/ 737 Max: When will you be confident to fly on one

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annieman 04 Feb 2020

When leaving Manchester Airport recently I saw 4 x 737 max parked near the end of the runway. There will be a fix, there will be training for the pilots. The approprite authorities will have sign them off. But when will you be happy to fly on them?

plyometrics 04 Feb 2020
In reply to annieman:

Never. 

gethin_allen 04 Feb 2020
In reply to annieman:

Once they have been through all the adaptation they should hopefully be one of the most rigorously tested planes around. 

Although a friend who is involved in aerospace design claims that the basis design is flawd and they are whipping a dead horse.

Robert Durran 04 Feb 2020
In reply to annieman:

As soon as they are cleared to fly. They will probably be the safest plane in the air. Do you really think anyone is going to be taking any chances after what happened?

Post edited at 21:18
1
Wanderer100 04 Feb 2020
In reply to Robert Durran:

>Do you really think anyone is going to be taking any chances after what happened?

Do you want to be the one to find out they have taken another chance? Boeing are losing money for the first time time in their history and these disasters show they value profit more than human lives. I wont be risking a flight in one for a few years yet.

wintertree 04 Feb 2020
In reply to annieman:

Never.  The more I read about Boeing since the McDonnel Douglass merger the more appalled I am.  Rotten to the core and untrustworthy in the extreme - profit over life knowing that they as management individuals are Teflon coated,  Then again I gave up flying in 2013 so I can afford to be picky.

Post edited at 21:33
1
JLS 04 Feb 2020
In reply to Wanderer100:

>”I wont be risking a flight in one for a few years yet.”

How easy is it to find out what aircraft WILL be used when you book your holiday flights?

Post edited at 21:43
elsewhere 04 Feb 2020
In reply to Robert Durran:

> As soon as they are cleared to fly. They will probably be the safest plane in the air. Do you really think anyone is going to be taking any chances after what happened?

Yes.

There's huge financial pressure. When subject to much less financial pressure they responded with a safety critical system using a single sensor which is prone to getting bashed.

It's not the Boeing of old that valued engineers.

Post edited at 21:51
Ridge 04 Feb 2020
In reply to gethin_allen:

> Although a friend who is involved in aerospace design claims that the basis design is flawd and they are whipping a dead horse.

As I understand it, Boeing took a plane with relatively small engines (original 737), made them bigger and bigger until they wouldn't fit under the wings, so moved them forwards and upwards, completely changing the the design of the aircraft. They insisted on keeping the 737 designation to avoid the costs of introducing what was in effect a completely different aircraft.

Moving the engines made the plane liable to try and stand on it's tail when power was applied, so Boeing fitted the autopilot system that was able to overpower the pilot and push the nose down (and fly it into the ground), based on the input of one notoriously unreliable sensor (because having it cross check other instruments might have been a bit more expensive).

Absolutely criminal attitude to safety.

JLS 04 Feb 2020
In reply to Robert Durran:

>”As soon as they are cleared to fly.”

Surely anyone that’s ever had a Windows computer knows that even after two service packs the it’ll still be full of bugs. I’m a great believer in AS (artificial stupidity).

Arms Cliff 04 Feb 2020
In reply to JLS:

> How easy is it to find out what aircraft WILL be used when you book your holiday flights?

Plenty of web resources to tell you what plane models are flying scheduled routes. Not sure about charter flights. 

Steve Clark 04 Feb 2020
In reply to annieman:

I hope Boeing manage to find a way through this, even if it means scrapping the 737 MAX. 

Boeing have built some incredible stuff in the past. With the right management I'm sure they could again. They have built over 1600 777's over the last 25 years, the vast majority of which are still flying. That's thousands of flights every day, millions and millions of flights in total. 300-400 people on most flights. So far, there have been 28 crashes, 7 of which completely destroyed the plane. If you ignore the one that the Russian's shot down and the one that the pilot flew on a suicide mission into the Indian Ocean, total fatalities : 3. And one of them was run over by a fire-truck.

Post edited at 22:25
1
Toerag 04 Feb 2020
In reply to annieman:

When it's an airbus instead.

Dan Arkle 04 Feb 2020
In reply to annieman:

Happy to fly on them now. 

Pretty small risk. 

I'm also happy to point out all the things you do in life that seriously increase your chance of death, but you aren't afraid of as they are normal to you. You do nothing about these, and instead obsess over dramatic things that won't happen. 

Not aiming at anyone personally, but lets start with climbing, any alcohol consumption, poor diet, being overweight, not getting enough sleep, or exercise, doing a stressful job, driving to a standard that wouldn't pass an advanced driving test.

And I'll finish with failing to look after your mental health and keep connected with people - suicide is the leading cause of death among the young. 

2
L mondite 04 Feb 2020
In reply to Ridge:

>  They insisted on keeping the 737 designation to avoid the costs of introducing what was in effect a completely different aircraft.

They do seem to have taken the piss a tad with regards to grandfathering. Although it wasnt just them to blame but the airlines as well since they wanted as few types as possible to deal with in terms of training.

Robert Durran 04 Feb 2020
In reply to Wanderer100:

>  Boeing are losing money for the first time time in their history and these disasters show they value profit more than human lives. I wont be risking a flight in one for a few years yet.

And the way for them to stop losing money is for them, under intense scrutiny, to demonstrate beyond doubt the safety of their aircraft.

Timmd 04 Feb 2020
In reply to Dan Arkle:

> And I'll finish with failing to look after your mental health and keep connected with people - suicide is the leading cause of death among the young. 

Young men especially, regarding suicide. 

Gordon Stainforth 04 Feb 2020
In reply to gethin_allen:

> Once they have been through all the adaptation they should hopefully be one of the most rigorously tested planes around. 

> Although a friend who is involved in aerospace design claims that the basis design is flawd and they are whipping a dead horse.

It's seems very likely they'll cut their losses, which are huge, and scrap it. To preserve their good name. This plane, as you say, is a lousy design (or an old design crudely over-redesigned).

elsewhere 04 Feb 2020
In reply to Dan Arkle:

Good point, even the Max might be safer than the drive to the airport.

Although compared to stats quoted in the thread the max is has killed many more on far fewer flights than the 777.

Gordon Stainforth 05 Feb 2020
In reply to elsewhere:

In 21st century flying terms, the Max's record of fatalities is unacceptably appalling.

teh_mark 05 Feb 2020
In reply to annieman:

Never: fixing fundamental aerodynamic problems in software in commercial airliners is not the correct design approach, and no matter what they throw at the problem the fundamental aerodynamic issues will still exist. I'm also less than happy flying on the NG, which I believe is where they introduced one of the exacerbating factors - the smaller manual trim wheels which reduce the leverage available to the crew to retrim a grossly out-of-trim aircraft. Which can happen for reasons other than MCAS.

