Thursday, September 26, 2019

Boeing Crashes and the Human Factor

The NTSB investigators looking into the two deadly crashes of Boeing's 737 Max say the company failed to account for "the human factor":
The agency said Boeing had underestimated the effect that a failure of new automated software in the aircraft could have on the environment in the cockpit. When activated, the system, known as MCAS, automatically moves the Max’s tail and pushes its nose down. The system contributed to two crashes in less than five months that killed 346 people and caused regulators around the world to ground the plane. Boeing did not fully inform pilots about how MCAS functioned until after the first accident. . . .

In conversations with airlines and aviation unions following the crashes, Boeing executives said that the accidents could have been avoided if pilots had simply run a standard emergency procedure. But officials with the safety board suggested that Boeing was too confident the average pilot could easily recover the plane in that situation, because the company had not considered the chaos that ensued inside the cockpit.

“They completely discounted the human factor component, the startle effect, the tsunami of alerts in a system that we had no knowledge of that was powerful, relentless and terrifying in the end,” Dennis Tajer, the spokesman for the American Airlines pilots union, said of Boeing. . . .

When Boeing developed the Max, it assumed that if MCAS activated erroneously, pilots would immediately react by performing a standard emergency procedure. But the company had tested the possibility of an MCAS failure only in isolation, failing to account for just how chaotic the cockpit would become when the activation caused other malfunctions.

On the doomed Lion Air and Ethiopian Airlines flights, a faulty sensor triggered MCAS, which produced a cascading number of warnings that may have overwhelmed the pilots.

“They did not look at all the potential flight deck alerts and indications the pilots might face,” said Dana Schulze, the director of the Office of Aviation Safety at the safety board. “Multiple alerts and indications have been shown through years of research to have potentially an impact where pilots will not respond as perhaps you might have intended.”
This sounds to me like the essence of bad design, followed by bad testing and bad training for pilots. If the NTSB is right and the pilots in the fatal crashes faced not just one warning but a whole series, then the failure of Boeing to plan for that and prepare pilots to face it looks murderous to me.

1 comment:

Shadow said...

To the extent that this report is accurate about causes and weaknesses, and I wonder about that, this is maddening. Perhaps what isn't being said here is how much cost and scheduling got in the way of thorough testing. Personally, I find it hard to believe that after all these years of building commercial aircraft and briefing pilots and gathering other feedback, that anyone would be surprised there might be chaos in the cockpit.

And do they know the emergency procedure works under all conditions? I thought I remembered a pilot saying the procedure didn't work when he tried it.