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Old 27th March 2019, 10:56   #136
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by .sushilkumar View Post
Seems like Boeing is in real trouble. Now a plane makes emergency landing for engine failure.
The engine trouble could have occurred for a hundred reasons. These reasons can range from a maintenance issue with the engine, a fuel issue, bird hit, some other associated aircraft system having a problem or the engine itself, designed by CFM, malfunctioning. We cannot, in my opinion, add this to the list of Boeing's challenges with the MAX variant. We do not know if it is linked to the software issues.

About 105,000 commercial flights take off each day globally. About 48% to 50% of these are Boeing aircraft. ‎It would be normal for some Boeing aircraft somewhere to experience engine trouble each week. Engine trouble in one engine does not translate to fatality normally.

Last edited by V.Narayan : 27th March 2019 at 11:02.
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Old 27th March 2019, 13:27   #137
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by .sushilkumar View Post
. Now a plane makes emergency landing for engine failure.
Quote:
Originally Posted by V.Narayan View Post
Engine trouble in one engine does not translate to fatality normally.
I almost always cringe when I read in the press some airplane made an emergency landing. In many cases these emergency-landings are just pre-cautions. There was never an immediate threat to the ultimate safe of the plane, passengers and crew.

As a pilot as soon as problem develops, you keep flying the plane and you fix the problem, either eliminate or stabilize the situation. Ones that is done you need to re-think the rest of your flight and run through different scenario's.

If you have an engine problem and you end up shutting it down, the airplane does not fall out of the sky. (Unless you fly single engine planes as I do, . But you need to think through what to do next. You might not be able to maintain your altitude. Lower altitude and one engine operations, means higher fuel consumption. If you are flying a twin engine aircraft, if the other engine fails, you will have a real problem/emergency. So you tend to look for the most realistic option to land on one engine. That could involve just continuing to your destination, or return, or an alternative. Depends on the circumstance. The one engine out landing is not a big thing. Of course, the pilots will prepare for such a landing, there are different procedures/check lists and so, but they will have trained this dozens of time on simulators. No great shake.

Sully experiencing a loss of both engines and having to ditch in the Hudson is an emergency.

There is a well known case of a BA Boeing 747 which developed a engine problems shortly after take off in the USA enroute to London. The crew eventually had to shut down the one engine/ Weight up all their options and decided to cross the pond on the remaining three engines. The press reported it as "Jumbo jet makes emergency landing".

Jeroen

Last edited by Jeroen : 27th March 2019 at 13:34.
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Old 28th March 2019, 12:59   #138
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re: Boeing 737 Max crashes and grounding

For those who are interested in how this engine out scenario played out:



Looks like they lost the engine shortly after take off whilst still early in the climb and obviously, very near to the field they have just taken off from.

The pilot declares an emergency. Which is important, because it will get them priority over anything else happening in that air space. He also tells ATC immediately what the problem is (engine out) and what he needs (return to field). Good radio procedure.

There is a well known issue with pilots calling out an emergency. For some it is almost a stigma. Some pilots just will not call out an emergency. They might just request priority, but it is not the same thing at all. There is this believe that when you call out an emergency you will be investigated, by the authorities, your employer, it might be held against you in the future etc. Then there is the worst kind, where pilots thinks they are such hot shot pilots they do not need to call out an emergency. Real pilots do not call out emergencies sort of approach, they just land the plane safely without anybody noticing. Real macho, real stupid.

This plane would have landed safely, if the pilot had just requested ATC “to return to the field due to some technical difficulties.” (You need to provide a reason to deviate from your filed flight plan). It would have landed safely and nobody would have been the wiser.

But calling out an emergency is just a very wise precaution. Because in the world of aviation it gets you immediate focus and priority from everybody. Traffic in the area gets cleared, Fire engines get readied etc. All about precautions, safety first, just in case. Some procedures/check list will stipulate specifically “declare emergency”.

Yes, you will get a call from the FAA, you might have to file reports, but it is still the appropriate thing to do. Good carriers will look into every emergency that happens on their fleet, but pilots won’t be punished for it. Or should not, there are some stories out their of certain carriers who might take a dim view on calling a simple engine out, with an empty plane, an emergency.

I once declared an emergency very early on in my piloting career. I might have still been a student pilot at the time. Got great assistance from ATC. Landed safely, no problem. The next day I got a call from the FAA I believe, Told the guy what happened, he said, you did great and asked me to put my story in an email. That was it, never heard anything from it. Other than my flying club wanted to know what happened and asked me to present my experience during one of our club meetings.

Here an interesting link about this very topic and pilots reluctance:

http://code7700.com/emergency.htm

A few other pointers to what happens in the video.

