10. Using the 5/32-inch socket head screw wrench, loosen the two setscrews retaining the locking bar. Insert a screwdriver or similar instrument in the holes next to the setscrews, and force the locking bar toward mat D as far as possible. This will lock the replacement mat and clear the setscrew holes. Bottom the setscrews so that the locking bar remains in plain. (See view D of fig. 1 1-34.)
A section of runway replacement maybe required when groups of mats are damaged beyond repair or when excessive mat deflection and roughness, due to cavities under the mats, must be corrected.
The procedure for replacing a section of runway is essentially the same with or without a guide rail installation. However, with a guide rail installed, removal of typical keylock sections will proceed from the outer edge of the runway regardless of which side of the guide rail the repair is to take place. Without a guide rail and when starter keylocks are used, typical keylocks must be removed from the right-hand edge of the runway (or taxi way) when facing the end of the runway from the transverse center line. This edge of the runway exposes the female end of the keylock into which the special removal tool must be inserted.
The replacement of a section of the runway is accomplished in the following manner:
1. Remove the first typical keylock action by loosening the socket head screw at the first inboard connection. This screw only needs to be loosened until it is free of the male end of the adjoining keylock (about 7/1 6 inch). The screw should not be removed further since it is designed to be self-retaining and reassembly can be affected from this position.
2. Insert the prong of the removal tool under the turned down lip of the female connector and slide the keylock from its position, as shown in figure 11-35.
NOTE: The initial 3-foot or 6-foot keylock section will have to be pried out since the exposed end is merely an unfinished cross-sectional cut and will not accept the removal tool.
3. Loosen the next and subsequent connectors, as described previously, and remove the remaining keylock sections. If mat distortion is minimal, you may be able to remove more than one keylock section at a time.
4. Use blocking and pry bars to lift the first row of mats high enough to allow the locking bars to clear. Each mat has one pry bar. All pry bars should be operated at the same time for the full width of the runway (or taxi way) to prevent warping of the mats. The mats will readily hinge at the first longitudinal mat joint.
NOTE: If a guide rail has been installed, the adjacent mat maybe cut parallel to the guide rail. "This cut must be made so it severs the locking bar to allow the locking bar and the end connector to be removed from the guide rail.
5. With the row of mats raised, insert a bent rod or wire in the locking bar hole and remove each locking bar including the bars securing the cut piece of the guide rail. The first row of matting may then be disassembled and removed. (See fig. 11-36.)
Figure 11-35. - Typical keylock removal tool.Continue Reading