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Experts find faults on two more Lion Air Boeing 737 MAX 8

By Editorial Board,  Nov 03, 2018
Experts find faults on two more Lion Air Boeing 737 MAX 8

Jakarta - Inspectors have found flaws in two other Lion Air Boeing 737-MAX 8. A flight data display problem found on one of the planes might be similar to one reported in the previous flight of crashed Lion Air MAX 8, experts warned.

Indonesian ministry of transportation ordered inspections on all Boeing 737 MAXs operated by Indonesian carriers. 

The ministry announced that ten of the newly released jets that are owned by Lion Air and Garuda Indonesia had been inspected so far. Experts discovered a problem on a jet linked to its flight data display system while a glitch in a jet stabilization system has been spotted on another aircraft.

Speculations to rise over faulty flight data for the crash of Lion Air's 737 MAX 8

An engineer and a technician from Boeing have joined Indonesian inspectors to help with the quest. So far, no other government ordered inspections for the Boeing's re-engineered single-aisles. 

Authorities hope that data analyzed from recovered flight recorders may help reveal why the flight JT610 crashed into the Java Sea after a few minutes from takeoff, killing all 189 people onboard last Monday.

A technical issue reported on a previous flight has raised questions about whether Boeing's single-aisle has mechanical faults specific to the new model.

The Boeing 737 MAX series became the fastest-selling airliner in the commercial aviation history when it entered into service last year. 

To date, Boeing's re-engineered single-aisle family has accumulated 4783 orders. 219 jets are currently in service with airlines around the world.

 

https://airlinerwatch.com/experts-find-faults-on-two-more-lion-air-boeing-737-max-8/

 

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17 minutes ago, conehead said:

Apparently, the aircraft tech log has been leaked, and a copy is circulating on the internet. I haven’t seen it, but the previous flight had a snag referring to the elevator feel mechanism.

https://www.airlineratings.com/news/new-theory-lion-air-disaster/

I haven’t seen that but I have seen a printout of an ACARS message from the previous flight saying the captain’s air data was unreliable and they flew the rest of the trip on the FO’s instruments. 

Edited by J.O.

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Yes, they stated that as well, and that the pitot static system was inspected and tested, I’m not sure of the exact wording. 

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Certainly looks like a very high speed impact with the water.

Hitting the water at a high speed is just as damaging as hitting terra firma.

I certainly don't envy the divers with the grim job they have.

Might be beneficial to them  that when scuba  diving at 100 feet their time is very restricted.

I would imagine many may end up with  PTSD.

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9 minutes ago, Airband said:

Some reports indicating up to 1000 km/h.

I think that is just about 200km/h short of the speed of sound. . I wonder what the limiting IAS is on that model of 737..

 

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737 Max angle-of-attack sensor subject of Boeing bulletin

  • 07 November, 2018
  • SOURCE: Flight Dashboard
  • BY: Mavis Toh
  • Singapore

Boeing has issued an operations manual bulletin to 737 Max operators, covering air data sensors, following investigations into the crash of Lion Air flight JT610.

The manufacturer says it issued the bulletin on 6 November, directing operators to “existing flight crew procedures" to address circumstances involving erroneous angle-of-attack sensor information.

Angle-of-attack information is critical to avoiding the onset of stall conditions.Indonesia's National Transportation Safety Committee has indicated that the ill-fated flight “experienced erroneous input" from such a sensor, says Boeing.

It stresses that issuing bulletins or recommendations, when appropriate, regarding the operation of its aircraft is a "usual process".

“The investigation into Lion Air flight 610 is ongoing and Boeing continues to co-operate fully and provide technical assistance at the request and under the direction of government authorities investigating the accident,” the manufacturer adds.

Media reports had earlier surfaced saying that Boeing was preparing to issue a service bulletin to Max operators.

The NTSC has said that it believes the crashed aircraft had been operating with airspeed indicator faults during its last four flights. It also called on Boeing and the US National Transportation Safety Board to take necessary action to prevent future cases of faulty flight system readings.

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Further on the bulletin:

https://theaircurrent.com/aviation-safety/boeing-nearing-737-max-fleet-bulletin-on-aoa-warning-after-lion-air-crash/

This is a breaking story and will be updated.

Boeing will issue a service bulletin to 737 Max operators worldwide warning operators that the jet’s angle of attack sensor can produce erroneous indications causing the single-aisle jet to enter an aggressive dive, according to a senior industry official familiar with the action.

The bulletin comes after a newly-delivered Lion Air 737 Max crashed off the coast of Indonesia on October 29, killing all aboard. The bulletin is expected to say that Indonesian air safety officials have said that Lion Air flight 610 experienced erroneous angle of attack input.

