The marvels of modern engineering. A machine that repairs machinenes! Hope they don't replace the engineer job...
Fail-safe Kit is a tool for long term mid-rate repairs. Hitting the non-broken component with this tool will put a machine in place to do repairs on it. Cooldown from hitting it only applies if the component is already damaged. The work of the machine itself neither blocks any repairs from other repair tools nor interferes with enhancement tools. After the life-time of the machine has expired, it disappears from the component. Time can be prolonged by a repeated hit with the Fail-safe Kit. The machine keeps working even if the component is destroyed, but doesn't help rebuilding a component.
Due to the gradual character of repairs the Fail-safe Kit is an ideal tool for fixing low-rate damage from sources like pilot tools on engines or gas/tar/dust clouds.But lack of instant repair make it too risky as single repair tool in high-pressure situations on vital components, especially after rebuild. Combination with another repair tool (Rubber Mallet or Pipe Wrench) and fact of zero repair cooldown on undamaged component can give high repair efficiency in start of engagement. Also, the Fail-safe Kit can be used on guns (like Whirlwind Light Gatling Gun) loaded with Lochnagar Shot to allow shooting a full clip without interrupting for gun maintenance.
It should be noted that part of the tools and special abilities well-fitting with Fail-safe Kit, like Armor Kit or Mechanized Rebuild, are available in PvE mode only.
The Fail-safe Kit is can be used as single tool for pilot in some ships, but usage by gunner can be ineffective when taking incoming Shatter damage.