Posted on 11/24/2018 8:15:34 PM PST by the_daug
Here is a translation of the original preliminary Indonesian government investigation (released after DFDR analysis), without the DFDR plots.
For a view of the plots see original Indonesian document at below URL:
http://avherald.com/files/lionair_b38m_pk-lqp_jakarta_181029_knkt_data.pdf
LEGAL BASIS
In accordance with Law No. 1 of 2009, article 357, the state conducted an investigation of Lion Air, an accident of the JT 610 plane which had an accident in Tanjung Karawang on October 29, 2018.
In accordance with article 359,
paragraph 1, “The results of the investigation cannot be used as evidence in the proceedings”
Paragraph 2, “The results of the investigation as referred to in paragraph (1), which are not classified as confidential information, can be announced to the public”.
LEGAL BASIS
Investigations are carried out by the National Transportation Safety Committee (NTSC) and aim to find causes and provide safety recommendations.
Investigation also follows international provisions contained in the International Civil Aviation Organization (ICAO), Annex 13, which one of them gives rights to aircraft designers and aircraft-making countries, in this case the United States is represented by the National Transportation Safety Agency (NTSB))) Federal Aviation Administration (FAA) and Boeing.
INVESTIGATION ACTIVITIES
Besides NTSB, those involved in the investigation are Australia (ATSB) and Singapore (TSIB).
Two researchers from the Kingdom of Saudi Arabia (AIB) also came as observers to learn about investigations in Indonesia;
Bentos USA sent its tools and operators to the black box pinker detector (CVR) for BPPT’s efforts
On November 1, the FDR was found and on November 4, FDR data was successfully downloaded.
From FDR, 1790 parameters were obtained, for 69 hours, consisting of 19 flights including those who had an accident.
FDR data has been processed for analysis purposes.
ADVANCED ACTIVITIES IN THE LOCATION
• The NTSC team continued its CVR search with several methods using high resolution sonar side scanning, bottom-down profile, magneto, desludging, and ROV working class equipped with 4 cameras and robotic arms and diving.
• The location of the crash of the aircraft is very close to Pertamina’s oil pipeline and submarine cable, for this reason it needs to be sent with Dynamic Positioning
• For this purpose, the search program requires preparation that is not simple and takes several days.
ACTIVITIES THAT CONTINUE
NTSC has issued a recommendation to Boeing to improve the procedure. NTSC recommendations have been followed up by Boeing and FAA by publishing “Boeing, Flight Crew Operation Manual Bulletin and FAA, Emergency Advisory Directive”.
ACTIVITIES THAT CONTINUE
The machine evacuated from the sea has been damaged by collisions.
Next investigation process:
• Data collection related to aircraft maintenance, flight crew training.
• The Angle of Attack sensor component released in Bali was received by NTSC and will be inspected in Minneapolis and an inspection repair workshop in Florida.
• Request data to improve the AOA sensors installed at DPS from repair stations in Florida and will be discussed at NTSB. • The plan is November 28, 2018, the NTSC will issue an ‘Initial Report’. Previously, the NTSC together with the Ministry of Transportation (or other government agencies) and Lion Air, would deliver the results of a temporary investigation to the families of the victims.
This accident is the first time this has happened in the world for the B 737-8 MAX aircraft, so it is necessary to do flight simulation using engineering simulators and algorithms especially the MCAS system and others at the Boeing facility in Seattle as well as reconstructing the flight that had an accident and seeing the impact on the aircraft for the damage that occurred.
INVESTIGATION CHALLENGES
• NTSC does not have sufficient resources in major accident investigation handlers. Currently supported by various parties such as BASARNAS, BPPT, Ministry of Transportation, Pertamina, Ministry of Energy and Mineral Resources, TNI etc. Especially regarding facilities, such as ships, divers, fuel, etc.
• The number of investigator HRs for 10 people is not enough to carry out all investigative activities that have taken place in Indonesia. For example, in the same week there were 2 other accidents which the NTSC could not send investigators.
