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Old 03-10-2019, 07:05 AM
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157 Dead Ethipian Airlines Crash in New Boeing 737 Max


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An Ethiopian Airlines passenger flight from Addis Ababa has crashed on its way to Nairobi, killing all 157 people on board. The Boeing 737 passenger jet had 149 passengers and eight crew members on board, Ethiopian said in a statement. The ET 302 plane lost contact six minutes after takeoff at 8.38am local time and crashed around the town of Bishoftu, located 60 kilometers (37 miles) southeast of the capital Addis Ababa...

Sweden-based flight tracking platform Flight Radar24 said the plane’s “vertical speed was unstable after take off.” Ethiopian confirmed the aircraft was Boeing 737-800 Max, the same model that was involved in the Lion Air flight that crashed in October 2018 a few minutes after departing from Jakarta, Indonesia.
https://qz.com/africa/1569594/ethiop...kenya-crashes/

It was a brand new airplane delivered in November. Unlike many African airlines Ethiopian Airlines has a very good safety reputation.
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Old 03-10-2019, 08:46 AM
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Rather bad news for Boeing. Two of their brand spanking new model aircraft nosediving into the ground minutes after take-off.

Seems like there's a major design flaw.
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Old 03-10-2019, 09:30 AM
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Obviously we have no idea why Flight 302 went down, but obviously that's a hell of a suspicious coincidence.

In both crashes the pilot asked for permission to return to the airport almost immediately upon takeoff. In the case of Lion Air 610 it appears something was wrong with the aircraft's angle-of-attack sensors, at least.
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Old 03-10-2019, 02:30 PM
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Surprised Boeing isn't in majorly serious hot water now. Two crashes with no survivors. There ought to be airlines canceling their 737 MAX orders left and right right now.
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Old 03-10-2019, 02:48 PM
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Surprised Boeing isn't in majorly serious hot water now. Two crashes with no survivors. There ought to be airlines canceling their 737 MAX orders left and right right now.
Shhhh... Boeing crashing along with their planes is not good for the Seattle economy.

I'm praying for the families of the victims, and that the cause turns out to be simple: found and fixed quickly.
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Old 03-10-2019, 02:52 PM
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The crashes are many months apart.

And there's this post on Pprune:

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Originally Posted by rcsa on Pprune
Respectfully, and as someone who lives in africa and travels extensively round the continent, ET is a dreadful airline, running what we call a ‘chicken bus’ service (think of an African bus with chickens tied to the roof). Bole Airport is absolutely one of the worlds worst, and I’ve had more scary flights on ET than I have had on any other airline - and I am not a nervous flier at all.

Trundling around africa I’d rather fly KQ/SAA/RAM/THY before ET.

Personally I would wait a while before blaming the aircraft. It’s also possible it was something more akin to human (pilot/ground handling/security/ATC) error.
And there is a report that the plane had engine problems.

Quote:
Originally Posted by The Times of Israel
Ambassador Hanan Godar says he was on the same aircraft last week that crashed Sunday en route to Nairobi, killing all on board...

The Ethiopian Airlines aircraft that crashed on Sunday experienced engine trouble three days ago, Israel’s Ambassador to South Sudan Hanan Godar said, noting that he was a passenger on board the jetliner last week.
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Old 03-10-2019, 03:11 PM
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I worry about this because the MAX 8 is becoming quite common, and some members of my family fly a lot. Here in Canada Westjet flies the 737 almost exclusively on its North American routes, and some of them are the MAX 8. The 737 fleet overall represents fine well-established airplanes with an excellent safety record, but this is potentially very bad news for the MAX 8 (and 9). AIUI, in the interests of more efficient operation the new LEAP engines on the MAX 8 are mounted slightly forward and higher than engines on previous models, which gives the aircraft some unusual flying characteristics that could cause an upward nose pitch in some conditions of manual flight. To compensate, there's a system called MCAS that is supposed to detect this situation and automatically command the stabilizer trim nose down.

