Wasn't the design sound, except for the lack of hardware sensor redundancy and naively written software?
Why do they need to stop production and so on?
How would you possibly know that? If they missed two serious issues what makes you think they didn't miss more?
Err, make that three serious issues: https://www.cnn.com/2019/06/26/politics/boeing-737-max-flaw/...
Edit: 4 serious issues if you count "identifying problems and not fixing them": https://www.cnn.com/2019/05/05/us/boeing-737-max-disagree-al...
And if they're doing the new-plane certification and training anyway, the MCAS no longer has any point and could perhaps just be turned off?
Edit: Perhaps not— this comment asserts that the handling of the airframe sans MCAS is non-compliant with FAA requirements: https://news.ycombinator.com/item?id=21864584
* https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_orders_...
I doubt that doing a new type cert is tantamount to engineering an entirely new airframe. I think the thing that makes it less appealing to airlines now is the lack of faith in the integrity of Boeing engineering in general.
Airlines are in a tough spot as the only competitors to the 737 are made by Airbus. Airbus is, of course, up to its ears in orders and slowly scaling up the ex-Bombardier lines.
They might actually be better off just axing the MAX entirely and continuing to produce the 737 NG.
NG production ended (not without its own issues), it's not coming back. There is nearly zero chance of the supply chain attempting to retool for the NG. If Boeing can get the 737 MAX certified it will sell.
The issue is that a culture of self-interested mismanagement from factory floors up to our highest political offices has led the global economy to depend on the success of this plane which kills people.
Even if somehow by chance they manage to make this plane kill fewer people in the future, there will be no reason to think the actual problem has been addressed.
In France the train is ~50 x more carbon efficient. We will not be able to keep emitting like crazy forever (we actually should have stopped completely already :/ ) , especially when reasonable alternatives exist (the train if going not too far, teleconferences, ...). If we believe in the markets, the price of an air ticket should be maybe 50x higher than what it is today, in order to stop the insane emissions. Alternatively there could be an authority who decide if we have a good reason to take the plane.
People certainly immigrated before the airplane, but in general those were individuals without many options at home. Skilled immigration really took off during the Jet Age.
Just firing the CEO isn’t enough, they need to root out everyone complicit in this crime.
At this point they could probably still turn the 737 Max into a sellable product, but it will be different from the one promised if it requires a new type certification for pilots due to the different flight characteristics (which Boeing was trying to hide/minimize with MCAS).
The MCAS system itself is flawed in a number of ways, but the core problem (in my opinion) is the attempt to fit large engines under a too-small airplane, in the name of saving regulatory / training costs.
If you would retrain pilots then the 737 MAX can be safely flown without MCAS. Pilots just need to be familiar with the different aerodynamics.
Most planes have airframes that are aerodynamically stable in and of itself. The 737 Max requires software assistance to be at the same level of stability.
That, to me, is a fundamental flaw. In a multilayer system each layer needs to be safe in and of itself. The purpose of higher layers is to add functionality not to fix flaws in lower layers.
Given the fundamental flaws in design it was obvious there was a cultural problem at Boeing and the CEO needed to go. "We can't solve problems by using the same kind of thinking we used when we created them." -- Einstein.
Fighters like relaxed aerodynamic roll stability for roll rate. Now pitch stability issues are troubling. I don't think engineers would purposely relax pitch stability unless they had to.
I guess I'm saying you might want an airplane aerodynamically unstable in roll, but pretty much never in pitch so the fly by wire argument might not be valid here.
Not passenger aircraft. Only military.
They all do this. You have giant engines on the underside of the wing; what else would you expect to happen when you throttle up at low airspeed?
Source: https://www.seattletimes.com/seattle-news/times-watchdog/the...
Any standard-configuration airliner will pitch up when you throttle up at low speed.
The pitch-power coupling has been problematic on the 737 since Boeing went with GE engines. Thomsonfly almost got a classic to stall in Bournemouth ages ago and flyDubai managed to wreck an NG in Russia a couple years ago. It's possible, but unlikely, the 737 MAX is better behaved in this regard.
If there weren't significant aerodynamic problems with the 737 MAX it would be flying by now. This whole type cert / training thing is a red herring. The cost of slow and shuttering production both in financial and diplomatic terms far outstrips the cost of a separate type. Beyond that Boeing has a captive market. The only 737 MAX alternatives out there are made by Airbus, and Airbus has a healthy backlog for both the A220 and A320. While some airlines may be able to take the range / consumption hit with an NG other airlines, like Norwegian, were counting on the increased range of the MAX for certain routes.
You have two massive sources of thrust below the centre of gravity. If you advance the throttle it will create a nose-up pitching moment.
Correct. An A320 won't pitch up as dramatically as a 737, mostly due to FBW magic.
Ok, glad we agree it'll still pitch up.
Sure, the difference is that a 737 Classic, NG, or MAX with all of the nannies working can be flown into a stall with lots of throttle at low speed whereas the Airbus cannot. The pitch-power coupling on a 737 is far more problematic than on its competitors.
They seem to have some serious cultural issues, I wouldn’t trust them to do the job correctly. I’d suspect in the end what your suggesting is probably what’ll happen.
On the grand scale of things, the bigger issues with Boeing are how they do business and all the problems with their facturies that have surfaced recently. Beyond getting the 737 MAX to flight status, they have to resolve all the issues and the management problems which lead to them.
I think this is entirely true, but it's an interesting commentary on the structure of regulation: it's some small part technical investigation, and a much larger part public relations. I can't even argue they're wrong to operate that way, since their mission is to build public trust in air travel, but it produces absurd results in other areas, e.g. airport security theater.
What's so sound about a plane that stalls by default?
There are lots of things on planes where "if you don't do this" then "the plane crashes and burns". Having to adjust horizontal stabilizer trim as you gain speed is a minor addition.
MCAS was problematic because of how it went about doing so, and how pilots weren't properly trained on the change in how the trim needs to be adjusted. The idea of adjusting the trim doesn't seem fundamentally flawed to me.
(Not that I think the design is necessarily sound, see my direct reply to gp for why).
If the end result is that a new type certification is required for the 737 MAX, it may still be a viable product but not the one customers were originally sold on.