General aviation thread

[Top_Cat]

Yeah and that’s why whilst the plane might have done something unusual, the debate will centre around how well the drivers handled it, automation and how these pilots not brought up in the era of hairy-chested test pilots can’t handle anything without a checklist.

And for Boeing this will be just fine.

What’ll change that, one feels, is if they find that a real software fault. Something like, given conditions, other systems are now receiving incorrect data and now the plane will crash. Very unlikely. And on the engine thing, again, one feels that Boeing will only get into trouble there if it’s proven that makes the plane do something that completely reverses pilot logic for how a plane should handle. Like, in a stall, power off/stick forward/aeilerons and rudders neutral no longer applies or something of that level. Otherwise, it’ll be a ‘lessons learned’ thing.

 

[Spark]

Yeah and that’s why whilst the plane might have done something unusual, the debate will centre around how well the drivers handled it, automation and how these pilots not brought up in the era of hairy-chested test pilots can’t handle anything without a checklist.

And for Boeing this will be just fine.

What’ll change that, one feels, is if they find that a real software fault. Something like, given conditions, other systems are now receiving incorrect data and now the plane will crash. Very unlikely. And on the engine thing, again, one feels that Boeing will only get into trouble there if it’s proven that makes the plane do something that completely reverses pilot logic for how a plane should handle. Like, in a stall, power off/stick forward/aeilerons and rudders neutral no longer applies or something of that level. Otherwise, it’ll be a ‘lessons learned’ thing.

Isn't this exactly what people are accusing MCAS of doing?

 

[Top_Cat]

Don’t know, haven’t read much of the commentary. Last I read, the initial movement of the MCAS was to force the stick forward, what else happens after I dunno.

 

[Spark]

IIRC the grumbling is that on older 737 (and I think most Boeings), pulling the stick kills the electronic stabilisation with no further action required to do so. But with MCAS, you can pull the stick all you like, it won't shut off until you actually physically turn it off using a switch. So it's possible that the Lion Air pilots thought they were turning off whatever electronic system was making their plane go haywire, but in reality they weren't.

 

[Top_Cat]

That's why it's too early to say, tbh. Was the system malfunctioning or working as intended?

 

[Top_Cat]

Don't get me wrong, introducing a new system that directly impacts the controls without notice would be problematic and, incidentally, undermine the Boeing driver's aversion to flying anything French. But, whether the system was actually working or not is a pretty key question.

 

[Spark]

That's why it's too early to say, tbh. Was the system malfunctioning or working as intended?

The MCAS was apparently being fed bad data by a faulty angle-of-attack sensor

 

[Top_Cat]

Sure but a lot of things can do that which these guys train and have procedures for. The pitots were frozen initially on AF447 but the cause of that crash was eventually and correctly pinned on the drivers.

I'm hesitant to monday morning quarterback the pilots, emergency situation and all that. Also Boeing will do the bare legal minimum to fix any issue (such as remind pilots of the existing procedures, as they've done) and the investigation may yet uncover something within the system. However, the same plane had a prima facie similar situation on its previous flight and was landed safely. As you said, a real deal technical problem where thing fails = crashed plane is very unusual these days. Last one I think of is the 777 that crashed at Heathrow years ago and it required a very unusual combination of circumstances.

 

[Spark]

Yeah I think the big underlying concern is that Boeing being completely blindsided by the A320neo selling like sliced bread has made then push the 737 beyond its reasonable limits and design a plane which is frankly stall-happy, hence weird systems like MCAS which are, frankly, un-Boeing like. But we'll have to wait and see

 

[Dan]

Capitalism, eh?

 

[Spark]

TBF you would have to say aviation as close to a model industry wrt safety standards as it's possible to get

 

[StephenZA]

TBF you would have to say aviation as close to a model industry wrt safety standards as it's possible to get

Pretty much. But that is as much to do with the fact than losing your entire customer base every time a plane falls out of the sky is bad business rather than some sort of altruism.

 

[Ausage]

Altruism is so overrated.

Not falling out of the sky isn't.

 

[StephenZA]

Altruism is so overrated.

Thank goodness for that.... it is not a popular or common human trait.

 

[Top_Cat]

Yeah and as expected, Boeing and the FAA reckon this is just a wee bump, that the countries who've grounded MAXs are pussies and pilots should stfu.

 

[Spark]

Think the last thing Boeing needs right now is Trump getting involved. Can only imagine what his old time pilot friends are telling him.

 

[Spark]

https://apnews.com/0cd5389261f34b01a7cbdb1a12421e27

Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly.

The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot.

As described by the pilots, however, the problem did not appear related to a new automated anti-stall system that is suspected of contributing to a deadly October crash in Indonesia.

The Max 8 is at the center of a growing global ban by more than 40 countries following a second fatal crash, this time in Ethiopia, in less than five months. In the U.S., however, the Federal Aviation Administration and airlines continued to permit the planes to fly.

Still really am curious to know just how many bandaids this thing has for what increasingly feels like a design which has been pushed well past its useful limits and is aerodynamically sketchy.

She'll be right though, exactly the same plane as the NG, just throw a few software fixes on there and recertify, no questions asked /s

 

[vcs]

Yikes, makes you think. Thankfully I don't work on any "mission-critical" software, so I don't have any blood on my hands, so to speak.

 

[Spark]

https://theaircurrent.com/aviation-safety/the-world-pulls-the-andon-cord-on-the-737-max/

This article scans with a lot of what I've been reading elsewhere and especially why the 737 MAX exists in the first place (rather than the NSA/"early" 797) and how that drove the design decisions that seem to have led us to where we are today. Can't be stressed how much Airbus has changed the game by breaking into the traditionally "if it's not Boeing, I'm not going" US Big Three in a big way. Delta seems to be steadily shifting towards an Airbus-heavy fleet, American is merrily buying up a321neos, even United has a stack of a350s on order.

Nevertheless I still strongly suspect that this will not end up being a technical story about a plane, but a big story about corporate irresponsibility and regulatory capture in what was once the absolute gold standard.

 

[StephenZA]

So now Canada has grounded the 737 Max 8 and 9, because new information has come to light.
https://ipolitics.ca/2019/03/13/canada-grounding-all-boeing-737-max-8-aircraft/

Garneau said the decision to ground the aircraft in Canada was prompted by new satellite evidence from the Ethiopian Airlines and Lion Air crashes that appeared to signal similarities between the two flight patterns. The crash in Indonesia, he said, was caused by a faulty sensor that caused the autopilot to tilt the plane down suddenly.

However, Garneau cautioned that it was still too early to definitively link the two crashes but his office decided there was enough evidence to act.

“We feel that threshold has been crossed and that’s why we are taking these measures,” he said.

Garneau didn’t offer any timeline for when the investigation would be completed as investigators probing the Ethiopia crash still need to study the black box data for the flight.