EgyptAir Flight 990 departed JFK for Cairo. After reaching cruise altitude near Nantucket, it suddenly pitched down and crashed into the Atlantic Ocean. There was no apparent reason for the crash. The NTSB ultimately concluded that the cause of the crash was the co-pilot’s “intentional actions.” Specifically, the pilot suddenly pushed the yoke forward and held it there, killing all 217 aboard.

The Egyptian government disagreed with the NTSB’s conclusion, instead blaming the crash on a defect in the design of the 767’s elevator system. Boeing knew that if certain rivets in the elevator’s bellcranks fail, the elevator can jam, causing the aircraft to pitch down and become uncontrollable. Instead of requiring that the airlines replace the suspect rivets with more reliable fasteners, Boeing told the airlines to simply inspect the rivets more regularly. But Boeing knew even before the crash of Flight 990 that the inspection protocol was not effective in catching rivets that had failed. According to the Egyptians,

Equally, if not more disturbing, is the NTSB’s total disregard of the relevance of the unequivocal evidence of either sheared or deformed bellcrank rivets, not only on EgyptAir 990, but also on other Boeing 767 aircraft.

The FAA came to agree that simply inspecting the rivets more frequently was not the answer. So in March 2014 – 15 years after the crash of EgyptAir Flight 990, the FAA warned airlines that “failures or jams in the [Boeing 767’s] elevator system” can result “in a significant pitch upset and possible loss of control” and ordered airlines to replace the rivets with fasteners that were more reliable,

Boeing 767 Elevator Bellcranks

So far, so good. But, somewhat surprisingly, the FAA gave the airlines until 2020 to make the repairs.

Atlas Air Flight 3591 was, of course, a Boeing 767, just like EgyptAir Flight 990. And like EgyptAir Flight 990, the Atlas Air flight suddenly pitched down and crashed for no apparent reason.

If it turns out the Atlas Air Flight 3591 crashed because of what everyone seems to agree is a defectively designed elevator control system, one would have to ask why Boeing and the FAA gave the airlines six years to fix the problem.