Civil Aviation Development & Discussion

[hgupta]

Good this makes it much easier to ban MAX planes from ever flying in or over India.

[chetak]

After what happened to the Max and the lives lost, I'd rather take "stupid" regulators who forces safety regulations down the throats of all these cowboys. Lazy jokers wrecked the lives of countless families and are acting arrogant with regulators despite the catastrophe they were responsible for.

nothing stopped our guys from including a simulator training stint for the MAX.

This matter is entirely under the purview of the national regulator if it so desires.

Also, they had the same information available to other regulators and would have set a trail blazing path had they enforced and mandated a sim training stint.

IIRC, two ameriki operators of the MAX seem to have worked out their own solution to the MAX problem, despite the inactivity of the FAA, by having some set procedures of their own in place for the MAX

[chetak]

Good this makes it much easier to ban MAX planes from ever flying in or over India.

there is too much to lose for the amerikis, in terms of national pride, market share as well as their own eminent role in the global aviation industry.

in due course, they will whitewash the whole thing and work out a via media solution which will then be subtly pushed by the GOTUS

[Kartik]

After what happened to the Max and the lives lost, I'd rather take "stupid" regulators who forces safety regulations down the throats of all these cowboys. Lazy jokers wrecked the lives of countless families and are acting arrogant with regulators despite the catastrophe they were responsible for.

My 2 cents since I won't go into this topic in too much more details. Believe me, the engineering at Boeing is top class. Every time I am in the factories in Renton or Everett, I'm amazed. There has however been a dramatic change in the way the management works over the past decade. The competition with Airbus is what defines everything - and by that I mean timeline and cost. It is ALL about timelines and somehow bringing a business case for making an airline not switch from Boeing to Airbus and if possible, switch from Airbus to Boeing. It means that if you can extract any $ advantage out of not forcing airlines to send pilots to simulators even for a day (it costs a HECK of a lot in sim costs, lost productivity, hotel costs, per diem, you name it) in Miami, Gatwick, Singapore, Brisbane or Moscow, then marketing and sales will push for that. Pushing for 2 hour CBT versus a sim check brought about $ savings that were pitched to airlines to make them move in favor of the 737MAX. Anything that went against that - and MCAS did, was brushed under the carpet.

That is a management decision, not an engineering decision. Jokers who come from other industries (I have worked with a couple of managers with prior experience in other software firms but not aerospace who were absolutely hopeless and understood NOTHING about the domain they were working in) and brought the combative and every pushy culture and mindset of those organisations into Boeing.

[Kartik]

nothing stopped our guys from including a simulator training stint for the MAX.

This matter is entirely under the purview of the national regulator if it so desires.

Also, they had the same information available to other regulators and would have set a trail blazing path had they enforced and mandated a sim training stint.

IIRC, two ameriki operators of the MAX seem to have worked out their own solution to the MAX problem, despite the inactivity of the FAA, by having some set procedures of their own in place for the MAX

FAA itself was duped into accepting the requirement for no sim training and you're expecting the DGCA to catch this?

Even if they went through it with a fine toothed comb they wouldn't have realised what was going on and I don't expect DGCA to do that since pretty much everyone has now ceded authority to FAA or EASA. Both those bodies have the funding (actually they are under-funded but still) to take on the monumental task of going through with a fine toothed comb over all the hundreds of thousands and thousands of pages of documents that'll be produced for each program. FAA still can't manage it because the task is too huge.

[Kartik]

Good this makes it much easier to ban MAX planes from ever flying in or over India.

which is an absurd and completely stupid solution to a problem that has a fix. FAA will certify it, mandate sim training and things will go on.

What next? Ban all cars that don't have airbags because occupants will definitely not survive a 70 kmph head on collision or roll over? Ban all trucks because they're death traps with zero occupant safety features?

[hgupta]

Sorry I don’t trust the MAX design. It is inherently unstable due to a flawed design. I would not fly in a MAX plane or allow my family to fly those kind of planes. Nope.

[chetak]

this a hole has been de rostered pending the inquiry.

twitter

@IndiGo6E Your captain on 6E 806 from Chennai to Bangalore on January 13 Jayakrishna harrased, threatened and prevented me and my 75-year old diabetic mom from disembarking the flight and threatened to arrest us because we asked for wheelchair assistance.

