Ethiopian Airlines Crash/ B737MAX grounding

TomSweeney

dogmatix wrote: »

How will this impact on Ryanair? The longer the max’s return to service is delayed and more information becomes available on the various problems and Q.C. issues with this aircraft, can only continue to erode public confidence in the Max. Ryanair must be getting increasingly worried about passenger confidence/attitudes to the Max the longer this is dragged out.

Worst case scenario – the delays continue into early 2021 and all the while more and more problems are discovered with the design and quality control process until Boeing eventually bites the bullet and announces they are scrapping the whole program. Would Ryanair have a plan in place to deal with this, given that there are no more 737’ NGs under construction and Airbus replacements would be years away?

Whats wrong with 737 800s ?
Can't they use them ? - if MAX program is scrapped can't they re start building 800s?

GM228

TomSweeney wrote: »

Whats wrong with 737 800s ?
Can't they use them ? - if MAX program is scrapped can't they re start building 800s?

There are no more orders for the NG to start with, and the supply lines were wound down, no doubt the FAL jigs have also been removed or modified for the MAX or other programmes.

Henry Ford III

TomSweeney wrote: »

Whats wrong with 737 800s ?
Can't they use them ? - if MAX program is scrapped can't they re start building 800s?

They could in theory but in reality the 800s are no longer competitive - fuel efficiency and noise wise.

The Max was Boeing's answer to the A320NEO after all.

Bob24

Henry Ford III wrote: »

They could in theory but in reality the 800s are no longer competitive - fuel efficiency and noise wise.

The Max was Boeing's answer to the A320NEO after all.

Indeed, restarting production would probably be a very questionable move.

Must be very expensive and ressource consuming to restart production. And while they would probably sell a few to airlines which want to leverage 737 pilots everybody would know it is just a short term fix at the planes would en years behind in terms of full effeciency out of the factory. So airlines would probably not be ready to pay top dollar and would limit orders to what is absolutely necessary.

Fritzbox

TomSweeney wrote: »

ah jaysus lads!!!
https://www.bbc.com/news/business-51499777

When they are certified I presume they will do test flights, and test conditions, or will they just lash them back out to service and use passengers as guinea pigs ?

Getting the aircraft type certified means that the plane has successfully completed all its flight testing and is ready for commercial passenger service.

Tenger

Fritzbox wrote: »

Getting the aircraft type certified means that the plane has successfully completed all its flight testing and is ready for commercial passenger service.

Which is true. However we may well see it certified in the US and Canada before it gets its EASA cert. (or indeed other aviation regulators)
The FAA and Boeing have lost confidence from the global industry.

TomSweeney

Tenger wrote: »

Which is true. However we may well see it certified in the US and Canada before it gets its EASA cert. (or indeed other aviation regulators)
The FAA and Boeing have lost confidence from the global industry.

So unlikely to be flying by July in Europe ?

Van.Bosch

TomSweeney wrote: »

So unlikely to be flying by July in Europe ?

No one knows for sure but I highly doubt it.

blackwhite

TomSweeney wrote: »

ah jaysus lads!!!
https://www.bbc.com/news/business-51499777

When they are certified I presume they will do test flights, and test conditions, or will they just lash them back out to service and use passengers as guinea pigs ?

I am flying Norwegian BCN-OSL-EVE return 30/June - 9 July, according to my booking it is a 737 800 but if the MAX is back, I assume that could be changed.

Really don't want to be one of the earlier test batches....

Would they be likely to be using the MAX much on intra-European routes? Surely post-reintroduction the MAX would be back onto their TA routes first and foremost

Rawr

blackwhite wrote: »

Would they be likely to be using the MAX much on intra-European routes? Surely post-reintroduction the MAX would be back onto their TA routes first and foremost

I remember back before the MAX was grouded that some OSL -> DUB flights were using the MAX.

I also remember actually looking forward to maybe using a MAX on a trip back to DUB, since according to Norwegian's site the MAX needed 20 - 30 mins less time to get to DUB compared to an NG doing the same route.

Both BCN and OSL are big hubs from Norwegian. There's a good chance you'd see MAX planes going between them. Hell, I think I've occasionally noticed the odd Dreamliner going between them too (!)

