I believe this whole ordeal is the perfect portrait of exactly that happening at Boeing. Even now Boeing is pushing for the aircraft to re-enter service without pilots receiving actual simulator training.

Statistically, two sensors are more reliable than three.

See the second answer here:
https://aviation.stackexchange.com/q...attack-sensors

Their analysis is off. Assuming p=0.1% (probability of failure of any given sensor) and q=1-p (probability of successful reading from any given sensor), the chance that a fault goes undetected in a 2 sensor setup is NOT q*q=10E-6. In order for a fault to go undetected, both sensors have to fail in the same way. If the true reading should be 0, and both sensors fail with one giving a reading of +1 and the other giving a reading of -1, then this dual failure will be detected. In any case, what you don't want is for a simultaneous dual sensor failure where both sensors fail in the same way to cause a situation where the computer assumes that the two (failed) sensors are returning the correct reading because they failed in the same way. In a 2 sensor setup, this is exactly what would happen if both sensors failed in the same way. In a 3 sensor system, it could at least flash an alert and tell the pilots something is wrong because it has the input from that 3rd sensor. It might initially assume that the 3rd sensor has failed if the other 2 failed in the same way and are returning identical readings, but unlike the 2 sensor system, it won't just indicate that everything is ok.

Of course this analysis assumes that failures are independent events. Since these sensors are attached to the same plane and flying through roughly the same conditions, then any environmental conditions that cause a failure of one sensor may well cause a failure of another, in the same way. Also, if you were to put lots of sensors on a plane, the chance that any one sensor fails on a given flight actually goes up. If you have say 1 million AoA sensors on the same plane, there's a high probability that at least one of them is going to fail especially if the probability of failure is 1/1000. For the same reason, you don't create RAID5 arrays with tens of thousands of hard drives in them, because the failure that a second drive fails before the array can be rebuilt is actually quite high.

Looks like they found a parking place for the MAX jets:


Remember this the next time you get mad at someone for taking up two spaces in a parking lot.

That was months ago and they've used up a ton of it.

I’m not aware Boeing has made such a statement. Perhaps you could post a source or edit your post accordingly.

There is no AoA disagree light. It is an "AOA DISAGREE" message which appears on each pilot's primary display unit.

The AOA DISAGREE message has never been optional. The option is for a display of the AoA itself, also on each pilot's primary display unit. That option is typically only selected by airlines which also install the optional Heads Up Display (HUD), which includes an AoA display, for CATII/III approaches. Airlines which use the autoland feature for CAT II/III approaches don't typically have the AoA display as there are no procedures which utilize it.

After the accidents, a bug was found in the software which preventing the "AOA DISAGREE" message from displaying on aircraft that did not have the AoA display option.

Yes, UA will let you switch away from a 737-MAX, but you won't necessarily have great options because UA won't guarantee...

• Similar equipment (your new flight may be an ERJ instead of a 737)
• Similar seat (E+ may be all gone -- or only middle E+ is available)
• Similar route (you may have to connect -- maybe more than once)
• Same travel date (you may have to fly a day or two earlier or later -- depending on seat availability)

You make some fair and salient points, but I'll just reply to the the above.

My observations are purely taken from my past professional and personal experience and completely unrelated to the lawsuit above, the Union referenced or the Pilots quoted.

Without any due diligence on the issues, I'll offer the following:

Generally speaking, labor unions do things for a variety or reasons. Some of which I've experienced are: 1) taking stances to increase negotiating leverage; 2) a small special clique within the broader union trying to push an agenda; 3) tit for tit against Management for real or imagined slights; and, 4) good old fashioned green mail driven old fashioned greed. Regarding the article, I have no idea the background of the writer or the motivation driving the article. Does there exist a potential conflicts of interest? Is this article driven by someone from the Union? Friends of the Union? Regulatory agency? No idea. And, generally speaking, on an issue where I'm responsible for making a decision, I'd devote some resources to conducting some independent due diligence into the facts. This could be from sourcing it to a consulting or law firm who interviews current or ex BA employees, those involved in this dispute, gov't agencies involved and to source/analyze documents. With the only condition that under no circumstance are they to pass any potentially material non-public information, everything under the Sun is fair game.

