Methods and devices for differentiating an actual air drop of a gravity dropped weapon from an accidental drop of the weapon onto a surface. The method including: connecting a first end of at least one lanyard to an airframe; releasably connecting a second end of the at least one lanyard to a power generation device such that release of the second end with the power generation device initiates power generation by the power generation device; and releasably connecting a third end of the at least one lanyard to at least a portion of an air velocity sensor such that release of the third end one of activates or exposes the air velocity sensor to an air stream; and differentiating the actual air drop from the accidental drop based at least on a detection of an air velocity by the air velocity sensor.