EmailKid

The engines are a little different, but for all intents and purposes, it's the same plane as Classic

MCAS was the problem, and entire software was re-written (and nose down can now be overridden by pilots).

Plus pilots are now required SIM training, and at least as I understand it, US based airlines will have pilots fly empty planes for further training.

narvik

I'm convinced US airlines' pilots were and are "extremely careful" before, during and after all this MAX fiasco.
I certainly have never, ever doubted any United pilot not being extremely careful in their flying the planes, MAX or not MAX.

LarryJ

That was true before, too.

Training will be in simulators, not airplanes.

Aussienarelle

The issue in the design is they essentially kept a 50 year old frame and added newer engines with a different placement. So I agree the frame is similar to the frame designed 50 years ago but the overall design is different with the engines.

The point of the software is to make the plane "feel" the same to the pilots. They can write the software as many times as they want, in my mind the MAX has a fundamental design flaw.

EmailKid

OK, I'll bite.

What is the flaw?

xzh445

Exactly.

Plus ALPA

“Based on the Airworthiness Directive, ALPA believes that the engineering fixes to the flight-critical aircraft systems are sound and will be an effective component that leads to the safe return to service of the 737 MAX".
.

These groups would not be staking their reputations and livelihood, after two crashes, on something that has not been fully vetted and shown to be safe for return to revenue flights.

How many pilots would willingly take an aircraft to the skies that they thought was going to kill them?

LarryJ

That's a minor part of it. The primary reason that MCAS is required is to meet a certification standard which requires an increase in control forces as angle-of-attack (AoA) increases. Without MCAS, at very high AoA, the required control force to maintain, or continue to increase, the AoA does not increase enough. There is nothing in the MAX's normal flight regime that "feels" differently enough than an NG to require MCAS or any other modification.

In fact, the MAX design has improved a number of handling characteristics of the NG models that a pilot encounters routinely on nearly every flight and that has nothing at all to do with MCAS.

Very few, if any, airplanes will pass your test. Engineering is about compromises and aeronautical engineering even more so. Every airplane has compromises and small "fixes" whether software, system design, or aerodynamic to address such issues. Vortex generators, aerodynamic fences, strakes, artificial feel systems, hydraulic stick-pushers, the the elevator power system in the DC9/MD80 series, etc. are all used to "fix" what would otherwise be undesirable characteristics.

The error made in the MAX design was in the evaluation of the threat posed by an unscheduled MCAS activation. When that failure mode was evaluated, the assessment was made based on then pilots applying the runway stabilizer procedure in a timely manner. If it is, an unscheduled MCAS activation is no more than an inconvenience. The two accidents, during which neither crew followed the applicable procedure, revealed that the pilots could not be counted on to respond as predicted.

djmp

I agree with most of this but the “blame those pilots” trope is getting old. An F.A.A. test pilot, warned in advance, and in a simulator failed too:

“In at least one instance, an F.A.A. pilot was unable to quickly and easily follow Boeing’s emergency procedures to regain control of the plane. The pilot rated that failure as catastrophic, meaning it could lead to the loss of an aircraft midflight, the people said.”

mduell

And yet, the joint authorities cited assuming overseas pilots were like US pilots as something for the FAA to reconsider.

spin88

This really is an interesting business question. Due to the MAX delays, the cancellation clause on the MAX went away, and Boeing has over 400 cancellations as a result, and has indicated that another 1200 are at risk. Pre-Covid the argument was "well we need frames, and can't get airbus slots, so best to stick with the MAX" But with demand way down, and open delivery slots, absent getting a really good deal, it does seem strange to me that the airlines would just go ahead and keep taking MAXs. Perhaps the fleet standardization still wins out, but if you are DL or B6, you gotta be happy to be flying the (more comfortable) Airbus 320/321 which has a better public safety reputation.

While I am comfortable flying the plane safety wise, I don't look forward to the bathrooms (worst on any plane) or flying it in Y, so will book away for that reason.

But hey, flying it on 5-6 hour flights, see what it does to UA's customer satisfaction scores.

LarryJ

It's not as simple as blaming the pilots.

A procedure existed which, when followed, stops, and recovers from, the failure allowing the flight to continue to a safe landing. On both accident flights, the crews didn't accomplish the procedure. That's fact, but you are making a mistake if you're thinking that's "blaming the pilots". You have to find out why a qualified crew failed to perform as expected and the answers are usually systemic.

Both accident crews were properly trained and qualified so why did they fail to perform the applicable procedure? Relatively low, though completely acceptable, experience levels, the problem presenting in a manner that was different from how a runaway stabilizer might be assumed to present, and a combinations of seemingly unrelated warnings occurring in quick succession (distractions) are the ones that stand out to me. The fixes being implemented address all of these contributing factors.

The author of that article doesn't understand what he is reporting. He reports that pilots have "less than 40 seconds" to correct the problem and frames that as though it is unreasonable because he doesn't understand the context. If an engine fails, do you know how much time the pilot has to make corrective inputs? Less than five seconds, sometimes much less. How long can wait to take corrective when your car starts to drift out of its lane on the freeway? Certainly not anything close to 40 seconds. 40 seconds is an eternity.

The unscheduled MCAS, or any runaway trim, event does not become uncontrollable until the trim is near it's full travel and the airspeed is significantly higher than normal. That is the position that both accident crews eventually reached but it took a significant amount of time, several minutes, during which they didn't correct the problem, before it got to that point. In the simulator tests in the report they were starting out at full nose-down trim and at speed in excess of the 737s maximum speed limits. In that condition, it is very difficult, though not impossible, to control the airplane and recover. I've done exactly that exercise in the sim experimenting with varying degrees of out-of-trim and excessive speed. The key to a successful outcome from any stabilizer runway, in any airplane, is to stop the runaway promptly and to not allow the airspeed to become excessive. If you do that, it is not a difficult situation to manage.

The one thing that I still don't understand about both accidents is why the pilots didn't trim. When I'm flying an airplane, and the nose gets "heavy", I click the primary trim thumb switches a couple of times to remove the out-of-trim condition. This happens many dozens of times on every flight. You don't even think about it, you just do it. It is as much of a subconscious action as is making small steering wheel inputs to maintain your lane in a car. As the nose began to get heavier, why didn't the accident pilots do the same thing? The Lion Air Captain did, through 21 unscheduled MCAS activations, but his F/O and the Ethiopian Captain did not. That simple action would stop MCAS (for a 5sec pause) and allow you to remove all of the inappropriate trim input that MCAS had applied. That gives you all the time you need to work the problem. That would prevent you from getting into a situation with near-full nose-down trim and severely excessive airspeed (the Ethiopian airplane was eventually more then 100kts (115mph) faster than they should have been). I believe they are adding a memory item to appose the runaway with the primary time to the runaway stabilizer procedure to address this. When I flew Douglas (DC8 DC9) "Primary Trim ... Oppose Runaway" was the first step on the checklist.

buckeyefanflyer

UA 2703 flight testing today BFI to SEA. Note on flight status shows 737-900 ship 7519 Max not used in aircraft type description.

WineCountryUA

Boeing Makes First 737 MAX Delivery Since Lifting of FAA Ban (WSJ)

LarryJ

Did the site say "-900"? That's wrong. It's a 737-9. "-X00" is an NG (600 and greater), "-X" is a MAX.

TWA884

From United.com Flight Status:FlightAware had it right: