Lionair 610 crash

[Quickstatus]

A polite way of saying they didn't know what was going on. The AF mid Atlantic accident springs to mind.

I think this one is going to be quite different because fingers will be pointing in several directions.

Pilotcerror - yes but maintenance kept putting aircraft in the air, previous crew had similar problem but didn’t say anything. Boeing sold them a design that had a secret that allowed the stabilisers to be trimmed to a position from which there is no recovery by any pilot input

 

[suze2000]

Boeing sold them a design that had a secret that allowed the stabilisers to be trimmed to a position from which there is no recovery by any pilot input

This is what scares me the most. VA are getting a bunch of 737Maxes later this year.

 

[Quickstatus]

This is what scares me the most. VA are getting a bunch of 737Maxes later this year.

Well the secret is out now, so the industry will be incorporating it into their regular training.
Hopefully no other secrets

 

[Deleted member 29185]

Boeing sold them a design that had a secret that allowed the stabilisers to be trimmed to a position from which there is no recovery by any pilot input

This is what scares me the most. VA are getting a bunch of 737Maxes later this year.

From my understanding, the pilots could have taken back control, but they became somewhat confused because they didn't know about this quirk, were not trained in this quirk and Boeing assumed previous related, but dissimilar pilot knowledge would suffice in this unlikely event. It would appear they were wrong in that assumption, but hopefully now, Boeing are scrambling to correct an obvious error and airlines throughout the world are upskilling their pilots to at least be aware of this problem and the remedial action needed to control it and may possibly include simulator training to support it.

 

[Quickstatus]

They could have turned off the trim motors and manually (furiously) spun the trim wheels. Probably too late when the aircraft went nose down as the negative G would have made it incredibly hard or physically impossible. The crew had several opportunities before the aircraft went vertical

 

[AviatorInsight]

This is what scares me the most. VA are getting a bunch of 737Maxes later this year.

Yes we are, but our check and training system are all over the changes and I’d like to think the travelling public have faith in our abilities to handle any abnormalities. We have been working closely with Boeing for the introduction of the Max and have also revisited the trim runaway in the current simulator session for all pilots. This was even before the accident occurred. In addition to this, all of our pilots will be undertaking an upper recovery prevention training (in the simulator of course), but this package is designed to hone in and practice those procedures to give an understanding of what we have seen in recent accidents.

 

[Deleted member 29185]

our check and training system are all over the changes and I’d like to think the travelling public have faith in our abilities to handle any abnormalities

Many thanks for living up to you addy, @AviatorInsight!

 

[woodborer]

They could have turned off the trim motors and manually (furiously) spun the trim wheels. Probably too late when the aircraft went nose down as the negative G would have made it incredibly hard or physically impossible. The crew had several opportunities before the aircraft went vertical

Maybe it would have been a different result with different crew.

But also, maybe it would have been a different result if Boeing had told pilots about this feature.

 

[suze2000]

We have been working closely with Boeing for the introduction of the Max and have also revisited the trim runaway in the current simulator session for all pilots.

I just worry about what other surprises Boeing has put in. I think I'll be avoiding this plane type if possible at least until the end of the year.

(also, no doubt VA have squeezed Y seats even closer together, so likely another reason to avoid it)

 

[Quickstatus]

I just worry about what other surprises Boeing has put in. I think I'll be avoiding this plane type if possible at least until the end of the year.

(also, no doubt VA have squeezed Y seats even closer together, so likely another reason to avoid it)

Once the accident report is released we will officially know the anatomy of the accident and the root causes. I suspect the industry already has a good idea and measures undertaken to mitigate future occurrences.

Aircraft are highly complex these days and coupled with equally complex procedures and governance. For this reason It is unlikely that all unintended consequences will ever be known before the fact.

 

[AviatorInsight]

I just worry about what other surprises Boeing has put in. I think I'll be avoiding this plane type if possible at least until the end of the year.

(also, no doubt VA have squeezed Y seats even closer together, so likely another reason to avoid it)

I understand your concern and I'm certainly not going to force anyone to fly on something they're not comfortable with. The Max has already been flying around for a while now elsewhere and when you think about how many other incidents have happened with aircraft that have been in service for years and those 'gremlins' had never been seen before, yet the crew displayed great airmanship to get their aircraft back safely.

Once I get full training on the machine I will put up a post on my experiences should that help. I will even call for the checkie to give me an uncommanded trim runaway and see what it does.

Re VA squeezing Y seats even closer together I have no idea about the Y seat pitch, yet there are talks of the longer -10 being placed on transcon only with 12 J lie flat seats (unconfirmed). I'll believe it when I see it parked at the gate.

