Originally Posted by SLFinAZ
(Post 10416710)
Amazing reading.
Basically what it confirms is that for competent well rested crews the potential MCAS issues are a minor speed bump. 2. They had more altitude than the crashed crews On a side note, the fact that the FAA kept the plane flying is (borderline?) manslaughter. |
Originally Posted by Roger_Murdock
(Post 10416627)
Originally Posted by bauble
(Post 10416610)
Does anyone have any information on instances of irregular MCAS activation that have been successfully handled?
MCAS is only supposed to operate well outside the normal flight envelope. However, at the time, Southwest was concerned about the source of the automatic throttle problem during autopilot that their pilots had reported. During two separate diagnostics, they decided to replace the AOA vanes even though neither seemed to have contributed to the problem. In other word, that automatic throttle problem experienced by Southwest is still unsolved even now. Those infamous vanes escaped unscathed after a close scrutiny. I wonder if the left AOA vane removed from Lion Air's PK-LQP in DPS, two flights prior to the fateful one, which was thought to be the source of erroneous indications would come clean as well. That will be interesting because the problem would then be in a much deeper area in the flight control sytem. Here's the little summary of that news... Southwest Replaced Flight-Control Sensors of the Kind Implicated in Lion Air Crash...The accidents in the South-West caused no emergencies and no one was hurt. They pushed what appear to be routine reports from mechanics who experience sensor problems. One was written on October 9 in Baltimore and the other on October 21 in Houston, the documents show, and indicate that both sensors have been repaired...Boeing and FAA did not have immediate comments on the Southwest maintenance records. The Southwest spokeswoman said the carrier replaced the two sensors in October on the same aircraft and determined that they were not the source of the automatic throttle problem. Two other Southwest 737 MAX 8s have replaced an attack angle sensor as part of routine maintenance due to external damage, such as a bird's shot in flight... |
Originally Posted by DaveReidUK
(Post 10416680)
The NTSB, as a party to the investigation, had (not unreasonably) been pressing for the recorders to go to the USA, but despite their fierce independence from the FAA, it would seem that the latter's decision to allow continued operation of the Max in the USA (not to mention Trump's comments) may have had a bearing on the decision.
Given that MAXs are being grounded like dominoes around the world, and the FAA is rightly or wrongly, being perceived as putting US commercial interests before safety, no one should be surprised at the decision to send the boxes to BEA or the NTSB. |
Originally Posted by Whispering T-Jet
(Post 10416697)
Whilst that crew proved they could actually fly, they then made an appalling "airmanship" decision to fly hundreds of miles over high terrain to Jakarta with an effectively jammed stab and no autopilot instead of returning to the 10,000' RWY in Bali 20-30 nm away. Furthermore the incident was not fully written up in the tech log. Commercial pressure maybe....
At this point MCAS has NOT been implicated although something - voice reports from other aircraft indicate unreliable airspeed - happened. It seems probable they didn't even make flap retraction height (thereby discounting MCAS unless they retracted flaps below flap ret. ht.). While we are waiting for some actual CVR/DFDR facts maybe you would like to read about Ethiopian's last 737 prang here: https://www.bea.aero/docspa/2010/et-...b100125.en.pdf which in one sentence can be summarised as: pilots can't fly. I'll get on a Max tomorrow if flown by say, Southwest. |
Originally Posted by SLFinAZ
(Post 10416710)
Amazing reading.
Basically what it confirms is that for competent well rested crews the potential MCAS issues are a minor speed bump. Doesn't mean that it isn't a very real issue but the bottom line specific to Lion Air is simple and compelling....crew error. As for the current tragedy we really don't know enough but it doesn't have any of the trim related oscillation seen in Flight 610... At some point the various regulatory agencies will need to figure it out. |
Originally Posted by DaveReidUK
(Post 10416702)
Nothing so complicated.
The aircraft simply transmits either a Ground Position ADS-B message, which for obvious reasons doesn't need to contain an altitude, or an Airborne Position, which does. |
Originally Posted by CONSO
(Post 10416747)
post 1041 ...
