mattp1987

I was wondering where that was coming from. I guess one could read that the MCAS was forcing the nose down while the pilots were trying to pull the nose up and conclude that the plane was oscillating due to aerodynamic instability. That's simply not what the term means though.

I agree that when the MAX is ultimately certified to fly again it will be a safe aircraft. Boeing and FAA don't want to sign off on an unsafe system, so I expect that they'll finally do what should have been done before the MAX was initially certified.

I, for one, would be sad to see the DC-9-class aircraft go. However, I can definitely see the advantage to Delta of reducing the number of type ratings needed by pilots as well as dealing with fewer engine parts.

emma dog

Both planes are the same physical dimension and Southwest has the exact same number of seats on both variants.

BearX220

So many additional concerns have erupted post-grounding, it is impossible to believe they will all have been caught and totally mitigated on the return-to-service date. The intrinsic problem with the MAX is that it was conceived in such a rushed, compromised moment by such irresponsible people, fixing everything wrong will be like playing a lifecycle-length game of whack-a-mole. You just don't know. And this is why I gave up on Gary Kelly at Southwest when he kept extolling the MAX as a superb airplane, even after it had killed hundreds. You just. Don't. Know.

You go ahead.

ethernal

Have you ever skimmed through the FAA Airworthiness Directives repository? Every plane has seemingly frightening issues and you ask yourself "how did they miss that?!". Many of them are not found until years and years of operation. The FAA is (rightfully) digging deep before providing a clean certificate. Many of these issues would have been detected only after years of operation - if ever. For example, all the noise on the manual trim wheel and the physical strength required to turn it - this issue has been present in the 737NG series for more than two decades without it causing a problem. Same thing with some of the wiring bundles.

That is not to say that these issues shouldn't be fixed. They should be fixed. But all planes - whether from Boeing, Airbus, or any other manufacturer - will always have some undetected issues. Modern planes are incredibly complex machines that are impossible to design perfectly given that humans ourselves are imperfect. The goal of aircraft design is to build defense in depth via redundancy, identify failure paths via systems analysis, and build in safety margins to account for the unaccounted. Admittedly these checks and balances failed here (again, bordering on criminal) - and there are definitely some systemic issues with Boeing's engineering and safety culture - but regulators are no longer sleeping like they were before. The fact it has taken so long to re-certify the plane is an indicator of that.

By the way - did you know that one of the reasons why Delta is probably trying to offload the 717s is because of a pending airtworthiness directive related to their seats? They will have to replace all of the current seats by 2022 in order to stay compliant because passenger's necks may break in otherwise survivable crashes due to the seat design and they likely don't want to be on the hook for that kind of capital cost to refurbish the cabins. Scary stuff, huh?

UnevenGray

I love when business travelers try their hand at aerospace engineering and try to comment on MCAS.

GW McLintock

United operates (operated? will operate?) the MAX 9 and recently put in an order for the A321XLR. Where that stands since the downturn, I don't know, but it was an example of a mixed fleet. Each plane serves a (slightly) different purpose. I'm sure DL could make it work as well.

-J.

ATOBTTR

Not all of us on this forum are just business travelers. Some of us *are* aerospace engineers who travel because our aerospace engineering work requires us to travel (and we also travel for leisure).
(And some of us aerospace engineers have either worked for or alongside Boeing specifically even).

mattp1987

I'm not sure who you're referring to specifically, but there are quite a few of us on here with (often multiple) aerospace/aeronautical engineering degrees and years of experience in industry/academia/military applications.

UnevenGray

I am commenting in general. A lot of people equate frequent flying to understanding the ins and outs of an airplane. That is simply not correct.

Already, upthread, you have one user citing aerodynamic instability, and in general, I have seen a lot of people try to come to the conclusion that bigger engines = heavier = MCAS was needed, which is also false.

I would also caution that just because you know the terms in the field doesn't mean that you understand the design principles. I have seen other degreed engineers arrive at the same incorrect conclusions.

Duke787

I understand the business aspect of this (which makes a fair amount of sense -- especially given the desperate situation BA is in and the ability for DL to effectively take the lease payments off their books in return for bargain basement new planes they won't need to pay for in the short-term).

As a traveler though, I'm in the camp of never getting on a 737Max and this would put a dent in my view on DL and would lead me to avoid DL in certain situations where typically I am completely brand loyal (unless pricing differential is crazy).

justsawaufo

It's very simple, we ALL have the power. An airline that uses the 737MAX is simply jeopardizing people's life - such airline will never get my business. Vote with your wallet.

GW McLintock

The same could be said about the NEO. Or the DC-10 or even the 747.

Vote with your wallet and walk. Flying is clearly too dangerous for you.

-J.

mattp1987

I assumed MSM was Main Stream Media. While most who decry the MSM are politically motivated by allegiance to a certain politician who doesn't like his actions or inaction scrutinized, I do think it's fair to point out that many media outlets often miss the mark on technical reporting. Outside of aviation-specific media outlets, I wouldn't expect most journalists to have a thorough understanding of aerospace engineering. Even when attempting to report on what is being published or stated by technical experts, it's easy to misinterpret the facts if you don't have a background in that area.

BenA

Poorly worded response on my part - I was trying to say I think it’s likely Delta would opt for the smaller 737MAX8 as a direct replacement for the -800s rather than taking entirely 9s or 10s.

ryw

My understanding is that for Delta, the A220 is basically a replacement for the B717s - if DL was planning to phase out the 717s anyways, to me it seems to make sense that if they can some type of deal as they phase them out, it'd be something they'd want to look into (though I'm no expert in the aviation business!).

Leaving aside questions of safety and consumer confidence, might the MAX10 be a viable replacement for the (smaller) 757s, since the new midsize replacement project seems to be on hold?
Also does DL have orders on aircraft that would replace the MD88s and 90s? Or would we expect them to shift some 737s and A320s onto those routes?