As soon as the pilot call out the emergency and tells ATC they need to return, ATC start helping them get back to the field in the quickest way. They need to fly a so called circuit. Essentially back tracking (so called downwind) parallel to the runway to start the landing approach into the wind.

You can hear ATC assigning them a block altitude 2-3000. Which means they can fly any altitude between 2000-3000 foot at their discretion. They do not need to tell ATC which altitude they’re at as long as it is between 2000-3000. They can just concentrate on flying.

You can hear ATC asking about “fuel and number of souls on board”. This is standard practice once an emergency has been declared. ATC wants to understand how long the aircraft can still be airborne and how many people are on the plane, which is an important aspect for the fire crews. You will notice that ATC seemed a bit surprised when the number of souls onboard is reported as 2. He asks for confirmation from the pilot, telling him he needs to total number, crew and passengers. He was not expecting a 737 just to have only two pilots on board.

Once they have have landed, there is an exchange between the pilot and ATC where to go. Gate or hangar. The pilot requests gate. ATC tells him to hold, because the fire crew still need to do a proper inspection. It might be an indication that as far as the pilots are concerned at that point in time, everything is fine. They have no abnormal indications in the cockpit and just want to go back to the gate. Not even hangar.

Note that although they have the fire crews at the readies, the pilot does not discuss the need to evacuate the plane upon landing with ATC. So by all means he was expecting a normal landing, just precaution to have the fire crews at the ready.

I hope this gives some insights as to what an emergency can look like. In this case, a lot of it is first and foremost precautionary, safety first. If they engine has been on fire, rather than just stopped working, it might have been handled somewhat differently. Because once landed they would be wary of any fire flaring up again and they might have discussed evacuation scenario’s too.

Jeroen

Last edited by Jeroen : 28th March 2019 at 13:14.
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Old 28th March 2019, 22:15   #139
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by V.Narayan View Post
The engine trouble could have occurred for a hundred reasons.
Agree fully sir but incidents like these will only lower people's confidence in the aircraft. for them, Its boeing 737 MAX engine which have failed not CFM or RR.
Not many know that boeing or airbus do not manufacture engines.
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Old 29th March 2019, 12:28   #140
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re: Boeing 737 Max crashes and grounding

Here an interesting link to an article on automation in aircraft. It has some interesting observations and comments on to how much pilots should know on how all the various system work.

It has some very specific reference to the sad crashes of these two 737 Max in relation to automation, piloting skills and insights into the MCAS and the use of the existing runaway trim procedure.

https://www.airlineratings.com/news/...ense-scrutiny/

On the Lion air incident it refers:

Quote:
When that investigation is completed, I believe improper actions by maintenance personnel and the accident flight crew will be the prominent causal factors.
Pilots put too much reliance on the automation and do not take manual control early enough. There is a long series of crashes where that phenomena has been the main cause.

Not much to do with Boeing. We will have to wait though.

It also highlights the significant difference between American pilot training and experience compared to many other nations. Which might sound like boasting, but it is probably true.

Jeroen

Last edited by Jeroen : 29th March 2019 at 12:31.
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Old 29th March 2019, 13:16   #141
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by Jeroen View Post
Here an interesting link to an article on automation in aircraft.

https://www.airlineratings.com/news/...ense-scrutiny/

On the Lion air incident it refers:
When that investigation is completed, I believe improper actions by maintenance personnel and the accident flight crew will be the prominent causal factors.


It also highlights the significant difference between American pilot training and experience compared to many other nations. Which might sound like boasting, but it is probably true.

Jeroen
Agree. This is pretty much what I wrote some pages back here
The pilot interfaces with the Auto-trim feature of the aircraft. The MCAS is part of the Auto-trim. Yes, it was Boeing's responsibility to mention this new system but does that change the pilot's interface to the Auto-trim? I guess it doesn't.
If the MCAS malfunctions, the results affect the aircraft's trim. The solution to this is to switch off the auto-trim. Not sure how knowledge of MCAS would've changed that course of action.

The MCAS was one of the contributing factors to the accident, but was it the sole contributor? It cannot be established till the accident-report is out.
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Old 30th March 2019, 20:39   #142
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re: Boeing 737 Max crashes and grounding

This is a nice interactive page of the issues with the 737 Max 8.


https://www.nytimes.com/interactive/...x-8-flaws.html
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Old 1st April 2019, 13:24   #143
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re: Boeing 737 Max crashes and grounding

https://www.khaleejtimes.com/interna...e-plane-crash-

"Pitch up, pitch up" were the words a pilot was heard saying on the Ethiopian Airlines flight just moments before it crashed three weeks back killing 157 people, reported the Wall St Journal.

