SEATTLE -- The 737 MAX is hardly the first case of a commercial aircraft launch or redesign that has run into serious problems. The debut of Boeing's own 787 Dreamliner, starting in 2011, was marred by everything from faulty supply chains and production delays to onboard fires from overheating batteries -- and a grounding for more than three months.
But you have to go back many decades to find the introduction of a commercial aircraft that has involved such a staggering loss of life, or has raised such uncertainties.
"I can't think of a time since perhaps the 1970s or even the 1960s, when you had two examples of a brand-new aircraft crashing within six months of each other, within the first couple of years of service," said Todd Curtis, a Seattle-based aviation safety expert who tracks aircraft safety data on the website AirSafe.com.
And although the 737 MAX's relatively short lifespan -- it was first delivered in May 2017 -- makes statistical comparisons difficult, at this point the 737 MAX has a crash rate that is roughly 14 times as high as the 737 series as a whole when measured by number of fatal crashes per million flights, according to Curtis' calculations.
Aircraft introductions and major redesigns are almost never problem-free, said Jim Hall, former chairman of the National Transportation Safety Board, which investigates aircraft accidents. In any new or redesigned aircraft, Hall said, "there may be bugs or things that were engineered that, in actual service, need tweaking and need adjustment."
What distinguishes the debut of the 737 MAX is not only the sheer magnitude of the tragedies -- a total of 346 lives lost on Ethiopian Airlines Flight 302 last Sunday and the Lion Air Flight 610 in October. As noteworthy is the fact that these two successive disasters occurred in what had been one of the safest eras in commercial aviation safety, when decades of work by manufacturers and regulators alike had succeeded in dramatically lowering the risks of serious crashes.
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Investigators don't yet know exactly what factors led to the crashes of either Ethiopian Airlines Flight 302 last Sunday or the Lion Air Flight 610 in October or to what extent the accidents are related. In grounding the aircraft Wednesday, the Federal Aviation Administration said the two flights "behaved very similarly," raising "the possibility of a shared cause for the two incidents that needs to be better understood and addressed." Boeing plans to roll out a software fix next month intended to solve the flight-control problem linked to the Lion Air crash.
Nonetheless, the events have raised daunting questions about an aircraft that is expected to be a major best-seller for Boeing and the next generation of a workhorse jet for the airline sector.
The twin crashes have also invited unwelcome comparisons to commercial aviation disasters from earlier periods, when the industry's ability to build aircraft -- and to understand why some of them failed -- was orders of magnitude below what it is today.
The classic case is the Comet, the world's first jet airliner. Launched in 1952 by British aircraft firm de Havilland, the 36-passenger Comet enjoyed massive commercial and cultural success for barely a year before a series of high-profile fatal crashes.