Wanderer100 05 Feb 2020
In reply to JLS:

Checking out the airlines fleet is a good place to start. 

http://www.easyjet.com/en/help/boarding-and-flying/our-fleet

Northern Star 05 Feb 2020
In reply to annieman:

The 737 should have been pensioned off a long time ago and replaced with a new model with a higher wing so that it could easily fit some higher bypass ratio (more fuel efficient) engines with less risk of ingesting foreign objects on the ground. 

Okay so the current 737 is an entirely new aircraft (i.e. it shares possibly nothing with the early versions apart from it's basic shape), but that basic shape is now compromised and has been stretched to breaking point it would seem.  Boeing would have been far better to start with an entirely new platform 10-15 years ago.  It now needs to do this in any case as the 737 is now seen as 'soiled goods' by many and it's design shortcomings have been publicly exposed.

That said, if the 737 Max does re-enter service after thorough testing etc then I would have no problems flying on one.  If I was an airline though, requiring a short haul jet then I'd be looking to Airbus right now, unless of course the lease deals on the surplus 737's were too good to refuse.

DaveHK 05 Feb 2020
In reply to annieman:

The practicalities of this thread are interesting. If you turn up at the airport and find your plane is a 737 max are you going to refuse to get on?

hang_about 05 Feb 2020
In reply to annieman:

Whatever happens they certainly won't be called a 737 Max.

Windscale -> Sellafield anyone?

teh_mark 05 Feb 2020
In reply to DaveHK:

If you care enough, it's very easy to avoid flying on one for leisure long before you arrive at the airport. There are few airlines (I'm certainly not aware of any at the current time) in Europe who operate an A320/737 mixed fleet, and therefore it's not difficult to ensure you book your flight with an airline operating the A320 - of which there are many to choose from.

Business travel is somewhat more tricky, of course.

Xharlie 05 Feb 2020
In reply to Robert Durran:

> ... Do you really think anyone is going to be taking any chances after what happened?

YES! I'm absolutely certain that, given any sliver of a chance to put profit ahead of safety, they absolutely WILL take any chances they want to.

The whole 737 MAX story is one of cost-cutting and prioritisation of profit -- even when the potential for additional profit is basically a rounding-error when measured against the cost of the aeroplane: the cost of two additional, redundant AOA sensors, for example!

The question in the OP should be: "When will you be confident to fly in any Boing, again?" This sort of profiteering never affects only ONE of a companies projects.

1
Neil Williams 05 Feb 2020
In reply to annieman:

When the EU says it is OK.  I don't trust the US on the matter as Boeing is American.  The CAA, well, if we're in Trump's pockets...

adsheff 05 Feb 2020
In reply to JLS:

> >”I wont be risking a flight in one for a few years yet.”

> How easy is it to find out what aircraft WILL be used when you book your holiday flights?

In the UK it's fairly easy to avoid a lot of them. Ryan Air Operate a 100% 737 fleet, and they've ordered hundreds of MAX's. So avoid Ryan Air. Tui also have a lot on order. Easyjet on the other hand run a 100 Airbus fleet, so you're safe with them. Also Flybe don't operate any so they're good too.

teh_mark 05 Feb 2020
In reply to Xharlie:

> The question in the OP should be: "When will you be confident to fly in any Boing, again?" This sort of profiteering never affects only ONE of a companies projects.

Indeed. The 787 battery saga, the MAX flaws, 737 NG cracking pickle forks (the bit which holds the wing to the fuselage)...the problem is one of culture, not a one-off. Just a continuation of the McDonnell Douglas doctrine of business, really.

Xharlie 05 Feb 2020
In reply to Ridge:

There were even more layers of cost-cutting and profiteering going on, however:

1. Provoked into panic reaction by Airbus -- who were eating Boing's lunch -- Boing tried to bolt oversized engines onto the venerable 737 airframe to avoid the costs of introducing a new one.

2. The engines caused a pitch-up-on-power problem: when the pilots throttled up, the plane pitched up.

3. Handling such a pitch-up-on-power problem is not really an issue but would require special training -- in actual simulators -- because the new aeroplane behaves differently to the old one.

4. To avoid special training, Boing introduced the automatic MCAS system to handle the behaviour and make the new aeroplane behave the same as the old one.

5. They assured regulators that flicking through some material on an iPad was now sufficient training for pilots. This was palatable for the airlines who, fundamentally, don't build aircraft themselves and trust the manufacturers and regulators -- perhaps too much. The plane was bought and sold.

6. The MCAS system was driven by a single, notoriously unreliable sensor. Triple redundancy would be necessary for any flight-critical system but was not considered necessary in this case because Boing stated that the pilot *could* override the sensor, if it failed.

7. Triple redundant AOA sensors were an optional extra. (Since the cost of the hardware amounts to little more than a rounding error on the scale of an aeroplane, I guess that this was done for business and market reasons.)

8. Not understanding any of the above and assured that they were buying a aeroplane that was cleared for flight even without triple-redundant sensors, the airlines (by nature, cost-cutters of the highest order) opted not to buy the triple-redundant sensors. This should surprise nobody.

9. Overriding the MCAS system was not a skill with which 737 Max pilots were endowed because they never received proper training, in a simulator and the process was both esoteric and entirely counter-intuitive for an aeroplane pilot of any cloth.

10. The presence of MCAS and the option to override it was mentioned in the iPad training material, apparently, but WHY one might need to was never explained -- presumably because that would give away the whole story of the points, above.

11. A browbeaten regulations board cleared the aeroplane, knowing and understanding nothing of any of this. (Again, I think that the thought of competition from Airbus probably encouraged their actions.)

--

The idea that any of the above could occur in a company as a one-off event for one, single project and, after a slap on the wrist, such ingrained corruption, ineptitude, profiteering and outright CONTEMPT FOR HUMAN LIFE could be eradicated from that company's very D.N.A. is entirely absurd and fantastic! Nie wieder ein Boing!

Post edited at 10:27
In reply to Northern Star:

But can you imagine the advertising opportunity for the airlines not flying them?

"Want to reach your destination rather than nose dive into the ground just outside the airport perimeter fence? Then fly with us, we don't lease 737 Max"

Obviously I am being facetious but it would be a big risk economically flying them when your competitors fly airbuses

Post edited at 11:25
Neil Williams 05 Feb 2020
In reply to Bjartur i Sumarhus:

Airlines don't generally advertise on that sort of basis, not least because if they were unfortunate enough to experience a fatality it would almost certainly cause the airline to collapse because it would end up looking somewhat hypocritical.

