Lion Air 737 MAX 8 Crashes in Indoesia

[righthandman]

“People like me” just want to have a way of not being in planes that seem to have a mind of its own and hurtling out of control killing all on board including the confused pilots.

[Gannet167]

The trouble is, confused pilots often are the problem. Protections like Alpha Prot and Alpha Floor can and do save the day. It would be difficult to replicate the Asiana SFO crash in an Airbus in normal law. The plane wouldn't let you.

Lion Air seems to be a malfunctioning system. What seems to make the situation especially problematic is Boeing didn't tell anyone about it. If true, that's a problem with aircraft manuals and type training. Presumably if the crew knew how the system works and were trained to handle a malfunction, we wouldn't be talking about it. This does not invalidate the engineering of stability augmentation, which statistically has done wonders for safety. If true, this situation is a compelling argument for proper AOM documentation and crew training on systems and procedures. Not to get rid of equipment proven to increase safety.

I flew a plane with a stall protection system which included a stick pusher. It was required for certification since the plane had such terrible stall characteristics, it was generally accepted that you'd need 10,000 get to recover it if it ever did stall. The SPS was great and likely saved lives. The one day that it failed because one AoA vane failed, we knew how the system worked, how to handle the failure and recover the plane safely. It did not invalidate the whole concept.

[pelmet]

Maybe planes (especially with sidestick controls) should have a red robust centrally located 3 position switch labeled “Auto L” @ 10 o’clock position, “Auto R” @ 2 o’clock position, and an “Auto Off” @ 6 o’clock position. There should also be 2 green lights below the L and R switch positions. The Auto positions (L or R) should normally be used by the PF and remain in that position if and only if reliable sensor inputs are fed to the corresponding pilot, otherwise the other side should be engaged and if that too is receiving unreliable sensor inputs then the Auto Off should disconnect any and all automation flying the plane and let the pilots do their piloting sh*t.

Other than the obvious which was already pointed out, autopilot, Airbii have a side stick priority function, meaning you can isolate a side stick from making any control input and put the aircraft solely on one stick.

If it’s a plane with a sidestick/FBW and the plane’s automation is disconnected and in full manual mode, one or both green lights should then light up on the corresponding side(s) anytime the sidestick is sending valid control signals to the various aircraft flight controls.

That’s why there are five flight computers, none of them talk to each other, and the plane only needs one to fly. Redundancy.

If you take the Airbii in to manual, it overrides any flight envelope protection. And it’s up to you, the pilot, to make sure to do as you said and make sure there are no “pitch disagreements...” or control disagreements.

All these freaking software safeguards are killing people. Commercial aircraft shouldn’t require a computer for stability argumentation. I just want the plane to behave something like what I learned to fly on. And then make sure that the good button pushers also retain basic flying skills otherwise drive a taxi.

Nope. Definitely not. They prevent people like you from “knowing better”

One of the companies that I worked for had a fleet of Airbus aircraft. Fortunately, we had a pilot who knew better. The Airbus training at the time made no mention that their wonderful aircraft flight control design could ever do wrong. After all, it was an Airbus and that would be "imposseeble". The system would save the passengers from the pilot, not the other way around.

Then one day a flight departed on one of those wet snowy days, fortunately with a pilot who knew better. They were climbing out in the higher levels when the Airbus decided that the pilot was placing the aircraft ina dangerous position. So it overrode everything and started descending.........at TEN THOUSAND feet per minute. The pilots tried pulling back on the control sticks but to no avail. It kept descending. Fortunately, the pilot who knew better, who also happened to be a check airman decided that he had had enough and did what Airbus should have trained pilots to do but did not. He disconnected the flight computers(known as ADR's) by pushing some buttons on the ceiling and all returned to normal.

Of course Airbus refused to believe that their aircraft had done anything wrong when informed of the incident but slowly, the recorded evidence became irrefutable. It turns out that.....similar to many jets, there are AOA vanes on the Airbus. There is a protective plate at the base of the AOA vanes where they enter the aircraft fuselage. Airbus was worried about ice crystals affecting these plates which are unheated so they created a replacement plate known as a conic plate. The problem was that the new conic plate was susceptible to water entering this area on the ground and then freezing in flight which is exactly what happened. The vanes froze at a certain AOA down low. That partcular AOA was lesser angle than what it would be at higher altitudes where such an AOA is near the stalling AOA. So the computers thought the aircraft was stalling even though the indicated airspeed was just fine. Fortunately, this pilot knew what to do even though the manufacturer had not told him what he should do if such a thing would ever happen because....such a thing would never happen.

Airbus apparently issued what is known as an OEB to inform pilots of this issue and modified their training(and perhaps their AOA vanes). They did send a representative to one of our pilot safety meetings part way through their investigation to discuss the incident and while doing their best to avoid admitting blame on the manufacturer, they couldn't really do so. I knew they would try to hide this as much as possible so I specifically asked if a report on this specific incident would be published and was told yes. Haven't seen anything yet.

