It creates a new level of comfort in economy class with a far lower cost than traditional business class or other lie-flat products. However, passengers do not usually have access to a higher level of service than their fellow economy class passengers. United Airlines' Relax RowLie-flat economy class to come to America's legacy market by 2027After being teased in March this year, United Airlines hopes to debut its Relax Row lie-flat economy class product in 2027. You can book Vietnam Airlines' lie-flat economy class seating on an impressive range of routes. Sky Sofa passengers who are Lotusmiles members will also earn bonus miles when booking a Sky Sofa.