SDM 05 Feb 2020
In reply to Dan Arkle:

> Happy to fly on them now. 

> Pretty small risk. 

> I'm also happy to point out all the things you do in life that seriously increase your chance of death, but you aren't afraid of as they are normal to you. You do nothing about these, and instead obsess over dramatic things that won't happen. 

> Not aiming at anyone personally, but lets start with climbing, any alcohol consumption, poor diet, being overweight, not getting enough sleep, or exercise, doing a stressful job, driving to a standard that wouldn't pass an advanced driving test.

The issue with accepting Boeings now is that it is an endorsement of the concept of putting their profits over the lives of the consumer. If they get away with it this time, there is no incentive for them to improve; they will continue to put profit over safety, with potentially worse consequences in the future. The only way to change this culture is to make it hurt their profits badly.

For this to be effective though, airlines would need to be aware of why people were choosing not to fly on their fleet of Boeings so that they could adjust their fleet accordingly and/or put pressure on Boeing for a cultural change.

There are other things we do that are more dangerous than flying. But flying should be incredibly safe and there is no reason why people should accept it being anything less.

In reply to Neil Williams:

Airlines don't generally advertise on that sort of basis

Of course, but can see memes flying around social media and as this thread demonstrates...there are a lot of nervous flyers out there who definitely care what planes airlines fly. Why would Ryan Air (for example) fly 737 Max if Easy Jet had an airbus fleet. 

They pretty much cover the same market so I would expect Easyjet to take market share in this hypothetical scenario

Neil Williams 05 Feb 2020
In reply to SDM:

> There are other things we do that are more dangerous than flying. But flying should be incredibly safe and there is no reason why people should accept it being anything less.

I agree - and that's why I would put my trust into the European Union aviation authorities in determining if it's safe or not - and as Ryanair are Irish that is who will tell them if they can start again or not.  The issue of how Boeing get punished for making some very wrong decisions in the past is slightly separate.

For what it's worth, almost everything we do is more dangerous than flying.  For instance, neither Ryanair (despite its cheap-and-nasty facade) nor easyJet (not really a low-cost other than in the fare pricing model) has ever had a fatal accident, both in over 20 years of operation.  The reason people fear flying isn't objective, it's because if you *are* killed on a flight it's going to be somewhat spectacular and potentially very painful, and you're going to know about it for at least a few minutes before it happens, too.  Generally people see that and don't consider that the likelihood is tiny.

Post edited at 11:50
StuPoo2 05 Feb 2020
In reply to JLS:

> How easy is it to find out what aircraft WILL be used when you book your holiday flights?

https://www.seatguru.com/findseatmap/findseatmap.php?airlinetext=Jet2&carrier=LS&date=02%2F16%2F2020&departing=02%2F05%2F2020&flightno=167&from=&from_loc=LON&to=&to_loc=&search_type=flight

Will even help you choose the good seats.

Timmd 05 Feb 2020
In reply to SDM:

As mentioned further up, this thread's tone is as if there's an element of choice in which aircraft one flies, having bought a ticket already.

1
teh_mark 05 Feb 2020
In reply to Bjartur i Sumarhus:

> Why would Ryan Air (for example) fly 737 Max if Easy Jet had an airbus fleet. 

Because Ryanair have 342 aircraft in their fleet, and 135 orders (source: Wikipedia). Every single existing aircraft is a 737NG, and every new order is a 737MAX. They have over 5000 pilots who are 737 type rated. The cost of retraining their existing pilots would be enormous, the additional overheads from operating a mixed fleet would be significant, and replacing their fleet would be a very long term exercise.

And I dare say that they get a hefty discount from Boeing, in a similar vein to Southwest in the US.

Neil Williams 05 Feb 2020
In reply to teh_mark:

Very much so.  I did hear that they resell them used for more than they pay for them new.  Not only because of the discount, though, but because a purchasing airline knows that having been used by a European airline they will have been maintained properly due to the stringent regulations.

Post edited at 14:00
jkarran 05 Feb 2020
In reply to annieman:

When they're put back in the air. The problems are understood, the solutions very highly scrutinised, the crews will be well informed of differences.

Even as is it's a damn sight safer than the vintage wooden ship I love to fly.

jk

nniff 05 Feb 2020
In reply to annieman:

Interesting the extent to which blame for cost cutting and profiteering is laid at Boeing's (and the airlines') feet.  That behaviour starts with us, the customers, chasing ever cheaper fares.  

4
Michael Hood 05 Feb 2020
In reply to Xharlie:

A few additions to your good post...

Boing were caught on the hop by Airbus's new version of the A320 and it's improved fuel consumption - lower running costs - more attractive to airlines.

The MAX (rather than a new airframe), wasn't just a "now" profit grab, it was also because a totally new airframe would take much longer to develop during which more market share would be lost (less long term profit).

Pilots are only allowed to fly one "type" of aircraft at the same time, where "type" means same control characteristics, etc. So for example the 757 & 767 are the same "type".

Having more "types" of aircraft in a fleet is obviously more expensive for airlines. By keeping the MAX as a 737, Boing were obviously selling on this.

The documentation about MCAS (presumably what the regulators saw) only had MCAS affecting the relevant control surfaces by x% (can't remember the number) so it was not classed as a critical system requiring sensor redundancy.

In reality MCAS had a y% effect where y =5*x (approx) which would make it a critical system requiring redundancy. The regulators were unaware of this and their procedures and testing didn't find out about this.

Rob Parsons 05 Feb 2020
In reply to annieman:

> When leaving Manchester Airport recently I saw 4 x 737 max parked near the end of the runway. There will be a fix, there will be training for the pilots. The appropriate authorities will have sign them off. But when will you be happy to fly on them?


The problem with the 737 Max is that it's aerodynamically unstable owing to the nacelles (themselves owing to the larger engines which have been brought forward; themselves owing to the entire redesign of the 737 to the Max.) Now that can all be controlled via appropriate avionics - but still ...

Is there any other aircraft in commercial service which is aerodynamically unstable?

jkarran 05 Feb 2020
In reply to Bjartur i Sumarhus:

> Airlines don't generally advertise on that sort of basis

Not pushed by the airlines! People in crowds are stupid. You erode faith in your competitor's fleet you erode faith in the whole industry, we're simply not that discerning and it's taken a long time and a lot of work to convince us flying is safe.

> Of course, but can see memes flying around social media and as this thread demonstrates...there are a lot of nervous flyers out there who definitely care what planes airlines fly. Why would Ryan Air (for example) fly 737 Max if Easy Jet had an airbus fleet.

Because they have them, their maintenance operation is tailored to them, A320s are on long back-order and sitting it out without a fleet for half a decade doesn't seem as appealing as spending on advertising to reassure customers their aircraft are new, well maintained, properly certified and their crew training tip-top. Whether or not it's true it's pretty much the only option they actually have.