The Lion Air crash two months ago was apparently due to faulty angle-of-attack (AOA) sensors that activated the automatic nose-down stabilizer trim. The flight apparently experienced wildly fluctuating altitude and vertical speed as the pilots presumably fought with the flight management computer. From what I've read the Ethiopian flight didn't experience these oscillations, but did dip in altitude and then regain altitude before finally going down, all within the first few minutes of flight, which may be suggestive of a similar problem.

After the Lion Air crash, Boeing issued an emergency operations bulletin stressing that pilots be trained to set the stabilizer trim cutout switches to the "cutout" position and leave them there in the event of symptoms of erroneous AOA data. If there is any significant commonality at all between the causes of the two crashes, the MAX 8 and 9 would likely be grounded pending a permanent resolution.
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Old 03-10-2019, 03:58 PM
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... From what I've read the Ethiopian flight didn't experience these oscillations ...
According to this Twitter post (linked from the PPRuNe site) which captured live flight data, it sure looks like the Ethiopian flight was experiencing wild variations in reported vertical speed similar to Lion Air. Much too early to reach conclusions, but this tentatively points to at least a superficial similarity that could be very bad news for Boeing and the MAX 8.
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Old 03-10-2019, 04:24 PM
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According to this Twitter post (linked from the PPRuNe site) which captured live flight data, it sure looks like the Ethiopian flight was experiencing wild variations in reported vertical speed similar to Lion Air. Much too early to reach conclusions, but this tentatively points to at least a superficial similarity that could be very bad news for Boeing and the MAX 8.
The Lion Air flight had a less experienced crew, so when the MCAS started interfering with the flight, they didn't know what was causing problems, they didn't have the situational awareness to shut the MCAS off.

After the Lion Ari crash, Boeing released new training that is actually pretty simple, "See those switches? turn them off". (Okay more complex than that, but for a pilot, pretty simple.)

With the flight crew in this crash being much more experienced, and should be aware of how to prevent the situation that caused the Lion Air crash, I would think that it would be a different problem.

Downside would be that that means that there is another fatal flaw on Boeing's newest airframe, does not bode well.

Or, it could be the same problem and the pilots didn't recognize what was going on.
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Old 03-10-2019, 06:56 PM
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In the latest updates, the people who perished in the crash were citizens of 35 countries including 8 Americans and a hugely disproportionate number of Canadians -- 18.

Also now appearing in the mainstream media is acknowledgement that, as I said earlier, the vertical speed of the aircraft was wildly fluctuating during takeoff. Other tentative evidence suggests that engine thrust was nominal. If all these facts are correct -- which is far from certain -- it does tend to suggest an AOA/MCAS issue perhaps commanding a nose-down stabilizer trim, raising a disturbing commonality with the Lion Air crash.
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Old 03-10-2019, 07:31 PM
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As to why so many countries one partial explanation is:
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According to the UN Department of Safety and Security in Kenya, 19 UN staff perished in the crash. The World Food Programme (WFP) lost seven staff, the Office of the High Commissioner on Refugees (UNHCR) lost two, as did the International Telecommunications Union (ITU). The Food and Agriculture Organization (FAO), International Organization for Migration (IOM) in Sudan, World Bank and UN Assistance Mission in Somalia (UNSOM) each lost one staff member. Six staff from the UN Office in Nairobi (UNON) were also tragically killed.
https://news.un.org/en/story/2019/03/1034391
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Old 03-10-2019, 08:31 PM
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I'd hate to think that a crew couldn't deal with an angle-of-attack issue. It looks like it stalled but I'm confused. If there was an airspeed issue then they would have kept the nose down until they could accelerate to a speed sufficient to begin climbing.

