My parent company I work for has a big chunk of the worldwide market for FAA Level D Full Flight Simulators. (My local business unit is a bit more, ah, specialized).
From a industry standpoint, this accident being the second in what five? months involving a type that has to date been extremely safe (and, in general, Aviation is extremely safe) is pretty unusual. Personally I'll be waiting for the accident analysis; the folks who do this for a living are extremely good at what they do.
I’m here. Don’t have much time to write now but to quote Blood Diamond- this is Africa. Lots of other possibilities for the Ethiopian accident besides MCAS activation and we really need to wait and see. The news media is fanning the fear and reporting misinformation as usual.Originally Posted by TGS
We have two others on this forum who also fly the Max. Maybe they will chime in.
One more thing - both Southwest and American have far more flight hours in the Max than pretty much everyone else combined and have not experienced these issues.
Part of my professional duties involve reviewing FDR data to support incident investigations on (non-Boeing) jet aircraft. I haven't been involved in a "real" accident investigation yet but I eventually will be in time.
Anyway, I can't tell you how many times review of the hard data has turned up something very different than what crew/owner/witnesses/"everyone" thinks happened.
The groundings right now are knee-jerk political reactions (whether public or private sector) intended to make the grounders seem like they're Doing Something. After all, the safest airplane is the one that never flies...
Let's wait for the data to come out.
"Political tags - such as royalist, communist, democrat, populist, fascist, liberal, conservative, and so forth - are never basic criteria. The human race divides politically into those who want people to be controlled and those who have no such desire." - R. A. Heinlein
The FAA, on the other hand, kind of likes to have facts to consider before issuing mandatory grounding orders or airworthiness directives.
"zOMG, two planes crashed! Ground the fleet!" is regulation by panicking. And, for what it's worth, I don'r remember the Euros grounding all of the A220s when AF447 has a somewhat mysterious crash into the Atlantic.
If we have to march off into the next world, let us walk there on the bodies of our enemies.
I am with @Suvorov on this one. The knee jerk reaction and mass hysteria of the media without all of the facts, does nothing to help aviation safety or the traveling public. Truth be told, we haven’t had many big aviation accidents in this era of social media. Imagine the social media reaction to TWA 800, USAir 427, United 585, and many of the other mysterious accidents over the years. You get the idea.
What is MCAS? Here it is in a nutshell: A pitch augmentation system function called Maneuver Characteristics Augmentation System (MCAS) is implemented
on the B737MAX to enhance pitch characteristics with flaps UP and at elevated angles of attack.
Here is how we can override it: “Flight Deck Crew to use the COLUMN TRIM switch or stabilizer aisle stand CUTOUT switches to override MCAS input.”
After moving the stabilizer trim switches to cutout, we just use our big trim wheel and fly the airplane without the autopilot.
There is a derogatory aviation term “Children of the Magenta Line,” that we use to refer to the pilots that are simply button pushers. The foreign carriers appear to be full of them.
Here in the states, I have full faith in any of the other Max operators. I have no problem putting my family on a Southwest, American, United, or Alaska 737 Max. All 4 of these carriers take pride in their flight crew training and procedures, and that is what separates our airlines from the rest of the world.
Thx for weighing in Suvorov & Guinessman. Not sure if he’s on a 737 Max but anyone seen GyroF-16 lately?
Last edited by OldRunner/CSAT Neighbor; 03-12-2019 at 09:28 PM.
https://www.wsj.com/articles/boeing-...re-11552413489
Boeing Co. BA -6.15% is making an extensive change to the flight-control system in the 737 MAX aircraft involved in October’s Lion Air crash in Indonesia, going beyond what many industry officials familiar with the discussions had anticipated.
The change was in the works before a second plane of the same model crashed in Africa last weekend—and comes as world-wide unease about the 737 MAX’s safety grows.
The change would mark a major shift from how Boeing originally designed a stall-prevention feature in the aircraft, which were first delivered to airlines in 2017.
U.S. aviation regulators are expected to mandate the change by the end of April.
Boeing publicly released details about the planned 737 MAX software update on its website late Monday.
Likes pretty much everything in every caliber.
What's EADS' / Airbus's stock sitting at since they announced the A380 product line to cease production?
Boeing isn't the only company installing these type of stall protection systems in their aircraft and we aren't seeing those other ones fall from the sky...
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Boeing's system here works a little differently than other systems have. From what I can read on the system, I personally don't particularly like how Boeing implemented it (as an aircraft systems engineer and private pilot); I don't like that it works off only one sensor at a time and I don't like that it just add in trim input without some kind of annunciation that it's doing something (IMHO it should at least pop up an "MCAS ACTIVE" advisory message for a few seconds or something). But after the Lion Air crash I would think anyone flying one of these would know about MCAS and how to deal with it if it starts misbehaving.
Some larger aircraft that aren't fly-by-wire, particularly those with T-tails, have a system that adds a control input to avoid a stall. But at least on the aircraft I work on, it's not a somewhat-subtle trim input--it's a very noticeable shove forward that you won't mistake for anything else.
Were I a betting man, I'd bet a beer or two that this accident has nothing whatsoever to do with MCAS. Unfortunately, even if I'm right, the airplane will probably wind up forever saddled with an undeserved reputation for being "dangerous".
"Political tags - such as royalist, communist, democrat, populist, fascist, liberal, conservative, and so forth - are never basic criteria. The human race divides politically into those who want people to be controlled and those who have no such desire." - R. A. Heinlein
There is nothing subtle about trim inputs in a 737 flight deck. The trim wheels are enormous, relatively speaking, so you can manually turn them if need be. Trim inputs involve those wheels spinning that are loud and very noticeable.
The normal takeoff and climb sequence involves automated trim without additional annunciation. But that is expected behavior at that point in the climb.
I have zero experience with the Max but I am curious if MCAS activates without letting the crew know.
Additionally, if there is a failed Alpha Vane on one side, wouldn't you also get an airspeed mismatch on the roll at 80, maybe a few knots P vs CP? And then an airspeed disagree in-flight? For you aerospace engineers, yes alpha is used by the ADIRU for airspeed calculations.
Regardless, I spent a quarter of my life flight testing the 737NG/derivatives and they are all like my children. I hate when bad things happen that involve them.
End of the day the pilots need to be able to recognize the problem first. And then fix it based on training. Easier said than done sometimes. Shortly after takeoff is a tough place to work out longitudinal aircraft control problems.
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