The 747 has proven to be a very popular freighter, carrying around half of the world's air freight. To maintain this position, Boeing designed a freight variant of the 747-8, named the 747-8 Freighter or 747-8F. The company launched the freighter version on November 14, 2005. The 747-8F is the initial model to enter service. As on the 747-400F, the upper deck is shorter than passenger models; the 18 feet 3 1⁄2 inches (5.575 m) stretch is just before and just aft of the wing. With a 975,000 lb (442,000 kg) maximum take-off weight, it is to have a total payload capability of 308,000 lb (140,000 kg) and a range of 4,390 nmi (8,130 km). Four extra pallet spaces were created on the main deck, with either two extra containers and two extra pallets, or three extra pallets, on the lower deck. The 747-8F is expected to achieve a 16% lower ton-mile operating cost than the 747-400F and offer a slightly greater range.