• NTSC does not yet have storage facilities for aircraft parts that have been appointed for further evaluation. Meeting rooms with other country teams and existing coordination rooms are not adequate.
• B 737 Max 8 aircraft, including new aircraft types and most of the systems use digital, so to understand this new system we KNKT need time to study the aircraft system and to be able to analyze the problems that exist.
Considering each side of flight instruments are independent of each other, if the instrument transfer switch does not work, then we have a double AoA failure and or double computer failure (not likely) and so far I have not heard anyone is suggesting that nor apparently does the FDR indicate that was the issue. Of course with the AoA, by the book go immediately to the tie-breaker . . . the standby attitude indicator. Reading the report, says the left side, Captain wrong, so switch to first officer side..... Report only says first officer side airspeed "significantly higher" does not make it wrong. Captain airspeed could be wrong. Tie breaker for speed is "standby indicator" and/or set a known power setting and at least we are in the ball park.
What I meant when I mentioned compound emergencies was the fact that in the simulator crews are not given two separate emergencies to deal with at the same time, as a matter of practice. I didn't mean a single source failure affecting several systems resulting in a lot of confusion (which this was not).
I agree the standby is the first place to look to identify the bad airspeed (from the data plots it appears they were split by about 20 knots, and stayed that way with the First Officer's as the higher airspeed). They also had a stick shaker on the Captain's side but that could have been the result of a pitot/static problem (not the other way around), and it was only on one side. So determining which speed to rely on came first (already suggested by the stick shaker). Then the appropriate action would be to go to the "airspeed unreliable" checklist. It would direct them to identify the reliable side, turn off the autopilots (disable them with master cutoff switches), turn off the flight directors, establish known pitch/power settings to stabilize the flight path, then switch over to the correct CADC on the bad side, then, after the flight path is stabilized address the various alerts -- see what you have. If you have a stick shaker, the checklist would direct them to lower the nose with the pitch/power set to known settings (assumes AOA is not lying). The checklist is complex -- but says nothing about disabling the pitch trim, a problem that only manifested after they were in the clean configuration, and even then only intermittently as MCAS actuation was interrupted about 20 times by the Captain's yoke trim. I think they had more than one malfunction -- one pitot/static related and one was AOA vane related. The airspeed split drove them to the unreliable airspeed checklist (a checklist that mentions stick shaker as a possible indication). But the stick shaker never went away (see the DFDR plots) because the stick shaker on the Captain's side was primarily the result of the AOA on the left side being stuck at about 20 degrees up. Even when they did speed up the stick shaker did not go away as the checklist suggests, and the fact that the AOA (causing the stick shaker) is what drives the unknown-to-them MCAS to drive the trim down caused them to get into an intermittent tit-for-tat pitch trim battle with the MCAS, even as they are trying to source the instrumentation to both sides from a single, reliable source, to address the airspeed issue (and maybe indicated altitude -- that parameter not shown on the graphs). Their battle with pitch trim was successful until the very end -- perhaps the Captain transferred control to the First Officer and the MCAS won because the Captain didn't communicate his off-and-on battle with the trim, before they were even finished with running the checklist for unreliable airspeed.
So what I am saying is, a crew with proper training, following procedure, could conceivably have been tripped up by this compound emergency -- a stuck AOA, pitot/static issues, and a secret (to them) system interfering with normal actions (the MCAS). There were alerts, sounds, and other distractions, time constraints (the MCAS was persistent though intermittent), communication problems, etc.
