Ethiopian airliner down in Africa
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That is normal for a 737. I have lost count of the number of times that has happend, both on Classics and NGs. The sudden pitch down on engaging the autopilot is pretty standard too - it is nornally caused by a baro-error in the autopilot computer.
The really disappointing thing, is it looks like the Max is equipped with the same old autopilot that was fitted to the Classic, with all its limitations and foibles. So I presume the Max still cannot do Cat IIIb landings. What I always wonder, is where Boeing gets these old 1980s microprocessors from, to run these autopilot computers. Do they have a source in China that still makes the 286 processor?
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I have flown the NG since it was new, and I have NEVER had any trim issues like this. Or trim issues at all.
I have a thing or two to say about the STS system, but it does what it is supposed to do.
I just don’t agree with what it is doing.
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Agree in total
However, one question is the training of the pilots to a standard of knowledge applicable to the product they are flying. The pilots may be experienced and of sufficient skills to fly, but have they been given an adequate knowledge for this aircraft ?
These questions are for us to ask and answer, without relying on politicians or bureaucrats
However, one question is the training of the pilots to a standard of knowledge applicable to the product they are flying. The pilots may be experienced and of sufficient skills to fly, but have they been given an adequate knowledge for this aircraft ?
These questions are for us to ask and answer, without relying on politicians or bureaucrats
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Well in this case the combination of those appears to have set the airborne indicator in just 20% of the paved runway available at a groundspeed of 93kts - plus maybe 10 kts wind. Not a factor in the safety of the aircraft, but it appears to have resulted in us being able to analyse reported altitude at several data points during the remaining take off roll, and whilst they are all located slap bang along the centreline and the speeds look reasonable, one or two of the altitudes look a bit odd and make me wonder like Tucoma Sailor about where rotation was first attempted.
Last edited by slip and turn; 13th Mar 2019 at 16:57. Reason: take off not tale off!
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Mode-C gives 1013 baro altitude.
Mode-S gives 1013 baro altitude.
ADS-B also gives 1013 baro altitude, to be compatible with the above.
Flarm and PAW give GPS altitude.
As far as I know, FR24 is simply picking up ADS-B 1013 pressure altitudes, so you will need to know the QNH of the day, and the altitude of the airport, to calculate the true height of the aircraft. Transponders were designed for seperation on airways, not for separation with terrain, so the older units all used 1013 baro, and ADS-B follows suit.
(If ADS-B used GPS Alt, then ATC would not be comparing like with like. However, newer systems like Flarm and PAW can happily use GPS Alt, because they all use GPS, so they are comparing like with like.)
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According to this Reddit comment https://www.reddit.com/r/flying/comm...hread/eidycdx/ due to a programming error the MCAS can be triggered by transient bursts of high AoA e.g. during climb. I have no way of knowing if this is true or not, but if it is, and if Boeing knew about this as early as August 2018, it's pretty damning.
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My bitch with Boeing is that even the Classic was a revision too far. Can you imagine using 1950s B-707 systems in the 21st century..? And then the NG was a double stretch too far. But then the Max? So these 1950s B-707 systems will still be running a century after they were designed? They are having a laugh, surely.
Silver
Last edited by silverstrata; 13th Mar 2019 at 16:44.
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As far as I know, FR24 is simply picking up ADS-B 1013 pressure altitudes, so you will need to know the QNH of the day, and the altitude of the airport, to calculate the true height of the aircraft. Transponders were designed for seperation on airways, not for separation with terrain, so the older units all used 1013 baro, and ADS-B follows suit.
FR24 don't export one or the other in their downloadable CSV data, I haven't determined which, but both are visible in the web UI during interactive usage.
Garneau gave a very confused answer when asked about that towards the end of the press conference, presumably he hadn't been properly briefed by his minions. He went on about satellite providers, nations sharing data and all sorts of stuff.
In an earlier comment, he talked about the ET flight profile being compared with a standard 737 departure, so I would guess the "satellite" reference was really about GPS/ADS-B data.
In an earlier comment, he talked about the ET flight profile being compared with a standard 737 departure, so I would guess the "satellite" reference was really about GPS/ADS-B data.
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The above is not related to my comments, but this question highlights an important point. Everyone has an agenda. Everyone. The question is whether that agenda is trying to be objective, focused on identifying and solving the real causes of the problems, honestly, in good faith, with safety absolutely first and foremost...or is it a subjective, biased agenda (biased either way)? When suspicions arise about corners being cut because the accountants don't like the numbers, or that regulatory bodies may be biased in favour of a manufacturer, or vise versa, then rather than jumping to conclusions or dismissing such suggestions out of hand, or being a 'fanboy' for heaven's sake, everything needs to be examined cooly and calmly to get to the truth.