It looks like MCAS is the cause, what most of the experts have been alluding to.
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Old 3rd April 2019, 12:50   #144
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re: Boeing 737 Max crashes and grounding

The part in bold is deeply discomforting. The blood is entirely on Boeing/FAA's hands.

Suffering a crash because of lack of knowledge of physics/metallurgy is one thing; lack of intent due to monetary/strategic implications is a whole lot worse and unpardonable.

Quote:
Pilots flying Ethiopian Airlines Flight 302 initially followed emergency procedures that were laid out by Boeing before the plane nose-dived into the ground, according to preliminary findings reported in the Wall Street Journal.

Citing unnamed sources familiar with the investigation, the WSJ reported that despite following the steps, which included turning off an automated flight-control system, pilots could not regain control of the Boeing 737 MAX 8.
https://edition.cnn.com/2019/04/03/a...ntl/index.html

Last edited by libranof1987 : 3rd April 2019 at 12:52.
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Old 3rd April 2019, 21:52   #145
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One more Boeing 737 Max crashes in Ethiopia

Quote:
Originally Posted by libranof1987 View Post
The part in bold is deeply discomforting. The blood is entirely on Boeing/FAA's hands.
]

There is absolutely no factual information in this article, so it is simple premature to draw any conclusions. To add, I'm seeing people reporting that the pilots disabled something and next switched it back on.

I just checked and the preliminary report has not been published but is expected any day now.

If the pilots used the correct procedure and used it correctly that would be cause for alarm. As far as we know this procedure did work for the Lion Air flight prior to the fatal flight.

I hope the preliminary report is explicit enough to give some insights as to what happened in that cockpit. Disabling auto flight control system is not specific, besides it is essentially hear say, until it comes from a proper source which in the case of aviation accident is the respective authority in charge of the accident investigation
Jeroen

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Last edited by Jeroen : 3rd April 2019 at 22:03.
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Old 4th April 2019, 13:58   #146
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re: Boeing 737 Max crashes and grounding

The following graphic shows the forces on the Boeing 737 MAX tail that at high speed can lock up the jackscrew and make it nearly impossible to move the stabilizer manually.

Boeing 737 Max crashes and grounding-d3rvd6sueaarwes.jpg

Source: Twitter @dominicgates
Article: https://www.seattletimes.com/busines...iopian-flight/

This is a speculation though.

As losses due to grounded aircrafts pile up, these proceedings will further delay the fix. Both FAA and Boeing are losing their credibility by the day!

What's in store? Assume Boeing fixes the plane to 'normal', will flyers accept it?

Are we going to witness something even bigger than expected! Future times are interesting for the Aviation industry.

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Old 4th April 2019, 14:15   #147
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by surjaonwheelz View Post
The following graphic shows the forces on the Boeing 737 MAX tail that at high speed can lock up the jackscrew and make it nearly impossible to move the stabilizer manually.
I was under the impression that the new generation aircraft have fly-by-wire for the control surfaces.

So this would mean that the movement of the horizontal stabilizer is not actually "manual" by nature. This should not have any limitation for the movement of the control surface as external forces are accounted for when the system is designed.

Please correct my understanding, if incorrect.
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Old 4th April 2019, 14:48   #148
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re: Boeing 737 Max crashes and grounding

The preliminary report looks damaging to Boeing.

https://twitter.com/flightradar24/st...509187072?s=19
Attached Thumbnails
Boeing 737 Max crashes and grounding-img_20190404_144813.jpg  

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Old 4th April 2019, 18:32   #149
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re: Boeing 737 Max crashes and grounding

Quote:
Originally Posted by AbhisheKulkarni View Post
I was under the impression that the new generation aircraft have fly-by-wire for the control surfaces.

So this would mean that the movement of the horizontal stabilizer is not actually "manual" by nature. This should not have any limitation for the movement of the control surface as external forces are accounted for when the system is designed.

Please correct my understanding, if incorrect.
There really is not a (technical) definition of what constitutes a fly by wire plane. On the 737 series, including the Max the flight controls are still connected primarily by cables and pulleys and there is (hydraulic) power assistance.

Boeing "markets" the Max as having FBW spoiler system. Apart from acting as speed brake and to brake lift on landing, they also help with roll control.

But simply put, FBW only the spoilers, the (most of the ) rest is down to muscles with a bit of hydraulic power assistance here and there.


Quote:
Originally Posted by BoneCollector View Post
The preliminary report looks damaging to Boeing.

https://twitter.com/flightradar24/st...509187072?s=19
this is not the preliminary report. This is a response from Ethiopian Airlines on the preliminary report.

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Old 5th April 2019, 00:33   #150
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Here is the preliminary report:

http://www.ecaa.gov.et/documents/204...8-d7af1ee17f3e

Anybody care to make conclusions?

Jeroen
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