March 10 dawned in Addis Ababa with excellent visibility and little wind, perfect flying weather that nonetheless became a backdrop for tragedy. That morning, Ethiopian Airlines Flight 302 crashed minutes after takeoff, killing all 157 people aboard. Emergency responders discovered only burning wreckage and bodies. The victims’ loved ones were left to grieve and wait for answers.
The world waits with them. The incident was the second fatal crash involving a Boeing 737 Max 8 in just five months. Another Max 8, flown by Indonesia’s Lion Air, also crashed quickly after takeoff in October, killing everyone aboard. Experts have speculated that a new automated system meant to prevent “aerodynamic stalls”–which occur when a plane isn’t producing enough lift and are addressed by pointing its nose down–may have sent the Lion Air plane into a dive after detecting a stall where none existed.
In the case of Ethiopian Flight 302, it will take months, maybe even years, to determine the cause of the crash. What we know about the Lion Air crash comes from only a preliminary report. But together, the incidents pressured airlines and their regulators worldwide to act–and shone a harsh spotlight on the Federal Aviation Administration (FAA), the agency that oversees U.S. aviation safety.
After the second crash, China, Australia and Ethiopia were quick to ground the Max, which has been Boeing’s fastest-selling plane ever. Other places, including the E.U., followed suit. In the U.S., however, the FAA insisted the plane was safe to fly, even as it announced a new requirement that airlines install an April software update for the Max. But the pressure was intense. Passengers bombarded Southwest and American Airlines, which both fly the aircraft, with Twitter requests to change airplanes, and flight attendants’ unions demanded that their employers ground the plane. Boeing lost $12.7 billion in market value on March 11 alone. Many American travelers, assured on every flight that the FAA was concerned about nothing more than their safety, began to wonder.
Then came the abrupt reversal. On March 13, during a briefing on another subject, President Trump announced that “all of those planes are grounded, effective immediately.” The airlines worked quickly to rearrange their fleets, and even Boeing appeared to scramble to get ahead of the news. In a subsequent announcement, the company said that while it still had “full confidence in the safety of the 737 Max,” it was recommending that all of the planes worldwide be grounded temporarily as the company works to understand what went wrong.
That’s the question. Two unrelated crashes in five months is awful luck. Two crashes caused by the same issue is something far worse.
As recently as March 12, the FAA had said it had “no basis” to ground the aircraft, and Transportation Secretary Elaine Chao even flew on a Max 8 with her staff from Texas to Washington, D.C. She wasn’t alone: in the time between the Flight 302 disaster and the FAA’s about-face, the Max 8 flew between U.S. cities dozens of times, carrying hundreds of passengers. Boeing has a generous lobbying budget, and the company’s chairman phoned Trump personally to argue against grounding the plane.
The FAA said its shift in policy came after it received new information from the developing investigation. Data collected from the Ethiopian crash site, combined with satellite-based tracking data, “indicates some similarities between” the Ethiopian Airlines and Lion Air crashes, the FAA reported on March 13. Those data, the agency continued, “warrant further investigation of the possibility of a shared cause.”
While regulating air travel serves to reassure the public, zigzagging is never helpful. Flying remains the safest major means of travel, so perhaps the most striking aspect of the disaster response was that the FAA itself was fanning apprehensions about air travel. The agency is running on autopilot; none of its top three officials has been confirmed by the Senate. But it does have precedent for grounding an entire type of aircraft, and the 737 Max 8 is just beginning commercial service and so is still in limited use worldwide. Its grounding will likely have a minor impact on most passengers.
“There’s no question in my mind that if those two events had happened in our country, the aircraft would be grounded,” said Jim Hall, a past head of the National Transportation Safety Board, speaking to TIME before the FAA announcement. A handful of complaints from American 737 Max pilots have been logged in a federal database since the aircraft’s introduction in 2017, though it’s unclear if those issues are linked to the two downed aircraft. Michael Barr, a former Air Force fighter pilot and an accident-investigation instructor, criticized the agency’s decision to wait.
The world’s 737 Max fleet will remain grounded until further notice, and Boeing and the FAA alike will surely face additional questions. As for answers, the world will look to Flight 302’s black boxes, which are on their way to be analyzed in France. Whatever they reveal should make aviation safer in the future–if the system works the way it should.
With reporting by W.J. Hennigan
This appears in the March 25, 2019 issue of TIME.