ijgordon

I think a LOT of people would vehemently disagree with you, even those that think Boeing royally screwed this up.

The issue from my understanding is not any inherent instability with the plane, it's just that, in certain corners of the flight envelope (meaning in very specific situations unlikely to be often encountered), the plane will handle somewhat differently than a 737-NG. That's totally and 100% fine, if pilots are trained on how to handle the plane in those conditions, with checklists, and simulator time, and whatnot. But that would likely require a new type certificate, which is exactly what Boeing (well really, its customers, including AA) wanted to avoid, for cost/speed reasons, since pilots would need to be certified on the new plane. So, among other things, they came up with MCAS to make the plane mimic how a 737NG would handle in those scenarios, that was supposed to be invisible to the pilots. If this were a fly-by-wire aircraft, like Airbuses and some of Boeing's more modern widebodies, this all would have been built into the flight control system.

MCAS was quite clearly very poorly implemented, but it's not an issue with the aircraft. For example, the change in placement of the engines has less an impact on the aircraft's center of gravity than cargo (or pax I supposed) could depending on where it's loaded.

JDiver

IMO the design changes between the original 737 and the NG were more radical than between NG and MAX in some ways, given the larger, higher bypass engines used on the NG radically altered the geometry of the aircraft. I’ll add illustrations below.

What’s interesting is the demonization of the MAX, probably by people who have been happy to fly multiple 737s - which had a major design fault that contributed to a number of uncontrolled rudder movement incidents due to the single, double valved power control unit. This resulted in - guess what - two crashes killing all aboard and some other reported incidents ultimately requiring an FAA AD note to order the fix. (Not to mention on the other side of the divide Airbus has its own problems when A320 problems were surfaced by the Air France AF 447 incident.)

The jet era has been punctuated by design failures where that were addressed when the cost of lives exceeded the cost of repair.

The world’s first commercial passenger jet, the De Havilland DH-106 Comet, imploded at altitude from fuselage stress cracks originating at the corners of the <ahem> square windows. Grounded. Redesigned. Flew successfully for years, and I flew in a number of Comet IV-C.

The Lockheed L-188A Electra had a major design flaw that caused structural failure of the wing from “undampened propeller whirl mode”, wherein flutter was induced by oscillations of the outboard engine nacelles which reached a magnitude sufficient to fail the right wing. The aircraft shed its wings in mid air. Two aircraft were lost, BN 542 and NW 710. Lockheed redesigned the engine mounts, nacelles, and cowlings, and modified the wing to improve strength capabilities. The Electra flew safely after, and I flew in any number of Electras operated by AA, EAL, PSA, AirCal, etc.

The Douglas DC-10 had a double design error in the new baggage hatches and lack of pressurization vents in the floor causing failure, sudden fuselage decompression, floor collapse severing all control cables to the empennage, resulting in the total loss of TK 981. Nearly two years later AA 96 crashed from the same causes, but the brilliant cockpit crew crew used differential engine thrust to land the aircraft and nobody aboard was injured. The design issues were rectified. The DC-10 flew and still flies with cargo carriers. (The ‘10 suffered other notable incidents, particularly the engine separation incidents caused by another design safety failure coupled with faulty maintenance procedures used by Continental and American.)

Etc. with a number of similar developments.

The 787 just had an AD note issued by the FAA affecting 787's tire and wheel "threat zones" that could be the source of damage under certain conditions and cause loss of breaking and steering power. Boeing and airlines had identified this two years ago, the FAA mandated the required the safety changes required to assure compliance wasn’t merely voluntary. And there were the battery issues. Not to mention radical changes as the first aircraft with major components made of carbon fiber. (Having lived through these aviation developments, my first Dreamliner flights were last year. I’d already chosen to book away from MAX aircraft for a few years.)

There’s a recurrent theme here one might call engineering boldness supplemented with hubris - necessary for technological advancement, but entailing a degree of risk, whether it's nuclear power or aviation. And in aviation, the recurrent theme has been flaw discovery and a fix when cost if lives exceeded cost of repairs. 737 MAX: here we go again.

Two possible issues at least with the MAX - the ones mentioned in this thread already and another unmentioned one: the Angle Of Attack sensors used in the MAX and several other aircraft have been written up in 216 incident reports where the devices failed or had to be replaced or fixed. The frequency of malfunction and Boeing’s repeated insistence, repeated yesterday to CNN, that using a single AOA output instead of sampling both AOA outputs through sampling or comparative processes in MCAS : “Single sources of data are considered acceptable in such cases by our industry." CEO Muilenburg has been repeating this nonsense as if mere repetition justified it.

It looks like the MAX will be decertified with all the changes described previously and may ultimately be the safest 737 yet. But the cost has been high.

Illustrations of 737 aircraft flown by their order-initiating airlines. Look at the engines and their mounting positions. The original -100 “Fat Albert” has its low bypass engines mounted fully under the wing. The NG has moved that engine forward in a completely different position and redesigned pylon. The MAX has an elongated nose gear and redesigned pylons / mounting due to the increased engine diameter and size.