TomSweeney

Rawr

TomSweeney wrote: »

If it helps at all, I feel that it's very unlikely that the Norwegian MAX fleet would be flying as soon as this June / July. Whatever fix(es) Boeing have for the MAX still need to be applied to Norwegian's current batch of Max aircraft, which I guess are mostly stranded at various airports around Europe.

And that's all assuming that Boeing even get the green light in Europe before June.

Tenzor07

Of all the operators of the Max, i'd have no hesitation at all about getting on a Norwegian Max 73...

I'm only hoping that they bring back the Dublin to Stewart route...

errlloyd

Tenzor07 wrote: »

Of all the operators of the Max, i'd have no hesitation at all about getting on a Norwegian Max 73...

I'm only hoping that they bring back the Dublin to Stewart route...

The Norwegian ones did not have the original AOA Sensor misalignment warning light right? I believe some of the 737 MAX aircraft had an optional extra safety feature that may have helped the pilots avoid MCAS stalls and Norwegian had not paid for this extra.

Generally, though I agree completely. Good airline and I used to fly that SWF route all the time. Dublin to New York is now 50% more expensive.

Hotblack Desiato

Fritzbox wrote: »

But the MAX flew for around 800,000 hours in commercial service and none of the airlines ever complained about the location of the engines or the aerodynamics. Problems ensued with the flight control systems - which is/has been rectified - allegedly.

Boeing -
- designed a plane with a fundamental aerodynamic flaw
- bodged on MCAS, with no backups or failsafes, to 'fix' the flaw
- increased the capabilities of MCAS to the point where it can crash the plane
- lied/'omitted' to inform the regulator about the actual capabilities of MCAS
- chose not to inform its airline customers that MCAS existed at all.

So why would the airlines have been complaining about something Boeing never told them about? And when it failed, Boeing blamed the pilots.

As for 'rectified' a few lines of code isn't going to fix this puppy, not as far as EASA are concerned anyway.

Fritzbox

Hotblack Desiato wrote: »

Boeing -
- designed a plane with a fundamental aerodynamic flaw
- bodged on MCAS, with no backups or failsafes, to 'fix' the flaw
- increased the capabilities of MCAS to the point where it can crash the plane
- lied/'omitted' to inform the regulator about the actual capabilities of MCAS
- chose not to inform its airline customers that MCAS existed at all.

Don't all swept wing jet airliners possess this "fundamental aerodynamic flaw" to one extent or another, why pick on the MAX?

As regards your other points, I agree with them to one extent or another, but they are being rectified at the moment, the MAX is certainly returning to service in the next few months.

As for 'rectified' a few lines of code isn't going to fix this puppy, not as far as EASA are concerned anyway.

When did EASA say that? If EASA really had that attitude why then are they carrying out a flight test and certification process with the MAX if they already believe the aircraft's fundamental design is flawed? AESA have already said they are going to re-certify the Boeing 737 MAX, they just never said when.

wandererz

Tenzor07 wrote: »

Of all the operators of the Max, i'd have no hesitation at all about getting on a Norwegian Max 73...

I'm only hoping that they bring back the Dublin to Stewart route...

Flew to Stewart on the MAX.
On the way back, there was a delay that extended from 30mins,to 2hrs to 3hrs & then cancellation of the flight.
Apparently due to "failure of the GPS system".
This on a brand new aircraft!

Tenzor07

wandererz wrote: »

Flew to Stewart on the MAX.
On the way back, there was a delay that extended from 30mins,to 2hrs to 3hrs & then cancellation of the flight.
Apparently due to "failure of the GPS system".
This on a brand new aircraft!

When was that? Could be related:

https://www.google.com/amp/s/www.forbes.com/sites/zakdoffman/2019/06/09/hundreds-of-u-s-flights-canceled-as-gps-based-aircraft-navigation-system-fails/amp/

Hotblack Desiato

Fritzbox wrote: »

Don't all swept wing jet airliners possess this "fundamental aerodynamic flaw" to one extent or another

No. This is caused by the size and position of the engines. Read the thread.

As regards your other points, I agree with them to one extent or another, but they are being rectified at the moment, the MAX is certainly returning to service in the next few months.

