Perhaps they sent her an SMS?
3423 posts • joined 19 May 2010
In the OG models, they mainly run a display. The pilot notes it's wrong/disagrees with the copilot's display, and ignores it, logging a maintenance ticket. That does not make the evening news.
Yep, fair point. It would be interesting to find out how many times that happens, and how reliable the AOA sensors normally are.
I thought it had already been established - at least for LionAir - that the reason that the MCAS kept triggering was that the AOA sensor was providing erroneous data?
Such that even after the plane had pitched nose down below the horizon, the MCAS was still seeing a high AOA and responded by adding more nose-down trim.
Yes, absolutely correct. But in Boeing's corporate world, the costs of doing it properly were deemed greater than doing it quickly. Guess which won.
Also note that no model of 737 has more than two AOA sensors, so already the rule-of-three is broken.
A point raised by someone on PPrune is however interesting:
There are literally thousands of conventional 737s of various types still flying around every day, using the same AOA sensors as those fitted to the MAX, so why do we not hear about many failures? It would suggest that in general, the AOA sensors are pretty reliable.
But then that begs the question, what is different about the MAX that caused the AOA sensors on two separate airframes to fail in such quick succession?
Why did it require TWO crashes to begin to realize that there's something wrong?
Because Boeing and the FAA collectively stuck the fingers in their ears and denied that there was anything wrong. Until the preliminary report from the LionAir crash, they didn't even own up to the fact that MCAS was installed.
Lest we forget, it's only a week ago that the FAA was still expressing "complete confidence" in the 737MAX, and that was AFTER the second crash.
Was this wheeze from Boeing an attempt to avoid that extra cost (thus making the plane more attractive to airlines) ?
It was a way for Boeing to claim that the new 737 MAX handled in a similar way to the old 737NG and 737/800, thus allowing them to bypass new type certification for the aircraft, which would have delayed the roll out and cost more.
All new planes require that pilots have to be trained in their handling and control, so that is a normal, accepted cost to the airlines.
were I European I'd rather be spied on by the Americans than the Chinese
As a European, I'd much rather be spied on by the Chinese, they are less likely to try and sell my soul and my info to the highest bidder.
America has been Europe's best friend for the last hundred years. We've jumped into 2 major wars and kept the peace since WW2, and spent trillions on Europe's defense.
We've jumped into 2 major wars and caused many more minor ones since WW2, and spent trillions undermining Europe's defence.
You don't seem to have considered the possibility that for most Europeans (and I include British people in that for the moment) the risk that there is a "possibility" that China can snoop on their network traffic, is considered to be far less worrying than the risk that the USA can snoop on their network traffic.
European countries don't necessarily want to "go after" Huawei, especially not until there is some actual evidence of them doing something - you know, like the evidence we have that Cisco snoop on networks for the USA.
given that the FAA has access to the actual Flight Recorder and that they have issued a Continued Airworthiness Notification (PDF) to the International Community (CANIC) related to the Boeing 737-8 and Boeing 737-9 (737 MAX) fleet, it would be safe to say that the flight recorder did not show trim against the limits or faulty AoA data.
You are again making assumptions that are not valid. The FAA do not have access to the Flight Data Recorder, it is currently with the NTSB, and the FAA released their CANIC before the Ethiopian FDR had even been recovered.
the pitch axis (a sudden pitch downward in climb out is what happened in both crashes) seems to be what the software system was designed to compensate for in the MAX versions of the 737.
The MCAS is designed to induce a pitch down to counteract the fact that the engine nacelles are lower, longer, and further forward on the 737 MAX and therefore can cause a pitch up in certain conditions.
The MCAS rotates the whole stabiliser to achieve this, and can therefore induce sufficient downward moment that the elevators cannot compensate for it even with full upward deflection.
As currently configured, the MCAS doesn't compare the inputs from both Angle of Attack sensors, it only works off the one which the currently running Flight Control Computer is using.
I would hope that part of the forthcoming update would address that and include a comparison, but it's still not ideal. In most aviation control loops, a vote of three is the minimum used to identify a faulty sensor.
Because that would be, and I put it mildly, a Fucking Stupid Design.
Agreed. Unfortunately, as the 737 MAX is not counted as a new aircraft, but merely a modification of an existing airframe, it relies on "grandfather" rights and did not have to go through a CoA renewal.
EDIT: Link to Airworthiness Directive released after LionAir incident https://ad.easa.europa.eu/blob/2018-23-51_FR_Correction.pdf/AD_US-2018-23-51_1 (PDF)
One other thing, most aircraft systems rely on multiple parallel data paths. A single failed sensor should not have caused anything more than a red indicator somewhere. If that was really the immediate cause of the Lion Air crash, then something else must have gone badly awry.
One of the problems with Boeing's Maneuvering Characteristics Augmentation System (MCAS) is that it only uses two AoA sensors, and loss of only one of them will trigger the system to keep adding nose-down trim to try and bring up the airspeed.
someone with strong technical knowledge, excellent negotiation skills, experience managing IT operations in a complex multi-vendor environment, and “significant track record of owning end-to-end in-house technology service delivery”.
Who is this mythical beast?
Just like asking for developers with 20 years experience of programming in Kotlin or Go, or datacentre technicians with 10 years of experience working with Server 2016.
Not sure who you are aiming your comments at, but I've owned and driven Series 2A, Series 3, early (pre Defender) One-Ten, later Ninety, Range Rover P38, Discovery 1 and Discovery 2.
I don't have a prejudice, but I'm well aware that more modern Land Rovers have a very poor reputation for electrical reliability, and there have been various quality issues (TDV6 engine for example).
They do have the advantage that a 999 call will connect to any network regardless of your contract operator or phone locked down settings. If it can get a signal it can make the call.
You seem to be missing the point I'm making.
EE (and other operators) seem to be complaining about having to provide 95% coverage for the UK.
But there are still parts of the UK without even basic GSM signal availability, never mind 3G or 4G.
You can't make an emergency call if there is no signal, and it is the out-of-the-way places where this is most required that the networks don't want to cover.
* Or do you really need 100 Mb/s all over the Cairngorms?
Yes, the whole point (or one of the major points) for replacing airwave with mobile was to allow the emergency services to use mobile data in preference to voice.
However, as others have said, there isn't even basic GSM coverage in quite large parts of the British Isles, so ambulances, police cars etc will have no contact with their base, and their base will have no contact with the vehicles.
Which is a bit of a drawback for an emergency service.
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