Let's not forget the A330 stalled all the way into the Atlantic by an experienced pilot outfoxed by it or the earlier A320 which descended into trees during an airshow amid controversy over misbehaving engine control software and evidence tampering. Boeing dropped a bollock with the Max but the competition won't go for their throat over safety mistakes, none of them are squeaky clean and any one of them could have found themselves in Boeing's pickle.

jk

Post edited at 14:28
L mondite 05 Feb 2020
In reply to Rob Parsons:

> The problem with the 737 Max is that it's aerodynamically unstable owing to the nacelles (themselves owing to the larger engines which have been brought forward; themselves owing to the entire redesign of the 737 to the Max.)

I thought it was only in specific rare scenarios and that pilots could be trained to handle it.

However the problem was it would need specific training potentially up to being a different type with all the associated costs for the airlines as per Michael Hoods email.

Plus if it did end up being a new type there would be the question whether all the things grandfathered in which are no longer deemed safe for modern airlines (stuff like the evacuation options) would no longer be covered.

In reply to teh_mark:

I am not disputing any of that. But if people stop buying tickets so they can fly airbuses then Ryan Air will go out of business. plain and simple, regardless of any discount Boeing give them. Adapt or die (hopefully not in one of their 737MAXs lol)

I did say all of the above is hypothetical and only used Ryan air and easy jet as examples of two airlines without knowing their fleet.

SDM 05 Feb 2020
In reply to Timmd:

> As mentioned further up, this thread's tone is as if there's an element of choice in which aircraft one flies, having bought a ticket already.

Obviously there isn't. The time to make that decision has to be before tickets are purchased.

For making the other airlines aware of why you chose not to fly with them, social media campaigns tend to be very effective.

In reply to jkarran:

Everything you say makes complete sense. But, the "people in crowds are stupid" is the most valid point.

Brand new planes crashing killing all on board because the plane has been designed beyond a sensible point, this fact becoming mainstream publicly. A brand new fleet that has famously been grounded for months whilst Boeing try and fudge a fix so they can be controlled by the pilots, again wide public knowledge. Airlines that (as you have explained) will be reluctant to the point of actually unable to do anything except accept the software fix and extra training rather than possibly change suppliers..because they are hamstrung with the dangerously designed planes.

Just asked two colleagues if they remember the Boieng 737 max crashes and it being grounded and they did with some detail. I then asked them if they remembered any airbus crashes and they couldn't to any specific parameter (other than knowing that some most probably have crashed) 

Personally I would fly on one after the fix, but wouldn;t surprise me at all if this model is doomed. We will know as soon as Michael O'Leary ditches it (not saying he will, or even could without going out of biz) but he will prob be the first to react if it becomes apparent the public still don't trust this plane

Post edited at 15:11
teh_mark 05 Feb 2020
In reply to mondite:

> I thought it was only in specific rare scenarios and that pilots could be trained to handle it.

As I understand it, as the angle of attack approaches the critical angle of attack - the point at which the wing stalls - the engine nacelles begin to contribute lift, resulting in a reduction in the stick force required to continue raising the angle of attack to the point that the aircraft stalls.

This is contrary to what any pilot would expect, and I believe it is contrary to certification requirements, which require stick force to progressively increase up to the stall. It could be trained for, as can all manner of deviant handling characteristics, but the aircraft wouldn't be able to be certified with those characteristics. With good reason - we're not talking about, say, carefully selected military pilots flying intrinsically unstable aircraft, we're talking about an aircraft which needs to be flyable by any average commercial pilot. An aircraft that handles completely opposite to what you would expect in fringe scenarios is eventually asking for trouble.

And so MCAS was introduced to increase the stick force as the aircraft approaches the stall. It does this by applying nose-down trim, which makes it physically harder to continue raising the attitude of the nose. Trim is not a primary flight control, and is used to 'trim out' stick forces so the aircraft maintains a desired attitude without the pilot constantly applying pressure to the yoke. Ab initio pilots learn very early on that you don't use trim to fly the aeroplane. And yet Boeing have introduced a system that is essentially using trim to fly the aeroplane.

So it's wrong on multiple levels. It's a crude software patch to fix an intrinsic aerodynamic flaw, that works in a questionable manner, and that (as was originally designed) doesn't have any logic to stop it trimming the aircraft fully nose-down, which is a situation from which one can't recover. And in the scenario which results in MCAS going rogue, the workload on the flight deck is probably already very high. And it looks vaguely like an existing automated trim system, so in the heat of the moment the crew may not realise that the intermittent trim applications are a system gone rogue until they're in a situation from which it is very difficult to recover.

That is my understanding as a PPL.

jkarran 05 Feb 2020
In reply to Bjartur i Sumarhus:

> Just asked two colleagues if they remember the Boieng 737 max crashes and it being grounded and they did with some detail. I then asked them if they remembered any airbus crashes and they couldn't to any specific parameter (other than knowing that some most probably have crashed)

It's pretty much the latest high profile case, it'll be largely forgotten in time. Who among you honestly refused to get on a DC10 when the doors started popping open in flight and the No.2 engines started lopped the tails off?

> Personally I would fly on one after the fix, but wouldn;t surprise me at all if this model is doomed. We will know as soon as Michael O'Leary ditches it (not saying he will, or even could without going out of biz) but he will prob be the first to react if it becomes apparent the public still don't trust this plane

If the public don't trust it the reaction will be to try to counter that with advertising and a re-brand. If that fails I'm sure they'll cut their losses before one brand contaminates the other but they'll differentiate and ditch the Max, not Boeing, not the 737 because realistically they just can't!

If that happens the existing Max's probably won't be scrapped, they'll be reworked into a new or perhaps an older model.

jk

Post edited at 15:57
felt 05 Feb 2020
In reply to Bjartur i Sumarhus:

This has always seemed murky:

https://en.wikipedia.org/wiki/Air_France_Flight_296

In reply to jkarran:

"It's pretty much the latest high profile case, it'll be largely forgotten in time. "

This is where I disagree. The 737max cannot avoid bad publicity, because every time it is in the news its due to a story that relates back it's appalling safety record and poor design.

This is the plane crash news story that won't go away and will continue dragging on for years (and don't Boeing know it)... with publicity like this (from wiki) "Jan-Arwed Richter, head of JACDEC said: "The sharp reduction in fatalities compared to 2018 is—at the risk of sounding macabre—due to the grounding of the 737 MAX in March."

Doesn't get much worse than that.