Lawsuits are a dime a dozen, especially class action ones. I'm from an industry where if any company's earnings fail to meet expectations for greater than 10% or if the market valuation falls by greater than 10%, the next day about 5 or 6 class action suits soliciting victims hits the wires. I'm not suggesting these complaints are without merit (have no opinion on the one referenced above), but I'm used to seeing them weekly. It's all background noise and whatever their claims have already been factored in and we just ignore them. It's just greenmail. Unless it's a complaint on an unknown issue, completely irrelevant, far as I'm concerned.

I have no idea who the Pilots are who are speaking in behalf of the Union, but I have no reason to dispute their conclusions. I only know that in any organization, I can find you a few who will be on either side of any dispute, especially one as complex and fluid as this one. By nature of whom they're representing, all I can surmise is that their interest is tied to that of their Union. This may mean nothing at all, but it's a known "potential" conflict of interest.

As to the pilots here? I take them at their word. Perhaps, they do have a conflict of interest or hidden agenda. I don't know, but until proven otherwise, I will take them at their word and believe them to be both honorable and above board. Not suggesting the Pilots quoted above with opposing views aren't equally honorable and above board, but only they may have a potential conflict of interest representing a specific side and interest of which I'm aware.

All fair points.

My main point was not that I necessarily believe the WN pilots or their union more than the UA pilots here, but that there are well trained western airline pilots who don’t agree on all the aspects of this case. I have no desire to spend a lot of time researching this, but one example found via a Google search:

https://www.seattletimes.com/busines...7-max-crashes/



There are thousands of experienced pilots in the US. It is unlikely that they would all agree on anything. And it is difficult for us to judge who is right.

The challenge is most of us on this issue are placed into a position making a judgement on something which we know very little about. The only thing I know about flying was playing Microprose's Falcon 4.0. And, if you've seen the many times I've crashed landed (can still hear the "pull up, pull up, pull up"), I'm probably the least qualified to judge anything relating to air worthiness.

So, I'm left with making my decisions based on the counsel of experts, such as the engineers and those who fly these things. I have no idea whose right, but, at least the the moment, there has been ZERO fatalities associated with a US carrier, American pilot or over US airspace. This is a fact.

To clarify, you mean Max related fatalities, correct? 83% of Max deliveries went to non-US carriers so the US had little exposure.

And the first US delivery of a MAX was August 29, 2017. So, 19 months in service, followed by 10+ months grounded; so MAXes have only been capable of having accidents in the US for about 65% of their existence.

Yes.

Allow me to clarify. When making decisions, I use the "bottoms up" approach, as opposed to a "tops down" one. Not to diminish the lives lost or any alleged wrongdoing on Boeing/FAA; but, far as I'm concerned, everything that's happened to get us here is irrelevant, and none of my business. My *only* concern is what I should do in 6 - 12 months when faced with the decision to board or allow my family to board the MAX. That's it.

As mentioned above, I'm not an expert and as ntqtaff saliently observed, it's hard for me to 1) know whom to trust, or 2) even understand some of the technical stuff I'm reading. So, I try to start with the simplest universal fact and go from there, as follows:

1. Fact - No MAX fatalities in US air space or US carrier. Perhaps a small sample size, but nonetheless a fact undisputed.
2. Airlines I fly - AS/AA/DL/UA/WN - are amongst the safest in the history of transportation.
3. when possible, I avoid regional aircraft (whether it be First, Second, or Third world) - too many short trips, pilots may fatigue & air frame under more stress
4. American mainline pilots are the most rigorously trained and capable in the world.
5. and, so on....

Then, I just go from there and research/consult as necessary until I'm swayed one way or the other--sometimes during the process, I change my mind several times. When making decisions, I prefer to remove all emotional, unnecessary or irrelevant concerns, and just focus on the (a fact would be ideal, like to keep it simple) most important fact(s) followed by relevant and reliable data in conjunction with the consultation with, hopefully, objective and independent experts.

So the last ever NG was delivered today to KLM. No more MAX in production for the moment. First time Boeing stopped 737 altogether.