Posted on 03/10/2020 3:13:13 PM PDT by Yo-Yo
Eight days after a Boeing Co. 737 Max went down in the Java Sea, killing all aboard, the planemaker issued a worldwide warning to pilots identifying the malfunction that triggered the crash.
The bulletin, which was followed almost immediately by a similar notice from U.S. regulators, listed the symptoms cockpit crews faced in such an emergency and explained how to counteract it. News reports described the problem.
Yet less than five months later a second 737 Max went down, slamming into a field in Ethiopia, after suffering the same malfunction. As the one-year anniversary of that crash approaches, many questions remain about why the two pilots lost control.
Was the bulletins technical language clear enough? Did Boeing and the regulators who signed off on the warning underestimate the chaos of alarms blaring in the cockpit of the doomed jet? Could the pilots have been fatigued or sick? Should, as one whistle-blower has suggested, Ethiopian pilots have gotten more training on the malfunction?
I think thats a central question: Why? said Jeffrey Guzzetti, the former head of the FAAs accident investigation bureau. Theres all kind of potential underlying threads.
A flaw in the design of the 737 Max has already been identified as a main reason for the crash of a Lion Air plane near Jakarta. The Ethiopian Aircraft Accident Investigation Bureau hasnt released its findings but a preliminary report out last April showed a similar malfunction also occurred on that flight.
The Ethiopian investigators are poised to release an interim report on the March 10 crash in coming days. A draft of the report focuses on Boeings flawed design according to people who have seen it.
Ethiopian government officials and the airline have steadfastly defended the pilots. Transport Minister Dagmawit Moges in April said they followed all the procedures repeatedly. Airline Chief Executive Officer Tewolde GebreMariam has bristled in interviews over implications that the crew didnt perform properly.
A committee of the U.S. Congress on Friday issued its own preliminary findings on the Max and said its design and development was marred by technical design failures, lack of transparency with both regulators and customers, and efforts to obfuscate information about the operation of the aircraft.
Boeing added a flight-control feature called the Maneuvering Characteristics Augmentation System, or MCAS, which was programmed to automatically drive down the nose in some circumstances, without adequately assessing its risks, Indonesias National Transportation Safety Committee concluded in October.
The company assumed pilots would respond to a malfunction of MCAS within four seconds, but the Lion Air crash and an incident on the same plane a day earlier showed that wasnt realistic, the investigation found.
Yet the environment was different for the Ethiopian crew.
Boeings bulletin on Nov. 6, 2018, and an emergency directive by the U.S. Federal Aviation Administration didnt specifically name MCAS, but the system was widely identified in news reports within days.
The bulletin listed nine possible symptoms in such a failure. If any of them occurred while the plane tried to nose down on its own, the directive said: do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
In the nomenclature of aviation, that meant perform an emergency checklist shutting off power to the motor driving down the nose and keep it off.
The directive was made a part of the Ethiopian carriers manuals. Within two days of Boeings notice, a senior Ethiopian Airlines pilot had emailed the companys crews to reiterate the warning, according to records reviewed by Bloomberg News.
Teasing out clues for why Captain Yared Getachew and copilot Ahmed Nur Mohammod reacted the way they did is critical, according to several former crash investigators and safety experts. Not only will it help shed light on the grounded 737 Maxs flaws and whether initial warnings were adequate, but it also is relevant to broad issues of pilot training and competency, they said.
According to the Ethiopian preliminary report, the pilots took several vexing actions.
They performed an important step in Boeings recommended emergency response to the malfunction: shutting off power to the electric motor that was driving down their nose. But they then restored power shortly before losing control.
They also left the planes throttle set to takeoff power, which prompted it to fly faster than its maximum allowable speed and made it far more difficult to control. Other actions, such as trying to activate the autopilot, appear to have been opposite of what they should have done in the emergency.
It would be easy to simply point the finger at the pilots, but that doesnt take into account the calamitous conditions in the cockpit, said John Cox, a former airline pilot and president of the consulting company Safety Operating Systems.
A failed sensor was triggering multiple errors and warnings, including a loud thumping noise on the captains control column signaling -- falsely, it turned out -- the plane was nearing an aerodynamic stall. They also had unreliable airspeed and altitude readings.
Its unfair sitting in an office saying they should have known how to respond, Cox said. Investigators should examine how the chaos would have impacted the pilots performance, he said.