Each time this plane will be in the news in the future (obtaining it's licence back to fly, to Boeing being in financial trouble to Airlines looking to change fleet etc etc) all roads will lead back to the two crashes that we all remember...unusual because they were brand new planes, nose diving to certain death with pilots unable to do anything to stop it.

I agree most plane crashes are forgotten in time, but I don't think this model can shake those crashes so easily, It's an ongoing news story that will continue for a lot longer constantly reminding the public that they would probably rather fly on a different plane.

Timmd 05 Feb 2020
In reply to SDM:

> Obviously there isn't. The time to make that decision has to be before tickets are purchased.

> For making the other airlines aware of why you chose not to fly with them, social media campaigns tend to be very effective.

I guess that's something the airlines will have in mind already too, regarding their reputation and keeping/gaining customers. The airlines and passengers are both keen on safety and reputation, for reasons which are slightly different and which overlap.

Post edited at 16:43
1
jkarran 05 Feb 2020
In reply to Bjartur i Sumarhus:

> This is where I disagree. The 737max cannot avoid bad publicity, because every time it is in the news its due to a story that relates back it's appalling safety record and poor design.

Until it's re-certified when they can start talking about how stringent that process was and the lessons learned and fed back into their deep and valued safety culture, its efficiency, low noise, comfort, low cost... at the moment it's an unlanced boil.

> Each time this plane will be in the news in the future (obtaining it's licence back to fly, to Boeing being in financial trouble to Airlines looking to change fleet etc etc) all roads will lead back to the two crashes that we all remember...unusual because they were brand new planes, nose diving to certain death with pilots unable to do anything to stop it.

Except re-trim. It's just no more horrifying than any other crash given they're mostly preventable with clear hindsight. Wait until the spectre of counterfeit and illicitly recycled parts hits the news, or another murder suicide, or a bomb, that'll instantly displace the worry about a specific model.

> I agree most plane crashes are forgotten in time, but I don't think this model can shake those crashes so easily, It's an ongoing news story that will continue for a lot longer constantly reminding the public that they would probably rather fly on a different plane.

Well I don't agree but I'm often wrong about these things, we'll have to wait and see how the market responds if and when it gets re-certified.

jk

Post edited at 16:43
teh_mark 05 Feb 2020
In reply to jkarran:

> Except re-trim.

The few videos of pilots trying this in the simulator are enlightening.

jimtitt 05 Feb 2020
In reply to annieman:

Someone just landed a 737 in pieces in Istanbul........

wbo2 05 Feb 2020
In reply to annieman:we all still remember the DC-10

wercat 05 Feb 2020
In reply to Bjartur i Sumarhus:

it is possibly the Comet of this century. I'm not talking about tanks either

Post edited at 17:35
Steve Clark 05 Feb 2020
In reply to jimtitt:

> Someone just landed a 737 in pieces in Istanbul........

The same airline (Pegasus) over-run/crashed a 737 on the same runway at Istanbul on Jan 7th this year ! 

Michael Hood 05 Feb 2020
In reply to Michael Hood:

Wish I could spell Boing properly 😁

Also, I remember the DC10 doors and other bits and thinking "never going to fly on one of them, it's obviously just badly designed".

wintertree 05 Feb 2020
In reply to jkarran:

> and the No.2 engines started lopped the tails off?

I just kind of assumed everyone knows that one.  A surprising number of flights (ie more than zero) have made it back with people alive in similar circumstances.  The DHL Baghdad flight seems like quite a miracle.  

> Wait until the spectre of counterfeit and illicitly recycled parts hits the news,

It was about a decade ago a mate of mine retrained for heavy jet maintenance.  I was horrified to hear about the prevalence of counterfeit parts in the maintenance supply chain.  

Post edited at 18:33
Timmd 05 Feb 2020
In reply to wintertree:

The prevalence of counterfeit medicines is pretty shocking, too. I saw about somebody in Africa with type 1 diabetes who had died because of counterfeit medicines entering from China, her sister was understandably determined to crack down on them and stop them from entering her country.

Post edited at 18:51
1
Northern Star 05 Feb 2020
In reply to Neil Williams:

> Airlines don't generally advertise on that sort of basis, not least because if they were unfortunate enough to experience a fatality it would almost certainly cause the airline to collapse because it would end up looking somewhat hypocritical.

Virgin used to advertise their long haul fleet with 4 engines because it was apparently deemed safer in the public's opinion, and also 4 engines allowed them to avoid restrictive ETOPS restrictions.

"4 Engines 4 Long Haul" https://www.airlinereporter.com/wp-content/uploads/2013/08/4Engines4LongHaul.jpg

wercat 05 Feb 2020
In reply to annieman:

while on the subject of Boeing, I was in the team that had to amend the BA maintenance programs just before the Y2K work began because the original airframes bought at the end of the 60s had reached 1 million flying hours, bursting the IMS database field that could only hold 999,999 hours for any parts from the airframe down to the smallest serviceable or replaceable part with a service interval or life measured in or keyed to in those flying hours records

But then the aircraft "looks" right.

Post edited at 20:07
wercat 05 Feb 2020
In reply to Michael Hood:

my dad lost a client in that Paris DC10 breakup

Neil Williams 05 Feb 2020
In reply to Northern Star:

Ah, yes, I remember that now.

The funny thing about 2 vs. 4 is that, if you ignore multiple engine failures caused by factors external to the engine where it makes no odds how many you have, if you have 4 engines the chance of a failure is twice if you have 2.  Of course with 4 the impact is lower, but there is always the chance the failure is uncontained and causes other damage e.g. explosive decompression, and because they are smaller a 4 engined jet can maintain altitude on 2 but not 1.  So it doesn't necessarily follow that 4 is better overall, or at least not to the extent that the layman might think.

Post edited at 20:26
IainL 05 Feb 2020
In reply to Neil Williams:

When there was a choice 10 to 20 years ago, most airline pilots on personal flights over oceans would chose 4 engined planes. 3 engines was the least they would fly in. ETOPs with 2 engines was a fudge to allow the 777 to cross the Pacific.

Dave the Rave 05 Feb 2020
In reply to annieman:

You would have to be half mad to get on some tin can with engines and rely in some form on a human that has built these planes. I know a few that construct these planes and wouldn’t rely on them to turn a tap off!

Safe! You believe that? Moo haha

wintertree 05 Feb 2020
Michael Hood 05 Feb 2020
In reply to wercat:

My first agent (contract IT) died in the Manchester plane fire and my accountants  (small family practice) lost a member of staff in the Herald of Free Enterprise tradegy. Someone we knew ended up (by being late I think) unintentionally on the flight after Lockerbie.

These events are actually closer than we realise.