Maybe, maybe not, but nice crystal ball you have there :rolleyes:

AESA have already said they are going to re-certify the Boeing 737 MAX, they just never said when.

Citation needed. If they've already made up their minds then no need for a recertification process at all.
I think you're confusing the process and the possible end result of that process. But there can be no guarantees about that result or how long it takes to get there.

GM228

Fritzbox wrote: »

Don't all swept wing jet airliners possess this "fundamental aerodynamic flaw" to one extent or another, why pick on the MAX?

They don't.

The reason to "pick on" the MAX is because it is against Airworthiness Standards to have a potential abnormal nose-up pitching problem, the MAX has this problem by design because Boeing altered the position of the wings and engines, the purpose of the MCAS system was then to augment the aircraft flying characteristics to counteract the problem and bring the frame within standards, this system was severely flawed, especially the lack of redundancy (or redundancy at an optional cost) and not even telling it's customers it was present in the first place.

Fritzbox wrote: »

AESA have already said they are going to re-certify the Boeing 737 MAX, they just never said when.

Well no they havn't, the EASA basically stated that various standards have to be proven by Boeing before they even consider it. In fact in their last official update on design change requirements the EASA stated "our design review is not completed yet and we have not reached a conclusion yet on that matter".

There is also a new major issue with the MAXs, the wiring, Boeing confirmed the wiring didn't meet standards, but both they and the FAA agreed that there was no need to re-wire them, however, the EASA is apparently insisting they be rewired, this could potentially be another major delay (and a very costly one) to their re-entry.

Fritzbox

Hotblack Desiato wrote: »

No. This is caused by the size and position of the engines. Read the thread.

I should have specified it was those airliners which have their thrust line well below the aerodynamic centre – typically low-winged aircraft with pod-mounted engines – such as the B737 and A320. It’s an asymmetric thrust problem. However the 737 (going back all the way to the 737-200) seems to suffer from the problem a lot more than the A320 – the MAX, worse of all.

In fact, the A320 Neo has its own pitch instability problems too – not in the same league as the 737 MAX of course…

https://www.flightglobal.com/programmes/a321neo-operators-alerted-over-excessive-pitch-anomaly/133574.article
https://www.aerotime.aero/ruta.burbaite/23713-easa-alerts-airbus-a321neo-operators-over-excessive-pitch-issue
https://leehamnews.com/2019/07/19/bjorns-corner-airbus-a321neo-has-pitch-up-issue/

Maybe, maybe not, but nice crystal ball you have there :rolleyes:

Is there reason to believe it won’t be, in the USA at least?

Citation needed. If they've already made up their minds then no need for a recertification process at all.
I think you're confusing the process and the possible end result of that process. But there can be no guarantees about that result or how long it takes to get there.

Well let’s put it this way, EASA have not yet said they weren’t going to certify it. I mean, if AESA had a fundamental problem with the aerodynamics or the MCAS system of the MAX they would have scuppered the aircraft’s certification by now, wouldn’t they?

AESA may still have their reservations – they may still want a third AoA indicator fitted – but it doesn’t sound from this article that they are about to block certification of the MAX just yet?

https://www.reuters.com/article/us-ethiopia-airplane-easa-exclusive-idUSKBN1X021S

Fritzbox

https://www.theguardian.com/business/2020/feb/06/boeing-737-max-regulators-fixes-needed

International air safety regulators are likely to agree on the design fixes needed to return the Boeing 737 Max aircraft to service after two deadly crashed, the administrator of the US Federal Aviation Administration (FAA), Steve Dickson said on Thursday.

Dickson declined to put a timeframe on the plane’s return to service but said that the Max could take a certification flight in the next few weeks...

...Speaking at an airline industry event in London, Dickson said that international regulators including European Union Aviation Safety Agency (EASA) broadly agreed on what needed to be fixed...

But in January the FAA and Boeing they were also reviewing a wiring issue that could potentially cause a short circuit on the grounded 737 Max.

Officials said the review was looking at whether two bundles of wiring are too close together, which could lead to a short circuit and potentially result in a crash if pilots did not respond appropriately.

“They have not given us a proposal on the wiring yet,” Dickson said.

“I wouldn’t say I’m worried. I want them to take whatever time they need to give us a fulsome and a data-driven proposal.”

