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Old 10th March 2019, 15:16   #1
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Default Boeing 737 Max crashes and grounding

Another Boeing 737-800MAX has crashed today. It was an Ethiopian airlines flight ET302. The aircraft was apparently around 4 months old. Boeing has not taken corrective measures it seems. India has over 20 of these MAXs between SpiceJet and Jet Airways.

https://m.timesofindia.com/world/res...e=WhatsApp.com

Last edited by BoneCollector : 10th March 2019 at 15:18.
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Old 10th March 2019, 15:51   #2
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Very eerily similar to the Lion air crash. Both lost contact within few minutes of taking off.

RIP souls on board who couldn't make it.
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Old 10th March 2019, 19:11   #3
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Quote:
Originally Posted by Lij View Post
Very eerily similar to the Lion air crash. Both lost contact within few minutes of taking off.
Second such accidents in five months - brand new Boeing 737 MAX 8 went down minutes after take off. Serious questions will be raised on safety of Boeing 737 MAX 8.

Ethiopian Airlines plane crash: Crash similar to this DOOMED Boeing 737 flight, pilot says

Quote:
The brand new Boeing 737 MAX was on its way to Nairobi, Kenya, from Addis Ababa when it disappeared off the radar at 8:44am (GMT). The airline released a statement saying the airline lost contact with Bole International Airport six mintues after take off before crashing 60 kilometres South-east of the airport. Former British Airways pilot Alastair Rosenschein said there is likely to comparisons with the Lion Air Flight 610 crash, with both crashes involving a brand new Boeing 737 MAX aircraft.
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Old 11th March 2019, 08:25   #4
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Meanwhile, China has grounded its entire domestic fleet of 737 Max planes.

This could be a wild co-incidence or something horribly wrong with the plane (or lack of training after modifications to the software); considering the two fatal accidents to the same plane within such a short amount of time.

Quote:
China grounded its entire domestic fleet of Boeing Co. 737 Max 8 planes after one of them crashed in Africa on Sunday, as scrutiny intensifies on the U.S. manufacturer’s best-selling jet that’s now been involved in two deadly accidents in five months.
Not just China,

Quote:
Indonesia’s transportation safety committee said Monday it will discuss the possibility of grounding Boeing 737 Max jets operated by the nation’s airlines. Jet Airways India Ltd. and SpiceJet Ltd., two Indian airlines that use the 737 Max jet, and the country’s regulators have asked Boeing for information following the Ethiopia crash.

Cayman Airways, the flag carrier airline of the Cayman Islands, says it is suspending operations of both its Boeing 737 Max 8 aircraft effective March 11 “until more information is received.”
https://www.bloomberg.com/news/artic...x-caijing-says
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Old 11th March 2019, 09:47   #5
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

This is what happens when you apply lipstick on a pig. Trying to add sophisticated flight protection like anti stall on a conventional/non fly by wire aircraft is increase of crew workload in emergency.
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Old 11th March 2019, 10:05   #6
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Found this on FB
Why did Lion Air's Boeing 737 MAX crash? This is the same plane that crashed for Ethiopian Airlines yesterday - and that SpiceJet is still flying in India. By a pilot pal of mine:

The key issue is that when Boeing fitted new fuel efficient engines, which are heavier & more powerful on 737 MAX, engineers found the centre of gravity had moved backwards, potentially making the aircraft less stable (more prone to a stall/loss of control).

To compensate, they put in a system call MCAS (Manoeuvring Characteristics Augmentation System) which would pitch the nose forward if the angle of attack increased above a certain threshold. This would happen even if aircraft was flown manually, effectively letting a computer-directed system take away control from the pilots.

In the Lion Air case, a spurious signal from the Angle Of Attack sensor triggered this system, causing the aircraft to repeatedly dive into the ground, in spite of pilots valiantly fighting to regain control.

The shocking thing is that this new feature was not even informed to the pilots globally, neither was this emergency practised during simulator training. The pilots would have been totally caught by surprise, with only minutes left before a crash.

We will need more facts before we can speculate on the latest crash involving the Ethiopian aircraft.

However, I agree something seems to be amiss with the Boeing 737-Max aircraft.
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Old 11th March 2019, 11:05   #7
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Quote:
Originally Posted by Guna View Post
Found this on FB
Why did Lion Air's Boeing 737 MAX crash? This is the same plane that crashed for Ethiopian Airlines yesterday - and that SpiceJet is still flying in India. By a pilot pal of mine:

The key issue is that when Boeing fitted new fuel efficient engines, which are heavier & more powerful on 737 MAX, engineers found the centre of gravity had moved backwards, potentially making the aircraft less stable (more prone to a stall/loss of control).

To compensate, they put in a system call MCAS (Manoeuvring Characteristics Augmentation System) which would pitch the nose forward if the angle of attack increased above a certain threshold. This would happen even if aircraft was flown manually, effectively letting a computer-directed system take away control from the pilots.

