Ethiopian Airlines Crash/ B737MAX grounding

devnull

GM228 wrote: »

And then of course you get Tweets like this:

https://twitter.com/joe_elway/status/1105117584171651072?s=19

It does seem to be a bit of "Ryanair bashing" to me, people forget about the likes of Norwegian or Southwest and FlyDubai (SE and FD have the two largest fleets?) who actually operate them at present unlike Ryanair.

Telegraph in on the act now:
https://twitter.com/johcraw/status/1105123777778733057

Like another newspaper, uses a photo of a 737-800 and mentions Ryanair as a MAX user.

I guess using a photo of an actual 737-800 MAX with someone who actually operates them and only mentioning those airlines in the article wouldn't allow them to have a dig.

Limpy

India have issued a directive where a pilot needs to have 1000 hours flight experience, Co pilot 500 hour to fly the 737 max.

There is big money involved in this plane so I would imagine it will be a political football for awhile.

Imagine if Boeing was a Russian company. There would be a lot more cheerleaders calling for it to be grounded.

Youdunnit

Limpy wrote: »

India have issued a directive where a pilot needs to have 1000 hours flight experience, Co pilot 500 hour to fly the 737 max.

There is big money involved in this plane so I would imagine it will be a political football for awhile.

Imagine if Boeing was a Russian company. There would be a lot more cheerleaders calling for it to be grounded.

It's interesting

I mentioned earlier the US has 737 max sales to Vietnam and the FAA has approved Vietnam for flights to US

Seems to be all part of a deal

billy few mates

circular flexing wrote: »

Trying to reliably transmit data from air to ground would be a nightmare (especially the amount of data being generated by modern aircraft), there would simply be too much latency for it to be reliable.

I disagree, the technology is already there, look how much information you can see on FR24, racing cars use similar telemetry, buses, taxis and even pizza deliveries are using similar technology in its basic form. Once the data is monitored and recorded the transmission and storage of it is only a minor hurdle which could be easily overcome if it ever become a requirement.

ironclaw

billy few mates wrote: »

I disagree, the technology is already there, look how much information you can see on FR24, racing cars use similar telemetry, buses, taxis and even pizza deliveries are using similar technology in its basic form. Once the data is monitored and recorded the transmission and storage of it is only a minor hurdle which could be easily overcome if it ever become a requirement.

Oh boy. It's not that simple.

A couple of factors that spring to mind:

Object Speed - Most cellular networks have a speed rating, that is how fast an object can be moving relative to a tower and still be usable. 3G was around 120km/h and later generations I think we're trying to get upwards of 200km/h. Of course, that' in a lab under perfect conditions. It doesn't apply when you have a plane at 30k ft in the atmosphere.

Data Consistency & Integrity - It doesn't really matter if you are missing a few bytes from an F1 car or you miss an update from the pizza guy. It's a huge issue if you are pulling that data from a plane that may be required to review an accident. Error rates can quickly increase when you have bad connections and error checking can only get so good.

Bandwidth - The amount of data being sent from a plane would be sizable and if you wanted to make sure you had the latest data for say an accident, it needs to be close to real time. Imagine you now have thousands of planes in the air every day and they are each sending sizable chunks of data. You rapidly start to run out of spectrum and channels (Shannon limits etc)

FR24 isn't sending huge packets of data. It's a really simple data system and it's one way in a 'fire and forget' fashion.

In short, consumer tech isn't remotely comparable to the hurdles you'd face on a plane.

kippy

billy few mates wrote: »

I disagree, the technology is already there, look how much information you can see on FR24, racing cars use similar telemetry, buses, taxis and even pizza deliveries are using similar technology in its basic form. Once the data is monitored and recorded the transmission and storage of it is only a minor hurdle which could be easily overcome if it ever become a requirement.

You are severly underestimating the amount of variables involved in the flight of an aircraft.