12:15 PM - 13 Jan 2020

[Avtar Singh]

Ralph Nader excoriates new boeing boss, his niece died in one of the crashes...
----new boss is part of the problem
----many years in ge where he learnt severe cost cutting from welch... ge hollowed out
(embarrassing for cnbc droid because they love welch)
----calhoun has no qualifications to turn boeing around
----ELEVATE ENGINEERS TO DECISION MAKING RATHER THAN FINANCIERS

https://www.youtube.com/watch?v=L_1DzryaMAY

737 max has certainly turned the anti-airbus maxim on its head ===>>>
"if its boeing I aint going"

also the americans had certified the 777 to fly without standby instruments.
because the new wonderful systems are so reliable!!!
====>>>> greedy money grabbing american corpses
the uk CAA (civil aviation authority) told them you had better install
standby instruments or it is not flying

god bless america

[Raveen]

Ralph Nader excoriates new boeing boss, his niece died in one of the crashes...
----new boss is part of the problem
----many years in ge where he learnt severe cost cutting from welch... ge hollowed out
(embarrassing for cnbc droid because they love welch)
----calhoun has no qualifications to turn boeing around
----ELEVATE ENGINEERS TO DECISION MAKING RATHER THAN FINANCIERS

https://www.youtube.com/watch?v=L_1DzryaMAY

737 max has certainly turned the anti-airbus maxim on its head ===>>>
"if its boeing I aint going"

also the americans had certified the 777 to fly without standby instruments.
because the new wonderful systems are so reliable!!!
====>>>> greedy money grabbing american corpses
the uk CAA (civil aviation authority) told them you had better install
standby instruments or it is not flying

god bless america

Airbus has its share of crashes and deaths due to screwy engineering too - remember the pilot whose son killed everyone by triggering a software bug on a A320 iirc?

[jaysimha]

https://www.wings-india.in/

Wings India 2020

March 12-15,2020, Begumpet Airport, Hyderabad, India

[Rony]

Interesting points

Why is Air India always in loss ?

https://www.quora.com/Why-is-Air-India- ... -Singh-820

[Rishi_Tri]

Interesting points

Why is Air India always in loss ?

https://www.quora.com/Why-is-Air-India- ... -Singh-820

Points and arguments are superficial.
- Delhi experiment with private buses - I am sure people shall recall that private Red Line buses were banned after it resulted in veritable war on Delhi roads among operators, not to mention numerous people killed on roads by killer drivers / buses. Were eventually replaced with Blue Line buses and even those replaced by buses run under DTC. BTW, having commuted in my student days in those buses, the DTC buses were not empty.
- Air India Load Factor - My experience and those of many others that I know, the Air India flights Internationally and Domestically are jam packed. Demise of Jet Airways and international direct flights from India to rest of the world has placed Air India in much better position. I can support by photographs that on International routes Air India flights are cleaner, better than almost all Gulf Carriers. In my opinion only a couple of European airlines are better than AI, otherwise AI is way better.
-Air India Operations - If the powers be are serious, they shall seek operational excellence. Turnaround times, aircraft availability, route rationalization, resource allocation, services for other airlines and so on. Operations make or break a services business.
-Employee and Finance Costs - Employees should be well compensated. Question is how do you get the most out of the employee / pilot base? As to finance costs, refinance if the opportunity is there.

More than anything else, Air India can be profitable but question is - are the powers be serious about Air India? I guess not. Aviation has been huge missed opportunity of the last decade and Air India's problems are symptomatic of that.

[Rishi_Tri]

https://www.livemint.com/companies/news ... 45855.html

Air India trims losses by 40% in run-up to disinvestment
24 Jan 2020, 11:49 PM IST - Rhik Kundu

New Delhi: Air India Ltd narrowed its operational losses between April and December by over 40%, ahead of the planned sale of the state-run carrier, which is expected to kick off next week, two senior airline officials said on Friday.

The reduction in losses was the outcome of a lower interest burden after half of Air India’s debt was transferred to a Special Purpose Vehicle (SPV), as well as better operational performance, one of the officials said.

Operational losses in the April-December 2019 period stood at ₹1,045 crore, down from ₹1,960 crore in the same period of the previous year, the first official said.

“The airline earlier spent close to ₹4,000-4,500 crore a year for servicing its debt. This figure has now come down to ₹1,400-1,500 crore after a large chunk of the airline’s debt was moved into an SPV last year," said the second official mentioned above.

Meanwhile, Air India’s overall passenger yield, or revenue earned per kilometre, rose by about 6.7% during the comparative nine month period, the first official added.

Air India, which had a 12.7% share of the domestic market, carried 18.36 million domestic passengers in 2019, according to data from the Directorate General of Civil Aviation. The national carrier had ferried 17.61 million passengers in 2018.