According to the official familiar with the bulletin, Boeing warns operators that the angle of attack issue can occur during only manual flight. The erroneous AOA input can pitch the aircraft’s stabilizer trim down for up to 10 seconds as a time.

The plane maker is expected to caution pilots to use the electric stabilizer trim to reverse the downward stabilizer trim, but the nose-over can begin again five seconds after those switches are released, the official added.

The repeated uncommanded nose down action can be stopped by deactivating the stabilizer trim system, according to the official. Boeing warns that the stabilizer system can reach its full downward position if not counteracted by pilot trimming the aircraft and disconnecting the stabilizer trim system.

The service bulletin is likely to be the prelude to a formal airworthiness directive from the Federal Aviation Administration.

Boeing did not immediately respond to a request for comment.

The bulletin is expected to be issued as early as Wednesday morning, according to Bloomberg News, which first reported the impending operator notification.

Edited by Don Hudson

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20 minutes ago, Say Again, Over! said:

Reminiscent of the Rostov crash?

In the Rostov crash, it was the pilot that ran the stab trim continuously (via the control column switches) not the auto flight system. In this instance it appears the auto flight system was initiating the stab trim movement (erroneously).

How do you know the stab trim is running on a 737? That noisy spinning wheel beside your knee......

Edited by rudder

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25 minutes ago, rudder said:

In the Rostov crash, it was the pilot that ran the stab trim continuously (via the control column switches) not the auto flight system. In this instance it appears the auto flight system was initiating the stab trim movement (erroneously).

How do you know the stab trim is running on a 737? That noisy spinning wheel beside your knee......

Apparently a run away stab trim can be counteracted  by using the CC switch but if the switch is released, 5 seconds later the trim will run away again. The only way to stop a faulty trim is to use the CC switch to run the trim back to where the pilot wants it and then move the STAB TRIM CUTOUT switches  to CUTOUT

 

The symptoms and action required is expanded here in the YELLOW highlighted area. (Boeing Bulletin)

http://www.avherald.com/h?article=4bf90724&opt=0

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5 hours ago, rudder said:

In the Rostov crash, it was the pilot that ran the stab trim continuously

Thanks rudder,

I wasn't sure if they had found out that it was pilot action or not.

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8 hours ago, Malcolm said:

"Only in Manual Flight"?  Now that is scary.

Well, you are in a no win situation. You can't be in or go into A/P mode because you'd have an air-data discrepancy, yet the AD says STS runaway trim wont happen in Auto Pilot mode?

No good arguing over it now, the problem the Lion Air crew encountered was the proverbial 'elephant in the room' one. Looked for the expected UAS and got kicked in the bum.

 

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A quick thrust/attitude reference for S&L flight on the NG/MAX for those who may care.

Flaps extended........10° NU and 80%N1
Flaps up.......4° NU and 75% N1

Passed to me by a respected training pilot.

  • Like 1

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That right there is "How to Stay Alive 1.01". Every pilot should have to commit something similar to memory and be trained to use it.

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Indonesia conducts special audit on Lion Air

  •  
  •  
  •  
  • 07 NOVEMBER, 2018
  •  
  • SOURCE: FLIGHT DASHBOARD
  •  
  • BY: FIRDAUS HASHIM
  •  
  • SINGAPORE

Indonesia's transport ministry is conducting a special audit on Lion Air, following the crash of one of its Boeing 737 Max 8 aircraft on 29 October.

Transport minister Budi Karya Sumadi said at a 5 November press conference that the audit would cover aspects including personnel qualification and standard operating procedures.

He adds that an initial audit, involving ramp checks of the 11 in-service 737 Max 8s operated by Lion and flag carrier Garuda Indonesia, were conducted over the weekend and that both carriers passed the initial checks.

Sumadi was also quoted in local media reports as saying that discussions have been held with ICAO, the European Union, and the US Federal Aviation Administration to assist in the special audit, as well as to assess areas for improvement.

Flight Fleets Analyzer shows that as of 7 November, Lion Air operates 10 737 Max 8s, while flag carrier Garuda Indonesia operates one of the type.

In a press release dated 5 November, Indonesia's National Transportation Safety Committee called on Boeing and the US National Transportation Safety Bureau to "take any necessary action" to prevent future cases of faulty airspeed indicators that could affect the in-service Boeing 737 Max fleet worldwide.

This came after the NTSC revealed that the crashed 737 had operated with a faulty airspeed indicator for its last four flights, based on downloaded information from the jet's flight data recorder.

As of 6 November, 186 body bags containing human remains have been recovered from the search area. Indonesian police and relatives are assisting with victim identification, says the country's national search and rescue agency Basarnas on its Twitter account.