This is a lot of dead people. Boeing needs to get way out in front on this.
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Old 03-11-2019, 09:14 AM
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It appears that manual override can be hard to achieve once bad AOA data starts to pitch the nose down unless one follows the cutout procedures. The Boeing Operations Manual Bulletin released after the Lion Air crash states:
In the event of erroneous AOA data, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds. The nose down stabilizer trim movement can be stopped and reversed with the use of the electric stabilizer trim switches but may restart 5 seconds after the electric stabilizer trim switches are released. Repetitive cycles of uncommanded nose down stablilizer continue to occur unless the stabilizer trim system is deactived through the use of both STAB TRIM CUTOUT switches in accordance with the existing procedures in the Runaway Stabilizer NNC. It is possible for the stabilizer to reach the nose down limit unless the system inputs are counteracted completely by pilot trim inputs and both STAB TRIM CUTOUT switches are moved to CUTOUT.
This is probably the most comprehensive overview I've yet seen of the AOA and stabilizer trim system on the 737 MAX.

Note that at this point it's not established that this had anything to do with the Ethiopian crash.
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Old 03-11-2019, 12:02 PM
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China, Indonesia, Ethiopia have all grounded the 737 Max:
https://arstechnica.com/information-...esia-ethiopia/
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Old 03-11-2019, 01:03 PM
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Meanwhile, American Airlines and Southwest and a bunch of international airlines are still flying them. Among Canadian-based airlines, so is Westjet and Air Canada. I mentioned Westjet as being a predominantly 737-based carrier, but actually Air Canada owns more of the MAX 8 models than WJA. WJA has 13 MAX 8s while ACA has 24. By coincidence AAL also has 24 MAX 8s, SWA has 35.
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Old 03-11-2019, 02:20 PM
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Why not just have a stick shaker but not stick pusher?
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Old 03-11-2019, 03:03 PM
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There's been some talk around here that the quality of Boeing's airplanes has declined since more and more parts are manufactured all over the world and shipped here for assembly. I don't know the basis for comparison as in when this started happening on a large scale.
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Old 03-11-2019, 03:59 PM
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There's been some talk around here that the quality of Boeing's airplanes has declined since more and more parts are manufactured all over the world and shipped here for assembly. I don't know the basis for comparison as in when this started happening on a large scale.
I seem to remember a previous Boeing CEO saying something to the effect he'd like to see the company basically become a design bureau based in Chicago. I do remember seeing the quote about wanting to be "a virtual manufacturer".
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Old 03-11-2019, 04:38 PM
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This is quite an informative graphic.

It clearly shows the erratic vertical speed and gives a better perspective than the raw numbers of the aircraft's inability to gain any significant altitude above ground level, as opposed to the reported "above mean sea level" numbers. It hardly ever attained an altitude of much more than 1000 ft AGL except at the very end, when it was at around 1500 ft and the transmissions ended. These are the live feeds from presumably the ADS-B transmissions, not the flight data recorder which has been found but not yet analyzed.

Last edited by wolfpup; 03-11-2019 at 04:38 PM. Reason: Can't type
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Old 03-11-2019, 04:48 PM
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This is quite an informative graphic.

It clearly shows the erratic vertical speed and gives a better perspective than the raw numbers of the aircraft's inability to gain any significant altitude above ground level, as opposed to the reported "above mean sea level" numbers. It hardly ever attained an altitude of much more than 1000 ft AGL except at the very end, when it was at around 1500 ft and the transmissions ended. These are the live feeds from presumably the ADS-B transmissions, not the flight data recorder which has been found but not yet analyzed.
The tower would have seen that they never climbed above 1000 ft AGL. That's pattern altitude for a small plane and based on the lower graph they weren't in a position to return to the airport. It was in trouble and whatever was directly in front of them was their next landing zone. It sounds like it stalled and nosed in.

Locals on the ground said they saw material and smoke coming from the plane. They may have hit a flock of birds or picked up FOD off the runway and destroyed an engine.

from BBC

Several witnesses who worked in the farmland below the plane's flight path told the Reuters news agency they heard loud rattling noises coming from the aircraft and saw billows of smoke and debris in its wake as it made a low turn over the fields.

