When Lion Air Flight 610 plunged into the Java Sea off Indonesia shortly after takeoff last October, killing 189 people, analysts and passengers alike were cautiously satisfied in the aftermath with Boeing's explanation that its state-of-the-art 737 Max aircraft is safe.
The fatal Ethiopian Airlines air crash, which killed 157, at the weekend has shaken that belief.
There was an element of victim-blaming in the aftermath of the Lion Air tragedy, with aviation insiders in Ireland pointing to Indonesia's historically shoddy safety record as a way to alleviate queries about issues surrounding the so-called "game-changing" 737 Max.
The 737 Max is perfectly safe, they said -- it is most likely poor safety and pilot error that brought Lion Air Flight 610 down.
It is a different story today. Ethiopian Airlines has an excellent, though not impeccable, safety record and is the envy of others within the industry not only in Africa but across the world.
While it would not to fair or accurate to cast aspersions on the safety of Boeing's wonder plane just yet, it is surely prudent to ask hard questions.
Put simply, pilots have said they were not trained in new features of an anti-stall system that are different from previous 737s.
The automated system is designed to help pilots avoid raising the plane’s nose too high, which can cause the plane to stall, or lose the aerodynamic lift needed to keep flying.
The system automatically pushes the nose of the plane down. But if that nose-down command is triggered by faulty sensor readings -- as suspected in the Lion Air tragedy -- pilots can struggle to control the plane, which can go into a dive and perhaps crash, according to a Boeing safety bulletin and safety regulators.
You don't get do-overs or mulligans in aviation, where innocuous human errors or technical faults can snowball into a chain reaction of catastrophic events, often fatal.
With 5,000 orders of 737 Max aircraft from airlines around the world, and many billions of dollars on the line, the stakes could not be higher for the world's biggest planemaker, which saw a tenth wiped off its value as spooked investors jettisoned shares yesterday.
Irish passengers may not have taken much notice previously, but there is a good chance that many were transported across the world on a 737 Max since mid-2017.
Norwegian Air International uses the plane for its Irish flights to the US east coast, including Cork's first-ever transatlantic route to Providence, Rhode Island. Shares in that firm fell almost 7%. The airline is taking it seriously, but not grounding flights like some airlines.
Norwegian’s director of flight operations, Tomas Hesthammer, said: "All of our Boeing 737 Max aircraft are operating as normal. We are in close dialogue with Boeing and follow their and the aviation authorities’ instructions and recommendations. Our passengers’ safety is and will always be our top priority.”
Ryanair waxed lyrical about the 737 Max in February's quarterly update. A query from this reporter regarding the 737 Max yesterday went unanswered.
"We will take delivery of our first five 737 Max gamechanger aircraft from April. These aircraft have 4% more seats, are 16% more fuel efficient, have 40% lower noise emissions and...will drive unit cost efficiencies over the next five years," it said last month.
It is due to take 42 deliveries from August until next March, and has options to buy 210 in total.
The Irish Aviation Authority is taking notice: "We await further information from the accident investigation team, the manufacturer Boeing, the US Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA) on the circumstances of this accident.
"As safety is paramount to passenger and aircraft operating crews, the Irish Aviation Authority will issue notification to all operators of Irish registered Boeing 737 Max as soon as any further information becomes available."