Boeing do have a patent in for some technology to transmit a subset of the data to a central repositry.
More here:
https://www.theguardian.com/commentisfree/2014/mar/09/malaysia-airlines-flight-mh370-black-box

As others have said, if it were feasible/possible it would already have been implemente/done but at massive massive cost, and no one wants to support those costs.

cnocbui

Roger_007 wrote: »

I just saw on the news that the two recorders have been recovered but they may be badly damaged.
Why is it not possible to transmit the flight data in real time to a ground-based database so that finding the recorders wouldn't be so vital after an accident. It could also be used to quickly locate a plane that went down in a remote area, or at sea or to assist maintenance engineers to resolve any problem which occurred during a flight.
Each airline could maintain its own database or subcontract to a third party. Once a flight has landed without incident the data for that flight could be wiped.

One reason is that planes spend a lot of time flying over places where there are no mobile phone towers, let alone a network of incredibly expensive dedicated aviation radio receiving stations. Think of flights across the Pacific and Atlantic.

cnocbui

Roger_007 wrote: »

There wouldn't be such a vast quantity of data. All you would be transmitting is a code for each parameter and a value for that parameter at, let's say, five second intervals. The total amount of data for an average flight wouldn't be as much as would be contained in an average YouTube video.
Also, you would still retain the 'black' boxes so you wouldn't be totally reliant on the ground-based database. You would not be substituting what you have now with something else, you would be adding to it.

You are forgetting the cockpit voice recorders have probably been just as useful, if not more so, than the flight data recorders.

Damien360

kippy wrote: »

You are severly underestimating the amount of variables involved in the flight of an aircraft.

Boeing do have a patent in for some technology to transmit a subset of the data to a central repositry.
More here:
https://www.theguardian.com/commentisfree/2014/mar/09/malaysia-airlines-flight-mh370-black-box

As others have said, if it were feasible/possible it would already have been implemente/done but at massive massive cost, and no one wants to support those costs.

I thought Rolls Royce have live engine monitoring particularly on A380 and Lufthansa were using this service according to Google. How are they transmitting that data and are the data packets much smaller than say flight data ?

cnocbui

Damien360 wrote: »

I thought Rolls Royce have live engine monitoring particularly on A380 and Lufthansa were using this service according to Google. How are they transmitting that data and are the data packets much smaller than say flight data ?

I believe they use the INMARST network of satellites.

kippy

Damien360 wrote: »

I thought Rolls Royce have live engine monitoring particularly on A380 and Lufthansa were using this service according to Google. How are they transmitting that data and are the data packets much smaller than say flight data ?

Engine data is one small subset of the data and as we've seen with a number of cases it's not even "full" data - just a subset of same.
Not feasible for larger data amounts.
Again, it comes down to cost.

GM228

https://www.nytimes.com/interactive/2019/03/11/world/boeing-737-max-which-airlines.html

The NYT has an accurate up to date list of groundings and seems to have live (ish) updating as for example the Comair status changed within minutes of their announcement.

Safehands

STB. wrote: »

Ryanair is preparing to deploy its very first MAX jet on routes to Tenerife and Thessaloniki from London-Stansted on 14 March.... ie this coming week. 50 more being delivered by end of year.
10% of their fleet will be the 737 Max 8 HC by end of next year. The HC mod is just a tag signifying capacity for extra passengers.
https://airlinerwatch.com/ryanair-to-station-its-first-boeing-737-max-8-hc-in-london-stansted/

Whatever one thinks of Ryanair, they are a very safety conscious airline. These incidents will give them the heeby jeebies, especially as so many airlines are grounding their 737 Max aircraft. Many people are rightly concerned about flying on these new planes, I suspect that Michael O'Leary will be having high level discussions about the wisdom of introducing these new aircraft at this time. He certainly won't be having photoshoots and advertising campaigns about their introduction.
Difficult for them, and the crews who have to fly them.
My thoughts are with the families of the deceased in Ethiopia.

GM228

Meanwhile, C-FAXD is in the air the last hour on delivery to Sunwing.

https://www.flightradar24.com/SWG9910/1fc4faac

In light of the groundings I wonder will this be the last 737 MAX to leave BFI for a while?

