A vehicle passenger seat assembly for a passenger cabin of a vehicle includes: a pair of side frames; passenger seats disposed between the pair of side frames. Each of the passenger seats includes: a back portion configured to support a back of a passenger; and a bottom portion configured to support a hip of the passenger. The vehicle passenger seat assembly further includes: a first horizontal beam that connects the pair of side frames and is disposed at the same vertical height, from a floor of the passenger cabin, as a lower end of the back portion.