GM228

Fritzbox wrote: »

I should have specified it was those airliners which have their thrust line well below the aerodynamic centre – typically low-winged aircraft with pod-mounted engines – such as the B737 and A320. It’s an asymmetric thrust problem. However the 737 (going back all the way to the 737-200) seems to suffer from the problem a lot more than the A320 – the MAX, worse of all.

But no plane has ever specifically required a software fix to correct any potential inadvertent pitch instability issues.

Fritzbox wrote: »

In fact, the A320 Neo has its own pitch instability problems too – not in the same league as the 737 MAX of course…

https://www.flightglobal.com/programmes/a321neo-operators-alerted-over-excessive-pitch-anomaly/133574.article
https://www.aerotime.aero/ruta.burbaite/23713-easa-alerts-airbus-a321neo-operators-over-excessive-pitch-issue
https://leehamnews.com/2019/07/19/bjorns-corner-airbus-a321neo-has-pitch-up-issue/

You rightly note not in the same league as the MAX, but, it should be pointed out the issues with the MAX where physical design related which required software to correct, the issue on the NEO was a software issue with the ELAC L102 (the Elevator Aileron Computer) which could potentially cause an excessive pitch when certain conditions were met.

They are not really comparable though are they? There's a difference between software incorrectly causing an excessive pitch, and software trying to correct a physical design which causes an excessive pitch.

GM228

Fritzbox wrote: »

https://www.theguardian.com/business/2020/feb/06/boeing-737-max-regulators-fixes-needed

Note what is said:-

But in January the FAA and Boeing they were also reviewing a wiring issue that could potentially cause a short circuit on the grounded 737 Max

No mention of the EASA, but hardly surprising given it was a speech delivered by Steve Dickson.

The EASA want them rewired, the issue has caused the upcoming FAA re certification test flights to be cancelled.

Hotblack Desiato

Fritzbox wrote: »

I should have specified it was those airliners which have their thrust line well below the aerodynamic centre – typically low-winged aircraft with pod-mounted engines – such as the B737 and A320.

No. Pitch-up on applying thrust exists on all (low-wing) aircraft with underwing nacelle mounted engines. If anything the 737 MAX should be less affected by this than the 737NG, because the centre of thrust of the engine is higher up. It's not a "hit throttles, pitch up" problem and never was. It was due to the engines/nacelles being so high up (top of nacelle level with wing) and forward relative to the wing they were actually generating lift as angle of attack increased. This meant that pitch-up control force decreased as AoA increased, and this is not permitted under FAA regulations. Hence MCAS.

It’s an asymmetric thrust problem.

No, that's when an engine which is not on the centreline of the aircraft loses thrust.

However the 737 (going back all the way to the 737-200) seems to suffer from the problem a lot more than the A320 – the MAX, worse of all.

No idea what you're talking about here in relation to older 737s.

In fact, the A320 Neo has its own pitch instability problems too – not in the same league as the 737 MAX of course…

https://www.flightglobal.com/programmes/a321neo-operators-alerted-over-excessive-pitch-anomaly/133574.article
https://www.aerotime.aero/ruta.burbaite/23713-easa-alerts-airbus-a321neo-operators-over-excessive-pitch-issue
https://leehamnews.com/2019/07/19/bjorns-corner-airbus-a321neo-has-pitch-up-issue/

3 links all referring to the same issue which has caused zero aircraft to crash. Airbus are restricting the permissible centre of gravity of certain aircraft until they update the FMS of relevant aircraft. They CAN fix it in software, because they went fly by wire well over 30 years ago now, so any change to the aerodynamic behaviour of an aircraft, or an exceptional case in software such as this one, is easily dealt with. NB this situation is very much a "corner case" and the restrictions affect very few operational scenarios, so not comparable to the MCAS disaster at all. Trying to conflate the two raises questions.

Is there reason to believe it won’t be, in the USA at least?

The FAA (Boeing's pet federal agency) can do whatever they want, the rest of the world will not necessarily follow, and it won't do Boeing much good if it can only fly internal US flights.

Well let’s put it this way, EASA have not yet said they weren’t going to certify it. I mean, if AESA had a fundamental problem with the aerodynamics or the MCAS system of the MAX they would have scuppered the aircraft’s certification by now, wouldn’t they?