Shn99

GM228 wrote: »

Meanwhile, C-FAXD is in the air the last hour on delivery to Sunwing.

https://www.flightradar24.com/SWG9910/1fc4faac

In light of the groundings I wonder will this be the last 737 MAX to leave BFI for a while?

The MAX hasn’t been grounded worldwide, it’s up to the airlines or local regulators to ground it at this moment in time. Airlines will continue to receive them unless they decide to delay them

GM228

Shn99 wrote: »

The MAX hasn’t been grounded worldwide, it’s up to the airlines or local regulators to ground it at this moment in time. Airlines will continue to receive them unless they decide to delay them

Yes I'm aware of that (and none yet grounded in Canada), but in light of the growing list I do wonder if Boeing themselves will delay the aircraft, obviously that will depend also on developments arising out of the recorders.

Grandeeod

Safehands wrote: »

Whatever one thinks of Ryanair, they are a very safety conscious airline. These incidents will give them the heeby jeebies, especially as so many airlines are grounding their 737 Max aircraft. Many people are rightly concerned about flying on these new planes, I suspect that Michael O'Leary will be having high level discussions about the wisdom of introducing these new aircraft at this time. He certainly won't be having photoshoots and advertising campaigns about their introduction.
Difficult for them, and the crews who have to fly them.
My thoughts are with the families of the deceased in Ethiopia.

I thought Ryanair were only receiving the first MAX at the end of April.

faoiarvok

Roger_007 wrote: »

It could also be used to quickly locate a plane that went down in a remote area

This part is just becoming operational, run from the IAA’s North Atlantic Comms centre in Ballygirreen:
https://aireon.com/services/aireonalert/

This is just satellites “passively” (probably not the right term) receiving transponder information already being broadcast by the aircraft’s transponder, and not the kind of technology you’re talking about however.

billy few mates

kippy wrote: »

You are severly underestimating the amount of variables involved in the flight of an aircraft.

Boeing do have a patent in for some technology to transmit a subset of the data to a central repositry.
More here:
https://www.theguardian.com/commentisfree/2014/mar/09/malaysia-airlines-flight-mh370-black-box

As others have said, if it were feasible/possible it would already have been implemente/done but at massive massive cost, and no one wants to support those costs.

Actually I have a fair idea of the amount of data and variables involved which is why I mentioned it. Some people here are suggesting it can't be done for technical reasons, others are suggesting it can't be done for cost reasons, which is it?
We can send HD television signals across the globe by satellite but we can't transmit telemetry via the same systems..?
It will never become a reality until it becomes a legal requirement, and then it will happen pretty quickly because the technology already exists, it's just the will that's missing.
Even if it started off with certain limited data samples it would have to be better than the current system where everything hinges on the recorders being found and the data on them being readable.

plodder

ironclaw wrote: »

Bandwidth - The amount of data being sent from a plane would be sizable and if you wanted to make sure you had the latest data for say an accident, it needs to be close to real time. Imagine you now have thousands of planes in the air every day and they are each sending sizable chunks of data. You rapidly start to run out of spectrum and channels (Shannon limits etc)

FR24 isn't sending huge packets of data. It's a really simple data system and it's one way in a 'fire and forget' fashion.

Exactly, FR24 uses thousands of receivers distributed around the world, each connected to typically wired broadband. The system is not limited by communications bandwidth. Whereas satellites have only limited radio spectrum available to them, are therefore highly limited in the amount of bandwidth available. The Lion air recorder data was recovered and there's every reason to believe it will be from this accident as well.

billy few mates

Modern flight recorders record hundreds if not thousands of parameters but they're not all mandatory parameters as required by legislation. The DFDAU decides what data is recorded, and at what sample rate, a lot of the data recorded by the DFDR is used for reliability, trend monitoring and maintenance purposes. If they started by transmitting the mandatory parameters at reduced sample rates it would be better than nothing. The transmission of voice recordings as recorded by the CVR would take up zero bandwidth.

kippy

billy few mates wrote: »

Actually I have a fair idea of the amount of data and variables involved which is why I mentioned it. Some people here are suggesting it can't be done for technical reasons, others are suggesting it can't be done for cost reasons, which is it?
We can send HD television signals across the globe by satellite but we can't transmit telemetry via the same systems..?
It will never become a reality until it becomes a legal requirement, and then it will happen pretty quickly because the technology already exists, it's just the will that's missing.
Even if it started off with certain limited data samples it would have to be better than the current system where everything hinges on the recorders being found and the data on them being readable.