Anyways...what is the lesson. Perhaps, there is something to be said about learning some more about your aircraft above and beyond what the manufacturer tells you. Not ridiculous minutia but interesting systems knowledge. I suppose it is like the instructor many years ago said when describing the electrical control for the prop....."if there is a problem, get rid of the electrical sh*t". Same with the Airbus, get rid of the computer sh*t. Boeing too, I suppose. And if things settle down after that perhaps best not to turn it back on.

I always read my FCOM updates and compare with what was written in previous issues and mark it down. I see Boeing removing some detailed info from the fuel system description recently. Minor stuff but perhaps they feel we just don't need to know....sort like in the Lion Air case.

[tps8903]

What year did that happen at your old company? When I read your post it reminded me of the Check Ride crash of the A320 in France that was featured on Mayday a few years back.

Official Report (en francais):
https://www.bea.aero/fr/les-enquetes/le ... -approche/

English Summary:
https://flightsafety.org/asw-article/ch ... -goes-bad/

[pianokeys]

Anyways...what is the lesson. Perhaps, there is something to be said about learning some more about your aircraft above and beyond what the manufacturer tells you. Not ridiculous minutia but interesting systems knowledge. I suppose it is like the instructor many years ago said when describing the electrical control for the prop....."if there is a problem, get rid of the electrical sh*t". Same with the Airbus, get rid of the computer sh*t. Boeing too perhaps. And if things settle down after that perhaps best not to turn it back on.

100% agree.

I was referring to pilots who "know better" as in the cocky-legends-in-their-own-mind type. The ones who think the airplane isnt doing what its supposed to and end up planting it in the ground. But its the true wizards of flying who can tell the difference between a problem, and a problem. There were a handful of incidents when the 320 first came on the scene where flight crews were fighting the airplane from doing what it was supposed to, keep it flying and keep it flying safe and it all boiled down to, as you said, not knowing the systems. If you know what the airplane can, will, and wont do, you can stay ahead of it and fly the plane. And not have the plane fly you.

Interesting incident though, and it doesnt surprise me that Airbus didnt want to believe or acknowledge what was going on. During those events I mentioned, and those other ones that were more public and caused hull losses in its early days, Airbus really tried very hard to snuff out any negativity on the type.

[righthandman]

A rather poorly written article, but before official accident investigation reports comes out it shows a rather nasty flight profile.
https://www.nytimes.com/interactive/201 ... ckpit.html

[Eric Janson]

Preliminary report released.

http://knkt.dephub.go.id/knkt/ntsc_avia ... Report.pdf

They really need to find the CVR to see how the crew responded and what caused them to lose control of the aircraft.

Lion Air was negligent allowing this aircraft to be dispatched - a test flight should have been done first imho.

The fact that they continue to operate despite their appalling safety record doesn't say much for the regulator imho.

Boeing is negligent for not informing crews about a new system installed in this aircraft imho.

[Meatservo]

Boeing is negligent for not informing crews about a new system installed in this aircraft imho.

I'm very surprised they didn't. This "new" system doesn't sound philisophically a whole lot different than various Q-feel systems, or electronic flap/trim compensators, or stick shakers and pushers, all of which helpfully modify the plane's handling characteristics, ironically, to make it fly "more like the type we learned on" to quote righthandman's lament about manual-flight automatics.

All of which, also, are pretty well-explained during ground-school and operating manuals.

Heck, even the lowly DeHavilland Otter has a mechanical system that trims the nose down for you a little, when you put flaps down. Hardly anyone is free of some kind of control augmentation or other.

What is the difference with this particular system? By that I mean, how is it different in its basic philosophy? I understand it was incorporated in order to counter an abnormally high nose-up pitching moment caused by more-underslung-than-usual engines? Is that right? Is it not just basically an enhanced form of stick-pusher?

I find it very unusual and disappointing to hear that this enhancement wasn't mentioned in ground-school. Is that not the purpose of ground-school?

[Eric Janson]

Boeing is negligent for not informing crews about a new system installed in this aircraft imho.

What is the difference with this particular system? By that I mean, how is it different in its basic philosophy? I understand it was incorporated in order to counter an abnormally high nose-up pitching moment caused by more-underslung-than-usual engines? Is that right? Is it not just basically an enhanced form of stick-pusher?

From the various discussions on the Internet I understand the engines on the Max 8 are further forward of the wing than on previous models.

At high AOA the engine nacelles will develop lift causing a further nose up pitch moment. The MCAS system is designed to trim nose down to help offset the pitch up moment.

The FDR traces clearly show the system trimming nose down as a result of a false AOA input. It shows the crew trimming nose up to oppose this.

On a previous flight the stab trim cutout switches were used and the aircraft was trimmed manually. The crew was under the impression that the Speed Trim System was trimming in the wrong direction when in fact it was the MCAS which they didin't know existed.

