The double deck of the Airbus A380 .
The upper deck extends along the entire length of the fuselage.
This allows for a cabin with 50% more floor space than the Boeing 747-400, and provides seating for 525 people in standard three-class configuration or up to 853 people in full economy class configuration.
The double deck of the Boeing B747
The upper deck does not extend along the entire length of the fuselage.