Lufthansa Boeing 737-100 “Classic” (-100 and -200)

United Airlines Boeing 737-800 “NG” (encompasses -600 on)

Air Transat Boeing 737-800 “NG” (better illustrates engine mounting)

American Airlines Boeing 737 MAX 8

DenverBrian

First, all that happened in the early 1990s. Half of FT wasn't even born then. Very ancient history. And I clearly remember being alarmed about the 737 at that time, but it didn't affect me much, because I was on mostly 757s and widebodies then, because that's what the airlines flew more commonly to domestic big cities.

That's a roundabout way of describing "tombstone mentality." We. should. be. beyond. this. in. 2019.

The "demonization" of MCAS is occurring precisely because two crashes in the same model aircraft within five months should absolutely never happen in this day and age. We should know better.

JDiver

I wholeheartedly agree. We should know better, and history repeats itself. Even the pattern. “Radically” new aircraft, certified and lauded by the press, two (or more) catastrophic hull losses, fleet is grounded, media hullabaloo ensues, repairs are effectuated, media moves to newer news and flying public quickly forgets. Rinse and repeat.

It’s almost as if some newer aircraft require blood sacrifice before the overlooked or unforeseen engineering and safety issues lead to fixes leading to safe aircraft. It’s ridiculous in this age, IMO. Due diligence, more thorough testing and evaluation, opting for enhanced safety and redundancy, erring on the side of caution would seem preferable to that.

I’ve learned the lessons history has afforded me, and that is why to this day I don’t fly in new, unproven aircraft. E.g. the Dreamliner first flew passenger a flight in October 2011; my first Dreamliner flight was April 2018. I’ll be more willing to fly the MAX once it is recertified and begins proving itself because these issues were surfaced and are under intensified scrutiny.

Boeing is hopefully examining their culture, and of course they’re lawyerung up in anticipation of a lot of lawsuits. I sincerely hope going forward the industry reflects on this flawed pricess and steps up to the challenges in spite of delayed profits that might require.

Regardless of the reasons for AA having ordered the “optional” safety enhancements for their order of 100 MAX, I’m really glad they did. I hope going forward AA can find the motivation for doing that so they can regain momentum on what appear to be increased mechanical breakdowns and reduced operational capability.

bchandler02

Jdiver makes some good points on the challenges of other models, but to me the difference is that had Boeing not been trying to cheat the system to avoid a new type, they would have better designed frame to not require so many workarounds. No doubt they could take 80% of the MAX design and apply it to a new frame and it'd be a great plane - with proper engine placement, ground clearance, etc that would eliminate the need for MCAS.

ijgordon

My understanding is that this would have introduced all sorts of design issues. Longer landing gear to increase wing clearance/height for the bigger engines? You need somewhere to put the landing gear, which probably would require a new fuselage/wing design. And probably more. I don't know if that 80% figure would have been possible, it may have effectively needed to be a clean sheet design. And they didn't have the time -- AA would have ordered the A320neo.

DenverBrian

Boeing had a plane that already had longer landing gear and plenty of room for bigger engines. It was called the 757. @:-)

VegasGambler

"Handles somewhat differently" seems to be a bit of an understatement. I prefer "kills everyone on board".

My point here is that the MCAS is not a good solution, in my opinion. The problem is not that it was poorly implemented; the problem is that it is necessary at all.

cmd320

I mean, the reality is that the 737 MAX was just not a good solution. Boeing has finally been caught with their pants down on the 737 and it’s time the ancient design was finally killed off. As someone said upthread, the 757 would have been a far better platform off which to grow than the already Frankenstein-ed 737 platform.

flyingeph12

Hindsight is always 20/20, however. I agree that from a current perspective the 757 would have been a far better platform off of which to grow (and I relish every time I am able to fly on the 757), but at the time Boeing decided to end the 757 program back in early 2000s aviation trends were not what they are today.

cmd320

While I don’t disagree that hindsight is 20/20, 15 years hasn’t exactly seen the narrowbody aircraft market shift all that much. And as a massive corporation and one of the biggest players in the market, I would have expected Boeing to be a bit more forward-thinking. Especially since even at that point, the 737 lagged behind the narrowbody porduct offered by Airbus.

DenverBrian

Bad decision without any thinking beyond the next quarter. Boeing desperately needs another 777 clean sheet program, just for a narrow body plane. They are already caught with their pants down.

IADCAflyer

A slight correction here. 737 "classic" is known within the aviation circles as the 737-300, -400, and -500 series. The -100 and -200 are known as the "original" 737 series.

Interstingly the two crashes you allude to (UA 585 and US 427) involved different models of the 737. UA 585 was a 737-200 and US 427 was a 737-300. There was a near crash involving Eastwind 517 (also a 737-200), but the pilots were able to rectify the problem before the plane reached a point of no return.

enviroian

Agreed. Plane is a dinosaur.

LBJ was in office when it took it's first flight.

jspira

Longtime AA Forum Moderator JDiver was interviewed about the current 737 situation here - and makes some very important points (he might as well have cited George Santayana's quote, "Those who cannot remember the past are doomed to repeat it".)

Boeing Wants You to Trust the 737 Max: Here’s One Expert’s View

by Anna Breuer

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This link is to an online source to which I contribute and/or have a financial interest