In February 2019, the central government set up Air India Assets Holding Ltd to park accumulated working capital loans not backed by any asset, standing at about ₹29,464 crore, four subsidiaries, non-core assets such as paintings and artefacts, land bank, and other non-operational assets. The Centre plans to sell these assets.

Air India’s accumulated losses in the past decade stood at about ₹69,575.64 crore, aviation minister Hardeep Singh Puri had told Parliament in December.

The national carrier posted a provisional net loss of ₹8,556.35 crore in FY19, against a net loss of ₹5,348.18 crore in the previous fiscal.
The Centre hopes to divest its entire stake in the New Delhi-based carrier after failing to offload a 76% stake last year.

[chetak]

The Sikorsky S-76B (N72EX) helicopter he was a passenger in was owned by him






KOBE BRYANT, DAUGHTER GIGI DIE IN HELICOPTER CRASH ...

[Raveen]

Interesting points

I can support by photographs that on International routes Air India flights are cleaner, better than almost all Gulf Carriers. In my opinion only a couple of European airlines are better than AI, otherwise AI is way better.

No way are the racist EU based carriers any better than the Gulf based ones. Year after year they are trumped in every rating by the Asian carriers.

[nachiket]

FAA itself was duped into accepting the requirement for no sim training and you're expecting the DGCA to catch this?

The FAA has had an incestuous relationship with US aircraft manufacturers for a long time. That basically means Boeing now but in the past it included McD etc. Recall their royal fk-up back in the 70's with the DC-10 cargo door design flaw which led to the Turkish Airlines crash and loss of 300+ lives even after the NTSB had already identified the issue in a previous incident.

The FAA has not learnt from their past mistakes. The reason modern civil aviation is so safe is thanks to high safety standards (and a safety "culture") by the manufacturers themselves and the efforts of crash investigators to do rigorous RCA after incidents (all incidents, not just crashes). But as you mentioned the management changes at Boeing have ended up indirectly harming the safety culture there and the FAA is completely useless in catching that. Their stubborn reluctance to even ground the MAX fleet after the second crash was horrifying to say the least.

[chetak]

x posted from the political thread


Comedian Kunal Kamra heckling Arnab Goswami in an indigo airlines flight

kamra has been suspended for six months from flying indigo

Hardeep Singh Puri, the Aviation minister is telling other airlines to suspend kamra for six months as well

Good show

Hardeep Singh Puri Verified account @HardeepSPuri

MoreHardeep Singh Puri Retweeted IndiGo
Offensive behaviour designed to provoke & create disturbance inside an aircraft is absolutely unacceptable & endangers safety of air travellers.

We are left with no option but to advise other airlines to impose similar restrictions on the person concerned.

IndiGo Verified account @IndiGo6E

@MoCA_GoI @HardeepSPuri In light of the recent incident on board 6E 5317 from Mumbai to Lucknow, we wish to inform that we are suspending Mr. Kunal Kamra from flying with IndiGo for a period of six months, as his conduct onboard was unacceptable behaviour. 1/2

7:19 am - 28 Jan 2020

https://www.youtube.com/watch?v=JesYAfYUGsA




Comedian Kunal Kamra heckling Arnab Goswami in aeroplane

[SriKumar]

Jokers who come from other industries (I have worked with a couple of managers with prior experience in other software firms but not aerospace who were absolutely hopeless and understood NOTHING about the domain they were working in) and brought the combative and every pushy culture and mindset of those organisations into Boeing.

Two questions: How were these guys even hired in the first place? How come co-workers did not see through their ignorance after a month or two in the job? Usually a couple of months is enough to figure out whether they have any real knowledge or not.

[sudarshan]

Good this makes it much easier to ban MAX planes from ever flying in or over India.

which is an absurd and completely stupid solution to a problem that has a fix. FAA will certify it, mandate sim training and things will go on.

What next? Ban all cars that don't have airbags because occupants will definitely not survive a 70 kmph head on collision or roll over? Ban all trucks because they're death traps with zero occupant safety features?

No no, this is not about safety features. Safety features address those things which the manufacturer can't control, such as an accident or roll-over. In the case of the MAX, the manufacturer deliberately tweaked the design to be inherently unstable. This was done (so far as I can tell) to generate fuel savings .

