Lion Air 737 Max 8 fatal crash

a reply to: Zaphod58

This is like that Michael Crichton book but in real life. I can only imagine what the atmosphere at Boeing is like right now.

a reply to: Zaphod58

Exactly. This is the sort of "stuff" that gets you ADs issued.

I got nothing with this guy.

In an interview Thursday, Capt. Todd Insler, chairman of the United branch of ALPA, the Air Line Pilots Association union, broke ranks with his counterparts at American Airlines and Southwest Airlines who earlier this week publicly complained that this wasn’t disclosed to pilots during training or included in the 737 MAX pilot manuals.

Insler said many systems on an airplane work in the background without the pilot’s knowledge. He compared it to watching television: “I don’t need to know how it works.”

www.seattletimes.com...

a reply to: Zaphod58

"I don't need to know how it works."

From a pilot no less.

Dangerous sentiment that one!

Especially since it seems the malfunctioning system that he "don't need to know how it works", crashed an aircraft.

P

a reply to: pheonix358

But it wasn't (evidently) MCAS that malfunctioned. It worked just as advertised. The AoA sensors failed. MCAS then did what it was supposed to do with that (erroneous) data. Should pilots be aware? Probably. In the rare event the AoA sensors all go belly up, it becomes something you'd not want active. But given how many complaints over the years there have been about how abruptly the 737 enters an accelerated stall, I doubt MCAS goes anywhere. Aircrews will just be made aware of circumstances in which they should override the trim-down.

a reply to: RadioRobert

The Angle of Attack sensor did not fail. Boeing want the public to believe it was a simple sensor failure because that exonerates Boeing from liability & certification issues.



The DFDAU sent faulty signals but the AoA sensor was replaced after four previous roller coaster flights. The entire Pitot system was also cleaned & inspected after JT43.



The originating problem was faulty encoding of digital signals to the FMC.

It is standard operating practice to engage Autopilot at 400ft AGL after take off. JT610 ought to have been on autopilot which means MCAS should not have intervened at all, however where pilot displays disagree on airspeed, altitude & AoA the FMC will disengage the autopilot. This explains how MCAS managed to engage in the climb.




Boeing are using tame journalists at Seattle Times and New York Times to spin stories offloading blame and responsibility from Boeing, to plant in the public imagination a false theory of what caused Lion Air JT610's crash.

originally posted by: Zaphod58

Soerjanto Tjahjono, the head of the safety agency, said during a Wednesday briefing that it was not clear if there was a systemic problem with this type of aircraft.

“We cannot yet say that there is a design flaw with the plane,” he said, adding that the Max 8 appeared to have developed a problem with the angle of attack sensor only after technicians had changed it the day before the doomed flight.

www.nytimes.com...

You're a real sucker for officials must be right syndrome

originally posted by: Zaphod58
a reply to: sy.gunson

As opposed to you thinking you're the smartest person around and are infallible?

You pooh poohed the MCAS system.
I predicted the MCAS system was the problem.
All you have proven to date is your ignorance

a reply to: sy.gunson

I didn't "pooh pooh" MCAS once. And you didn't mention MCAS until about three posts ago. You have said from post one that the spoilers deployed and the crew didn't notice. MCAS has nothing to do with the spoilers and only controls the elevator trim.

Boeing are utterly wrong blaming the Stabilizer trim and AoA sensor.

The Angle of Attack sensor was replaced after a roller coaster flight from Bali as JT43. On that flight there were also discordant airspeed problems and High Angle of Attack issues. With a new AoA sensor fitted you can rule out Boeing's conclusions.



If MCAS engaged during the climb, then pilots likely trimmed the nose down intentionally to regain control. the fact that JT610 was flown at high speeds weel in excess of VMO and definitely in Mach Buffet territory suggests more likely they were fighting MCAS deployment of spoilers

a reply to: sy.gunson

Except that MCAS doesn't deploy spoilers. It's sole function is to trim the elevator nose down to prevent a stall. Absolutely nothing about it written anywhere says anything about MCAS having anything to do with the spoilers.

theaircurrent.com...

a reply to: sy.gunson

You're right. You want to pull crap out of thin air, have fun with that.

a reply to: sy.gunson

With a new AoA sensor fitted you can rule out Boeing's conclusions.

Why? This does not follow. From their own safety bulletin, they've talked about erroneous AoA information, but haven't ascribed where the erroneous AoA information was injected into the control system. I could see that, for example, if there was an electrical or electronic fault, you could replace the AoA sensor 100 times and still get the same anomalous AoA information every time. The investigation is on-going.

If MCAS engaged during the climb

MCAS refers to a range of different functionality and can manipulate both trim and spoilers. Which MCAS function are you referring to and which control surfaces were effected?

then pilots likely trimmed the nose down intentionally to regain control

Why? Do spoilers cause an extreme pitch up movement and require flying in excess of VMO? This does not follow.

he fact that JT610 was flown at high speeds weel in excess of VMO and definitely in Mach Buffet territory suggests more likely they were fighting MCAS deployment of spoilers

Why?

It seems to me that a combination of faulty air data, control augmentation, and human factors were likely at play. Also, their story makes more sense than yours.

Boeing are using tame journalists at Seattle Times and New York Times to spin

Rubbish. The Seattle Times article is scathing and is extremely high quality journalism.

a reply to: C0bzz

I've seen parts replaced many times that didn't fix the original problem. Southwest just announced they had two Max 8s have their AoA sensors replaced before 610 went down. The sensors weren't the cause of the problem the crews saw, but replacing them was part of the troubleshooting process.