Timmd 05 Feb 2020
In reply to Michael Hood: Statistically speaking one is more likely to be okay than not when travelling by airliner, though, so long as the type certification to operate has been rigorously applied and what have you. It's the safest way to travel of all forms of transport available.  

A relative used to get Aerospace Magazine and was a member of The Royal Aeronautical Society, IIRC they got a society magazine too, and I used to read them and found it very reassuring if I was ever going to fly, behind the scenes there's protocols to allow for human fallibility, so that when somebody works on an aircraft, somebody else checks their work, and somebody else checks the work which has been checked upon. Compared to rail travel and everything else it's incredibly safe. 

Post edited at 23:24
1
Pan Ron 05 Feb 2020
In reply to annieman:

Its perfectly normal for aircraft to be designed in a way that renders them uncontrollable by a human from take-off to landing, with computer controlled interventions dozens of times per second needed to keep them pointed in the right direction.  This has been the case since the 1970s.

The pitch issues of the 737 MAX appear to require better software and sensors. The aircraft itself, regardless of its quirks, appears to be airworthy.

10
teh_mark 06 Feb 2020
In reply to Pan Ron:

Do you have any reference to support that absurd assertion?

Neil Williams 06 Feb 2020
In reply to teh_mark:

It isn't true of passenger aircraft, but it is of some military ones.  Google "relaxed stability".

Rob Parsons 06 Feb 2020
In reply to Pan Ron:

> Its perfectly normal for aircraft to be designed in a way that renders them uncontrollable by a human from take-off to landing ...

For things like fighter jets, absolutely. But, other than the 737 MAX, are there are any aircraft in commercial service which are designed in (or behave in) that way?

wintertree 06 Feb 2020
In reply to Pan Ron:

Anything designed to be “dynamically unstable” requiring computer control for stable flight is small, military and has ejection capability for the meat bags if it all goes wrong.  Airliners should be inherently stable and capable of being flown with direct controll. 

Michael Hood 06 Feb 2020
In reply to Pan Ron:

Fighters are designed to be on the point of being unstable because it allows them to manoeuvre more "tightly".

The way I heard it was to image a ball at the minimum of a y=x^2 curve for commercial aircraft, but a ball at the maximum of a y=-x^2 curve for fighters. Both can be stable but it takes lots of effort (computer control) to keep the fighter at the maximum whereas the commercial plane should naturally fall back to the minimum.

Following on from that, 737 MAX, it's all in the name 😁

teh_mark 06 Feb 2020
In reply to Pan Ron:

And to chuck in to the base points that jet transports shouldn't - and don't - exhibit dynamic instability, the 737 isn't fly-by-wire and doesn't have any of the clever software protections or control laws of the Airbus philosophy of control. The pilot of any 737 of any vintage is physically actuating the control surfaces with every control input. There is no  computer sitting in the middle making invisible corrections other than the autopilot - which only acts when it's engaged, and doesn't do anything like what you imply.

Post edited at 09:21
Neil Williams 06 Feb 2020
In reply to teh_mark:

Indeed.  This specific issue wouldn't occur with an Airbus because the issue would be handled transparently by the fly by wire.  But other issues can and do occur when there are failures relating to the FBW - such as that Air France crash in the Pacific caused by confusion relating to false airspeed readings.

Enty 06 Feb 2020
In reply to adsheff:

> Ryan Air Operate a 100% 737 fleet, and they've ordered hundreds of MAX's.

I didn't know this. Can you clarify that the current fleet are the ok ones and they have ordered the dodgy ones? Or the current fleet are dodgy too and they have ordered more dodgy ones?

E

teh_mark 06 Feb 2020
In reply to Neil Williams:

I still hold the opinion that the ultimate cause of that accident was gross negligence of the crew. At the heart of the matter, a trained crew held an aircraft in a stalled attitude through 40000 of descent until it impacted the ocean. Unreliable airspeed, fatigued crew, startle factor of the autopilot disengaging - I can understand how the upset came to happen, but to fail to recognise the stall and have a complete breakdown of CRM through the subsequent long plummet into terra firma is incompetence of the highest order.

1
teh_mark 06 Feb 2020
In reply to Enty:

The current fleet are all 737NG, and all their orders are for the 737MAX. They seem to have taken the shrewd decision of removing 'MAX' from the branding on the aircraft though...

The MAX is still grounded; no airline in the world is operating revenue flights with them.

Enty 06 Feb 2020
In reply to teh_mark:

So 737NG - good?

737MAX (The ones that they pissed about with) all grounded yet still Ryanair have 100s on order?

E

teh_mark 06 Feb 2020
In reply to Enty:

The NG is the previous generation of 737, and has a good safety record. Last year though, problems with cracking in a critical bit of metalwork (the pickle fork' - which essentially holds the wing to the fuselage) were discovered. I've heard it speculated that the cause is substandard manufacture, which is outsourced form Boeing. As always, Pprune is educational if you can cut through the dross.

https://www.pprune.org/rumours-news/625886-737ngs-have-cracked-pickle-forks-after-finding-several-jets.html

Ryanair currently have 210 MAX on order, according to Wikipedia.

Timmd 06 Feb 2020
In reply to teh_mark:

That's such an interesting thread.

MarkJH 06 Feb 2020
In reply to Rob Parsons:

> For things like fighter jets, absolutely. But, other than the 737 MAX, are there are any aircraft in commercial service which are designed in (or behave in) that way?

All commercial rotary wing aircraft (when hovering at least)?

Rob Parsons 06 Feb 2020
In reply to MarkJH:

> All commercial rotary wing aircraft (when hovering at least)?

Fair point. I don't know anything useful about helicopters and such. Let me rephrase my question as referring to fixed wing aircraft.

MarkJH 06 Feb 2020
In reply to Rob Parsons:

> Fair point. I don't know anything useful about helicopters and such. Let me rephrase my question as referring to fixed wing aircraft.

Probably best. In any case,  I doubt that accident rates in helicopters would help make the case that dynamic instability is fine as a starting point for aircraft design....

cb294 06 Feb 2020
In reply to Bjartur i Sumarhus:

Ryanair in Germany are currently advertising on radio for the upcoming holiday flight season, boosting their "eco credentials" by pointing out that they always fill their planes (trueish, if translated as cancelling half booked flights) and that they have ordered a fleet of modern, fuel saving planes (also trueish, except that they are not allowed to fly them for the foreseeable future....).

I wonder whether these ads will still run once they are allowed take their maxes into service.

CB

teh_mark 06 Feb 2020
In reply to cb294:

They are factually correct: you can't get more environmentally friendly than an aeroplane that never leaves the ground!

MonkeyPuzzle 06 Feb 2020
In reply to Neil Williams:

> Ah, yes, I remember that now.