What was that inherent instability? The fact that the center of gravity of the aircraft is shifted significantly enough from the center of lift (wings), that, left to itself, the aircraft has an irrepressible tendency to pitch forward - and eventually land on its nose. Ever made a paper airplane and threw it, only to watch it pitch forward on its nose? I always mentally went *OuCH* when that happened. So to compensate for this inherent instability, the manufacturers used software to keep pushing the nose up! On top of that, the wings themselves were made narrower (and longer I think), again in the interest of some few percentage points of fuel savings.

For the aircraft which crashed - so far as we can tell - the software kept trying to push the nose up. When the angle gets too steep, the aircraft will go into a stall, i.e., the wings will fail to generate lift, and the whole contraption behaves like a block of concrete rather than a flying machine. Every pilot DREADS a wing stall. Recovering from one of those will take a miracle. So the pilots had to keep fighting with the software, trying to push the nose down, and the software panicked and overcompensated. There was no way to turn off that software feature, or if there was, the pilots weren't trained enough to know how to do it. Totally predictable end result (except, apparently, for the Boeing management ).

No safety feature is going to address this. The solution is to junk the aircraft and start afresh - the design is flawed to begin with, I for one am not going to trust any software patch added on top of this flawed design. Even if the pilots are given full control (disabling the software compensation), they will have to be eternally alert, watching the aircraft's nose (so to speak) - no taking breaks or trusting the auto-pilot. Basically, the pilots will have to take over the role of stabilization of the aircraft from the software. It's like driving a car which is deliberately designed to have higher thrust on the left wheel over the right (in the interest of fuel savings), so the car keeps turning to the right, unless somebody or some software is constantly jerking the steering wheel *just enough* to compensate. Over-compensate, and the results are equally disastrous. On top of that - have software to compensate, have that software malfunction, have the driver panic and try to jerk back the steering wheel, with no way to turn off the software - and you have the recipe for D-I-S-A-S-T-E-R right there. This is no longer about air bags or seat belts. It's madness to get into such a car.

EDIT: Saw your point about sim training - are you suggesting that this is a fix for the problem? Let me put it this way. Take the example of the car above, deliberately designed to thrust one wheel more than the other, thus having an inherent tendency to turn, and having added software to compensate for this tendency by tweaking the steering wheel. The software has to do this at any speed, whether on a Chennai road at 3 km/day, or on a highway at 100+ km/hr. The problem will occur when the software overcompensates for any reason. The problem could also be initiated by any bump on the road, sudden fuel injector malfunction, bird hit, or whatever - basically any transient instability - this will have to be taken into account by the software, which eventually has to overcome the transient instability (and thus restore the inherent instability and continue compensating for it!).

Now, if the manufacturer offers additional driver-training as a fix for the potential problem of software overcompensation for the inherent instability, what should the regulator do? Certify the car, or not?

[SriKumar]

^^^ As far as I can recall the software was designed to push the nose down and not up. If it sensed a stall- which is what happened in both cases due to faulty AoA sensors, the nose would be pointed down and the engines accelerated ( to generate speed, and therefore lift, in an attempt to recover from a stall). Did not google this to confirm.

HOwever, yes the engines pushed forward relative to wings meant that the C.G. is forward, meaning default configuration pitched the nose down ( by how much, I dont know). I can understand this within the context of fighter aircraft which are deliberately made unstable, but not sure if this concept has ever been applied to large commercial aircraft.

[UlanBatori]

Why Air India is the best airline in the world (cross-posted from the OT Education dhaga)

Slightly OT but IMO, not OT: this is the result of the Indian Education System.

I asked Air India's Flying Returns to please change my email address from an official work address to a gmail. They responded within 24 hours! AWESOME or what? Here is the response:

Flying Returns <donotreply@loyaltyplus.aero>
KYC documents uploaded by you have been verified to match details on your profile.
Incase the name on your Flying Returns-FFP profile was different than that on the passport or photo ID uploaded by you, same has been corrected and updated.
Now you can avail the benefits of Flying Returns Program.

And then came this:

From CHGMYREGD FFPEMAIL <chgmyregdffpemail@airindia.in>

Dear Member,

As your Email OTP has been verified by you, a service fee will be charged.