Hmmm . . . . SUPPOSED to be disabled... but if not ????? |
Originally Posted by davionics
(Post 10416586)
Witness accounts need to be impeccably interpreted. Surprised to see witness accounts publicity released so fast. I believe they are worthless. A colleague who works on eye witness interpretation comments:
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Originally Posted by RTM Boy
(Post 10416777)
Since risk assessment for safety purposes in any environment needs to allow for circumstances and variables - ie there is no such thing as 'safe or 'unsafe' - it's not an absolute - if you are saying that flight crew can only deal with the MCAS system if a certain (highest) level of competence, alertness, awareness and training, then that is very worrying. It's akin to saying that Top Gun fighter pilots are capable of handling the MCAS scenario we've been discussing, so only Top Gun fighter pilots should be allowed to fly the Max 8. I know I'm stretching the point, but surely flight crew within the bell curve must be able to respond effectively on a model of aircraft with thousands of orders? If not, I have to ask whether the MCAS system itself and the circumstances in which it is deployed has been correctly risk assessed.
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 |
FWIW- as a SLF who has been in the industry- Boeing for decades a few items tweak me
1) To allow a SINGLE sensor with NO comparison/matching/voting to take control on a ' intermittent ' or ' sometimes ' basis is just plain wrong wrong wrong 2) Without splittinh hairs regarding just when most pilots engage autopilot, or put flaps up, both seem to commonly happen at ** relatively ** low altitudes. And most birds/fowl also fly at relatively low altitudes. Yes some have been found at 15,000 to 20,000 feet- but I'm focusing on majority issues. Birds strike aircraft often in the 'nose' area, which means a slightly higher probability of damage to AOA sensor - AT LOW ALTITUDE which when coupled with a single path control again IMHO is a bad idea. 3) Inertial systems can now define an approximate flight path, ground speed, altitude and work as a simple ' crude' backup or possibly a non external sensor compare ( believe 777/787 does incorporate similar INS compare/standby function ??? ) 4) Both the Boeing/FAA games re certification/analysis and change in the DER process need be scrubbed as it seems to have alllowed/overlooked the basic ' redundancy'/"safety' issue for 'critical " sensors/controls. ( and 787batteries ! ) Just my .000001 :( |
Originally Posted by slip and turn
(Post 10416781)
So how does a 737-MAX 8 or a 738NG or any other late model aircraft know when to transmit via ADS-B that it has become airborne?
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Originally Posted by slip and turn
(Post 10416781)
So how does a 737-MAX 8 or a 738NG or any other late model aircraft know when to transmit via ADS-B that it has become airborne? And if it does, and gets it wrong at 93kts groundspeed, against what are all its subsequent pressure altitude reports calibrated?
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Originally Posted by slip and turn
(Post 10416781)
So how does a 737-MAX 8 or a 738NG or any other late model aircraft know when to transmit via ADS-B that it has become airborne? And if it does, and gets it wrong at 93kts groundspeed, against what are all its subsequent pressure altitude reports calibrated?
A WOW switch is usually just a microswitch in the MLG which indicates whether an aircraft is airborne according to the amount of oleo extension., |
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As an IT ex-developer we always understood that we needed a business or industry expert to look at/understand and accept our design, even if not understanding every line of geeky code. Would any pilot anywhere accept a design that might, even in normal , not failure-mode, trim Down for 10 seconds? How was this software ever approved? |
Originally Posted by MartinAOA
(Post 10416819)
Canadian Transport Minister holding live press conference to address 737 MAX - Marc Garneau @ 15:30Z
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BREAKING:
Canada's press conference is happening now. New information has come from validated tracking data, shows similarities to the Lion Air crash. While it's too early to make any conclusions, based on this data, they are issuing a safety notice and banning the planes from its airspace. Source: Just dialed into the media press conference |
Originally Posted by CONSO
(Post 10416834)
just joined the EU and others - no passenger flights over canada for max - quoted satellite data and probable similarfity to lion air
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Originally Posted by positiverate20
(Post 10416708)
Report quote:
Aircraft pitched to 260 KTS with trim inputs, then re-pitched to 240 KTS. The trim system would activate for 1-2 seconds and then immediately reverse itself, trimming in opposite direction. I directed FO to ask for intermediate stop on climb, where we then stopped at FL230. Advised ATC we were experiencing a trim system problem. 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 |
Originally Posted by CONSO
(Post 10416834)
just joined the EU and others - no passenger flights over canada for max - quoted satellite data and probable similarfity to lion air
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