What is a key characteristic of most MANPADS regarding their self-destruct mechanism?

Most Man-Portable Air-Defense Systems (MANPADS) are designed with a self-destruct mechanism that activates after a specific amount of time if the missile does not successfully engage its target. The characteristic that these systems typically self-destruct within 15-17 seconds serves multiple purposes, including safety to minimize the risk of unintended casualties or damage when the missile fails to reach its target, and to reduce the likelihood of the missile being captured and repurposed by an adversary. This time frame strikes a balance between allowing enough time for the missile to engage a potential target while ensuring it does not remain a threat indefinitely if it goes astray. In summary, the 15-17 second window is a standard feature designed for both operational effectiveness and safety.