It's not acceptable to install a system on an aircraft and not provide information about it imho.

[Meatservo]

It's not acceptable to install a system on an aircraft and not provide information about it imho.

I could not agree more emphatically. This is what I was really trying to say in my last post. Every other similar system I have ever encountered, (by "similar" I mean some artificial scheme incorporated into an aircraft's control system to make it feel more "aerodynamically normal" shall we say,) is quite openly and thoroughly explained in the aircraft FCOM.

It's entirely the reason we have "ground school" for various aircraft types. Otherwise, we might as well just get in and drive, like a Mom taking the van to soccer practice. I'm pretty sure I could figure out how to fly just about anything after a few turns through the simulator in order to work out how to start the engines and such, as long as I experienced no malfunctions. Why bother paying attention in ground school if there are going to be secret, hidden systems?

[ant_321]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much. I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

[pelmet]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much.

A good way...or one of the ways that one should look at this is.....there can be lots of information given that is nice to know, not need to know and there can be different angles to looking at accidents for conclusions(eg....an aircraft 1 pound overweight and therefore illegal, yet successfully taking off for years from a long, sea level runway then crashed at a short high elevation runway). Perhaps what the info was given to the pilots in the QRH section for this type of scenario will be important and whether this info was used successfully by the previous flightcrew.

I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

My favourite logbook entry from maintenance...."ground check serviceable". Well it didn't work in the air which can be a lot different environment than on the ground for certain snags. I remember one aircraft type where the elevator trim would become inoperative in flight(including the back-up trim which was a separate motor). Always had a ground check serviceable reply. Turns out they used the wrong grease in the system which would freeze up the system in the very cold temps at altitude, but eventually thawed enough to work in the lower altitudes/after landing. Some entertaining possible theories came out of that snag until it was finally fixed.

[W5]

I agree that Boeing should have informed crews but do you think it would have made a difference in this case? They essentially had an unscheduled trim incident. Every plane I’ve ever flown has had memory items for that, including the 737. The crew on the previous flight got it right, the second not so much. I think the real question in all this is, how did the aircraft get signed off by maintenance without such a serious issue being fixed. “Could not replicate on ground” maybe?

Swapped around for troubleshooting

[goingnowherefast]

That's up among my least favorite words to see in a logbook. Guarantees the reoccurrence, just don't know where.

[Eric Janson]

Very interesting discussion about this accident on PPRuNe.

One of the items posted is this video of the Boeing Stickshaker going off for 5 minutes.

https://www.youtube.com/watch?time_cont ... rjTUvhpBlE

This will drown out the sound of the stab trim moving and is extremely distracting.

It's quite possible the crew didn't notice the uncommanded nose down trim inputs.

They really need to recover the CVR.

[pelmet]

From a Nov. 26 article headline I just clicked on...…

"Pilots Get More MCAS Details; Troubleshooting Procedures Unchanged".

Have any procedures changed yet? Or is this just a case of a lot of headlines of people saying they didn't know some details about a system but it really doesn't matter in terms of what to do if there is a problem.

[ant_321]

From a Nov. 26 article headline I just clicked on...…

"Pilots Get More MCAS Details; Troubleshooting Procedures Unchanged".

Have any procedures changed yet? Or is this just a case of a lot of headlines of people saying they didn't know some details about a system but it really doesn't matter in terms of what to do if there is a problem.

You hit the nail on the head. There is already unscheduled trim memory items and a checklist.

[GARRETT]

This guy explains things pretty well I think.

https://www.youtube.com/watch?v=zfQW0upkVus
https://www.youtube.com/watch?v=1sZfeFJ9n0I

[pelmet]

They really need to recover the CVR.

As an update from a little while back......

"Indonesian Navy divers have recovered the cockpit voice recorder (CVR) from Lion Air flight 610, a Boeing 737 MAX that crashed into the sea Oct. 29, 2018.

Photos show the heavily scratched CVR after its recovery, although it is not yet known if the device is damaged. Local media reports indicate the CVR was found buried in mud at a seabed depth of 30 m (98 ft.), about 50 m from where the flight data recorder (FDR) was found.

The Boeing 737 MAX aircraft crashed soon after takeoff from Jakarta, killing all 189 passengers and crew. The FDR was located and recovered within days of the crash, but mud, strong currents and other factors impeded the search for the CVR. Tracking signals had been detected from the CVR in November. The 90-day battery life of the device’s tracking beacon was due to expire around the end of January.

Lion Air called off its search for the CVR on Dec. 29, 2018. However, the effort was relaunched with assistance of the Indonesian Navy.

The CVR could shed more light on what happened during the final flight of the Lion Air aircraft. Other evidence, including data retrieved from the FDR, indicates the pilots were struggling to control the aircraft prior to the crash. According to a preliminary report, the aircraft’s automatic trim system kept pitching the aircraft down because of faulty inputs from angle of attack sensors."