Speaking of surprises...

[Oldman731]

...the Indonesian 737 pilots appear to have gotten a big one.  Yikes.

"Boeing Co. BA -2.11% withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month’s fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots.

The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 models—intended to help cockpit crews avoid mistakenly raising a plane’s nose dangerously high—under unusual conditions can push it down unexpectedly and so strongly that flight crews can’t pull it back up. Such a scenario, Boeing told airlines in a world-wide safety bulletin roughly a week after the accident, can result in a steep dive or crash—even if pilots are manually flying the jetliner and don’t expect flight-control computers to kick in.

The Boeing 737 Max 8 features a new stall-prevention system that may have contributed to crash of Lion Air flight 610.

Erroneous information sent from data probes to the plane's flight control system may have triggered a sharp descent.

If the sensor reading shows the nose of the plane is rising too far, the automatic stall-prevention kicks in, pushing the nose down.

But on the Lion Air flight, the faulty data may have activated the system even though the nose wasn't rising. Pilots would have had to quickly switch off the system to recover.

That warning came as a surprise to many pilots who fly the latest models for U.S carriers. Safety experts involved in and tracking the investigation said that at U.S. carriers, neither airline managers nor pilots had been told such a system had been added to the latest 737 variant—and therefore aviators typically weren’t prepared to cope with the possible risks.

“It’s pretty asinine for them to put a system on an airplane and not tell the pilots who are operating the airplane, especially when it deals with flight controls,” said Capt. Mike Michaelis, chairman of the safety committee for the Allied Pilots Association, which represents about 15,000 American Airlines pilots. “Why weren’t they trained on it?”

https://www.wsj.com/articles/boeing-withheld-information-on-737-model-according-to-safety-experts-and-others-1542082575?mod=hp_lista_pos1

- oldman

[Busher]

Through almost 40 years of professional aviation, I watched the "office" go from virtually no automation, through rudimentary autopilots, to today's computers that barely include the human pilot in the information loop.
I am retired now so there will be those that say that this is just an old man speaking, and maybe it is; but one fundamental still remains... From the beginning of automation, we were taught not to put blind faith in the machine.... if the airplane is not doing what you expect, disconnect and fly it.
One of the best First Officers I ever flew with is now a senior Captain with a major airline which of interest has a very large fleet of B737's including the Max. He often laments to me over coffee, that he has forgotten how to fly. Apparently, it is his company's policy that the automation be used immediately after takeoff until short final on approach... unless of course an auto-landing is mandated by weather. He jokes that he an his First Officers log an annual total of 7-10 minutes of hand flying.
Some years ago there was noise being made in ALPA that pilots should be demanding much more training in Basic Operating Skills - A nice name for hand flying. As many of you know, there is a growing pilot shortage and the shortfall of qualified personnel is not helped by the FAA's minimum 1500 hours to crew a Part 121 cockpit; possibly supporting a strong argument for enhancing basic flying skills.
It is far too early to comment on the ultimate cause of this horrific accident. It is an American made airplane so the NTSB will be involved and we will eventually know that facts. I just hope that a simple autopilot/autothrottle disconnect was not the answer.

[Puma44]

“Why’s it doing that?” commonly heard in NG (Next Generation) 737 cockpits, especially in the early days.

[eagl]

Don't quote me, but...

Press trim switch opposite of runaway condition.
Trim disconnect switch - disconnect
Manually trim pitch using trim wheel

You'd think that's easy, but try doing it while fighting up to full nose down pitch trim plus the stick shaker as the aircraft accelerates and tries to dive into the ground right after gear retraction.  2 hands on the controls to try to keep the nose up, trim disconnect switches are over on the FO side, so who keeps their thumb on the electric trim switch, who pulls the throttles back a bit so it isn't accelerating so fast, while stick shaker pulses.

And oh yea training for stick shaker is to lower the nose, so you're fighting AGAINST repeated training events in the sim by pulling against the stick shaker.

The only indication of what's really going on is the trim wheel spinning forward, but no indication WHY.  Because Americans are terrified of AOA gauges, have been for decades (go back to 1988-1989 issues of AOPA pilot to see the hot debates on why we shouldn't put AOA gauges in airplanes). 

