Shielded Mild Detonating Cord (SMDC).- The 31 SMDC segments (fig. 6-12) act as the plumbing for the emergency egress system. The SMDC connects all external and internal jettison handle/ initiators; all connectors, tees, and manifolds or one-way transfers; all explosive charges; and all explosive shaped charges. Each SMDC segment is loaded with 1 to 2 grains per foot of hexanitrostilben I (HNS I). When initiated, the extremely high velocity and pressure of the cord is focused onto the end of the next adjacent SMDC segment, which acts as an acceptor charge.

Shielded Mild Detonating Cord (SMDC) Manifold.- Two SMDC manifolds are located on the pilot's and copilot's bulkhead. The SMDC manifold acts as a check tee or one-way detonating transfer device. The SMDC manifold is a self-contained unit housing a sealed receptacle for dual-shaped charges. Any detonation entering the side ports from either direction will transfer to the aft port. Any detonation originating from the aft port (TACCO or SENSO) segment of the SMDC manifold will not transfer back into the side portions. This would occur when either the TACCO or SENSO elects to cut the respective hatch; the remaining two windows and the opposite hatch would not be affected.

MAINTENANCE REQUIREMENTS Maintenance on ejection seats is primarily performed during aircraft inspections. The ejection system could be called a dormant system, as it is only operated in an emergency situation. A true functional test of the complete system can-not be performed because of the destructive functions of some of the components. For this reason it is of the utmost importance that you thoroughly know all aspects of the ejection system that you perform maintenance on and follow all the steps for testing components as outlined in the maintenance instructions manual (MIM).

Figure 6-12.- Shielded mild detonating cord tip (typical).

WARNING Do not perform maintenance on equip-ment with installed cartridges except in the presence of personnel capable of rendering aid if necessary.