It's currently grounded and not certified to fly in EASA airspace, so I have no idea what point you are trying to make here. EASA will not certify the MAX to fly again in their airspace until they are fully satisfied, and by all indications FAA certification of this aircraft is not going to be accepted without question like it has been up until now.

AESA may still have their reservations – they may still want a third AoA indicator fitted – but it doesn’t sound from this article that they are about to block certification of the MAX just yet?

https://www.reuters.com/article/us-ethiopia-airplane-easa-exclusive-idUSKBN1X021S

That article is months old and was discussed on this thread months ago and it's basically pure speculation, based on assumptions of "everything going well" which the article itself then disputed due to more revelations of misconduct at Boeing.

EASA have raised other issues, such as the difficulty in practice of correcting a severe out of trim condition on the 737 even after the pilots have disabled auto trim / MCAS. If they mandate a redesign of that then it's goodnight Irene as every Classic and NG flying will be grounded as well until they're fixed.

GM228

https://www.google.com/amp/s/www.bloomberg.com/amp/news/articles/2020-02-29/faa-tells-boeing-more-training-for-737-max-pilots-may-be-needed

Boeing has already acknowledged pilots need more specific training/simulators, but this raises more issues for them:-

U.S. regulators have told Boeing Co. that pilots may require additional training to properly respond to emergencies on the 737 Max after airline crews failed to perform proper procedures in simulator tests.

This is probably the most worrying, despite an elevated awareness, additional training received (as per the proposed training plan) and the new software installed:-

The pilots, who had received additional training proposed by the company, failed to finish emergency checklists related to the automated system involved in both 737 Max crashes, known as Maneuvering Characteristics Augmentation System.

In addition, they had difficulty with emergency procedures related to sensor failures, erroneous altitude and airspeed readings and the autopilot, among others, according to the letter.

The tests also showed that some pilots were confused about how the autopilot behaved in some circumstances and their interactions with the plane’s automated warning systems were distracting.

The next question is are the failings down to insufficient training, lack of experience or the design of the cockpit and systems? Something tells me it's certainly not la lack of experience.

Hotblack Desiato

I've posted along these lines before - imho Boeing's whole man-machine interaction paradigm is looking increasingly untenable. Applying half-assed automation on top of what is basically a 1950s airframe. Airbus made the big investment and took the big risk 30+ years ago and now are well set up for any future changes to the 320 family resulting in only minor software fixes. They could even introduce a totally new 320 family replacement, and make it fly just like a 320 in software. When the MAX flies again, it's looking certain that specific training will be mandated, which is precisely what Boeing tried to avoid - Southwest imposed a financial penalty on Boeing if the MAX turned out to need additional training. Although the cost of that ($1m per aircraft, IIRC) is the least of Boeing's worries now.

Turbulent Bill

GM228 wrote: »

The next question is are the failings down to insufficient training, lack of experience or the design of the cockpit and systems? Something tells me it's certainly not a lack of experience.

Most human factors studies like this require a representative cohort of subjects, which for the MAX would mostly be 737 NG pilots with various levels of experience. Nobody is going to have confidence if the procedures can only be pulled off by crack test pilots.

My guess is that the MAX requires significantly different crew responses to an NG, yet looks and feels very similar, so falls between two stools. Crews under pressure revert to what they're familiar with, and get confused when it doesn't work as expected.

It's not unusual to have poor initial results in HF studies like this, and they're often structured to discriminate between different failure modes (poor design, poor training etc.). If they fail multiple studies, though, it points towards something more serious.

Pronto63

Is the current virus scare a mixed blessing for Boeing / airline industry?

For the last couple of months we have been hearing about how the industry will struggle, capacity wise, during the busy summer months without all the grounded “Max” aircraft.

Looks as though seat sales are starting to take a bit of a hammering!

MJohnston

No, I don't there's a mixed blessing here, I'd say it's pretty much all bad news for the airlines.

Fritzbox

A “culture of concealment”, cost cutting and “grossly insufficient” oversight led to two fatal crashes of Boeing 737 Max aircraft that claimed 346 lives, a congressional report has concluded.