Unofficial speculation - The pilots might have seen the faulty AOA gauge pegged full up or mismatched between CA and FO sides, if American civilian aircraft had AOA gauges.  I think SWA HUDs have AOA info in there but I don't get one on my side and I'm too lazy to pull out the FRM to check right now.

I'm still pissed at the idiots 30 years ago arguing that AOA gauges amounted to information overload.  Those jerks and their mythology about AOA are probably responsible for a couple hundred stall/spin mishaps over the last few decades, where a simple AOA gauge would have provided instant visual feedback to the now-deceased pilots about how close they were to the stall.  Add another hundred-plus deaths that I attribute to the anti-AOA superstition that still keeps that critical performance gauge from being installed in every aircraft.  Bunch of freaking witch doctors and their chickenbones.

[eagl]

And think about the crew coordination.

PURE SPECULATION FOLLOWS:

Stick shaker goes off, one pilot thinks "push"

Second pilot says "airspeed is too high, we can't be stalling, PULL"

First pilot says "airspeed might be unreliable (plugged pitot tube gives rising airspeed as altitude increases and they were climbing after takeoff)"

Second pilot cross-checks pitch and power, repeats his call to pull

First pilot remembers training about the airbus that was in a deep stall for several minutes from cruise altitude all the way to crash with the pilot pulling the whole time, and keeps thinking PUSH

So they spend some time comparing airspeed indicators and other performance indications while the trim continues (possibly unnoticed) to run forward.

At some point the full nose down trim plus stick shaker plus increasing airspeed (plus maybe flaps still down?) makes it physically impossible to pull the nose up.

At what point in there do they calmly transition to the runaway trim procedure, when the key information they need (system operation description from Boeing plus an AOA gauge for each AOA sensor) is not available?  They very likely had time time to verify that both CA and FO airspeed and altitude matched, however AOA sensor data goes into the trim system to help prevent a stall when the gear is up.  So a faulty AOA sensor reading up in the stall region would start running nose down trim and turning on stick shaker right at gear retraction.  With the throttles still at takeoff and flaps possibly not retracted, you're going to go from bad to unrecoverable in a matter of seconds. 

No training program I am aware of will have a pilot actuate the nose up pitch trim when the stick shaker is activated, however that is actually the correct response to this failure!  The only way you would know is to verify AOA mismatch, and that information is not available to the pilot.

Basically the word is that existing procedures are sufficient to handle this emergency, if you can figure out what's going on in time.  And that's the current media spin, that Boeing might not have included the link between the AOA sensor and the stall prevention inputs of nose down pitch trim and stick shaker when the training products were distributed.  With no knowledge of that system operation mode and no AOA gauge, the pilot has to make it the leap AWAY from his training (stick shaker = push the nose down) to do the exact opposite.  In the absence of an AOA gauge, the only clue is the pitch trim wheel spinning forward.  Except that the pitch trim wheel *normally* runs forward some as the plane accelerates after gear retraction.  Again, the missing pieces are the missing AOA gauge and system operation (and differences from other type variants) training passed from boeing through the operator's training department to the pilots.

[eagl]

.

[pembquist]

The only indication of what's really going on is the trim wheel spinning forward, but no indication WHY.  Because Americans are terrified of AOA gauges, have been for decades (go back to 1988-1989 issues of AOPA pilot to see the hot debates on why we shouldn't put AOA gauges in airplanes). 

I didn't know there was an anti AOA gauge sentiment. I learned to fly in the mid 90s and since I was always more interested in experimental AC I only ever really read pubs like Kitplanes and Sport Aviation and they were always enthusiastic about AOA gauges. I have a hard time imagining a compelling argument to not use them, information overload? that seems like a really stupid argument. I can see why you find it maddening.

[bustr]

How far away are AI only passenger carriers? The last 30 years has also been the continued arguments about how inefficient and error prone due to physical realities human pilots are. The computer controlled cockpit with the pilot only involved at take off and landing has been that goal along with eventually removing pilot input during those two events. AI don't decide to commit suicide into the Alps with their unwilling passengers. AI still can't handle ice spins in cars yet and this event sounds like it's equivalent in the air.

