w e b 77Keep reading to find out 10 things you didn’t know about the B77W. 10. It is the Most Numerous B777 Variant. The B77W variant of the 777 is the most common of its type,Find the best seat wiht our American Airs Boeing 777-300ER (77W) seating chart. Use this seat map to get the most comfortable seats, legroom and rec before booking.