MIL-STD-461 CS117

CS117, introduced in MIL-STD-461G, assesses an equipment’s ability to withstand high-voltage transients induced by lightning strikes on cable bundles. In real-world environments—especially in aerospace, aviation, and defense—lightning can couple significant energy into harnesses or interconnecting cables, potentially causing severe disruptions or failures in electronic systems.

To simulate these conditions, CS117 employs specially designed lightning waveform generators capable of producing multiple waveforms that replicate various lightning events (e.g., initial strokes, intermediate and continuing currents). These waveforms, each characterized by a specific amplitude, rise time, and pulse shape, are injected into the Equipment Under Test (EUT) via coupling devices such as injection probes. The test is typically repeated at different waveforms and pulse levels, ensuring a broad evaluation of the EUT’s resilience.

Throughout the testing process, the EUT is monitored for performance degradation, data corruption, system resets, or other malfunctions. Successful completion of CS117 indicates that the equipment can continue to operate reliably despite exposure to extreme lightning-induced transients. Consequently, meeting CS117 requirements is crucial for mission-critical systems and safety-related applications, demonstrating that the design is robust and capable of withstanding real-world lightning threats.