jrl767

the text between the switches on the face of the panel is the same on both the NG and the MAX ... "NORMAL" above an arrow indicating the "UP" position for the switches

that configuration would **seem** to imply that normal procedures are for the crew to verify the switches in the NORMAL position (regardless of what the actual position label says), and the action to disengage the stab trim in the event of a runaway would be to push the switches to the down position

etch5895

For what its worth, as a BA shareholder, I voted to flip the board of directors. That this was an optional safety feature is incomprehensible to me.

LarryJ

Low visibility approaches below 1/2 mile require special equipment, procedures, and authorization. These approaches are called CAT II and CAT III approaches.

The B737 (NG & MAX) can qualify for CAT II/III approaches in either of two ways. They can use the dual-autopilot Autoland function or use a hand-flown approach with the aid of a Heads-Up-Display (HUD).

CAT II/III operations with the HUD require the AoA indication and AoA Disagree warning; Autoland operations do not.

Airlines that opt for the HUD options also opt for the AoA indicators and AoA Disagree warning. Airlines that opt to use Autoland do not.

DenverBrian

How many people are dead because airlines have opted for autoland vs. hand-flown? @:-)

LarryJ

None that I'm aware of.

There's no reason to believe, nor data to suggest, that those indications would have made any difference on the accident flights. "AoA Disagree" isn't going to lead them to the runaway stabilizer procedure.

It may turn out that the stick shaker, and airspeed discrepancies (with "IAS DISAGREE" messages on each PD), were factors in diverting their attention away from the persistent unscheduled nose-down trim inputs.

USA_flyer

Tui has 15 Max jets and has said that if the plane isn't flying by mid July, it's gonna cost them €200m in extra fuel and leases.

I imagine they will ask Boeing to cover it.

tmiw

Looks like MCAS is now officially related to the ET302 crash, as people have been suspecting: https://arstechnica.com/information-...ian-737-crash/

WHBM

In that case, why have Boeing now said they will make the AoA Disagree indicator standard.

https://www.smh.com.au/business/comp...28-p518be.html

LarryJ

You would have to ask them.

My guess would be that they're doing anything they can to address the negative press on the issue. The "light" is actually a message on an LCD display. It's just a software "switch" to turn it on. Doesn't actually cost them anything in additional parts or installation labor.

chipmaster

Amazing to me that BA installed a piece of software that would take over w/o the pilots knowing while the plane is at its most vulnerable point and lights/switches would be options or counter-intuitive, hiding it, simply astounding lack of common sense.

The negative press will for sure build as more comes out and some heads will roll as sacrifices to the public opinion gods.

The business aspects at this time seems to be relief that news was still MCAS, better the same stupid design/problem versus something else more complicated and a bandaid fix will come shortly on the bandaid. BA stock pops, liability likely a few billion including the liability lawsuits, lawyers will be field day as will the press.

Plato90s

Given that Boeing used to charge extra for that feature (and some airlines have paid), this also costs Boeing future anticipated revenue.


The fact that Boeing is still working on software fixes suggest that they are doing what VW did - trying to find a "solution" that validates their original selling point.

In this case, I would speculate that Boeing still hopes for a way to change the software so as to claim that pilots don't have to go through specific training for the 737-Max. Once again - sales goals over safety needs.

LarryJ

Boeing started working on software changes shortly after the Lion Air accident. It's been less than six months and they are close to having the new software ready for release. That is very fast. There's a bug in the current FMS (Smith Industries) software on the 737 NG that prevents us from using the (recently added) RTE2 function (allows two separate routes/flight plans to be stored at once). The fix for that bug is expected to take a couple of YEARS before it is released.

Training is classified as Initial, Recurrent, Differences, or Upgrade.

If an airline had only the MAX variant of the 737 then the pilots' Initial training which would cover only the MAX.

Most airlines with the MAX will already have the 737 NG on which their pilots are already qualified. To add the MAX the pilots would receive Differences training. New pilots would receive Initial training, which could be on either the NG or MAX, then Differences training on the other. An airline would typically do the Initial course on the variant that they have the most of then do differences on the other(s) but that's up to them. At my airline, we do Initial on the 737-800 then differences on the 737-700, 737-900, 737-900ER, and now 737-9 MAX.

There's never been any question that the MAX would require Differences training. The only question is what that Differences training would involve.

Regarding MCAS, there isn't very much to know. It's a system that is transparent to the pilots. We don't see it. We can't control it. We have no way of knowing when/if it is activating. The only thing we need to know is that it has the potential to cause a runaway stabilizer and, if it does, the existing runaway stabilizer procedure will stop it. We've all already practiced the runaway stabilizer procedure in our initial training.

Plato90s

As noted in the news coverage, Boeing sold the 737-Max on the premise that minimal training would be required.

It is my belief, as a non-aviation professional, that Boeing spent the months between the Lion Air crash and the Ethiopian Airline crash trying to find a way to modify the software so that they can stick to that claim.

chrisl137

*Any* software change that they're going to roll out to an entire fleet of aircraft that could change the flying characteristics is likely to take that long. The actual problem has to be identified, analysis done, the changes actually developed, and thoroughly tested. I don't do aircraft, but when I work with companies that apply their aircraft processes to what I'm getting I get to deal with all of that. I'm usually getting one or two or three of something and their processes are designed to make sure that changes are safe on everything that they've already delivered and will have to updated, as well as future deliveries. I'd be surprised if Boeing didn't have multiple teams working parallel paths - at least one involving keeping the flight characteristics the same as the NG, and at least one other not constrained by that.

ian_btv

It seems that critical, mirrored mechanical sensors (e.g., AoA, pitot) merit a standard status or warning indicator in the event of disagreement of readings. Of all the costs for technology and readouts in the cockpit, I don't understand why such obvious safety features could be so cost-prohibitive (or profitable) that they would only be offered as options. Optional seat belt for the co-pilot? Optional second yoke? This is such a simple exercise. It defies logic, MCAS susceptibilities or not.

I would be very curious to know if the design engineers identified and documented this issue, and if so, how it was countermanded as a 'needed' item and changed to 'optional'.

We would never have walked on the moon before the USSR with this sort of process in place. In many ways, this fundamental lack of logic matches that of the Soviet leadership's approach to the space race - push, push, push and hope statistics work in your favor ... and worse yet, hide or distort the truth if there is a failure. Business and politics both are so susceptible to lying. Science and engineering, however, cannot exist without truth.