Richard Feynman's role in the Rogers Commission into the Challenger disaster is an example of cutting through agendas to show that not only the Swiss cheese holes lined up, but also that the knowledge and skills to make and use the stuff in the first was lacking to a calamitous extent. He famously said; "For a successful technology...reality must take precedence over public relations, for nature cannot be fooled." Shuttle launches were suspended until changes were made not only to rocket boosters, but also protocols, systems, etc. In these circumstances being pro-Boeing or anti-Boeing is idiotic beyond belief.
Over three decades later, we have social media to propagate agendas at the speed of light. Many PAX see the news, read tweets and texts and worry about the plane they're booked on. They jam phonelines, apparently. In response Kayak now lets users exclude the Max 8 from searches https://uk.reuters.com/article/us-bo...-idUKKBN1QU1AW
Any way you look at this Boeing, and airlines using the Max 8, have a major problem and one where timescales of investigation and the 24 hour news agenda don't align. Be that as it may, we must give the investigators the space to do a thorough, objective job. If the Max 8 is grounded for many months, so be it. The prospect and consequences of a third similar incident without fully understanding the Lion Air and ET crashes would be unforgivable.
Richard Feynman's role in the Rogers Commission into the Challenger disaster is an example of cutting through agendas to show that not only the Swiss cheese holes lined up, but also that the knowledge and skills to make and use the stuff in the first was lacking to a calamitous extent. He famously said; "For a successful technology...reality must take precedence over public relations, for nature cannot be fooled." Shuttle launches were suspended until changes were made not only to rocket boosters, but also protocols, systems, etc. In these circumstances being pro-Boeing or anti-Boeing is idiotic beyond belief.
Over three decades later, we have social media to propagate agendas at the speed of light. Many PAX see the news, read tweets and texts and worry about the plane they're booked on. They jam phonelines, apparently. In response Kayak now lets users exclude the Max 8 from searches https://uk.reuters.com/article/us-bo...-idUKKBN1QU1AW
Any way you look at this Boeing, and airlines using the Max 8, have a major problem and one where timescales of investigation and the 24 hour news agenda don't align. Be that as it may, we must give the investigators the space to do a thorough, objective job. If the Max 8 is grounded for many months, so be it. The prospect and consequences of a third similar incident without fully understanding the Lion Air and ET crashes would be unforgivable.
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You claim that trim errors are normal for the 737 NG and Classic.
Are you now saying this is only applicable for poorly maintained 737 aircraft?
What sort of remote data does Boeing have about that specific flight? Did ET have some remote health management service arrangements or something similar for the engines?
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Does such a remote health management system transmit data real-time to the ground? Or is data collected during the flight and sent to a station after the flight?
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Indeed, it is an incredibly brave (although I recognise others may choose a different word) decision to allow the aircraft to continue to fly in the present circumstances.
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By receiving ADS-B from orbit, they may have received data for longer than what has been available from ground based receivers until today. From orbit, terrain interference should be much less.
No, as stated up-thread ADS-B emits BOTH barometric and GNSS ellipsoid altitude when both have onboard sources. Which for the 737-8 is true.
FR24 don't export one or the other in their downloadable CSV data, I haven't determined which, but both are visible in the web UI during interactive usage.
FR24 don't export one or the other in their downloadable CSV data, I haven't determined which, but both are visible in the web UI during interactive usage.
I'm confused about the FR24 reference, though. Their subscription plans grid does indeed state that Gold members get access to geometric height, but I've just replayed a selection of Max 8 flights (Air Canada, Icelandair and LOT) and for every one the GPS altitude on screen stays stubbornly on "N/A".
That said, I'm not sure why we're agonising over GNSS height as I haven't the faintest idea what height the ellipsoid is at Bole.
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it could be raw data shared from the Ethiopian investigation - only to be shared between regulating agencies at this time. But more likely yes - he is truly just a politician at this time
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That is normal for a 737. I have lost count of the number of times that has happend, both on Classics and NGs. The sudden pitch down on engaging the autopilot is pretty standard too - it is nornally caused by a baro-error in the autopilot computer.
The really disappointing thing, is it looks like the Max is equipped with the same old autopilot that was fitted to the Classic, with all its limitations and foibles. So I presume the Max still cannot do Cat IIIb landings. What I always wonder, is where Boeing gets these old 1980s microprocessors from, to run these autopilot computers. Do they have a source in China that still makes the 286 processor?
Silver
Last edited by Ian W; 13th Mar 2019 at 16:50. Reason: remove NASA