The Boeing 747-400 is a wide-body aircraft that is a variant of the 747 Family. The 747-400 the second largest variant in the family and includes the second largest 'upper deck' of the family as well. This variant is also the first variant to be equipped with winglets. The 747-400 is the most successful variant of the family comprising of more than 25% of the 747s ever produced. The 747-400 is no longer in production but it is still flying today on some of the busiest routes on the planet. The 747-400 can hold 400+ passengers in a three-class layout and typically flies long or very-long range routes with high demand. Despite the popularity and capabilities of the 747-400, it's allure has been declining in recent years as operators look to replace them with more fuel efficient, lightweight, twin-engine airplanes that have similar capacity and range for better economics. Although the number of aircraft flying are declining, it remains a very popular airplane with spotters & photographers as well as the general public.