system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how come airplanes only have a seatbelt across the lap?

Why don’t they have a cross body belt like cars do?
gpt
car accident means you're likely to fly forward; crossbody seatbelt keeps you from moving horizontally. plane turbulence means you're likely to fly up as it falls; crosslap seatbelt keeps you from moving vertically.