"When it was hovering, fire was following its tail, then it tried to lift its nose," said one witness, Gadisa Benti. "When it passed over our house, the nose pointed down and the tail raised up. It went straight to the ground with its nose, it then exploded."
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Old 03-11-2019, 06:26 PM
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Why not just have a stick shaker but not stick pusher?
First up, MCAS is not a stick pusher, the stick pusher is a separate system that literally shoves the stick forward just prior to a stall.

As for why have a stick pusher at all, first you need to look at the stalling characteristics of traditional straight wing aircraft. What happens in a docile C172 as it stalls is that you first get some buffet as turbulent air off the wings interacts with the ailerons and elevator and just generally vibrates the airframe. Next, as the stall is entered fully, the point on the wing the lift force acts through, the centre of pressure, moves aft. This causes the aircraft to pitch nose down which pretty much breaks the stall unless the pilot holds the yoke back. So you have the stall warning, the buffet, to indicate the aircraft is about to stall, and then you get the stall identification, the dropping of the nose, as the stall occurs. This is very nice behaviour that requires no special mechanical features.

As aircraft became bigger with artificial feel in the controls and swept wings, the traditional stall characteristics were found to be either missing completely, not sufficiently pronounced, or even reversed. In larger aircraft, including straight wing turbo-props, there is not enough natural buffet felt through the airframe or the controls to give sufficient warning of an impending stall. The stick shaker is designed to mimic that buffet, it is a stall warning system. Jets with swept wings were also found to either not have the nose down pitch associated with the stall itself or they would do worse things such as pitch up and deepen the stall. Aircraft like this that showed adverse stalling characteristics were fitted with a stick pusher which does two things; it mimics the nose down stall identification of a traditional straight wing aircraft, and it forces a recovery prior to entering the stall. The pusher is a stall identification system.

So you see the shaker and pusher serve different purposes. Not all aircraft with a shaker have a pusher. The smaller Dash 8 turboprops only have a shaker, however the larger 300 and 400 series Dash 8s have a shaker and a pusher. The B747 had such good handling characteristics that it did not have a stick pusher except for some certified in the UK that had a pusher fitted because the UK test pilots were unhappy with its stalling and thought it needed one. Airbus FBW aircraft don’t have a shaker or a pusher. In normal law the flight computers literally won’t let it stall while in the degraded laws the stall warning system is an aural alarm “STALL STALL!” and there is no stall identification as such, just the warning.

The MCAS is different. I’m not an expert on it at all, but I understand the new LEAP engines fitted to the B737 Max had to be moved further forward and higher on the pylon compared to older engines due to the short undercarriage so that there was enough ground clearance. This new engine position produced some odd aerodynamic effects at high angle of attack that resulted in the nose pitching up. The aircraft could not be certified like that and the fix was to fit a system that trimmed the nose forwards at high AoA to counter the nose up pitching moment of the engines. It’s not a replacement for the pusher.

The Airbus A320 NEO, which also has CFM LEAP engines as an option, already had good ground clearance so they didn’t have the issues trying to fit the large engines on to the existing airframe.
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Old 03-11-2019, 06:27 PM
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To the topic. The comparison with the Lion Air crash is inevitable and obvious but a bit premature.
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Old 03-11-2019, 09:06 PM
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Looking at the WIKI site for 737 MAX it says 17 inch ground clearance on the engines. That seems really low for an engine.
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Old 03-11-2019, 09:47 PM
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It is fairly low. By comparison, the A320 with the same engine has a clearance of 22 inches.
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Old 03-11-2019, 10:40 PM
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Looking at the WIKI site for 737 MAX it says 17 inch ground clearance on the engines. That seems really low for an engine.
A unique characteristic of the 737 Link
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Old 03-11-2019, 11:05 PM
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A unique characteristic of the 737 Link
the plane that crashed is a 737-MAX with the new LEAP engine. It's not flat on the bottom but they had to lengthen the nose gear to maintain 17 inch ground clearance.