Of course we'll never know, but given a little more time this crew might have worked through all the problems and could have returned safely -- but they ran out of time. Were they running any checklists (airspeed unreliable checklist, addressing the first issue?). Maybe they eventually would have treated the MCAS actions as runaway trim. If they had slowed down and put down the flaps it would have saved them since the MCAS would be cut out, but perhaps they were speeding up to eliminate the stick shaker by direction from a checklist (see above). Most inflight emergencies are dealt with methodically with a checklist, one emergency checklist at a time (perhaps punctuated with normal required checklists, such as the approach checklist). This LionAir crew didn't get that advantage. There are many 'if only they had only done this....' theoretical scenarios. We will know a lot more when the CVR transcript is analyzed. There's supposed to more info released on Nov. 28th, but I doubt it will reflect the benefit of knowing what is on the CVR.
I still have a lot of questions too.
you state . . . "What I meant when I mentioned compound emergencies was the fact that in the simulator crews are not given two separate emergencies to deal with at the same time, as a matter of practice."
You are correct. As a matter of practice, designed dual failures are no longer practiced in the simulators. Mostly because the reliability record of the modern airplane is so good. However, (I say however too much eh? LoL) However, a good simulator syllabus is set up so that a single failure of one system affects multiple systems, be it pressurization, hydraulics and in this case unreliable flight instruments. This forces the flight crew to work together, prioritize, identify and manage the abnormal. Crews are not expected to perform without error, rather to learn how to work together and manage, and yeah deeper system knowledge for future use.
"I didn't mean a single source failure affecting several systems resulting in a lot of confusion (which this was not).
In my humble opinion, experience and statistically speaking, for sure this was a single source failure that just so happen to effect other systems. I will be happy to buy you beer if I am wrong on this. Dual failures occurring at the same time with today's airplanes are statistically unheard of.
Now your excellent point that the crew was experiencing something never trained before is correct. With the facts as we know them, we could spend hours in the bar, have a great time, discussing how to manage the flight deck. With the known indications and system knowledge we could talk for hours about what to do when this crew only had seconds to do with no do-over. But for me that is much of the joy in flying, talking shit and learning.
Since I am almost 11,000 miles from where you are, going to the bar is probably not going to happen. But with the known facts as we understand them to be (always subject to change) I found it interesting you choose unreliable airspeed as the starting point.
Again, in this case no wrong no right, it least its a starting point and we are doing something. And If I understand correctly, you choose that because we are hearing a stick shaker and most likely an aural warning "Stall Stall"
My perspectivem my actions based upon what we know.
So we know this all happened when the flaps was commanded up, so our altitude is 1,000 feet above the ground because we are not doing a noise abatement procedure as we should. Yeah all that noise and a stick shaker at a 1,000 feet is pretty serious sh@T. Many pilots might be looking to change there underwear in that moment, no doubt. Not a simulator, ya gotta get right or you die.
First place my eyes go to is my primary pitch instrument and that is the Attitude indicator. We are trained Auto-pilot off, pitch, power, trim as necessary, flaps and speed break up check. in what? 3 seconds? Never timed it. Never mattered, no need to rush.
Now in that moment, several things are going to be observed, I just pitched down approximately 4 degrees nose down as per my Attitude Indicator my auto-pilot has been disconnected, and yet I am still hearing a stickshaker and Stall Stall aural warning. Yup, I agree, that would confuse most. But we are professional pilots and we make alot of money for this single moment.
In that moment, I need to scan, cross-check my attitude indicator with my standby attitude indicator, That's not technique, that's required. I have my thrust full forward, so airspeed, even overspeed is the least of my concerns. (prioritize). Now I would expect my PNF pilot not flying to be helping about now with some callouts. Speed, altitude, I would even expect him to pull back the throttles if he observed an overspeed approaching.
Now here is where it gets interesting. According to what we now know, all of sudden I am going to feel a "heavy yoke" and down pressure on the yoke. (MCAS effect), I am going to use my electric trim switch on the yoke to trim the nose up. As we now know . . . that aint going to work. And now we know we are in some very serious shit like we have never seen before.
Now mind you, we are about 11 seconds into this event. I have one advantage that is not always available. Clear weather so I can look outside and determine what is going on. (spatial awareness). So back to the problem.