The fee for changing the registered unique Email for the first time will be 420 FR points with each subsequent change
invoking an increase of 1000 points to the last charged penalty making the charges as follows-
> 1st change of Unique Registered Mobile Number or E-mail ID @ 420 FR Points.
> 2nd change of Unique Registered Mobile Number or E-mail ID @ 1420 FR Points.
> 3rd change of Unique Registered Mobile Number or E-mail ID @ 2420 FR Points.
> 4th change of Unique Registered Mobile Number or E-mail ID @ 3420 FR Points and so on.
If you agree to pay the service fee, kindly write a request on the self-attested copy of your passport. In the request kindly mention the following-
1) Name and Nine Digit FFP Number
2) Existing Registered Email ID
3) Existing Registered Mobile Number
4) New Email ID with the relevant reason for the change
5) Assurance cum Undertaking not to seek a change of Email in next six months
6) Approval for charging the Service fee
7) Date of Request
The Request should be sent from the Email id that needs to be updated.
For further clarification about the request refer to the following link:
http://www.airindia.in/images/pdf/Q-1-A ... k-Here.pdf

If the change of email is from official to personal, then kindly mention this in your request. If your request is found legible then no service fee will be charged.

Regards,
Team FFP
Air India

IOW, instead of spending 5 seconds changing the email in their records, they send me that and ask me to Fill Out This Form With Self-Attested That and This other and pay them - and UNDERTAKE NOT TO REQUEST ANOTHER EMAIL CHANGE FOR SIX MONTHS BECAUSE THAT MIGHT CREATE MORE WORK FOR THEM.

5) Assurance cum Undertaking not to seek a change of Email in next six months

Unfortunately if I send that Steel Wire Salute they will probably get the Honnorabal Mantri to ban me and get other airlines to ban me, so it is better to just let their junk mail go to my old address.

[sudarshan]

^^^ As far as I can recall the software was designed to push the nose down and not up. If it sensed a stall- which is what happened in both cases due to faulty AoA sensors, the nose would be pointed down and the engines accelerated ( to generate speed, and therefore lift, in an attempt to recover from a stall). Did not google this to confirm.

HOwever, yes the engines pushed forward relative to wings meant that the C.G. is forward, meaning default configuration pitched the nose down ( by how much, I dont know). I can understand this within the context of fighter aircraft which are deliberately made unstable, but not sure if this concept has ever been applied to large commercial aircraft.

I think you're right, something else was keeping the nose up, and the software was designed to prevent stall. So the pilots were fighting to keep the aircraft from a crash landing on its nose. Same end result, however.

Fighter aircraft generate thrust from the jet action of the exhaust itself, and in addition, can take advantage of thrust vectoring. Commercial aircraft have those huge fans (turbofan engines) to generate the thrust. Kind of like the flight characteristics of an eagle or falcon, vs. a duck or goose. The pilots of fighter aircraft are trained to take those high-g forces. Can't do that on a commercial craft. Just pointing out, I'm sure you're aware of all that.

[Dileep]

^^^ As far as I can recall the software was designed to push the nose down and not up. If it sensed a stall- which is what happened in both cases due to faulty AoA sensors, the nose would be pointed down and the engines accelerated ( to generate speed, and therefore lift, in an attempt to recover from a stall). Did not google this to confirm.

HOwever, yes the engines pushed forward relative to wings meant that the C.G. is forward, meaning default configuration pitched the nose down ( by how much, I dont know). I can understand this within the context of fighter aircraft which are deliberately made unstable, but not sure if this concept has ever been applied to large commercial aircraft.

What happened was, the engines were moved forward and up. There was no issue of balance. There is no need to be, since weight can always be rearranged. The problem was, the thrust vector now acts at a point farther than the CG, and hence induce a pitch-up moment. More the thrust, like takeoff run, more the pitch-up. This becomes a problem when the AoA is on the higher side. If the air is humid, it becomes worse, since lift is higher. There is a possibility for uncontrolled pitch-up in certain cases.

The cheap solution was to add the pitch-down trim movement when AoA is high and engine thrust is high etc etc. The first problem was, there was only one AoA sense input. The second problem was there is no way to turn that off.

So, the software took over and added pitch-down trim, which the pilots could not override.

The best solution was to re-design the whole thing, but that will need pilot training that cost money. They tried to follow Airbus. Same plane-Same way to fly onlee. And people died.

[chetak]

Apparently, the CAS didn't kick in if the flaps were extended.

[nachiket]

Dileep it was worse than that. The worst thing they did in this entire sordid saga was that they did not tell the pilots that the MCAS had been added and what it was supposed to be doing. And they did not mandate any additional training. 737NG pilots who had to transition to the MAX had to literally do a training course on their iPads and they were done! The only reason Boeing did not mandate simulator training despite the changes was to be able to advertise that airlines could switch from the NG to the MAX without spending money on training. It would give them an advantage over Airbus in the market.

It only cost 300 lives.