 

[Scarlett]

I suspect, if the contents ever become public...

I may be cynical, but the contents will likely be transcribed (in part) on WhatsApp within the day of them being downloaded from the CVR.
Certainly the pax manifest for the accident flight was being sent around in just over 2hrs after the accident. It is what it is.
Unless of course the download is being done outside Indonesia, in which case it might be a day or so later.

 

[RooFlyer]

We have been working closely with Boeing for the introduction of the Max and have also revisited the trim runaway in the current simulator session for all pilots. This was even before the accident occurred.

Not sure how much you'd like to or can say ...

This implies that Virgin at least was aware of the 'runaway trim' issue; I wonder if it was explicitly revealed by Boeing or if someone in Virgin figured it out?

 

[jb747]

A polite way of saying they didn't know what was going on. The AF mid Atlantic accident springs to mind.

The AF accident will always be remembered as an amazing event...because they should have known what was going on...as it was totally a pilot initiated event. The pilot who did most of the flying simply wasn't a pilot. In no world does holding full back stick from altitude do anything other than stall the aircraft.

Equally, in this event, assuming it was MCAS, whilst they would not have known the reasons, it would have been presenting itself as runaway pitch trim, which should be easy to detect. Trim input is quite obvious....

Although not as expert as many others on here, I feel that Lion Air is a completely different kettle of fish. The AF disaster appears to me to be a case of a pilot making very bad decisions, despite his training. Lion Air appears to me to be a case of the pilot simply never having been trained or made aware of some lethal quirks the plane had inbuilt.

In both cases, a simple flying solution was available, but in the AF case the opposite was chosen. In Lion's case we don't know the why yet.....

As a generalisation, flying issues are normally easy to detect, and most have logical flying inputs to correct them. Automation issues can be much harder to work out...which is why automation is normally abandoned as soon as it does something you don't expect or want. BTW, for those looking forward to the pilotless aircraft....that happens all of the time.

Runaway trim is not a new thing, and Virgin doing training on it does not mean they know any of the Max's secrets. In my world, there was a procedure for it in the A4....and every Boeing that I've flown had a fix for it.

 

[AviatorInsight]

Not sure how much you'd like to or can say ...

This implies that Virgin at least was aware of the 'runaway trim' issue; I wonder if it was explicitly revealed by Boeing or if someone in Virgin figured it out?

It wasn’t meant to be that they knew a secret as such, rather than to say that with a proper cyclic program, most of the memory items (and this includes runaway trim) should be covered in a 24 month cycle.

Regardless of what caused this issue (MCAS or whatever else), it’s about knowing your aircraft. Staying on top of procedures.

 

[tgh]

Great input from the pilot's .. thank you

 

[woodborer]

Interesting article (at least for me), on the MCAS thing in the 737. This bit especially

In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight.

Behind the Lion Air Crash, a Trail of Decisions Kept Pilots in the Dark

 

[Berlin]

Another pretty good article (so I thought) that looks more at the general pros and cons of automation in the coughpit and how some airlines are cutting corners with their training: Lion Air crash shows coughpit computers are no substitute for pilot skills

 

[Quickstatus]

Im putting an MCAS question here rather than the Ethiopian 737Max8 thread because we dont know what happened to ET302

Boeing says MCAS electrical trim can be turned off - just like the procedure for a Runaway trim.
However, MCAS does not present as a runaway trim, rather it pushes trim nose down 2 deg then stops then keeps doing 2 deg every few seconds. (But it still would be an Pilot uncommanded trim).

Is it possible therefore because it does not look like a runaway trim, the pilots are not thinking to use the runaway trim procedure as a fix (remembering the fight deck would at this time be quite chaotic and startling)

 

[jb747]

Boeing says MCAS electrical trim can be turned off - just like the procedure for a Runaway trim.

Yes, it can be.

However, MCAS does not present as a runaway trim, rather it pushes trim nose down 2 deg then stops then keeps doing 2 deg every few seconds. (But it still would be an Pilot uncommanded trim).

Where are you reading that it stops after 2º? From what I recall of the Lion trim input graph there were sustained inputs that only stopped when trimmed against.

And 2º of what? Pitch change? That's enough for a couple of thousand feet per minute of altitude change. Pitch trim setting...the effect would be large, far out of proportion for such a seemingly small number.

Is it possible therefore because it does not look like a runaway trim, the pilots are not thinking to use the runaway trim procedure as a fix (remembering the fight deck would at this time be quite chaotic and startling)

Hard to say, but given that it does not respond to the normal initial actions, it may well be a case of too late.