When I was between jobs I worked the ramp for the new 747-8's. Not sure if it's any different than the 747-400 but we had to walk the entire ramp before each flight landed to look for FOD. The airport had to drive the runway looking for the same thing.

This could be another Concorde. Engine picks up FOD and comes apart after rotation. If the PIC didn't have solid control of the plane and tried to circle back then it gets ugly pretty quick.

I'm not an engineer but I wonder if the new composite fans are as robust as the metal ones.

Last edited by Magiver; 03-11-2019 at 11:07 PM.
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Old 03-11-2019, 11:25 PM
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There's been some talk around here that the quality of Boeing's airplanes has declined since more and more parts are manufactured all over the world and shipped here for assembly. I don't know the basis for comparison as in when this started happening on a large scale.
Boeing KC-46 tankers for the USAF were recently found to have debris left inside the wings upon Air Force inspection. Does seem like some corner-cutting.
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Old 03-11-2019, 11:45 PM
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Well the 737 has always had very low ground clearance, if it was a FOD issue I’d think it would have presented itself by now. Concorde involved FOD rupturing a fuel tank which then caused the further issues. The failure was specific to the entire Concorde design.
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Old 03-12-2019, 12:39 AM
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from Reuters:
Half a dozen witnesses interviewed by Reuters in the farmland where the plane came down reported smoke billowing out behind, while four of them also described a loud sound.

“It was a loud rattling sound. Like straining and shaking metal,” said Turn Buzuna, a 26-year-old housewife and farmer who lives about 300 meters (328 yards) from the crash site.

“Everyone says they have never heard that kind of sound from a plane and they are under a flight path,” she added.

Tamirat Abera, 25, was walking past the field at the time. He said the plane turned sharply, trailing white smoke and items like clothes and papers, then crashed about 300 meters away.


the plane would have been too low for explosive decompression so they might have had an open cargo door or an engine completely disintegrated and tore into the fuselage.
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Old 03-12-2019, 11:00 AM
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UK and Germany have now banned all MAX 8's from their airspace.

I'd guess some preliminary results have been released to interested parties.
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Old 03-12-2019, 12:34 PM
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I record Air Disasters on the Smithsonian Channel and my entirely anecdotal impression is that stalls are the most-often cited proximate* cause of airliner crashes (at least in the episodes I've seen). Followed perhaps by "controlled flight into terrain."

*proximate only -- note that the root causes leading to the stall may be many things.

If the eyewitness reports of papers and clothing trailing the plane in midair are accurate, that's certainly an interesting data point, indicative of structural failure.
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Old 03-12-2019, 04:47 PM
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If the eyewitness reports of papers and clothing trailing the plane in midair are accurate, that's certainly an interesting data point, indicative of structural failure.
Or a cargo door open. If something ahead of the engine tore loose and took out the engine then it's going to be a multiple factor event.

I wasn't kidding when I said Boeing needs to get out in front of this. It's spiraling out of control for them.
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Old 03-12-2019, 04:49 PM
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I'm not sure how much credence I would give to those eyewitness reports, as there are many possible sources of confusion.

The CEO of Ethiopian Airlines has made statements to the effect that:
  1. The pilot had "flight control problems", which is consistent with the speculation above
  2. That the pilots had received additional training on the flight procedures involving the 737 MAX 8 after the Lion Air crash -- presumably referring to the stabilizer trim cutout procedures referenced above
  3. That he believes "the similarities are substantial" with the Lion Air crash
Meanwhile most countries have now grounded the MAX 8, with the strange exceptions of the US and Canada and a couple of others. This has created odd situations where some aircraft already in flight to Europe had to turn back because they wouldn't be allowed into its airspace. Air Canada, meanwhile, has cancelled a number of flights to the UK from the eastern part of the country that use the MAX 8.

