Aerospace and Aircraft Design Rhombus Airplane cabin business class seat. by Rockwell Collins / Advanced Design Group Rhombus is a business class seat that leverages lightweight and proven technology for today’s traveling needs. It is fully electric, replacing many heavier mechanically actuated seats. Rhombus also provides a lay-flat sleeping option, typically not found in a mechanical business seat. Designed for long distance flights, the seat is meant to be the business traveler’s home in the sky. It offers industry leading storage options and class leading comfort in all modes of flight.