Another area investigators should review is the adequacy of the Boeing bulletin, Cox said. While it mentioned the multiple failures that could occur at the same time, it didnt expressly warn crews about how chaotic they could be, he said.
Such pilot warnings have been criticized as inadequate in previous accidents, Guzzetti said.
The U.S. National Transportation Safety Board, for example, criticized the FAA for a similar type of warning it issued to pilots after an earlier model of the 737 crashed near Pittsburgh in 1994.
It should be something they are looking at, Guzzetti said. How effective was the wording, the presentation and the prioritization?
While it will be impossible to know exactly what Getachew and Nur were thinking during the frantic five-minute flight, crash investigations typically follow a basic script to get clues.
They take a close look at pilots lives in the days prior to the crash for signs of illness, fatigue or other personal factors that could affect their actions.
In the Lion Air crash, investigators found that the captain was sick and the copilot had been called in at 4 a.m. as a substitute for the scheduled crew member.
The type of training that pilots received and how well they performed in their careers are also areas that can help investigators understand accidents.
Nur, the 25-year-old Ethiopian copilot who was almost new to the plane, might get attention from investigators. He had only 361 hours of flying experience in his brief career and less in the 737: 56 hours in the Max and 151 hours in other models of the plane. He had been flying the aircraft for less than 90 days.
Pilots training and skills have been relevant in multiple previous accidents.
Both of the Lion Air pilots had exhibited problems in those areas, Indonesian investigators found. Most significantly, the copilot had had difficulty locating checklists and performing in emergency scenarios.
A Canadian man who was a pilot for Ethiopian Airlines before resigning last year said he tried before the crash to warn the carrier that crews werent adequately prepared.
In the months after the Lion Air accident, Bernd Kai von Hoesslin frequently quizzed copilots he worked alongside about the MCAS bulletin and most of them couldnt answer detailed questions, he said in multiple interviews with Bloomberg News.
The airline called von Hoesslin a disgruntled former employee and disputed his allegations in statements. The airline strictly complies with all global safety standards and regulatory requirements, it said in a Twitter post last year.
Von Hoesslin submitted records to the U.S. NTSB, which is participating in the probe, but hasnt been contacted by Ethiopian investigators, he said in an email.
The quality of training at the airline should also be a part of the investigation, said Roger Cox, a former NTSB investigator and airline pilot.
Representatives of the airline didnt respond to requests for comment on this story.
Were crews adequately taught to be comfortable flying a plane manually during an emergency? Were junior pilots coached to speak up when a captain made a mistake? Were they given realistic emergency scenarios during training?
These are not just questions that could help explain why the Ethiopian crew lost control, but probing them for answers could help improve safety across the world, Cox said.
Have you done enough to ensure that those guys together have an adequate ability to handle an emergency? he said. Its an extremely important question to ask.
First World Piots knew what to do and how to fly out of all it.
Third World pilots do not have air sense nor do they have judgment.
Exactly!!! They are not qualified to fly sophisticated Aircraft! They might be able to fly a Constellation but I doubt it!
A Canadian man who was a pilot for Ethiopian Airlines before resigning last year said he tried before the crash to warn the carrier that crews werent adequately prepared.
Computer 2 wins, Pilots 0 wins
Let me tell you something! I worked for Boeing on Their AWACS project and they put their planes through a rigorous flight test. Evidently the AOA never faulted during their flt test or they would have fixed it before delivery of their first jet.. When they found out something was amiss they sent out advisories telling of the danger. If the airlines ignored that that is their fault.. Like I said before these foreign 3rd world countries do not train their crews very well..
Bad Pilots without the needed info....
The day before the fatal crash another crew in the same aircraft experienced the same MCAS problem due to the broken AOA sensor. A check pilot in the jump seat immediately recognized what was happening, switched of the stab trim motors, and was able to complete the flight safely.
Why was this pilot able to react correctly but the other company pilots couldn’t? Why was the problem not reported or fixed before the same plane was flown the next day? There are 10,000 mechanical things that can and do go wrong with complex aircraft that aren’t due to design flaws and must be handled by trained and alert human crews. The incident happened because of a chain of small errors that accumulated into a fatal disaster.