Last edited by wolfpup; 03-12-2019 at 04:52 PM.
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Old 03-12-2019, 06:42 PM
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Might US airlines have to ground them because passengers won't want to fly on them? I wonder when/if that becomes a factor.
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Old 03-12-2019, 06:53 PM
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Boeing Co. is making an extensive change to the flight-control system in the 737 MAX aircraft implicated in October’s Lion Air crash in Indonesia, going beyond what many industry officials familiar with the discussions had anticipated...

The change would mark a major shift from how Boeing originally designed a stall-prevention feature in the aircraft, which were first delivered to airlines in 2017. U.S. aviation regulators are expected to mandate the change by the end of April. Boeing publicly released details about the planned 737 MAX software update on its website late Monday. A company spokesman confirmed the update would use multiple sensors, or data feeds, in MAX’s stall-prevention system—instead of the current reliance on a single sensor...

The anticipated fix also will limit the extent of the flight-control system’s downward push on the plane’s nose. And it will rely more on technical safeguards than memorized pilot responses if the system misfires. Boeing said the change would come with updates to pilot displays, operation manuals and crew training.
https://www.wsj.com/articles/boeing-...d=hp_lead_pos1
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Old 03-12-2019, 07:30 PM
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Not to be a cynic, but "an extensive change" to a sophisticated flight control system released into the field for passenger-carrying airliners in just six weeks doesn't sound like there's very much time for testing, including the crucial element of regression testing -- retesting all existing functionality to ensure that the new features haven't inadvertently broken something else. The most recent FAA Airworthiness Directive states somewhat cryptically that "the FAA anticipates mandating these design changes by AD [Airworthiness Directive] no later than April 2019". It sounds to me like Boeing is working voluntarily under the oversight of the FAA with the understanding that the changes must be in place by the end of April, which seems to imply that someone thinks it's urgent.
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Old 03-12-2019, 08:38 PM
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From the same article:

"U.S. officials have said the federal government’s recent shutdown also halted work on the fix for five weeks."
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Old 03-12-2019, 08:52 PM
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I'm not sure how much credence I would give to those eyewitness reports, as there are many possible sources of confusion.
Witness Gabiahu Pikado told Hadashot 13 that "smoke was billowing from the plane's rear end, and then it crashed with a boom."

Maalka Galto, the farmer whose field the plane crashed in, said, "I saw smoke and heard strange noises. Small objects, that looked like papers, fell from the plane. Suddenly I heard a strange sound, the plane made a sudden turn - and it crashed."

Another eyewitness:
"A fire started burning in the plane's tail. It tried to lift itself up but started moving from side to side. In the end, after it flew over our house, the front of the plane turned down and its tail went up. It crashed straight into the ground and then exploded."

Tegegn Dechasa: “The plane was in flames in its rear side shortly before the crash. The plane was swerving erratically before the crash.”

Gebeyehu Fikadu said he saw flight ET302 'swerving and dipping' while 'luggage and clothes came burning down'



Seems a little too detailed and consistent to be confusion.
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Old 03-12-2019, 09:00 PM
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People who live along the flight path have a pretty good idea of what aircraft sound like.

If it was making strange noises, smoking, and stuff was raining down then I don't think it was a software issue.

Last edited by Magiver; 03-12-2019 at 09:01 PM.
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Old 03-12-2019, 09:45 PM
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If it was making strange noises, smoking, and stuff was raining down then I don't think it was a software issue.
You've obviously never used Windows
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Old 03-12-2019, 09:53 PM
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Seems a little too detailed and consistent to be confusion.
Quite possibly so. I'm just saying that witness recollections of sudden unexpected events can be notoriously unreliable, and these accounts are neither indicative of root cause nor do they seem to correspond with the statement of the Ethiopian Airlines CEO who was presumably privy to the ATC conversations. There may have been structural failure following unknown causative events.

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You've obviously never used Windows
LOL!

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Old 03-12-2019, 10:03 PM
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This could be another Concorde. Engine picks up FOD and comes apart after rotation. If the PIC didn't have solid control of the plane and tried to circle back then it gets ugly pretty quick.
A single engine failure wouldn't cause a crash though, right? What are the chances of runway FOD causing a double engine failure?

