United Airlines said Thursday it expected to keep its six Boeing 787s out of service until May 12, as the cutting-edge airplane remained grounded worldwide due to battery problems.
United, the only US airline with the 787 Dreamliner, just two days ago announced it would keep them on the ground through March 30.
United has "tentatively" scheduled a 787 on its Denver route to Tokyo's Narita International Airport on May 12, UAL spokeswoman Christen David said in an emailed response to an AFP query.
"We are taking the 787 out of our schedule through June 5, except for Denver-Narita," she said.
A person close to the situation noted the Federal Aviation Administration investigation of overheated lithium-ion batteries on the 787 was ongoing and schedule adjustments were necessary.
All 50 787s in service around the world have been banned from flight since January 16 after battery smoke forced an emergency landing of one and a battery fire occurred on another.