It's a combination of both. That's what I've been saying.
And I'll say that of it could be done with good results it would already have been done.

Thing is, in the majority of cases the recorders are found and the data is readable so what percentage of cases would these features help with investigations and is the cost and additional technologies required to support it justified?

FrancieBrady

Very dignified and poignant tribute to Michael Ryan from his mother. Seemed like quite a man. RIP

Shedite27

billy few mates wrote: »

Actually I have a fair idea of the amount of data and variables involved which is why I mentioned it. Some people here are suggesting it can't be done for technical reasons, others are suggesting it can't be done for cost reasons, which is it?
We can send HD television signals across the globe by satellite but we can't transmit telemetry via the same systems..?
It will never become a reality until it becomes a legal requirement, and then it will happen pretty quickly because the technology already exists, it's just the will that's missing.
Even if it started off with certain limited data samples it would have to be better than the current system where everything hinges on the recorders being found and the data on them being readable.

They can monitor spaceships landing on Mars, of course it's possible if they wanted, but currently airline development is about getting people places as cost-effectiely as possible

Shn99

The FAA have issued a CANIC, A Continued Airworthiness Notification to the International Community, which reaffirms the airworthiness of the 737MAX to airlines and all parties concerned

plodder

Shedite27 wrote: »

They can monitor spaceships landing on Mars, of course it's possible if they wanted, but currently airline development is about getting people places as cost-effectiely as possible

The issue is more about scale than distance though. One estimate I saw says there can be up to 10,000 commercial aircraft in the sky at any time. Even just transmitting the voice recording of that number of flights at the same time would use a huge chunk of the available bandwidth of a system like INMARSAT. It would be phenomenally expensive, for not much benefit.

cnocbui

Shn99 wrote: »

The FAA have issued a CANIC, A Continued Airworthiness Notification to the International Community, which reaffirms the airworthiness of the 737MAX to airlines and all parties concerned

Well given the FAA seem to have been in bed with Boeing the whole time, it would have been surprising if they had done anything else.

Irish Steve

I've just looked at FR24, and as of a few moments ago, they are tracking somewhere in the region of 14,000 flights worldwide. A significant number of those flights are out of range of a cellular tower system, so to capture adequate real time data from all of these flights, a significant network of satellites, similar to the GPS network would be needed, and the reality is that the cost of putting such a network into place, and the ongoing operating costs, would be very significant, and getting worldwide international agreement for such a network would be another very significant issue, and the number of accidents that need a data capture resource of this nature is still happily very low indeed.

The unfortunate reality is that the incidents with the Max are looking suspiciously like the same sort of scenario that was responsible for the Kegworth crash, even though the reasons were different, and that failing is very much a problem of crew information and training, compounded by a lack of clarity from Boeing. Had the crew of the Kegworth accident made the right diagnosis of the fault, it was completely survivable, but for a number of reasons, they made a fatal wrong diagnosis, and shut down the wrong engine.

There have been strong arguments made for a number of years that "grandfather rights" for certification and type ratings should be disallowed when there have been significant changes to the aircraft when compared to the original certified design, and there can be no doubt that the difference between the original 737 (200) family and the Max range are very significant. At one time, Boeing produced an "analog" version of the 300 series to suit South West, as they didn't want to deal with the massive differences between the 200 and the 300, as that would have caused them a lot of rostering and scheduling problems.

