to the outer/closed position...(This is how I have observed most [Customer Service] Agents close the B-737 forward entry door)...then the door 'bounces' outboard sufficiently to allow the door to latch properly. This particular aircraft is not modified with the extra rear latch micro [proximity] switch as the newer aircraft are. Therefore; when this aircraft door is closed and the rear [latching] rollers failed to engage inside the latch [cams]; the door warning light is extinguished; indicating a 'closed' door. It was not closed properly at all though. Note: the micro [proximity] switch; indicating door closure; is in the upper forward latch [cam track]; and ALWAYS latches with the door closed. It is this pilot's opinion; that one of two things is happening on this aircraft and very possibly numerous company aircraft:1) The [door] hinge assemblies are bent; cracked or loose.2) The [fuselage] structure where the hinges are attached is damaged or cracked. 3) The hinge attachment point on the door is damaged or bent; due the numerous emergencies our air carrier has experienced with the aft rollers not engaging and the fact this is a known issue; reference the additional aft [proximity] switch installations on the forward doors on our newer aircraft. I request an immediate inspection of this aircraft by knowledgeable maintenance personnel educated or experienced in this B-737 door issue. The sign-off of this aircraft regarding my pilot report is not a satisfactory one in my opinion.

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.