A cabin revamp unveiled by Delta Air Lines two years ago is continuing with the start of reconfigurations of its Boeing 747-400s with lie-flat seats.
FlightglobalPro's database shows Delta operates 15 of the widebody model.
Delta in January 2010 announced a $1 billion investment in fleet and lounge upgrades scheduled for completion by mid-2013.
The lie-flat seat installation has been completed on the first aircraft, which operated its first flight from Tokyo Narita to Detroit on 26 January, said Delta. The carrier expects to complete the installations on all the -400s by October.
Each 747-400 will feature 48 of the lie-flat seats on the upper and lower deck of the aircraft. Each seat has a power outlet, USB port and a widescreen video monitor.
Similar to Delta's other international aircraft, the carrier plans to offer its Economy Plus product on the -400s, which will feature 42 seats with 35in of pitch in each aircraft.
In June of last year Delta completed lie-flat seat installations on its 777s and 767-400ERs.