[189 Dead] Lion Air: How could a brand new plane crash?

[Danke]

The NTSC has indicated that the accident flight experienced erroneous angle of attack (AOA) information.
Today, Boeing issued an Operations Manual Bulletin to all Boeing 737 Max operators stating that an erroneous AOA can cause the pitch trim system to trim the stabilizer nose down when the aircraft is being manually flown.
Revised Boeing Operating Instructions instruct crews, in the event an uncommanded nose-down stabilizer trim is experienced on the 737 Max with any additional indications or effects (listed in the Operations Manual Bulletin), to complete the Runaway Stabilizer Non-Normal Checklist to ensure that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
The FAA has issued an Emergency Airworthiness Directive to mandate the Boeing Operations Manual Bulletin effective upon receipt.

[Brian4Liberty]

The NTSC has indicated that the accident flight experienced erroneous angle of attack (AOA) information.
Today, Boeing issued an Operations Manual Bulletin to all Boeing 737 Max operators stating that an erroneous AOA can cause the pitch trim system to trim the stabilizer nose down when the aircraft is being manually flown.
Revised Boeing Operating Instructions instruct crews, in the event an uncommanded nose-down stabilizer trim is experienced on the 737 Max with any additional indications or effects (listed in the Operations Manual Bulletin), to complete the Runaway Stabilizer Non-Normal Checklist to ensure that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
The FAA has issued an Emergency Airworthiness Directive to mandate the Boeing Operations Manual Bulletin effective upon receipt.

I’m no pilot, but that doesn’t sound comforting.

[Brian4Liberty]

https://www.wsj.com/articles/boeing-...ers-1542082575

Boeing Withheld Information on 737 Model, According to Safety Experts and Others
Data related to a new flight-control feature suspected of playing a role in crash in Indonesia

By Andy Pasztor and Andrew Tangel Updated Nov. 13, 2018 1:56 p.m. ET

Boeing’s Problematic Flight-Control Feature: What We Know

The system which helps prevent Boeing’s new 737 Max 8 plane from stalling is potentially linked to the fatal Lion Air jet crash in Indonesia. WSJ’s Robert Wall explains what we know about the safety feature.

Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month’s fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots.

The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 models—intended to help cockpit crews avoid mistakenly raising a plane’s nose dangerously high—under unusual conditions can push it down unexpectedly and so strongly that flight...

“It’s not a bug, it’s a feature...”

[Brian4Liberty]

http://time.com/5453054/boeing-crash-737-max/

Pilots Say Boeing Didn't Tell Them About a Safety Feature Tied to a Deadly Crash

Two U.S. pilots’ unions say the potential risks of a safety feature on Boeing Co.’s 737 Max aircraft that has been linked to a deadly crash in Indonesia weren’t sufficiently spelled out in their manuals or training.

Boeing and the Federal Aviation Administration issued directives last week telling flight crews about the system, which is designed to provide extra protection against pilots losing control. That prompted aviators, unions and training departments to realize that none of the documentation for the Max aircraft included an explanation of the system, the union leaders said.

“We don’t like that we weren’t notified,” said Jon Weaks, president of the Southwest Airlines Pilots Association. Dennis Tajer, a 737 captain and spokesman for the Allied Pilots Association at American Airlines Group Inc., said his union’s members were also concerned.

The complaints from pilot union leaders at Southwest Airlines Co. and American are significant because of the size of those carriers’ 737 fleets and their Max purchases. Southwest is the largest operator of the 737 Max and has the most on order with 257 of the jets yet to be delivered. American, the world’s largest airline, has outstanding orders for 85 of the planes.

“This is not about silos and layers of bureaucracy, this is about knowing your airplane,” Tajer said. “We will always be eager and aggressive in gaining any knowledge of new aircraft.”

A bulletin from APA to American’s pilots said details about the system weren’t included in the documentation about the plane. “This is the first description you, as 737 pilots, have seen,” it said.

“The companies and the pilots should have been informed,” Weaks said. “It makes us question, ‘Is that everything, guys?’ I would hope there are no more surprises out there.”

Imagine this in a “self-driving” car:

“While driving the car manually, and the car erroneously turns on it’s own, be sure to double check the switch that shuts off the self-driving feature. If it is already in the off position, go ahead and toggle it on and off several times just to make sure.”

[Danke]

Still, a pilot should be able to counteract the nose down trim. The stick will get heavy. If you can trim it back, turn it off using the cut-out switches. That has been a procedure forever for runaway trim.