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If it was making strange noises, smoking, and stuff was raining down then I don't think it was a software issue.
SAS Flight 751 was an engine failure caused by a software feature that the pilots didn't know about.

Though if you are saying it doesn't sound like something caused by MCAS, you have a point.
  #43  
Old 03-12-2019, 10:09 PM
nearwildheaven is offline
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Might US airlines have to ground them because passengers won't want to fly on them? I wonder when/if that becomes a factor.
Yup, money talks.
  #44  
Old 03-12-2019, 11:12 PM
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With airlines and governments around the world shutting down Boeing 737 Max airplanes after a second deadly crash of the aircraft, U.S. Secretary of Transportation Elaine Chao is not only resisting the calls to ground the plane, she even flew one of the planes back to Washington Tuesday afternoon.
https://www.cnbc.com/2019/03/13/us-t...737-max-8.html

Such bravery!
  #45  
Old 03-12-2019, 11:36 PM
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Southwest Airlines just began service to Hawaii, and while they have not used this plane yet, plans are to use it almost exclusively in the near future. They seem to have ordered a bunch of them. This may not be good for Southwest. But local Hawaiian Airlines may be happy this is happening to the new competition.

So far, only one small Canadian airline flies the plane to here.
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Last edited by Siam Sam; 03-12-2019 at 11:37 PM.
  #46  
Old 03-13-2019, 03:24 AM
Tim@T-Bonham.net is offline
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Quote:
Originally Posted by RickJay View Post
Obviously we have no idea why Flight 302 went down, but obviously that's a hell of a suspicious coincidence.
Not really.
Given that there are about 400 of them in service (another 4600 on order), and they typically make 1-3 takeoffs per day, my very rough estimate is that there have been around 50,000 Boeing 737 takeoffs between these 2 incidents. I'd want a bit more info first.
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Old 03-13-2019, 08:23 AM
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Originally Posted by Tim@T-Bonham.net View Post
Not really.
Given that there are about 400 of them in service (another 4600 on order), and they typically make 1-3 takeoffs per day, my very rough estimate is that there have been around 50,000 Boeing 737 takeoffs between these 2 incidents. I'd want a bit more info first.
I'm guessing one crash per 50K flights is a much higher incidence rate than for other types of planes. OTOH, it's still far too low to draw any statistical conclusions.

Aircraft types can be grounded after a single incident, if a glaring flaw is revealed that clearly threatens safety. The cause of the Lion Air crash is pretty well understood at this point, but the cause of the Ethiopian crash is not - and the eyewitness reports of smoke and noises in the minutes prior to impact of the latter suggest that its cause isn't the same as for the Lion Air crash. IOW, not a clear pattern that justifies grounding all planes of the same type (unless the pattern that comes out of all this is that the entire airplane, from nose to tail, is a giant piece of shit made of cardboard and bailing twine).
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Old 03-13-2019, 09:33 AM
bump is offline
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A single engine failure wouldn't cause a crash though, right? What are the chances of runway FOD causing a double engine failure?
I would imagine that depends on the type and quantity of FOD on the runway.
  #49  
Old 03-13-2019, 09:47 AM
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Vacation charter airline Sunwing grounds its MAX 8 fleet for "evolving operational reasons". Translation: "we want to keep flying them, but they're banned at all our usual destinations". This event has apparently taken us to new frontiers of literary creativity.

Last edited by wolfpup; 03-13-2019 at 09:49 AM.
  #50  
Old 03-13-2019, 10:17 AM
Brayne Ded is offline
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Rea;;Y?


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Originally Posted by Helena330 View Post
There's been some talk around here that the quality of Boeing's airplanes has declined since more and more parts are manufactured all over the world and shipped here for assembly. I don't know the basis for comparison as in when this started happening on a large scale.
That is standard in the aircraft industry, and Airbus does it as well. And it has been done for quite a while. I am more inclined to look for a design problem, possibly in software.
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