The empath, Sherese, was introduced in The Plot to Kill a City (part 1 & 2). She wore this pilot helmet in one scene in The Plot to Kill a City Part 2, episode 107.
The helmet is a modified Directorate Pilot helmet. The Helmet went up for auction in 2009 but was incorrectly labeled as Wilma Deering's pilot helmet from an "unknown" episode in the Heritage Auctions 2009 Catalog No. 7004. Item No. 49084. Photos from Heritage Auctions