A method and combination for mitigating turbulent air flow across an actuator and a disc stack assembly of a data storage device. The combination includes a combination air plate and diverter with a retention member supporting an air plate/diverter member protruding through a diverter mounting aperture of a base deck. The base deck provides a diverter mounting surface confining the diverter mounting aperture and an attachment receptacle communicating with an attachment means to secure the retention member adjacent the diverter mounting surface. The method includes disposing the retention member adjacent the diverter mounting surface, press fitting an alignment pin supported by the retention member into an alignment receptacle of the base deck, securing the combination air plate and diverter to the base deck with an attachment means, and sealing an internal environment of the base deck from intrusion by an environment external to the base deck.