> The funny thing about 2 vs. 4 is that, if you ignore multiple engine failures caused by factors external to the engine where it makes no odds how many you have, if you have 4 engines the chance of a failure is twice if you have 2.  Of course with 4 the impact is lower, but there is always the chance the failure is uncontained and causes other damage e.g. explosive decompression, and because they are smaller a 4 engined jet can maintain altitude on 2 but not 1.  So it doesn't necessarily follow that 4 is better overall, or at least not to the extent that the layman might think.

So it's not as simple with two engines as thinking Boeing... Boeing... Bong?

Rob Parsons 06 Feb 2020
In reply to Robert Durran:

> As soon as they are cleared to fly. They will probably be the safest plane in the air. Do you really think anyone is going to be taking any chances after what happened?

As a comment on that: it might be out of order, but I can't help thinking that, if the Lion Air and Ethiopian Airlines crashes had occurred in Western Europe, say, rather than in Bongo Bongo Land, the reaction of both the licensing authorities and Boeing might have been a little more speedy. To have one fatal crash is bad; to have two in quick succession is appalling.

Neither Boeing nor the FAA come out of this looking very good. Or, for that matter, very honest. Trust is easy to lose, but it is hard to win.

jkarran 06 Feb 2020
In reply to wintertree:

> Anything designed to be “dynamically unstable” requiring computer control for stable flight is small, military and has ejection capability for the meat bags if it all goes wrong.

Try letting a phugoid oscillation develop hands off in a trimmed DG505, that's supposed to be dynamically stable. After the first two or three humps it's a really wild ride. Straps tight and eyes on the dials!

jk

Post edited at 15:57
GrahamD 06 Feb 2020
In reply to wintertree:

Its a lump of metal being blown through the air - how is that ever going to be construed as 'stable'

4
Neil Williams 06 Feb 2020
In reply to GrahamD:

> Its a lump of metal being blown through the air - how is that ever going to be construed as 'stable'

Because the shape of it makes it so.

IPPurewater 06 Feb 2020
eroica64 06 Feb 2020
In reply to annieman:

Never.

L mondite 06 Feb 2020
In reply to annieman:

Its fixes rather than fix as well. They have just reported finding a new bug and think there has been several others found whilst trying to sort the original one out.

Neil Williams 06 Feb 2020
In reply to mondite:

"737 Max, beta test edition"? :D

L mondite 06 Feb 2020
In reply to Neil Williams:

They did take "move fast and break things" software design philosophy a bit too literally.

wintertree 06 Feb 2020
wercat 07 Feb 2020
In reply to wintertree:

perhaps they aren't using FORTH enough

Naechi 07 Feb 2020
In reply to annieman:

> But when will you be happy to fly on them?

Once the climate emergency is over?

V1nc3nt 07 Feb 2020
In reply to annieman:

https://www.nytimes.com/2020/01/20/business/boeing-737-accidents.html

See the above about a 737 NG crash from 2009 : bad design, irresponsible decisions, cover up... The case is being re-opened, and Boeing announced they will not cooperate.

Very smart. See NYT article and the comments section. 

https://www.nytimes.com/2020/02/06/business/boeing-737-inquiry.html

No 737, any kind. 

Toerag 07 Feb 2020
In reply to cb294:

> Ryanair in Germany are currently advertising on radio for the upcoming holiday flight season, boosting their "eco credentials" by pointing out that they always fill their planes (trueish, if translated as cancelling half booked flights) and that they have ordered a fleet of modern, fuel saving planes (also trueish, except that they are not allowed to fly them for the foreseeable future....).

They've just been banned from running similar ads in the UK as they couldn't prove their claims:-

https://www.bbc.co.uk/news/business-51372780

Toerag 07 Feb 2020
In reply to wintertree:

> More bad news for Boeing QC today...


and this:- https://www.bbc.co.uk/news/business-51407951

Additional wiring problems that could cause short circuits i.e. loss of control or fire.

Toerag 07 Feb 2020
In reply to teh_mark:

> I still hold the opinion that the ultimate cause of that accident was gross negligence of the crew. At the heart of the matter, a trained crew held an aircraft in a stalled attitude through 40000 of descent until it impacted the ocean. Unreliable airspeed, fatigued crew, startle factor of the autopilot disengaging - I can understand how the upset came to happen, but to fail to recognise the stall and have a complete breakdown of CRM through the subsequent long plummet into terra firma is incompetence of the highest order.

How does one recognise the stall when your instruments are telling you you're not stalling?

1
cb294 07 Feb 2020
In reply to Toerag:

Good.

CB

Neil Williams 07 Feb 2020
In reply to Toerag:

> How does one recognise the stall when your instruments are telling you you're not stalling?

Airmanship.  I'm not a pilot, but if you are one you are more likely to have the feel for such things.  Such as the principle that if the nose is pointing up and you are losing altitude rapidly, there just might be something wrong with the instruments.

Post edited at 13:23
1
teh_mark 07 Feb 2020
In reply to Toerag:

Nose high attitude, phenomenal rate of descent, a huge discrepancy between power and pitch attitude.

Or as a poster above put it: airmanship.

Coel Hellier 07 Feb 2020
In reply to Toerag:

> How does one recognise the stall when your instruments are telling you you're not stalling?

If you're referring to the Air France South-Atlantic crash, the instruments *were* indicating stall.  Indeed a "STALL" alarm was blaring out loudly every few seconds continually throughout the episode. 

But, the relatively-inexperienced pilots were in such a confused state that they did not assimilate this information. 

Pan Ron 07 Feb 2020
In reply to teh_mark:

I don't see how that's an absurd assertation.

From about the F16 onward, every military jet has been dynamically unstable.  I suspect the anhedral or variable geometry of the C-5 or B1/F111 likely requires some kind of intervention, and no doubt many other aircraft demand it at different aspects of flight.  Any Airbus is outputting a substantially different set of control surface responses (potentially even the opposite) to what the pilot is commanding and it has been entirely normal for a pilots inputs to be moderated or replaced by computer inputs for decades.  At the extreme end, the X-29 was about as unstable as you could get and it was flyable out-of-the-box.  As commercial aircraft evolve to more efficient and fast, they will almost certainly end up going in the same direction and direct control (even if "direct law") is rare.

It is tried and tested over more than 50 years.  From one aircraft to the next, responses that are deemed appropriate will be inappropriate elsewhere; stick central or stick forward, in-to-spin or central aeleron, power off or on at stall?  Go from a jet and ignore p-factor?  Tail-draggers v nose-wheels?  Does pushing the levers forward on an L1011 produce the same response as a 767? From aircraft to aircraft the appropriate response for one will have you failing to recover in another.