[UlanBatori]

How does moving engine up produce nose-up moment, pls? I assume the engine thrust line on a 737 is located below the c.g. Such increasing thrust increases nose-up moment, I can understand that. If they moved the engine upwards (did they?) it would have reduced the nose-up moment. Confusing. No wonder the software was also confused.
What I read was that it went into an extreme yo-yo, like "Phugoid". I thought that was some kind of feedback time lag problem that caused a divergence.
The decision on cutting training cost must have been made at pretty high level. Goes completely against Boeing historic culture: Maybe they hired Airboos managers.

[nachiket]

UB saar, refer to Kartik's comment above about the new mgmt at Boeing.

[UlanBatori]

BTW, sudarshanji, definition of inherent instability may be slightly different. A plane is More Stable when the CG is forward of the center of pressure. IOW, single-engine WW1 plane. Unstable is when the c.g. is aft of center of pressure.

Stability is in the response to an inadvertent disturbance. If cg is forward, and it say, angle of attack increases, then lift increases, the wing pushed up, and nose goes down, reducing lift. Back to original. So when properly trimmed (by adjusting the tail elevator pitch setting), one can take one's hands off the 'stick' and the plane will fly itself on a steady path. This is done in cruise and even on approach to landing.

Baron Ludwig von Richtofen's plane is supposed to have landed by itself, after he had been shot through the head. (source: Ripley's Believe it Or Not, but quite plausible).

If OTOH, cg is aft of center of pressure, then if angle of attack goes up (nose pitches up), lift goes up, so wing pushes up, so angle of attack keeps rising. This is what happens to your paper airplane. The nose-down dive comes AFTER that, when the angle of attack passes stall, so lift suddeny comes down and nose falls down to negative angle of attack - and that keeps getting more negative. Gravity does the rest.

So on most airplanes, the lift on the tail is used to compensate for small changes in weight distribution. Ideally trimmed, tail should produce zero lift or maybe a slight positive. But at takeoff, the lift the tail is probably negative since it is trying in pitch the nose up.

I don't know what happened in the MAX change. I heard that for some reason, in the new design the bottom of the engine came too close to the ground, so they put in software to ensure that it did not hit the ground - during either takeoff or landing, I don't remember. Maybe pushing the engine forward was to ensure no ground strike during landing (attitude is nose-up).

The main complaint I read is that the thing bucked up and down and was impossible to control once it went into that mode. That sounds like "pilot-induced instability" where what the pilot does is exactly 180 degrees out of phase with what should have been done... not that I am faulting the pilots. This would happen if the software had the wrong delay set, too.
Fighter planes used to struggle with "pilot-induced Wing Rock" for similar reasons. The thing to remember is that the stall occurs with some significant delay after the angle of attack reaches stall... and does not recover from stall until angle of attack has gone well BELOW stalling angle. If the programming is done by ppl taught by Excellent Teachers, they would have no ****ing clue of such things.

[UlanBatori]

UB saar, refer to Kartik's comment above about the new mgmt at Boeing.

Right on target.
Boeing used to advertise that it had two Parallel and Equal Tracks: Technical and Mgmt. So in theory, Tech Fellow == VP. But there is an important difference. It is the Manager who is responsible for the product's budget, costs, schedule etc. So she must balance the risk that the TF and the engineers cite, against the cost. EZ to make cheap shots in ignorance so I won't claim to know what happened in this case - but there is enough indication that the problem was detected in simulators - but pilots were not trained to deal with it.

If you went in with the standard understanding and pilot-reaction, you would automatically push the nose down and increase the thrust if you felt stall approaching. I don't think anyone passes the first student pilot checkride without that basic instinct being evident. But if there was a phase lag involved in the software then this would induce divergent oscillations - and you would have nooooo idea what was going on until it was way too late.

BTW, they should re-open the investigation on that Airboos that went down off Brazil. The verdict that the plane stalled and fell down from 30K feet with two career jet pilots at the controls - due to "pilot error", was always beyond laughable. Similar thing killed an Ethiopian (and was SilkAir Airboos or Boeing?) I think Airboos covered up that software glitch and must be grinning now.

[nachiket]

I don't know what happened in the MAX change. I heard that for some reason, in the new design the bottom of the engine came too close to the ground, so they put in software to ensure that it did not hit the ground - during either takeoff or landing, I don't remember. Maybe pushing the engine forward was to ensure no ground strike during landing (attitude is nose-up).

