the door. On some installations, door hinges are adjusted by  placing a serrated hinge with an elongated mounting hole in  the proper position in a hinge support fitting. Using serrated  washers, the mounting bolt is torqued to hold the position.  Figure 13-48  illustrates this type of mounting, which allows  linear adjustments via the elongated hole.  accomplished with the aircraft on jacks and the gear retracted.  Doors that are too tight can cause structural damage. Doors  that are too loose catch wind in flight, which could cause  wear and potential failure, as well as parasite drag.  Each landing gear has specific adjustments and tolerances per  the manufacturer that permit the gear to function as intended.  A common geometry used to lock a landing gear in the down  position involves a collapsible side brace that is extended and  held in an over-center position through the use of a locking  link. Springs and actuators may also contribute to the motion  of the linkage. Adjustments and tests are needed to ensure  proper operation. The distance landing gear doors open or close may depend  upon the length of the door linkage. Rod end adjustments  are common to fit the door. Adjustments to door stops are  also a possibility. The manufacturer’s maintenance manual  specifies the length of the linkages and gives procedure for  adjusting the stops. Follow all specified procedures that are  Figure 13-49  illustrates a landing gear on a small aircraft  with such a side brace. It consists of an upper and lower  link hinged at the center that permits the brace to jackknife  during retraction of the gear. The upper end pivots on a  trunnion attached to structure in the wheel well overhead.  The lower end is attached to the shock strut. A locking  link is incorporated between the upper end of the shock strut  and the lower drag link. It is adjustable to provide the correct  amount of over-center travel of the side brace links. This  locks the gear securely in the down position to prevent  collapse of the gear. 13-28 Figure 13-48.  An adjustable door hinge installation for setting  door clearance. Figure 13-47.  Main landing gear door latch roller clearance measurement and adjustment. Drag and Side Brace Adjustment  Latch Roller Clearance Latch Roller Support Adjustment Latch cylinder Latch cylinder Latch hook (latched position) Latch roller (on door) 1/8 ± 3/32 inch Plate (serrated) Elongated holes Latched roller support (serrated) Latch hook (latched position) Latch roller (on door) B A Fairing door hinge Attach bolt Nut Hinge support fitting Serrated washers Bushing