My stabilizer trim is not doing what I commanded it to do, (electric nose up trim), I may or may not observe it moving, but for sure it is not doing what I just commanded it to do. What is the first priority? FLY the F'n plane! I need trim and I need trim NOW. So I manually trim my airplane. Technique calls for me to pull the handle out and start cranking, Yes, I still hear the stick shaker and stall warning, but I am setting my pitch on the attitude indicator, monitoring my airspeed, and maybe just maybe my FO has compared the instruments and he is advising me what he sees at the same time I am trimming my airplane.
So I manually trim my airplane, and as we now learn, the son of bitch is rolling forward UNCOMMANDED! I don't have to see it, I can feel it in the pressure of the yoke and my eyes are on the attitude indicator. Oh yeah, I have another problem, My attitude indicator is not indicating the same as my standby indicator, Soooo while reaching down again (2nd time to manually trim my airplane) I am asking my FO to confirm my attitude indicator. So I am looking at the attitude indicator while I am trimming (Hand flying) and now I learn my attitude indicator has failed and the damn stab trim keeps going forward.
Dual failure? No. Experience has shown and we teach, multiple failures at the same time are relational-ship. Once it was determined that our attitude indicators are different and we went to the referee (standby attitude indicator) and we saw which was correct, I reach up and select FO on the instrument transfer switch!
Gee, all my problems just went away. No more stick shaker, no more stall warning no more trim problem, and I even get Otto back (autopilot).
I say that because there is no way (statistically speaking) and per the previous 3 flights that experienced the same problem was there a dual alphavane (AoA) or dual ADIR (instrument computer) failure at the same time. They are independent.
What about the airspeed indicator? Don't know don't care, In this specific event as I describe. In another event Hell yes I care. Why? I have my pitch resolved, I have my power set to a known value, and I can feel and look outside and know all is normal or not.
Ok that was fun for me . . . agree to disagree, its all good. I did not check my work so I hope it all makes sense. For sure, between now and then facts will change. Bottoms up!
If you don’t know your airplane, it will kill you. It is as simple as that.
Not including the existence of the MCAS system is CRIMINAL!
Not training crews in the MCAS and how it operates is CRIMINAL.
Boeing and the airline, probably the pilot union, as well as the national “FAA” are guilty of murder.
This is just unforgivable.
PS. The Boeings that I have flown are the B-52, 727, 737, 747-400, 757, 767, and 777.
Think very carefully before flying a second world and don.t fly a third world airline. Experience and culture are rarely problems in the first world.
“Question...if they went through 20 on/off cycles of the the hor stab trim actuation by MCAS, why wouldn’t they have turned off the Stab Cutoff switches? They must have been exerting tremendous physical effort to pull back on the yoke as you say, but wouldn’t a serious pitch control problem like this have led them to cut off / disengage the hor stab drives?
It was panic time, confusion and distress ruled the day. They would not be “led” to do anything to save their or the passengers lives. I wonder when they actually gave up?
The stick shaker is something that gets your attention immediately, but if there is an "IAS disagree" or similar alert combined with a stick shaker then your senses really perk up. And that's where I was coming from. During the takeoff phase you're really focused on your instrument cross-check, so a sudden loss of speed preceding a stall is highly unlikely with the power up and a normal pitch picture -- more likely you're accelerating, cleaning up, and running the After Takeoff checklist. A difference in airspeed is the first thing you check for, so I'd look at the standby and cross-cockpit to the other pilot's instruments. We'd determine which is more accurate, fly off that one (even transfer control if necessary) and level off at a higher altitude. Then you figure out what you have, and what else to do. One flies the airplane and the other runs (whichever decided upon) checklist.
That's basically what you said, except the checklist part. Maybe you were getting to that. And that's what the crew of LionAir Flight JT610 did, maybe including running some checklists. Look at the data -- they were at about 5,000 feet for 8 minutes before they took a nose dive into the ocean. So I have no reason to believe they didn't do at least most of those things you mentioned.