Just because an aircraft requires interventions, even counter-intuitive or automated ones, doesn't mean it isn't airworthy or flawed in its design.  The implementation of measures to resolve it could be poor, or training insufficient, but claiming the MAX isn't airworthy is more tabloid headline stuff.

Pan Ron 07 Feb 2020
In reply to Neil Williams:

> Airmanship.  I'm not a pilot, but if you are one you are more likely to have the feel for such things.  Such as the principle that if the nose is pointing up and you are losing altitude rapidly, there just might be something wrong with the instruments.

At night, or in cloud, you lose those "feelings" though. 

It only takes a few seconds for disorientation to develop and the seat-of-pants sensations you can normally trust instead lead you to believe you are in an entirely different regime of flight than you really are. 

An easy to understand example is in a nose-down turn.  Airspeed is increasing, which you correct by attempting to pitch up.  But because you are in a turn, trying to pitch up increases the rate of turn, and g's and feeling of speed increase, you try to pitch up more, and everything is winding in more....until the wings tear off.  Airmanship might avoid that but its a surprisingly easy situation to get in to and very quickly.

teh_mark 07 Feb 2020
In reply to Pan Ron:

At some point during the long plummit towards the ocean, you'd sincerely hope that the lightbulb moment would happen: 'nose high, TOGA thrust, rapid rate of descent...maybe we're stalled'. I'd like to think that any pilot, with the nose pointing to the sky, the engines working for their lives and the aeroplane falling out of the sky, would recognise that the wing is probably stalled - with or without the ASI. I'd like to think an astute PPL would recognise this, let alone an ATPL who's earned a long-haul right hand seat.

It's a damning indictment of modern training. Clouds don't come into it, night doesn't come into, trouser sensations don't come into it. They had a fully airworthy aircraft with full instrumentation, minus the ASI, and they stalled it into the ocean from 38000'.

teh_mark 07 Feb 2020
In reply to Pan Ron:

It's an absurd assertion because we're not talking about fast jets, we're talking about a civil jet transport that doesn't have a system capable of making 'computer controlled interventions dozens of times per second' even if civil jet transports were designed to be dynamically unstable. Which they're not.

It's a completely irrelevant argument.

Pan Ron 07 Feb 2020
In reply to teh_mark:

> It's an absurd assertion because we're not talking about fast jets, we're talking about a civil jet transport that doesn't have a system capable of making 'computer controlled interventions dozens of times per second' even if civil jet transports were designed to be dynamically unstable. Which they're not.

There is.  Its called MCAS.  

The Air France pilots were of course negligent.  But I'm not sure that is necessarily the result of modern training.  If anything, modern training better enables pilots to simulate and deal with confusing incidents such as static pressure, aoa or pitot-tube malfunctions.  Even the best old-fashioned stick and rudder pilot could get thrown in IMC by the sorts of indications they were presented with.  It's not good, and its fortunately rare, but there is plenty of room for it.  Aircraft used to crash for myriad reasons by exactly these pilots.  It's more that it has become so rare, and technology so much better, that pilot error has become much more apparent.

It's noteworthy though that you seem to blame the pilots in the Air France for misreading the flight conditions.  But when something akin to a run-away trim condition results in a crash, this points more towards the MAX not being airworthy by design.  That doesn't seem particularly fair.  Having spent dozens of hours in Boeing cockpits, it's pretty difficult to ignore the clacking trim wheel and spinning white line.  On two occasions the pilots appear to be as guilty of 

1
Rob Parsons 07 Feb 2020
In reply to Pan Ron:

> There is.  Its called MCAS.  

Sure. But MCAS is where this entire conversation started.

Is there anything similar in any existing commercial aircraft, so far as you know?

MarkJH 07 Feb 2020
In reply to Rob Parsons:

> Sure. But MCAS is where this entire conversation started.

> Is there anything similar in any existing commercial aircraft, so far as you know?

Don't many T-tail aircraft (or other aircraft with poor stall recovery characteristics) have stick pushers linked to the AoA sensor?  It seems that Boeing's MCAS is a similar (but poorly designed) system.

rlrs 07 Feb 2020
In reply to annieman:

Someone name-checked the phugoid mode above. More info on this and other dynamic modes here:

https://en.wikipedia.org/wiki/Aircraft_dynamic_modes

There are five modes, divided between longitudinal (two) and lateral-directional (three).

Learn even more about aircraft stability and control by signing up for this handy course that includes an aircraft stability and control module:

https://www.cranfield.ac.uk/courses/taught/avd-option-aircraft-design

Fascinating topic.

Pan Ron 08 Feb 2020
In reply to Rob Parsons:

It really depends on what you are willing to consider interventions.  As above, stick-pushers are common.  T-tail blanking, or tail mounted engine pitching behaviour is hardly considered a design flaw, despite potentially catastrophic results.  I'm struggling to think of others but that's probably because they are so normal as to be unremarkable.  A 747, and probably a great many others, will (for instance) link reduced outboard aileron deflection to increasing mach number.  Without which regular pilot inputs become dangerous.  Likewise, I'd not be surprised if some manufacturers added automatic pitch correction/slat movement with flap deflection, purely on account of undesirable characteristics.  Yaw dampers.  Elevator or aileron horns if susceptible to flutter.  All kinds of aircraft can exhibit horrible flight characteristics at trim, CoG, or mach numbers that would be unremarkable in others, and you could even consider unique icing characteristics (ATRs?) as a unique design flaw.  Even undercarriage position can dramatically change behaviour and those well practiced coordinated turns with a bootfull of rudder on your cessna are million miles away from yoke-only turns on an airliner.

Basically, every aircraft type is unique and operations manuals for one might give procedures that are the opposite of another.       

Rob Parsons 08 Feb 2020
In reply to MarkJH:

> Don't many T-tail aircraft (or other aircraft with poor stall recovery characteristics) have stick pushers linked to the AoA sensor?  It seems that Boeing's MCAS is a similar (but poorly designed) system.

Yes - that does seem like a fair statement.

In reply to annieman:

I ran a research project for the USAF looking at stabilising the F16 if it loses control surfaces or associated actuation. This is extreme, but we showed that it is achievable even in such an inherently unstable platform. The 737 Max is certainly stabilisable in a robust way. Would I fly one any time soon? No way. It’s not a question of whether it can be made safe. The problem is Boeing allowing profit to become a metric in the design process and push through software and procedures in safety critical procedures which aren’t robust. It’s not the plane, it’s the manufacturer and the associated industry regulators.

wintertree 08 Feb 2020
In reply to paul__in_sheffield:

> it’s the manufacturer and the associated industry regulators.

Yes.  The regulators aren’t getting nearly enough of the blame here.  The commonalities with some of the Starliner problems more then hint at major structural issues in the company.  
 


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