A few questions here:

1. Do you now feel that this was the correct categorization (of course hindsight is 20/20...)?

2. Who made this categorization? My understanding (from media reports) is that it was Boeing.

3. Would you agree that the FAA should be making these decisions rather than Boeing?

It seems like the whole point of having the FAA is to take the decision about what is "safe enough" away from the people who have an economic interest in the outcome, to avoid any conflict of interest.

Thank you for the correction. I was basing my statement upon the specific mention of the 737-8 and -9 in the AD.

Sorry, I should have been more clear. I was referring specifically to the ET crash, where there are reports/theories that the pilots may have allowed the plane to get well out of trim, cut off the stabilizer at that point, and then were unable to get it back into trim manually. I did not mean to imply that it was a specific step in the procedure, and again, I appreciate the correction.

Thank you. That makes perfect sense. Would only that the expectation had proven correct. :(. In hindsight, the need for this to be a redundant system is obvious, but in foresight, I can see how it wasn't.

Again, thank you for the correction. So, in effect, the pilot is expected to push the nose up in order to compensate for the stabilizer pushing the nose down. The net result is that no change occurs, explaining why passengers don't feel this happening despite your statement that the plane may go out of trim many times during a flight. (And, in normal flight operation mode, the MCAS is designed to push the nose down if the pilots inadvertently bring it too far up).

That said, in context, I believe what I wrote makes sense, but is incomplete. Perhaps I should say, if you find yourself in a situation where your nose is down, you want to correct that before disabling the electric stabilizer. Again, I'm basing this upon reports of the ET crew cutting off the stabilizer while badly out of trim, resulting in needing to turn the manual trim wheel with excessive force to attempt to control the pitch..

^

Thank you again for taking the time to provide your insight.

My understanding is that Boeing makes recommendations to the FAA, which it can then approve or reject. Ultimately, the final authority belongs to the FAA, because they are the ones who issue the certification. So, Boeing says "we believe this item falls into this classification, and here's why."

The difference is I don't face a life or death situation in a car if it stalls, I have the luxury of pulling over to the side of the road. If my engine on the airplane fails, I have the luxury of looking for some sort of landing location. I might damage the airplane, but my goal is to survive. Boeing did something very different, it added something that at best gives you seconds to respond.

Boeing decided to add a layer of "Airbus" technology without telling anyone, without telling the FAA, buyers, or the pilots. That is a problem. The fleet is grounded. Boeing will lose money.
As a Boeing fan I want to see this aircraft back in the air as quickly as possible, but I want it done properly, without hidden features.

The broader theme is Ethiopian has a problem with pilots not following procedure. That's what makes their crashes (3 737s in a decade out of a small fleet!) more broadly a pilot problem than a 737 MAX problem.

The thing to do, immediately, is the runaway pitch trim procedure. Same one for the last five decades. Regardless of which pitch trim input or downstream component is causing an issue, follow the procedure, and you probably want to do so quickly.

This x1000!

I am not confident that the Ethiopian Civil Aviation Authority will produce an unbiased report. I am troubled by the preliminary report findings, which were released on April 2 by the Ethiopian Minister of Transport, that crew followed the recommended emergency recovery procedures.

My feelings are irrelevant. My posts are what I think, based on my experience and the applicable data that I have seen up to this point.

I have not seen any data to indicate that this initial categorization was inconsistent with the certification requirements. In other words, I have not seen anything that indicates that the original design did not meet the applicable certification requirements. As far as I can tell, it did.

After the first accident, Boeing made the decision to treat MCAS as a higher-level failure and began work on the necessary software modifications. If that determination had found that the original system failed to meet certification requirements then the fleet would have been grounded at that time. Certification standards are minimum standards that manufacturers, and operators, routinely exceed.

That is the responsibility of the manufacturer.

That is beyond both the authority and capability of the FAA.

The FAA sets the certification standards. Manufacturers are tasked with meeting those standards. The FAA oversees the process, reviews the data, and often makes additional requests or requirements of the manufacturer before certification is granted. This is similar to how a building inspector interacts with a building contractor. I believe it is very common throughout government agencies that have a safety oversight role.

The FAA would have reviewed Boeing's classification of MCAS and had the option to accept it, reject it, or make additional requirements to be met before granting acceptance.

Don't judge a book by its cover. TV is designed to grab eyeballs, so there is naturally going to be some attempt to grab those eyeballs. After that title card is some important information, including from Dennis Tajer at AA. Given his experience and position at AA representing the APA, I would think other pilots would give his words at least a minimum of deference.

Agreed. It would be great if this were a simple case of pilot error and not the major problem this is with one of Boeing’s most important aircraft. The deeper you dig into this aircraft though, the more you find that Boeing cut corners in a way that is really completely unacceptable in this industry, all because they say on their rears for too long dealing with problems with the 787 and neglecting the narrow body market.

The information provided by multiple very experienced flight crews and engineers in the 60 Minutes report is quite alarming. When you have the head of the AA pilot’s union stating that he doesn’t have confidence in the aircraft in its current state, that’s pretty clear.

USA Today reports that the software fix is complete, and now it's in the hands of the FAA.

I'm more confident in them than Boeing. Of course I'm also more confident in the decomposed corpse of Jeffrey Dahmer than any Boeing flunkie, but even so Ethiopia has been open about sharing data and the burden of proof is squarely on Boeing.

1. Yes, I think DAL C is the correct categorization of MCAS. DAL C has an expected failure rate of 1 per 100,000 flight hours or better. The failure is significant, but has a lesser impact than a Hazardous failure (for example, leads to passenger discomfort rather than injuries) or significantly increases crew workload (safety related).

2. The manufacturer, as always.

3. lol nope. The FAA wrote the regs and acceptable means of compliance, and verifies you followed them, that's their safety role. Same as EASA, the other tier 1 regulator IMO.

What about the likelihood that the failure kills everyone on board?

Anything can do that. Swiss 111 was brought down by a failure starting in a DAL E system. But only DAL A can do that without any possible mitigation.

Exactly! Boeing had responsibility for those 350 people who being killed. That's big problem!