The core issue is that the 737 is a 1960's design with a fuselage not very different from the even older 727. Back then not all small airports had air-stairs and the 737 was supposed to operate from these airports. That is one of the reason the fuselage sits so close to the ground (so that an inbuilt airstair could be included if necessary). Also the 727 had its engines on its tail instead of under wings so it did not need ground clearance.

Boeing has always used innovative techniques to somehow fit larger engines on the 737 over the decades. The Classic and NG had engines with distinctive triangular like intakes for this very reason.
The latest tactic was to lengthen the nose gear and change the engine position which required the MCAS to be added to compensate for the extra pitch up movement which the engines now caused.

The Airbus A320 does not have much of a problem because it is a 1980's design with enough ground clearance built in for fitting larger engines.

The main complaint I read is that the thing bucked up and down and was impossible to control once it went into that mode. That sounds like "pilot-induced instability" where what the pilot does is exactly 180 degrees out of phase with what should have been done... not that I am faulting the pilots. This would happen if the software had the wrong delay set, too.

The problem started not because of a software flaw but a faulty AoA sensor feeding garbage data to the software. They hadn't built the system to take inputs from 2 independent sensors and validate the readings. So the MCAS kept thinking the aircraft is pitching up too much even when it wasn't.

[UlanBatori]

I classify faulty sensor with faulty software: the software should have asked whether the sensor was kaput, and given control to the pilots like my Continuous Glucose Monitoring device saying that it does not believe the Glucose reading (only I know how many gulab jamuns I ate..).

Also sucha critical "sensor" should be checking itself frequently to see if is making sense.

The other thing is about these basic sensors. The Airboos Brazil crash was blamed on a Pitot tube or Static pressure tube icing and getting blocked so that the pilots thought (REALLY?) that the plane was either too low or too high etc. Impossible: they would sense from the engine thrust that they could not be so slow or low.

There **HAVE** to be other instruments to use in every cockpit these days. GPS altimeter? Differential GPS for speed? For angle of attack: how can that be high or low if the plane floor is basically level and you don't feel yourself levitating?

So I claim that every airline pilot will have all those senses built-in. They are ALWAYS terrified of the automatic gizmos.

IOW it **WAS** idiotic to allow a half-assed bit of software into the system, that could not deal with one faulty sensor. It should have said: "take over, I can't deal with this" if they were too cheap to provide backup sensors. Here the clear case is that the automatic something was fighting the pilots - and allowed to win. Airboos design philosophy, contaminating traditional Boeing caution.

The classic story that I have heard is of a Boeing airliner that suffered heavy damage. The entire hydraulic system running along the bottom of the fuselage to the tails, went kaput due to the damage. They should all have died. Except that there was a completely redundant hydraulic line running along the TOP of the fuselage for exactly that eventuality.
Trouble is that today's managers are allowed to override that "extravagance".

[nachiket]

UB saar, it gets worse. Check this:

https://www.extremetech.com/extreme/288 ... -as-extras

...new information indicates that Boeing sells upgrades to critical flight systems that might have improved their overall safety — but it sells them as value-added profit centers in much the same way you might add a stereo option to a car.

Boeing sells two MCAS upgrades that weren’t installed on either the Lion Air jet or the Ethiopian Airlines craft, according to the New York Times. The first is the ability to compare data from more than one AOA sensor via a display that would have shown readings from both at the same time. The second was a ‘disagree light’ that would have activated when contradictory data was being received from both sensors. Either might have alerted the pilots that something was wrong with the MCAS system specifically.

The secondary AoA sensor is sold as an extra! This definitely came out of the mind of a YumBeeYay finance stratagee type trying to squeeze every last penny out of customers. I can't imagine a Boeing engineer NOT asking for a redundant sensor to be included for such a critical system.

[UlanBatori]

Not only that, it is a US auto-dealership style, not even a decent Japanese style. Life-critical systems should **NEVER*** be "add-ons" as in

Oh! Our NEW IMPROVED standard system might go berskerk and kill all your passengers. But if you don't for some strange reason want that, you can buy our Extra Special Kit for a cool $20M per plane. Plus $10M for training your pilots.