The preliminary findings, issued by Democrats on the House transportation committee, conclude that Boeing “jeopardized the safety of the flying public” in its attempts to get the Max approved by regulators.

https://www.theguardian.com/business/2020/mar/06/boeing-culture-concealment-fatal-737-max-crashes-report

FishOnABike

Could this be Boeing's "Ford Pinto" moment?

banie01

Fritzbox wrote: »

https://www.theguardian.com/business/2020/mar/06/boeing-culture-concealment-fatal-737-max-crashes-report

If the MAX recovers from this, it may as well change its name to Phoenix.

The writing has been on the wall for quite a while regarding the flawed product and process that led to allowing the MAX be grandfathered in under the 737 type cert.

This report confirms an opinion of Boeing and its current situation that some of us on this thread have held for quite a while.
It is scathing.

L1011

Further convinced it'll never fly commercially again.

Possibly re-engine with CFM56 to return to original characteristics and sell the built ones as an aerodynamically tweaked NG (or with the bending landing gear for the longer version as it has a niche) to rescue some investment

The risk of a deep dive in to everything grounding the NG is still there too

Charles Babbage

I wonder if the present difficulties in the airline industry might not provide time for pilots to be trained on the Max?

banie01

L1011 wrote: »

Further convinced it'll never fly commercially again.

That's been my own opinion for quite a while.
The moves behind the scenes by the US to funnel cash into Boeing at the moment will be very interesting if it's ever raised at WTO too.

GM228

L1011 wrote: »

Further convinced it'll never fly commercially again.

Possibly re-engine with CFM56 to return to original characteristics and sell the built ones as an aerodynamically tweaked NG (or with the bending landing gear for the longer version as it has a niche) to rescue some investment

The risk of a deep dive in to everything grounding the NG is still there too

Would that be even possible without major wing modifications I wonder as the wings are designed for the more forward facing nacelle mountings.

They can dress it up all they like, but it will still be a MAX, or an 8200 or whatever it's called these days.

Not so sure of the it'll never fly commercially again, but, if that were the case could Boeing survive it? I doubt it.

L1011

I'd imagine it just needs a new pylon but I'm not in a position to be certain on that. My engineering qualification is in a very different area!

I would see Boeing Commercial Aircraft - the division - being sold for a dollar to Lockheed or similar to wash the debts if that does come to pass.

Tenzor07

L1011 wrote: »

Further convinced it'll never fly commercially again.
Possibly re-engine with CFM56 to return to original characteristics and sell the built ones as an aerodynamically tweaked NG (or with the bending landing gear for the longer version as it has a niche) to rescue some investment
The risk of a deep dive in to everything grounding the NG is still there too

Will never happen, Boeing and their customers and suppliers are in too deep now, would be a massive body blow to Boeing and would most likely lead to a break up and sell off of the company, plus will hurt airlines like Ryanair and Southwest the most who will have to switch to Airbus and completely redesign entire operations as well as keeping current NG's in the air for at least the next 10 years or more..

josip

Airbus must be looking at significantly increasing their A320 manufacturing capacity now.
And not a token single digit increase as has already been reported.

Nijmegen

josip wrote: »

Airbus must be looking at significantly increasing their A320 manufacturing capacity now.
And not a token single digit increase as has already been reported.

Well, considering the aviation industry is collapsing around our ears (I exaggerate... slightly) over Covid-19 I'm not sure you could make that bet with any certainty right now.

Tenzor07

josip wrote: »

Airbus must be looking at significantly increasing their A320 manufacturing capacity now.
And not a token single digit increase as has already been reported.

They still have a lengthy waiting period for aircraft delivery's which will take a number of years to complete...

This current crisis is still an escalating situation, plus it isn't the end of the world, however we have yet to see just what the full impact will be on the entire aviation industry, 2021 could see big changes...

goingnowhere

Airbus are getting a A320 line up and running in TLS

GM228

GM228 wrote: »

There is also a new major issue with the MAXs, the wiring, Boeing confirmed the wiring didn't meet standards, but both they and the FAA agreed that there was no need to re-wire them, however, the EASA is apparently insisting they be rewired, this could potentially be another major delay (and a very costly one) to their re-entry.