Now we have the scenario where Boeing have deliberately modified the flight characteristics of the Max in order to make it fly like the earlier versions, to the extent they have not made full disclosure of some of the effects of the changes to the people "at the sharp end", so the pilots are not fully aware of the things that can happen, or why they are happening, and the worry now is that there have been changes made to the systems that are not fully fail safe, or fully fail redundant, and it is even possible that the testing of the new systems was done on the basis of making sure it worked with valid data, but it seems (worryingly) possible that tests on completely spurious and invalid data were not carried through the process, and to make it worse, check list procedures and awareness training also appear to have been compromised.

The bigger concern is that these changes appear to have been formally agreed with and approved by the FAA, and it was the case that the FAA were supposed to be the people who made sure that manufacturers did not cut corners or bend the rules, and that role seems to have been more than slightly blurred, if what is coming out at the moment is to be believed.

A very long time ago now, I did some very in depth work on the A320 family for a BAE research division, and as part of that work we had to do some detailed research on the way that the aircraft could be flown in manual reversion, a failure state that was highly unlikely, due to the number of failures across multiple redundant systems that were involved.

We discovered that we were going to have problems doing the research in simulators, in that the European regulators had allowed the airlines in Europe to not train for that scenario, as it was deemed so insignificant statistically, the costs and time involved in training for it were deemed too high compared to the likely occurrence of a "real" event.

As a result, European certified simulators were unable to correctly model the handling of the aircraft in that failure mode, and we ended up having to go to a simulator in the States, where were were able to get the information we needed, as the FAA had taken a different view, and required the airlines to train for such a failure, so the simulators correctly modelled it. When we discussed this among a number of involved parties, the strong implication was that the "local" regulators had been biased by significant pressure from the local manufacturer, and I mention this here to make it clear that this sort of favouritism is not limited to one regulatory system.

We already know that there have been issues with the 737 family, as mentioned earlier, when the 300 first was introduced, while the failure was caused by a new engine issue, the Kegworth crash was partly attributed to changes made between the 200 and 300 that meant the crew were misled by the symptoms they saw, and their training on the differences had not highlighted some of those differences. There were also fundamental crew resource management issues in the cockpit which resulted in a massive change in the whole cockpit training methodology, but that's another subject that's not really for this thread.

Then, a number of years later, there were a significant number of unexplained crashes that were eventually found to be a problem with the rudder actuator system, resulting in a full hard over rudder lock, which was initially resolved by significant changes to operating speeds, the problem being that a rudder hard over at low speeds could not be overcome by the effect of aileron and spoilers, so the aircraft effectively kept rolling, and was unrecoverable. A 10 Kt increase in speeds meant that the aileron combination could overcome this, and that, in combination with a redesign of some of the hardware does appear to have resolved the issue, but it took a long time and too many accidents before it was resolved.

Now, while it's very early, it seems that there may be issues with the way in which Boeing have made changes to minimise the difference between the Max and the earlier generations, and those issues have not been fully documented and covered in the training on "differences". I hope it is that simple, and that there are no cut corners that have come out of the woodwork to cause these fatal accidents.

We can only hope that the highest priority will be given to getting the data off the recorders, and determining if there is a bigger issue than had been thought. I don't have adequate words to express the feelings I have about the loss of close on 400 lives, I just hope that what is causing these problems will be found and resolved before there are any more losses.

Roger_007

If there is so much technical difficulties with transmitting flight data to a land based database, how come many airlines are offering internet access to passengers. Aer Lingus are offering internet access on all their trans Atlantic flights.............Just wondering?

Mebuntu

Great post, Irish Steve. I have a question to ask.


If you were a 737MAX8 pilot I'd have assumed that you would have paid the closest attention to the Lion Air crash especially in relation to the MCAS and the action required if such an event should occur on one of your flights. I'd have thought that on every takeoff since then you would be watching intently for any signs of a repeat and be ready to take the appropriate remedial measures - maybe even to the extent of having your hand poised and ready to hit the cutout switches. (remember that the Lion Air's crew on the previous flight acted swiftly when it happened and saved the day).

So, my question is - is my assumption above correct.