Boeing was made the responsible party because they had the financial resources to compensate the victims and juries view them as greedy and evil. They forget that Boeing employees and families fly on the same aircraft as everyone else and have the best safety record of any aircraft manufacturer in the world. I would fly comfortably on any aircraft that the pilot and first officer put their own lives on.
“The bulletin listed nine possible symptoms in such a failure. If any of them occurred while the plane tried to nose down on its own, the directive said: do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight. “
Shutting off those switches also kills the electric trim control on the yoke since they those switches disconnect the motors entirely. If not for that then the planes would not have crashed. And if anyone a number of design issues were not present then the plane would not have crashed.
Doesn't mean much; son "Ace" never even finished high school. Went directly to college and flight school at 16.
'Course not every sixteen year old can pull that off!
You can google any airframe for the accidents and incidents. The majority of them are not by US carriers. Why?
Something should be done to address this big picture.
Maybe the rest of them thought that he was just a bad pilot.
Yes I worked for Boeing for 32 1/2 years and Boeing would never put out a A/V they knew was unsafe.. I worked on AWACS program. When we saw something wrong we wrote it up.. The engineers had to show it was fixed to the Air Force’s standards.. When I retired in 2007 Boeing did away with their Quality Control and started self policing.. I don’t know if that caused this problem or not.. Probably not!
We don’t need to learn how to land
The only thing that Boeing did right was to accept responsibility. Because at the end of the day the responsibility was theirs. The design issues were glaring to anyone with a brain and the slightest amount of technical understanding/experience.
And when you are designing an airplane then you always need to apply the premise that if anything can go wrong then it will.
But the whole point of this article is that the pilots did have the needed info.
The important thing is how many wimmens they have on their board.
It will fly again. And it will be the safest airplane ever manufactured.
You beat me by a few months, but I agree. Everyone at Boeing knows that safety is number one. Everyone.
My early background was in aircraft instrumentation and later on, after earning a degree in Computer Science, I worked in aerospace for a good number of years, so I feel pretty qualified to comment on this.
The crash of both planes seems to have been caused by faulty Angle of Attack (AOA) information being fed into a computer system which then drove the flight controls to force the nose down in order to avoid a perceived stall.
In my experience, sometimes the pilots would complain that their altimeters were erratic and after investigation we found that the problem was often caused by a dirty AOA probe. How’d we know? We had test equipment that we could hook up and fake out the aircraft by changing the static pressure in the tubing. We would power up the test equipment and simulate an altitude of, say, 10,000 ft., and then engage the computer which made changes to the altimeters. Then we would slowly turn the AOA probe and watch the altimeter. If its OK, it will change the altimeter in a controlled steady change. If the AOA probe was dirty, this would suddenly drive the altimeters thousands of feet in one direction and then thousands of feet in the other direction unpredictably. Of course, thats not good. The point is that a dirty and/or corroded AOA probe can produce WILDLY inaccurate AOA information.
On the 737-Max aircraft they apparently also sent the AOA information to a computer system, which is tied into the autopilot system, which drives the control surfaces and when they got wild AOA information they also got wild control surface changes. The pilots at first turned off the system but then, for some reason, turned it back on and couldn’t recover the 2nd time. I’m not a pilot, but after watching many, many episodes of “Air Disaster” I’ve concluded that a lot pilots today just aren’t very good at flying the plane manually anymore.
Many people have suggested that they should have a backup AOA probe. But with two probes how do you know which one is right and which one is wrong? I suppose you could have a third probe and then vote to see which data to use. I think this might lead to more problems than it fixes.
Knowing that the AOA data can be wild at times, I think I would use my computer systems to sample it at, say, 5 times per second. Within 1/5 of a second I think the readings should be pretty close together, within some reasonable limit. If consecutive readings were wildly different Id try to figure out the real AOA reading, discard the other(s), and raise some sort of fault code in the maintenance records. If it gets too bad, at some point the computer system may have to warn the pilots and shut itself down. My offhand thinking is in terms of perhaps 3-5 seconds.
Id probably look back farther than just two readings. A mathematician would be good here. There are mathematical techniques that can take a set of input data points and generate a smoothed output. This might be a good place for one of those. Use the smoothed out data in the autopilot system in order to avoid the wild behavior. Perhaps they already did this; I dont know.
Another thing would be to change out the AOA probes fairly quickly and refurbish them, hopefully before problems occurs. I don’t think we did this in the Air Force but then our pilots had ejection seats.
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