I see why GE got rid of the turkey who became Boeing chief. GE has had a long history of recruiting ABSOLUTE oiseules to top positions. No wonder their stock has tanked, now this jeenius is driving Boeing stock the same way.
I remember driving in heavy fog on a winding mountain road in Ulan Bator in a Honda Accord. The tail brake light warning indicator came on red on the dashboard. That was pretty critical in those conditions, so I pulled over and checked: no evident problem: both sides taillight and brake light lamps were working. The warning light did not go out.
Eventually I checked thoroughly. I turned out that each brake lamp had TWO lamps - for redundancy! One quit, the warning came on, but the other had taken over automatically. Nowhere in the manual was this advertised; no gloating in TV ads, no salesman mentioned this. Just quiet, REAL care for the customer!!
Imagine that in a US car. .. I don't know about Indian. We expected these sorts of things in the aerospace industry/airline/professions. We sneered at Airboos. But now Boeing has "caught up" with Airboos.
I guess Boeing stock will shoot up. Same corporate ethics as Goldman-Sachs.

[chetak]

UB saar, it gets worse. Check this:

https://www.extremetech.com/extreme/288 ... -as-extras

...new information indicates that Boeing sells upgrades to critical flight systems that might have improved their overall safety — but it sells them as value-added profit centers in much the same way you might add a stereo option to a car.

Boeing sells two MCAS upgrades that weren’t installed on either the Lion Air jet or the Ethiopian Airlines craft, according to the New York Times. The first is the ability to compare data from more than one AOA sensor via a display that would have shown readings from both at the same time. The second was a ‘disagree light’ that would have activated when contradictory data was being received from both sensors. Either might have alerted the pilots that something was wrong with the MCAS system specifically.

The secondary AoA sensor is sold as an extra! This definitely came out of the mind of a YumBeeYay finance stratagee type trying to squeeze every last penny out of customers. I can't imagine a Boeing engineer NOT asking for a redundant sensor to be included for such a critical system.

It is a basic fact of aviation design that flight critical systems do not have a single point of failure mode but have built in redundancies to avoid this.

The stock boeing 737 has 2 AOAs but it was wantonly disabled on the MAX thereby converting it into a single point of failure mode.

In the overall scheme of things, the cost of an additional AOA + comparator would be mere peanuts.

whichever idiot designer who did this and whoever signed off on it, both need to be first shot and then hung from the same lamp post.

[nachiket]

The designers and engineers won't be the ones making this decision. This is above their pay grade.

[chetak]

The designers and engineers won't be the ones making this decision. This is above their pay grade.

this is a flight critical system saar. A bit different from safety critical systems.

there is no pay grade bar on flight critical systems, or even any system for that matter.

Every aviation company has anonymous systems in place to report such stupidity and such reportings have to mandatorily reach the top.

Anyone from boeing could have even written or informed the FAA directly and also anonymously as well.

No one had the leeway to do what was done and the bleddy FAA's primary responsibility is to catch fatal errors like this and working on the taxpayer's dime it failed criminally in discharging its primary duties which, taken globally in the overall scheme of things, is to first safeguard the safety of the passengers and crew.

An old adage in aviation says that flight safety is paid for in blood and this has been proven to be true in almost all cases.

[Dileep]

How does moving engine up produce nose-up moment, pls? I assume the engine thrust line on a 737 is located below the c.g. Such increasing thrust increases nose-up moment, I can understand that. If they moved the engine upwards (did they?) it would have reduced the nose-up moment. Confusing. No wonder the software was also confused.
What I read was that it went into an extreme yo-yo, like "Phugoid". I thought that was some kind of feedback time lag problem that caused a divergence.
The decision on cutting training cost must have been made at pretty high level. Goes completely against Boeing historic culture: Maybe they hired Airboos managers.

Engines moved up and forward. So, the distance from CG increased. Also, the engines are wider and sitting forward, so they themselves are creating lift, which becomes worse at high AoA. The ****-oid was because the pilot was fighting the nose-down trim with the nose-up elevator input.

[UlanBatori]

Only vertical distance to the c.g. matters for moment due to thrust, hain? But lift due to engines at higher AOA is a different thing, true. So the software says: AOA! AOA! Pitch down!!! and the pilot is trying to pitch up.
Sounds like what happened when I tried to land a 747 on an aircraft carrier deck (in the simulator of course). HUGE time lag between control actuation and response. One does exactly the wrong thing. Ending in a splash of course.

[arvin]

The decision on cutting training cost must have been made at pretty high level. Goes completely against Boeing historic culture: Maybe they hired Airboos managers.

More like GE managers i.e Jack Welch who tried to convert an engineering comany into a financial one. RT had a program on this management culture. Bean counting, 'improving share holder value' and all that.
Regarding engine position even on B737 800 I have seen, the retracted reverse thruster covers are in close proximity to the extended wing leading edge during landing. I wondered whether they brushed against each other or not.