We don’t know yet what caused Ethiopian Airlines Flight 302 to crash on Sunday, killing all 157 on board, or whether there’s a common link to October’s crash of Indonesia’s Lion Air Flight 610, which claimed 189 lives.

But the eerie similarities — both involved Boeing’s new 737 Max 8 jetliners plunging to the ground shortly after takeoff — suggest the prudent course is to ground the 737 Max fleet until more is known.

More than 30 countries, including China and European Union nations, have already reached this sensible conclusion. As of Tuesday night, however, the Federal Aviation Administration, which regulates U.S. air travel, was a conspicuous outlier. “Thus far, our review shows no systemic performance issues and provides no basis to order grounding the aircraft,” said Acting FAA Administrator Daniel K. Elwell in a statement.

Perhaps not, but these facts are already known:
First, in an age when commercial jets are an almost unbelievably safe way to travel, it’s exceedingly rare for a newly designed and marketed aircraft to suddenly fall out of the sky — much less to have that happen twice within five months.
Second, preliminary findings in the Lion Air crash showed that the pilots struggled against an automated flight control system that errantly forced the plane into a fatal dive. Ethiopian Airlines CEO Tewolde GebreMariam told CNN on Tuesday that pilots of Flight 302 also reported flight control problems.