As an aside, I don't know why you mention attitude indicator failure -- that didn't happen in this case and is not related to the pitot/static instruments or AOA failure. There is no indication that the attitude indicator lost power, and that's very unlikely since it's hard-wired to the emergency bus anyway (unlike the first officer's attitude indicator).
Back to the level-off. You said
According to what we now know, all of sudden I am going to feel a "heavy yoke" and down pressure on the yoke. (MCAS effect), I am going to use my electric trim switch on the yoke to trim the nose up. As we now know . . . that aint going to work.
It did and it didn't -- it interrupted the .26 degrees/sec down trim by the MCAS for 5 seconds each time he trimmed, only to resume again, confusing the crew. Because Boeing designed it that way and didn't tell the operators.
You said:
Once it was determined that our attitude indicators are different and we went to the referee (standby attitude indicator) and we saw which was correct, I reach up and select FO on the instrument transfer switch!......Gee, all my problems just went away. No more stick shaker, no more stall warning no more trim problem, and I even get Otto back (autopilot).
The instrument transfer would alleviate the issues with differential airspeed (both flying off the same pitot/static system). If the stick shaker goes away there's still the AOA problem that is driving the persistence of MCAS -- it does not go away and so neither does MCAS. But you might be able to counter the MCAS trimming with counter-trim on the yoke and manual trim, short of the ultimate remedy of using the trim cutout switches, for a time. The LionAir JT610 crew did, and it worked for 8 minutes, but they needed to do more -- as we know from the emergency AFM revision issued by the FAA after the crash.
The emergency flight manual change directs crews as follows -- note there is no mention of the instrument transfer switch, it's a remedy for a separate problem (as I said) but likely a symptom of, and therefore related to the first problem (as you said):
The 737-8/-9 uses a Flight Control Computer command of pitch trim to improve longitudinal handling characteristics. In the event of erroneous Angle of Attack (AOA) input, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds. In the event an uncommanded nose down stabilizer trim is experienced on the 737-8/-9, in conjunction with one or more of the indications or effects listed below, do the existing AFM Runaway Stabilizer procedure above, ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
I did like your argument that these problems were all related to a single failure -- I don't know 737 systems that well and don't have a 737 Max flight manual -- but I would also say the 'other failure' is the fact that Boeing didn't advise the operators of the MCAS system. Now they've had to make an emergency revision to the flight manual to make up for their mistake after it became a major factor in the crash of LionAir JT610.
Boeing and the airline, probably the pilot union, as well as the national “FAA” are guilty of murder. This is just unforgivable. PS. The Boeings that I have flown are the B-52, 727, 737, 747-400, 757, 767, and 777.
We are in full agreement! And the emergency AFM change ordered by the FAA is damning to Boeing.
The huge settlements to follow will prove it.
Back in the old days, really old days, if there was opposite force used on either control column, to the direction of the “runaway” trim, a stabilizer trim jack screw “brake” was applied that stopped trimming in either direction. Of course this was the B-727 and it was a 1960’s design.
Yes, and it was analog all the way.
Doomed Lion Air plane's air speed indicator was malfunctioning for last four flights
"We found a malfunction in an air speed indicator instrument in the last four flights, including the crash flight," Capt. Nurcahyo Utomo of the National Transportation Safety Committee (KNKT) told CNN on Monday. "We ask NTSB and Boeing to work on this to prevent same accident happening in the future."
Utomo confirmed to CNN that there were two airspeed indicators in the cockpit. "One belongs to the pilot in command and one belongs to the co-pilot. One of them should have reacted to the airspeed indicator malfunction in his display," said Nurcahyo, confirming that the jet was in the pilot's control, set to manual.
https://www.cnn.com/2018/11/05/asia/lion-air-crash-plane-intact-intl/index.html
No link?
Thanks. Easy to read and understand.
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