Just coming back to this it looks like the FAA have bowed to the EASA and changed their tune in relation to the wiring:-

https://www.cnbc.com/amp/2020/03/09/faa-tells-boeing-that-737-max-wiring-bundles-are-not-compliant.html

The Federal Aviation Administration has formally rejected Boeing's proposal that it not modify nor move wiring bundles in 737 Max airplanes, according to people familiar with the decision

It was previously reported that the FAA supported Boeing, but the EASA had insisted on a re-wire:-

https://www.wsj.com/amp/articles/u-s-european-friction-over-wiring-is-latest-complication-for-737-max-return-11580597877

Potentially hazardous wiring inside Boeing Co.’s 737 MAX jets is the latest flashpoint between U.S. and European regulators and a further complication in the grounded fleet’s return to service, according to people familiar with the details.

Technical experts at the European Union Aviation Safety Agency want certain electrical wires relocated to reduce what they say are dangers from potential short circuits, which in a worst-case scenario could disrupt flight-control systems, according to these people.

<SNIP>

But engineers at the Chicago plane maker and high-ranking FAA managers, including the agency’s top safety official, contend moving the wiring isn’t necessary

It's also interesting to note that this issue could spill over into the NG as apparently it's the same wiring used.

banie01

GM228 wrote: »

Just coming back to this it looks like the FAA have bowed to the EASA and changed their tune in relation to the wiring:-

https://www.cnbc.com/amp/2020/03/09/faa-tells-boeing-that-737-max-wiring-bundles-are-not-compliant.html



It was previously reported that the FAA supported Boeing, but the EASA had insisted on a re-wire.

There goes any hope Boeing and the Airlines and Lessors had of a "mid-year" return to service.
Glad to see EASA taking a hard line.

Hotblack Desiato

L1011 wrote: »

The risk of a deep dive in to everything grounding the NG is still there too

One year ago today since the crash.

Some updates on Aviation Herald: http://avherald.com/h?article=4c534c4a/0090&opt=0

Apparently the crew tried to trim up manually but couldn't. This of course has implications for the NG.

From the CVR transcript:
- At 5 h 41 min 50 s, the captain requested the F/O to try moving the trim manually.
- At 5 h 41 min 50.5 s: a sound similar to the trim wheel handle extension was detected.
- At 5 h 41 min 51 s, the copilot confirmed “Trim up”
- At 5 h 41 min 55.5 s, the captain used an “expression of expectation”
- At 5 h 41 min 56 s, the copilot stated: “it is not working”.
The time during which the F/O tried to manually move the trim was then between 5 h 41 min 51 s and 5 h 41 min 56 s.

A comment on AvH:

The manual wheel for adjusting Trim is clearly something that Boeing has never tried to use in actual flight to correct trim, or if they have, they have failed to report that it doesn't work. On their own test equipment, at 12,000 ft and 340 knots, with the airplane in trim, the wheel is barely movable, and it's impossible to move if the aircraft has a -1.5 unit mis-trim (the max value for the test rig). In the accident flight, the aircraft would have required 60 turns of the wheel to return it to normal trim, with the wheel being almost impossible to turn even once with two hands. (It turns easily on the ground, shockingly).

So this trim wheel is just for show, apparently. Another regulatory issue?

cnocbui

Would that trim issue prevent approval and a return to service?

L1011

cnocbui wrote: »

Would that trim issue prevent approval and a return to service?

Yes, and if agencies are so minded it could ground the NG - it has the same system.

goingnowhere

L1011 wrote: »

Yes, and if agencies are so minded it could ground the NG - it has the same system.

Not quite the MAX has a smaller trim wheel this requires a greater force for the same level of trim applied.

All said every 737 going back to the 737-100 has the same basic issue, it is a plane from the 1950's (707 with 2 engines...) which is still full of wires and pulleys. Full reversion is another barrel of laughs.

You would need to execute some 'interesting' moves to unload the aerodynamic forces, i.e push the wrong way, quickly turn the wheel which would then be fairly easy to turn, pull up and try again. You run out of altitude fairly quickly as the MAX crews found out.

banie01

Has the Ethiopian crash report been released in full?

I heard a snippet on RTÉ that I think said the report from Ethiopia exonerated crew and airline fully and laid the blame fully on a flawed design?