In the Lion Air case, a spurious signal from the Angle Of Attack sensor triggered this system, causing the aircraft to repeatedly dive into the ground, in spite of pilots valiantly fighting to regain control.

The shocking thing is that this new feature was not even informed to the pilots globally, neither was this emergency practised during simulator training. The pilots would have been totally caught by surprise, with only minutes left before a crash.

We will need more facts before we can speculate on the latest crash involving the Ethiopian aircraft.

However, I agree something seems to be amiss with the Boeing 737-Max aircraft.

This the exact thing I mentioned earlier when I said lipstick on a pig. In the Airbus the fly by wire system only kicks in when the angle of attack goes over a preset limit called alpha protection angle, this is dependant on the configuration, cg etc. Even then the pilot can perform a full backstick manuver and the aircraft only adds toga power to keep speed 1.23 times above stall speed. In essence the pilot can perform a natural escape manuver to say avoid terrain and the aircraft doesn't stall. If you release your side stick the nose will pitch down until speed is just outside alpha protection and the toga power will help increase speed. In either case no dangerous manuver.
To replicate this system Boeing tried mcas but without much thought.
Boeing has blood on their hands, I guess it's the right time to say "if it's Boeing I ain't going"

Last edited by AirbusCapt : 11th March 2019 at 11:07.
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Old 11th March 2019, 11:35   #8
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Isn't it high time this darn aircraft is grounded till the root cause is ascertained. People's lives are more valuable than some aircraft company's profits. I guess Indigo has a few of them in their fleet. Not aware if any other Indian carrier owns/ leases this model.

When we still don't trust computers to run our cars, is it not a dumb idea to give the ultimate control of an aircraft to a computer. Just one stupid sensor that has gone haywire is all it takes in that case.

Last edited by longhorn : 11th March 2019 at 11:38.
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Old 11th March 2019, 11:38   #9
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Warning:Long Post

To better understand what is happening to the 737-MAX lets go back to the fatal Lion Air crash flight JT610. Caution: Right now we do not know what happened to the Ethiopian Boeing 737 MAX but its crash in what at first glance seems a worryingly similar situation does raise serious concerns. Let’s wait till we know more and not guess. First to the Lion flight.

Quote:
A key sensor reading on the Lion Air flight JT610, measuring the angle of attack, was faulty even as the pilots taxied out for takeoff. An angle of attack (AOA) sensor measures the plane’s angle between the wings and the air flow. The diagramme below illustrates the meaning of AOA for the benefit of readers who may not be familiar with the term.
Boeing 737 Max crashes and grounding-bankaoa.jpg

As soon as the Lion Air's 737 MAX was airborne, the captain’s control column began to shake as a stall warning. And from the moment they retracted the wing flaps at about 3,000 feet, the two pilots struggled — in a 10-minute tug of war — against a new anti-stall flight-control system that relentlessly pushed the jet’s nose down 26 times before they lost control.

Though the pilots responded to each nose-down movement by pulling the nose up again, they did not do what the pilots on the previous day’s flight had done: simply switched off that automatic flight-control system.

The data from the black box and other observations points to three factors that seem to have contributed to the disaster:

1. A potential design flaw in Boeing’s new anti-stall addition to the MAX’s flight-control system and a lack of proper and complete communication, by Boeing, to airlines about the system.

2. Lion Air’s maintenance shortfall that allowed the plane to fly repeatedly without fixing the key AoA sensor that was feeding false information to the flight computer on previous flights.

3. The fact that the Lion Air pilots did not to recognize what was happening and execute a standard procedure to shut off the faulty system. However on this point 3 I don’t want to be too harsh as I have not stood in their shoes as they dealt with an emergency and cockpit work overload.

In the MAX there are two AOA sensors. The two angle-of-attack sensors on either side of the jet’s nose differed by about 20 degrees in their measurements even during the ground taxi phase when the plane’s pitch was level. One of those readings was clearly completely wrong.

On any given flight, the 737 flight computer takes data from only one of the angle-of-attack (AOA) sensors, apparently for simplicity of design. In this case, the computer interpreted the AOA reading as much too high an angle, suggesting an imminent stall that required Boeing’s new MCAS (Maneuvering Characteristics Augmentation System) to kick in and save the airplane. This system of taking readings from one AOA sensor is a single point of failure.

When the MCAS system pushed the nose down, the Lion Air Captain repeatedly pulled it back up. But each time, the MCAS system, as designed, kicked in to swivel the horizontal tail and push the nose back down again.The data shows that after this cycle repeated 21 times, the captain ceded control to the first officer and MCAS then pushed the nose down twice more, this time without a pilot response. After a few more cycles of this struggle, with the horizontal tail now close to the limit of its movement, the captain resumed control and pulled back on the control column with high force. It was too late. The plane dived into the sea. In flying, as in other things in life, if your action - reaction keep following a fruitless pattern you normally try another tack as with each minute you may be getting closer to a irretrievable situation. But as I said before I don't want to be a keyboard warrior as I was not in the cockpit.