[Puma44]

How far away are AI only passenger carriers? The last 30 years has also been the continued arguments about how inefficient and error prone due to physical realities human pilots are. The computer controlled cockpit with the pilot only involved at take off and landing has been that goal along with eventually removing pilot input during those two events. AI don't decide to commit suicide into the Alps with their unwilling passengers. AI still can't handle ice spins in cars yet and this event sounds like it's equivalent in the air.

All well and good.  But, when the AI computer takes a dump, there has to be a well trained human pilot to “dummy down” the technology and fly the airplane. 

[1stpar3]

All well and good.  But, when the AI computer takes a dump, there has to be a well trained human pilot to “dummy down” the technology and fly the airplane.

I HAVE TOO ASK,PUMA44..Why all the #2 stuff with pilots. Had "POOPY SUITS" and NOW AI Taking a DUMP Must be what they fed you guys?. I was telling my Dad about your "WRITE UPS" on when you were in AF....I was talking about The Poopy SUITS...Dad stops me and raises an eye brow.."I could have used one of those, this morning when I was at the barn. I didnt make it back to the house in time". DAD, it was actually Cold Water Survival Suit. DAD.." Well it was cold and raining. Thats why I wanted to come back to the house"   

[bustr]

Since that big 747 accident at Tenerife the goal of the airlines and insurance companies has been to remove humans from piloting human carriers. The cost of accidents with loss of life or just several hundred law suits from survivors of a mishap takes years to recover under the slim margins carriers operate. How many full time pilots would have to be on the payroll so that all flights had well rested and not over worked humans doing all the work in the cabin if AI was all pulled out tomorrow? How much AI does the Military rely on in the air lift command with all of the young under paid pilots they have? How does the human error rate for the Military cargo and people carriers hold up to the civilian with AI and pilots who are just there for two functions? Who has the better hands on pilots in emergencies?

[Puma44]

Since that big 747 accident at Tenerife the goal of the airlines and insurance companies has been to remove humans from piloting human carriers. The cost of accidents with loss of life or just several hundred law suits from survivors of a mishap takes years to recover under the slim margins carriers operate. How many full time pilots would have to be on the payroll so that all flights had well rested and not over worked humans doing all the work in the cabin if AI was all pulled out tomorrow? How much AI does the Military rely on in the air lift command with all of the young under paid pilots they have? How does the human error rate for the Military cargo and people carriers hold up to the civilian with AI and pilots who are just there for two functions? Who has the better hands on pilots in emergencies?

You’ve got quite a bit of research to do Bustr.  Looking forward to what you find. 

[Busher]

Since that big 747 accident at Tenerife the goal of the airlines and insurance companies has been to remove humans from piloting human carriers. The cost of accidents with loss of life or just several hundred law suits from survivors of a mishap takes years to recover under the slim margins carriers operate. How many full time pilots would have to be on the payroll so that all flights had well rested and not over worked humans doing all the work in the cabin if AI was all pulled out tomorrow? How much AI does the Military rely on in the air lift command with all of the young under paid pilots they have? How does the human error rate for the Military cargo and people carriers hold up to the civilian with AI and pilots who are just there for two functions? Who has the better hands on pilots in emergencies?

To my limited knowledge, airline accidents that result in successful lawsuits for the injured and killed, do not cost the carrier anything except bad press. I believe the insurance they carry covers their total liability except in the rare case of "gross negligence or wilful misconduct" (ie. the suicidal German First Officer). And as a testament to the past safety of airline flying, that insurance on a per-boarded-passenger is shockingly cheap.

[Busher]

How far away are AI only passenger carriers? The last 30 years has also been the continued arguments about how inefficient and error prone due to physical realities human pilots are. The computer controlled cockpit with the pilot only involved at take off and landing has been that goal along with eventually removing pilot input during those two events. AI don't decide to commit suicide into the Alps with their unwilling passengers. AI still can't handle ice spins in cars yet and this event sounds like it's equivalent in the air.

For your consideration, the aircraft I retired on was state-of-the-art in automation. In my last full year of flying, I had at least two computer "burps" that would have resulted in a loss of control had there not been a couple of humans there to steer.
Would you trust your home computer, even three of them working in parallel with your life?

[save]

The Lion air plane was at 5k or so, not much time to figure out anything I guess.