notquiteaff

JimInOhio

I asked because you're the more knowledgeable one. What I know is over 300 people have died on a very new aircraft. I can't imagine people will keep saying "let the process play out" if another one falls out the sky this month. Of course that's not a grim prediction of that happening.

rockrich

Why should we wait until a third one falls out of the sky? Two hull losses are enough.

BB2220

BB2220

Kacee

How many of you who are saying "no problem" are aware of the actual airworthiness issue here? Namely that the MAX employs a new flight control system (MCAS), necessitated by the engine placement with the stretched 737 frame, which automatically pushes the nose downwards in certain circumstances, without pilot involvement. And that Boeing was able to talk the FAA into allowing an exception to the normal rule which would have required pilot training before they could qualify to fly the new aircraft.

It is strongly suspected that the MCAS system, combined with a faulty indicator, caused the Lion Air crash. The circumstances surrounding the ET crash suggest the same system may have been involved in that one as well. In short, there is ample reason to have concerns about this aircraft, particularly when flown by airlines that do not have the rigorous safety and training culture of carriers such as UA.

Aussienarelle

I am risk averse. However, what I do know is that there is usually a judgement call when dealing with recalls: cost vs benefit. Cost of payouts vs cost of grounding. It is all about the money.

With that said I am happy to defer to the wisdom of experts who understand aviation. I am not one of them but two deadly crashes of the same new aircraft type in less than six months gives me pause about catching the 737MAX-8. ET has a good safety and maintenance record. Many put the Lionair incident down to poor maintenance.

username

Stupid question: if this happens when the plane is still very close to the ground, does it give the pilots enough time to run through the checklist to "flip off the stabilizer cutout switches, in keeping with the emergency checklist "? Or, the checklist is in their mind and they can do this very quickly?

I was really afraid of the 737 since they had the US Air PIT crash and UA COS crash not too far apart in the 90s. Like any problem, until the root cause is known and a solution is figured out, it is kind of scary.

If Boeing and the FAA are proven to have improperly handled the certification/training process, I hope there will be some accountability. Of course, if this WAS the problem, then how do we trust the investigations will turn up the truth?

blueman2

Great points everyone. So let me rephrase: Has any airframe currently in commercial use had 2 crashes with 100% loss of life within first 2 years of service? There might be, but my research has not shown any yet. And since all that is relevant to someone who is flying TODAY are airframes that are being flown commercially TODAY, this is a relevant question. And while there is no evidence that the 2 crashes are related, I think this question is worth asking. .

EWR764

MCAS is not a new "flight control system", per se, as the 737MAX retains essentially the same hydraulic flight control system as every 737 that preceded it, which is why the MAX has the same type rating as every other 737 that's ever flown and only requires some differences training for existing 737 pilots to legally fly it. That's why the FAA ultimately agreed with Boeing and determined that the MCAS did not comprise such a substantial deviation from the flying characteristics of the 737 that would require a new type certification.

The news media briefly (and irresponsibly, I might add) pushed a sensationalist story of some all-new "rogue" system that Boeing secretly installed on the 737MAX flying the aircraft into a dive despite the best efforts of the pilots.

Indeed, for better or worse, it's the pilots that have the final say in control inputs, as compared to FBW aircraft like the 777, 787 or the post-A320 Airbus line. Given that, it is important to understand that MCAS is a safeguard designed to assist pilots in stall avoidance during a limited set of circumstances, namely:

- high angle of attack;
- clean configuration with flaps retracted;
- high bank angle; and
- autopilot disengaged.

If those conditions are not met, the MCAS is inactive. Even in the event of an unwanted MCAS activation, it can be disengaged momentarily or cut out completely. If it engages in the normal course of operations, without an instrumentation failure (which is now expected to be the root cause of the Lion Air crash), it is to get the airplane out of a critical AOA situation where an aerodynamic stall can be induced. The issue is that the Lion Air 7M8 'thought' it was approaching a stall, and engaged the MCAS to push down the nose to correct the condition. Unfortunately, it appears as though the pilots weren't prepared to manage this situation, and a combination of factors led to the crash... not unlike AF447.

Still, an instrumentation failure, or a flight control failure (such as pitch trim runaway) are not unique to the 737MAX and procedures have long existed for crews to follow in order to rectify the condition. Human factors can and will interfere with a crew's diagnosis and management of these situations, especially in critical phases of flight, and the combination leads to accidents. Again, nothing new here: https://www.aopa.org/news-and-media/...h-trim-runaway

This brings us to the Ethiopian crash today and the calls for the fleet to be grounded or actively avoided. The fact is that it is impossible to make any sort of meaningful determination as to cause in the hours which immediately follow a crash. A few years ago, before it became apparent that MH17 was shot down, there were knee-jerk calls for the grounding of the 777 fleet, and more commonly, of Malaysia Airlines, because of the close proximity in time to the MH370 incident. The correlation is disturbing, but not necessarily something that demands jumping to conclusions.

We can keep chipping away at the criteria to fit the facts... a grounding is by all means something that will be considered, provided some evidence of a systemic flaw is identified. I'd argue that the Lion Air crash has not yet presented evidence of a *design flaw*. Until then, such discussion would be premature.

cerealmarketer

Cappa

so how to tell if your flight is the max? I have a flight from MAD to EWR this week and I already suffer from high anxiety..... and now this. It says Boeing 767-300

jsloan

Welcome to FlyerTalk!

The MAX is a 737. The 767 is an entirely different class of aircraft. They're not related at all. UA's MAX fleet is identified as "Boeing 737 MAX 9" on the flight status information page and in search results.

Aussienarelle

Welcome to FT @Cappa The 767 is a different aircraft to the 737.

The 737MAX is a revamped version of the 737. I personally do not have concerns with either the 767 or 737. My concern is with the 737MAX-8

jsloan

The 737 MAX 8, specifically, is not flown by United at this time. UA flies the 737 MAX 9.

Because nobody knows if there's a systemic flaw, there's no way to know if it's limited to the 737 MAX 8 or if the MAX 9 would also be affected. The aircraft avionics are mostly the same; the MAX 9 is a lengthened version of the MAX 8, just as the 737-900 is a lengthened version of the 737-800.

But again, I'd caution everyone against speculation in the absence of evidence. That said, for anyone who will worry anyway: UA currently has 14 737 MAX 9 aircraft in their fleet. They have about 140 737-900s, and about 100 other 737s (-800 and -700).