HB 6167.24 is the part of the Chinese aviation industry environmental standard for civil aircraft airborne equipment that covers susceptibility to the transients induced by lightning. A lightning strike to an aircraft does not damage equipment only where it attaches; the current flowing through the airframe creates a magnetic field that induces voltages and currents in every cable run in the aircraft, and those transients travel to the equipment at the ends of the cables. The equipment therefore has to be tested in a way that represents the coupling rather than the strike itself, and this part specifies the test levels and the injection arrangements appropriate to each installation, including the methods in which a defined transient is applied to the cable bundle connecting the equipment and the levels corresponding to the exposure of the zone in which the equipment is installed. Because the equipment is qualified by the cable bundle and the connector rather than in isolation, the test configuration is part of the requirement.