"Runaway Stabilizer Non-Normal Checklist to ensure that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight."

[DamianTV]

Simply put, BATHTUB CURVE.

Everything fails eventually. But there is an obvious pattern with electronics. Its called the Bathtub Curve. A lot of new devices are made defectively so failure rate right out of the box is very very high. Then it drops down and stays relatively steady. Then after so long, it spikes again until there are no more functional devices. Device Failure occurs most frequently at beginning or end of the life of most electronics, not somewhere in the middle. The middle is where mechanical problems occur, but less so on electronics that are tested and should be up to snuff.

[luctor-et-emergo]

Simply put, BATHTUB CURVE.

Everything fails eventually. But there is an obvious pattern with electronics. Its called the Bathtub Curve. A lot of new devices are made defectively so failure rate right out of the box is very very high. Then it drops down and stays relatively steady. Then after so long, it spikes again until there are no more functional devices. Device Failure occurs most frequently at beginning or end of the life of most electronics, not somewhere in the middle. The middle is where mechanical problems occur, but less so on electronics that are tested and should be up to snuff.

An AOA sensor is more of a mechanical device to begin with. It's a fin on an axis that aligns itself with the airflow, indicating the difference in angle between the plane and upcoming airstream.

Something like this:


However, I'm used to a more simple version...

[Anti Federalist]

Sounds like they tried their damnedest to save the aircraft.

But the ever $#@!ing computers knew better.


Lion Air pilots fought to save airplane before fatal crash

https://nypost.com/2018/11/27/lion-a...e-fatal-crash/

By Yaron Steinbuch November 27, 2018 | 3:35pm | Updated

The pilots of the doomed Lion Air airliner fought to save the plane almost from the moment it took off – as its nose was forced down apparently by an automatic system that received flawed sensor readings, according to a report.

The nose was forced down more than a dozen times during the 11-minute flight, but the pilots managed to pull it up repeatedly until they finally lost control of the Boeing 737 Max 8, which slammed into the Java Sea on Oct. 29, killing all 189 people aboard, The New York Times reported.

Information from the flight data recorder confirmed investigators’ theory that the maneuvering characteristics augmentation system, or MCAS, installed on Boeing’s newest 737 was to blame, the paper reported, citing a preliminary report from Indonesian authorities.

The MCAS, which is meant to prevent the nose from rising too sharply, causing the plane to stall, instead forced it down due to bad information sent from sensors along the fuselage, findings show.

“The pilots fought continuously until the end of the flight,” said Capt. Nurcahyo Utomo, chief of the air accident subcommittee of the Indonesian National Transportation Safety Committee, which is leading the probe.

R. John Hansman Jr., a professor of aeronautics and astronautics at the Massachusetts Institute of Technology, told The Times: “It’s all consistent with the hypothesis of this problem with the MCAS system.”

Earlier this month, Boeing and the Federal Aviation Administration issued a safety alert, saying a sensor issue could cause the 737 Max 8 to nose dive and crash because of incorrect input from the sensors of the “angle of attack,” the angle of the plane or its wings relative to wind.

After the crash, pilots have complained that they had not been fully informed about the MCAS — and how they would have to respond differently in case of the type of emergency that downed Flight 610.

SEE ALSO
US investigators examine recovered parts of the doomed Lion Air jet that crashed into the sea on Monday, at Tanjung Priok Port in Jakarta, Indonesia.
Lion Air pilot reported 'speed and altimeter' problem hours before deadly crash
Boeing has said the proper procedures for responding to an incorrect MCAS activation were already explained in flight manuals, so there was no need to address this specific system in the new 737 Max 8.

In a statement Tuesday, the company said it could not discuss the crash while it remains under investigation but noted again that “the appropriate flight crew response to uncommanded trim, regardless of cause, is contained in existing procedures,” The Times reported.

Pilots also have pointed out a potentially critical difference between the system on the new 737s and the older models.

In the older versions, flight crews said they could help address the problem of the nose being forced down improperly — a situation known as “runaway stabilizer trim” — by pulling back on the yoke in front of them.

In the Max version, that measure does not work, pilots said, citing information they have received since the crash, according to the newspaper.

The pilots on Flight 610 apparently pulled back on their control columns forcefully to no avail, according to the information from the flight data recorder.

One of the angle-of-attack sensors on the fateful flight was replaced before the plane’s penultimate flight after having transmitted some incorrect angle and speed data, investigators have said.

