An aircraft passenger seat construction capable of in-flight rocking motion and berthing, wherein rocking motion and berthing are mutually exclusive features. The seat construction includes a fixed frame including spaced frame members each having a support surface to be rocked on, a rocking frame including a seat pan and spaced rockers, the spaced rockers positioned to rock on the support surfaces, guides carried on the spaced rockers engaged to travel within guide slots of the spaced frame members, a backrest pivotally attached to the rocking frame, and a leg rest pivotally attached to the rocking frame. The rocking frame may rock back-and-forth in-flight or may be locked at any given position based on passenger preference. The seat construction is compatible with or without other seat adjustment mechanisms such as tracking, swivel, lie-flat and recline adjustment mechanisms.