Boeing has further delayed first delivery of the 747-8 Intercontinental by three to six months to the fourth quarter of 2011.
As the passenger version of the new widebody, the 747-8I now trails first delivery of the freighter version by more than a year. The 748-8F is scheduled to deliver to Cargolux in the third quarter of 2010.
In November, development glitches forced Boeing to delay both aircraft types, with the 747-8I first delivery postponed from late 2010 to the second quarter of 2011.
Jim McNerney, Boeing chief executive, blames the new 747-8I delay on softening demand in the cargo market. Boeing has slowed the pace of 747-8F deliveries, which means the first 747-8I will not be inducted into final assembly until months later.
The new delay announcement comes only two months after a leadership change in the 747-8 programme.
Boeing has appointed Mohammad "Mo" Yahyavi as 747-8 programme manager, replacing Ross Bogue.
The 747-8F remains on track for first flight in the third quarter of this year, a Boeing spokesman says.
For the passenger version, Boeing is still looking for new airline customers. So far, the only commercial customer is Lufthansa Airlines with a launch order for 20 aircraft. Boeing has also sold eight more VIP 747-8Is, but two orders have been cancelled.