Originally Posted by
D Bru
Good point! Indeed, in a picture of a closed door plug on another MAX-9 (see below) that I now found, the flexible seal from the side of the door frame clearly continues and bends over the top, exactly as you indicate. So the cracks I perceived are in the sealant between the "flexible" rubber and the metal strips next to the top of the door opening, not in the door frame it self. But, taken together with the cracks at the top of the door plug itself at approximately the same hight, it indicates IMO that something frictioneous happened there in the process of the door plug blow out.
BTW, concerning this for me at least new picture (of as said another Max-9's inspected), I note that:
1. (and I well realise it was discussed earlier on) with the space between the roller guide (on the door plug) and the roller plate (on the door frame), given what we've seen about the actual roller length, the roller end itself IMO can hardly reach more than halfway to the centre of the arrestor bolt;
2.
the three of four visible bolts (and washers) securing the roller plate on the door frame show manipulation (broken paint). Probably as a result of torquing at regular maintenance. But I read somewhere (can't find it anymore) that supposedly also some of these bolts have been found loose at the ongoing inspections, apart from the bolts which attach the brackets guiding the lower vertical spring rods to the door plug frame. To note that the roller plate bolts of the accident plane don't seem to show any manipulation after having been painted following installation.
To point 2: those bolts are loosened/tightened for rigging of the door. The fitting and the frame pad it is bolted to have matching serrated surfaces as seen in a picture I pulled from post 569:
You can adjust the fitting up-down one serration at a time for rigging. I'm not sure when that happens or what drives the need to re-rig, but it's possible they measure steps and gaps during a pressurization test and adjust any observed aerodynamic steps.