The corresponding black-box-data charts from the same plane’s flight the previous day show that the pilots on that earlier flight encountered more or less exactly the same situation. Again the AOA sensors were out of sync from the start. Again, the captain’s control column began shaking, a stall warning, at the moment of takeoff. Again, MCAS kicked in to push the nose down as soon as the flaps retracted. Initially that crew reacted like the pilots of the fatal flight JT610, but after a dozen cycles of the nose going down and pushing it back up, they turned off MCAS using two standard cutoff switches on the control pedestal “within minutes of experiencing the automatic nose down” movements. There were no further uncommanded nose-down movements. For the rest of the flight, they controlled the jet’s pitch manually and everything was normal. The jet continued to its destination and landed safely.

Because the cockpit voice recorder has not yet been recovered from the sea bed we do not know more of what was transpiring in the cockpit. However, even if the flight crew is found partly culpable, the sequence of this tragedy also points to a potential design flaw in Boeing’s MCAS system. The sequence was triggered by a single faulty AOA sensor. A so-called “single point of failure” that could bring down an airplane is absolutely anathema in aviation safety protocols.
If the Ethiopian aircraft crashed for the same reason then Boeing has a lot to answer for on its new MCAS flight safety system. Flight safety systems ironically whenever newly commissioned have given us accidents till all the unseen bugs are ironed out. The Airbus A320's then new fly-by-wire system also led to a few early crashes in the mid/late-1980s.

After the Lion Air crash a few months ago both Boeing and the FAA had sent out directives on this matter and pilots have been keenly conscious of it. Which is why we need to pause drawing conclusions till more information is available.

Quote:
Originally Posted by AirbusCapt View Post
This is what happens when you apply lipstick on a pig. Trying to add sophisticated flight protection like anti stall on a conventional/non fly by wire aircraft is increase of crew workload in emergency.
Quote:
Originally Posted by AirbusCapt View Post
To replicate this system Boeing tried mcas but without much thought. Boeing has blood on their hands, I guess it's the right time to say "if it's Boeing I ain't going"
With due respect Sir, as a forum we stay away from bashing aviation OEM's.

In India Spicejet operates the 737MAX.

Last edited by V.Narayan : 11th March 2019 at 11:52.
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Old 11th March 2019, 11:42   #10
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

After China and Indonesia, Ethiopian also grounds the 737 Max8:

https://timesofindia.indiatimes.com/...w/68352649.cms

A quick and thorough investigation is now needed to get down to the cause.

Last edited by saket77 : 11th March 2019 at 11:46.
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Old 11th March 2019, 11:57   #11
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

This is so unfortunate. Speculation will not help but one can't ignore that both these accidents involve B737 max and similar circumstances.

The quicker Boeing finds out the cause, the better it is for them as well as all the airlines.

Grounding planes is a huge loss.
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Old 11th March 2019, 12:38   #12
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Quote:
Originally Posted by longhorn View Post
Isn't it high time this darn aircraft is grounded till the root cause is ascertained. People's lives are more valuable than some aircraft company's profits. I guess Indigo has a few of them in their fleet. Not aware if any other Indian carrier owns/ leases this model.

When we still don't trust computers to run our cars, is it not a dumb idea to give the ultimate control of an aircraft to a computer. Just one stupid sensor that has gone haywire is all it takes in that case.
Indigo has an all Airbus fleet.

As of now Jet Airways and Spicejet have the 737MAX in routine service.
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Old 11th March 2019, 12:43   #13
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Now all 737MAX in India are under the scanner. They are used by Jet & Indigo. These are the most economical and silent avatars of the 737 but have been plagued.

Let us hope there are no more crashes. It seems the Ethopia crash was also the same.
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Old 11th March 2019, 13:02   #14
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

OT: Clarification for some members who seem to be confused regarding the aircraft and airline type facing troubles presently.

Jet Airways and Spicejet have 737-800 MAX. The aircraft type which was involved in the Lion Air crash and the Ethiopian Airlines crash. It is made by Boeing.

Indigo, Air India and GoAir are having the Airbus 320 NEO, which is plagued with engine troubles in its Pratt and Whitney engines and already has a DGCA circular stopping its flights to Andaman.
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Old 11th March 2019, 13:09   #15
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Default Re: Lion Air Boeing 737 MAX crashes in Jakarta

Jet Airways and Spicejet have taken deliveries of 737 MAX in India. Ironically, all MAX of Jet Airways have been grounded due to their ongoing financial woes. So Jet is currently unaffected by this. Talk of silver lining on dark clouds!
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