Investigators have yet to recover the cockpit voice recorder, which could provide vital information about the pilots’ actions and whether they followed correct procedures to deal with the emergency.

The captain had handed the controls over to the first officer just before the plane plummeted on its flight from Jakarta to Pangkal Pinang.

[Anti Federalist]

Still, a pilot should be able to counteract the nose down trim. The stick will get heavy. If you can trim it back, turn it off using the cut-out switches. That has been a procedure forever for runaway trim.

"Runaway Stabilizer Non-Normal Checklist to ensure that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight."

Apparently that's not the way the MCAS override works on the new 737 MAX series.

I'd holler and scream about that, myself.

The stick (or yoke and rudder) should act like a stick, always, and should always override all remote or automated flight controls.

[Danke]

Apparently that's not the way the MCAS override works on the new 737 MAX series.

I'd holler and scream about that, myself.

The stick (or yoke and rudder) should act like a stick, always, and should always override all remote or automated flight controls.

Nothing has changed. You can override the trim down by trimming up electrically. The MCAS will reengage after 5 seconds of releasing the trim, so to prevent that, the pilots need to move the STAB TRIM CUTOUT switches to CUTOUT. Then if they need to further trim, they can do it manually.

[angelatc]

https://www.wsj.com/articles/boeing-...ers-1542082575

Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month’s fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots.

“It’s not a bug, it’s a feature...”

Riddle me this, B-Man: Doesn't this sort of disprove the libertarian theory that companies would never act against the interests of their customers? Obviously, government oversight didn't help here, but that's a different point.

[Brian4Liberty]

Riddle me this, B-Man: Doesn't this sort of disprove the libertarian theory that companies would never act against the interests of their customers? Obviously, government oversight didn't help here, but that's a different point.

Don’t know the details on theory, but real world experience tells me that CYA takes precedence over customer’s interests. If they think they can get away with something, they try.

Two Space Shuttle disasters were caused by taking chances that “it will work out”.

[Danke]

Riddle me this, B-Man: Doesn't this sort of disprove the libertarian theory that companies would never act against the interests of their customers? Obviously, government oversight didn't help here, but that's a different point.

It is a WSJ article two Capt.s quoted, but it is about training not withhold information.

Capt. Mike Michaelis does not say information was withheld. Technical manuals have the information. That doesn't mean pilots get all that information in training. But it is available, not withheld.

[Brian4Liberty]

Don’t buy that Boeing stock just yet...

———

Boeing Pilots Detected 737 Max Flight Control Glitch 2 Years Before Deadly Crash
October 18, 2019

New evidence indicates that Boeing pilots knew about "egregious" problems with the 737 Max airplane three years ago, but federal regulators were not told about them.

Investigators say the plane's new flight control system, called MCAS, is at least partially to blame for 737 Max crashes in Indonesia in 2018 and Ethiopia this year that killed 346 people. Acting on data from a single, faulty angle-of-attack sensor, MCAS repeatedly forced both planes into nosedives as the pilots struggled, but failed to regain control.

The pilots in the Lion Air plane that crashed in Indonesia last October did not know MCAS existed, as Boeing did not disclose any information about it in pilot manuals or in training material.

Newly revealed instant messages sent between Boeing's then-chief technical pilot for the 737, Mark Forkner, and another technical pilot, Patrik Gustavsson, in November 2016 indicate that Forkner experienced similar problems with MCAS during a test session in a flight simulator.

In a transcript obtained by NPR, Forkner writes that "there are still some real fundamental issues" with the system that he says Boeing engineers and test pilots "claim that they are aware of."

As the two pilots banter back and forth in the messages, Forkner says the system is "running rampant in the sim on me," then adding, "I'm leveling off at like 4000 ft, 230 knots and the plane is trimming itself like crazy."

Forkner calls the problem "egregious" and writes that he had "basically lied to the regulators (unknowingly)" before experiencing the glitch, when he had told the FAA that MCAS was safe and did not need to be included in pilot manuals.

Later emails, also newly disclosed, show Forkner still telling the FAA that MCAS didn't need to be covered in the manuals.
...
More: https://www.npr.org/2019/10/18/77145...ore-deadly-cra

[pcosmar]

Not Ready for Prime time..

They are pushing it.. and it would not be a bad thing if it worked,,, but it is NOT READY.

They want to remove human error.... in a world made up of Humans.