(Recasts with Washington events, adds background)
By David Shepardson and Maggie Fick
WASHINGTON/ADDIS ABABA, Sept 10 (Reuters) - Relatives of some victims of Ethiopian Airlines Flight 302 met with U.S. Transportation Secretary Elaine Chao for about two hours on Tuesday, six months after the plane crashed into farmland outside the capital Addis Ababa.
Paul Njoroge lost his three children, his wife and mother-in-law in the crash. He said Chao assured him and other family members that the 737 MAX would not fly again until she was convinced it was safe.
"My life has not moved an inch," Njoroge said at an event outside DOT headquarters. "I don't know how to live this life anymore."
A spokesman for Chao said the department has "undertaken unprecedented steps to investigate and understand the incident and the process of certification for this aircraft."
Late on Monday, the head of Ethiopia's police said the identification of human remains from the crash was complete.
The U.S. Congress is preparing to call Boeing executives to testify on the two fatal Boeing 737 MAX crashes that led to the plane's grounding in March. House and Senate panels are considering holding hearings in October, congressional aides say.
Democratic Senators Ed Markey and Richard Blumenthal said in a joint statement that they "strongly encourage Boeing to comply with all standards and conditions set by international regulators, and we expect detailed, precise, and translucent responses to requests for information throughout the process."
Boeing has said it plans to conduct a certification test flight in September and hopes to resume flights early in the fourth quarter.
Janet Northcote, a spokeswoman for the European Aviation and Space Agency, said the agency "intends to conduct its own test flights separate from, but in full coordination with, the (U.S. Federal Aviation Administration). The test flights are not scheduled yet, the date will depend on the development schedule of Boeing." She added: "EASA has concerns regarding the consequences of Angle of Attack sensor failures at aircraft level, and the ability of the flight crews to cope with the situation in critical phases of flight (such as take-off)."
Northcote said the concerns could be addressed "through improvement of the flight crew procedures and training, or through design enhancements, or a combination."
The Boeing 737-MAX slammed into the ground with such force that only fragments of those who died could be recovered.
Families heard the news that identification had been completed through the media.
Collecting and identifying the remains has been a fraught process. Families of those who perished complained of a lack of information about recovery efforts during which Ethiopian workers used metal aircraft parts to dig in the soil.
Relatives of the crash victims found bones at the site as recently as July, Reuters reported last week.
Many relatives are pressing for the farmland where the plane crashed, about 60km (37 miles) east of the capital, to be turned into a permanent memorial. (Additional reporting by Katharine Houreld, Writing by Maggie Fick and David Shepardson in Washington, editing by Ed Osmond)