The Lion Air 737 Max 8, registered PK-LQP, was operating as flight JT610 from Jakarta's Soekarno-Hatta International airport to Pangkal Pinang when it crashed into the sea near the town of Karawang, claiming the lives of all 189 passengers and crew on-board.

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I see that the APA has reacted and issued the following. 

Quote

737 MAX8 Emergency Airworthiness Directive


posted on November 10, 2018 09:22

737 MAX8 Emergency Airworthiness Directive

The recently released Emergency Airworthiness Directive directs pilots how to deal with a known issue, but it does nothing to address the systems issues with the AOA system, which may be the causal system in the Lion Air accident. This is significant. The positive takeaway is that we are advised, as pilots, that once we recognize the issue, we can stop the negative impacts by taking the trim system out of the loop.

At the heart of this investigation is the MCAS system (description from Boeing):

MCAS (Maneuvering Characteristics Augmentation System) is implemented on the 737 MAX to enhance pitch characteristics with flaps UP and at elevated angles of attack. The MCAS function commands nose down stabilizer to enhance pitch characteristics during steep turns with elevated load factors and during flaps up flight at airspeeds approaching stall. MCAS is activated without pilot input and only operates in manual, flaps up flight. The system is designed to allow the flight crew to use column trim switch or stabilizer aislestand cutout switches to override MCAS input. The function is commanded by the Flight Control computer using input data from sensors and other airplane systems.

The MCAS function becomes active when the airplane Angle of Attack exceeds a threshold based on airspeed and altitude. Stabilizer incremental commands are limited to 2.5 degrees and are provided at a rate of 0.27 degrees per second. The magnitude of the stabilizer input is lower at high Mach number and greater at low Mach numbers. The function is reset once angle of attack falls below the Angle of Attack threshold or if manual stabilizer commands are provided by the flight crew. If the original elevated AOA condition persists, the MCAS function commands another incremental stabilizer nose down command according to current aircraft Mach number at actuation.

This is the first description you, as 737 pilots, have seen. It is not in the AA 737 Flight Manual Part 2, nor is there a description in the Boeing FCOM. It will be soon.

APA Safety recommends that you familiarize yourselves thoroughly with the information provided by CA XXXXXXX, 737 Fleet Captain, and the AA 737 fleet team. We have been working closely with CA XXXXXXX to get you accurate information as quickly as it becomes available. The AA 737 fleet team has placed this information in CCIs to 737 pilots, in bulletins, and in changes to flight documents.

At the present time, we have found no instances of AOA anomalies with our 737 MAX8 aircraft. That is positive news, but it is no assurance that the system will not fail. It is mechanical and software-driven. That is why pilots are at the controls.

Awareness is the key with all safety issues. You are aware this anomaly may occur and there is a mitigation procedure. No different than should you experience an engine failure.

As we continue to receive details, we will provide them in emails only to the 737 group. We chose to send this initial email to all pilots because it is a subject that is generating a great deal of interest.

Should you have questions, please do not hesitate to email or call us here at APA Safety: XXX-XXX-XXXX.

Captain XXXXXXX
DFW 737I
APA Safety Committee Chairman

Halfnut is offlineReport Post  

 

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Question Captain XXXXXXX................Are you going to teach your pilots how to fly by disconnecting the magical stuff and manually flying the aircraft, by maybe  looking out the window......or perhaps reverting to NBAAS ???.

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Kip, I think there is a general move toward lower automation segments in sim sessions industry wide, that's more being driven by the go around decision and started before this.

That said, understanding what is happening at the root of an undesired aircraft state seems important no matter what the conditions.  While we assume 'looking out the window' would have helped, there is no reason to think a crew would not remain in manual flight after departing IFR.  Many of the olde guard still believe in doing this on a regular basis.  If I read this right, that manual flight and AOA disagree on this aircraft can result in this bad situation, then the crew is going to have to deal with it in IFR as well as VFR, potentially at a very low altitude.

It is an interesting thing - every time we add layer to this cake, no matter how well intentioned, there are side effects and risk of the new layer playing badly with the old.  Sometimes the side effects can be worse than the original issue.

Vs

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This AOA sensor fault occurred while in manual flight with nose down stab trim being applied repeatedly. The solution of course would have been to disconnect both stab trim however this was not a Boeing procedure. It is now as addressed by the Emergency AD. 

Edited by blues deville

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Are we seeing a one of problem with only that aircraft or are all 737 Max8 likely to have the same problem?  In other words, a basic fleet wide design flaw or only perhaps a manufacturing issue only on that hull?  It is a puzzle as to why other carriers have not experienced the same issue when you think about how many 737 Max8 are currently operating.

 

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