If only one or two safety switch pins have been removed and the DEF SYS DISPENSE ARM switchlight is pressed, what will happen?

When the DEF SYS DISPENSE ARM switchlight is pressed while only one or two safety switch pins have been removed, the switchlight will not illuminate. This behavior is consistent with the safety mechanisms in place for the system. Safety switch pins are designed to ensure that certain conditions are met before allowing the system to function or indicate readiness.

In this context, the absence of the necessary number of safety pins means that the system cannot confirm that it is safe to dispense. The illumination of the switchlight typically indicates that the system is ready for operation. Thus, without the proper configuration (which would normally require all necessary safety pins to be appropriately engaged), the switchlight will remain off, preventing any unintended activation or dispensing.

This understanding emphasizes the critical role that safety mechanisms play in aviation systems and the importance of adhering to safety protocols before operation.