The up lock rollers on the doors are then removed to allow the doors to be closed, and yet not become locked in the closed position. With the landing gear doors held in the closed position, each door s edge is marked where trimming is needed to maintain the specified clearances. The doors are then opened and the excess amount of material trimmed off. After you have completed the trimming and checked the doors for proper clearances, the landing gear is lowered and the door linkage and up lock rollers are installed. The distance the landing gear doors open or close depends upon the length of door linkage and adjustment of doorstops.
Adjustable door hinge installation.
Landing gear doors have specific allowable clearances that must be maintained between doors and the aircraft structure or other landing gear doors. These required clearances can be maintained by adjusting the door hinges and connecting links and trimming excess material from the door if necessary. On some installations, door hinges are adjusted by placing the serrated hinge and serrated washers in the proper position and torquing the mounting bolts, which allows linear adjustments. Figure 12-7 shows this type of mounting. The amount of linear adjustment is controlled by the length of the elongated bolt hole in the door hinge.