Another Boeing 737 Max-8 crash

I definitely agree, unreliable airspeed combined with a serious trim is definitely something I don’t want to encounter, and then you add in Indonesia ATC/terrain in the mix and you have a recipe for destruction, trust me I have flown there too many times.

 

There’s little else worse than questionable engrish from ATC on your last leg of a transcontinental flight, except Sovi ... I mean, Russian ATC, under any conditions.

 

Actually Russia is pretty good now, at least in the western part near Japan, Alaska and near northern China.

 

Maybe it’s just the private pilots flying business jets that they hate.

eg. Takeoff from Sheremetyevo, you may get vectored straight to the nearest aerial gunnery range, at 500 feet.

They would not give you a departure SID until airborne so you’d have to look it up as you’re flying runway heading towards military airspace.

 

@Monsterdood, where did you see that the stab could be positioned so that there’s not enough elevator authority to override the nose down moment? I don’t know if this is correct-I can’t find it in any of my 737 manuals. My experience in the simulator is that even with a badly mistrimmed stabilizer, there is still a combination of thrust and elevator that will get the nose up. Conversely, with high thrust and stab out of trim UP, it’s hard to get the nose down without trimming down or reducing thrust- which is one reason MCAS was designed.

It’s not reasserting control. It’s trimming down. You can trim back up at the same rate. After a few cycles of this, that would be a pretty obvious trim runaway. Stab Trim Runaway checklist. They didn’t do that.

As @dieterly points out above, the Lion Air airplane was flyable.

 

Not a fact, but from a pilot forum discussion on the Max. The thought was with the right thrust and elevator, you could override, but the wrong thrust and full trim may exceed the elevator authority. A bit of an aerodynamic bucket that once in, would be unrecoverable.

Apologies if it sounded like fact, but there was clearly some reason why a runaway trim was unrecoverable in two instances and the pilots couldn’t just pull back harder to stay out of trouble.

I’ll be at MA RA as crew and VIR riding so we’ll have to compare notes.

 

Corrected to say it may not have enough authority based on some other pilot forum discussion. The thought was that high speed, low thrust and full down trim would be a serious condition to avoid.

 

I would assume that you get some sort of CAS message or alarm after the trim runs for a certain number of seconds, right?

One of the things I hate about this playing out in the news is there is so much nuance to these things. There is a rush to put blame in one place and that’s just ignorant. It’s why the NTSB takes years to put out a report. It takes that long to fully understand what happened (if then).

On a side note, I got to tour the NTSB training center in Washington a couple of years ago. It was very eye opening. I got to stand in the cockpit of TWA800. That was something I’ll never forget.

 

That's eerie to just think about, let alone experience!!!

 

We don’t know that trim even played a role in the Ethiopian crash, let alone MCAS.

There are lots of situations where a pilots failure to fly the airplane can lead to unrecoverable situations.

In today’s news, the Lion Air crew had not been trained on the runaway stabilizer checklist. Nor had the Ethiopian crews. They JUST NOW started training an item that Boeing had considered a Memory Item since the first 737 delivery. The Lion Air crew that survived was reminded about the stab trim cutout switches by a Jumpseat rider.

This is just the tip of the iceberg. There are a lot of minimally qualified pilots flying in these foreign countries. Aviation safety worldwide is going to continue to suffer.

And why on earth send the black boxes BACK to Ethiopian authorities now?

This 737 MAX business is starting to make me cranky. I need to focus on racing.... and boobies. Those things always make me feel better.

 

There is a Stab Out of Trim warning light on the MAX. but really, to not notice the trim wheel turning for the amount of time it takes to get that far out of trim, while hand flying is the equivalent of not noticing that you’re bouncing your bike off the rev limiter with every shift.

 

What are the checklist steps when a stall is indicated? Say the pilots followed all the steps, is there a point where the list says to disconnect the MCAS? Just thinking what would have happened if the pilots did everything "by the book."

 

MCAS is there to put the nose down in case the idiiot between the yoke and the seat doesnt recognize an imminent stall. Its supposed to lower the nose by trimming the stabilizer. So you wouldnt disconnect it if you thought a stall was imminent.

Also it doesnt sound like Boeing even told anyone that MCAS existed since it should only act in rare instances.

 

wait..you're not supposed to do that how else can you look cool on the street

 

So what's the checklist process to diagnose the nose dropping against pilot input? What other conditions could cause the same situation other than a pilot stalling because they're dumb?

 

There is no checklist for a stall, Boeing recommends certain steps but at the end you fall back on training you learned as a 8 hour pilot. Disclaimer; I have never flown a narrowbody jet.

 

So apply power, nose down, gain airspeed, level off, smack whoever was at the controls. So if you do that and the plane is still trying to nose over and you can't get the plan back to level flight because it's trying to nose dive I guess your first instinct would be the elevator is fucked. Is there any situation where you would use max trim when maneuvering or just maintaining flight?

I hated power on stalls in a little 152.

 

Basically yes, and if the airplane is trimming unscheduled, as Boeing calls it, then you switch the STAB TRIM CUTOUT switches to CUTOUT. That’s what the guys on the flight before the Lion Air accident accident flight did. And remember, it’s not only for nosedown, the might for some reason start trimming nose up. I’m sure there might be times when you would use max trim, like some serious cargo shift but something I never want to see, because then you are in serious trouble. But you have to remember, there might lots confusion going, trying to figure out what airspeed indicator is correct, stall shaker is activated, overspeed horn is blaring, and even for well trained pilots and emergency like that is an handful.

 

I only fly bugsmashers like you Jed but what dieterly said is what I would do...and did do when I had elec trim run away.
Turned out to be a stuck/dirty switch on the yoke. Mine was easy cause I trimmed and let off the switch and it kept going. Re trimmed it and it went back the other way...so just pop the breaker.

Something the guys should have done on lion....hey WTF why did we just pitch down...fix it..re trim......damn it did it again...why is the trim wheel turning...hmmm stab trim checklist....ok turn it off...problem solved

 

Anyone provide the investigators with a link here? They should know that we can collectively solve anything. Been proven time and time again.