Families of passengers who died in one of the Boeing 737 Max crashes are meeting with Transportation Secretary Elaine Chao and holding a demonstration outside her agency's Washington headquarters.
Victims' relatives fear that the plane is being rushed back into service.
They want the Federal Aviation Administration to conduct a completely new review of the Max instead of mainly examining changes Boeing made to flight-control software.
They also want pilots to train on flight simulators before they fly the plane. Boeing, which wants to avoid further delays in bringing the plane back, believes computer training is adequate for now, with simulator sessions later.
The protest is occurring on the six-month anniversary of the crash of Ethiopian Airlines flight 302. A Lion Air Max crashed near Indonesia in October 2018.