facthunter Posted March 13, 2019 Share Posted March 13, 2019 Some 30 years ago the "makers" went down the path of trying to" pilot proof" their planes, and getting rid of the direct connection between the control column and the actual control surfaces.. Initially it was to prevent any overstressing of the plane's structure, then prevent stall, apply full power if you are too slow. Do an auto go around under some circumstances ( no wheel spin up), Auto spoilers various things worked by micro switches on the undercarriage and wheel rotation for autobraking . Stick shakers actuation based on AoA information from flight data microprocessors and so on... Unless you have done the actual aircraft TYPE course it's hard to relate "normal" flying concepts with living with the logic of some of these flight management systems. I've stated from the onset that Boeing have done the wrong thing here by not making clearly known all the info on the "New type DIFFERENCES" format. Nev Link to comment Share on other sites More sharing options...
Methusala Posted March 13, 2019 Share Posted March 13, 2019 Report just now from ABC that 2 US captains had unexplained nose down pitch immediately after engagement of a/p. Disengagement of auto pilot allowed normal climb to continue. Problem seems greater than Lion Air crash. 2 Link to comment Share on other sites More sharing options...
kgwilson Posted March 13, 2019 Author Share Posted March 13, 2019 I was at the aerodrome today & there was some discussion of the two 737-800 MAX crashes. After a while I decided to ask the question "If you had booked a flight somewhere leaving today and the aircraft was a 737-800 MAX what would you do?" Not one person said they would go if that was the aircraft. Their concern may well be unfounded but until the cause(s) of both crashes have been fully identified it is entirely reasonable. With many countries and airlines grounding these aircraft the travelling public are likely to avoid them like the plague. This must be a massive concern for Boeing as they appear to be tight lipped on this. They could announce all is well or temporarily ground the 800 MAX fleet. The trouble is they are damned if they do and damned if they don't. Public opinion has already determined what to do though. For the record I also said I wouldn't go in answer to my own question. 1 Link to comment Share on other sites More sharing options...
red750 Posted March 13, 2019 Share Posted March 13, 2019 America are not grounding them. The person in charge of grounding aircraft in the US is a former Boeing senior exec. Link to comment Share on other sites More sharing options...
pmccarthy Posted March 13, 2019 Share Posted March 13, 2019 It’s the Comet all over again. Link to comment Share on other sites More sharing options...
Downunder Posted March 13, 2019 Share Posted March 13, 2019 Just looking at the 737 wiki page. Flying for over 50 yrs and 10 000 built......So it's not the inherent design that's the problem. It shouldn't be too difficult to track down the problem here with a comparison of previous perfectly serviceable models.... Link to comment Share on other sites More sharing options...
Thruster88 Posted March 13, 2019 Share Posted March 13, 2019 "If you had booked a flight somewhere leaving today and the aircraft was a 737-800 MAX what would you do?" If it was in north America or Australia when we get them I would not have a problem especially if they were flown by this guy 1 3 Link to comment Share on other sites More sharing options...
red750 Posted March 13, 2019 Share Posted March 13, 2019 They've taken a Hillman Minx and hotted it up to a street dragster. 1 Link to comment Share on other sites More sharing options...
Roundsounds Posted March 13, 2019 Share Posted March 13, 2019 The golden rule in any aircraft fitted with flash automation, if it’s not doing as expected get rid of the automation. Once you’ve sorted things out and established in a safe state, then consider whether further use of automation is the best course of action. This applies to automated trim functions, the B737 has a published procedure to disable the automated trim function and revert to manual trim. The initial steps in this procedure are accomplished from memory. Boeing have not designed a system that will fly the aeroplane into the ground. “System” includes both aircraft systems and crew intervention. 1 Link to comment Share on other sites More sharing options...
IBob Posted March 13, 2019 Share Posted March 13, 2019 I would have thought that the golden rule in an aircraft with flash automation would be to ensure the flash automation flew the aircraft safely, rather than creating problem situations for the crews to solve. And under the circumstances, I personally find the suggestion that the fault lies with crews for not successfully managing that, offensive. As is the the inference that everything is okay because a previous crew survived. 1 Link to comment Share on other sites More sharing options...
red750 Posted March 13, 2019 Share Posted March 13, 2019 * * * BREAKING NEWS * * * Donald Trump has grounded all Max 8 and 9 aircraft in the US. - 7 News. Link to comment Share on other sites More sharing options...
red750 Posted March 13, 2019 Share Posted March 13, 2019 Boeing has now supported this decision, grounding all Max 8's around the world, quoting "an abundance of caution." Link to comment Share on other sites More sharing options...
Downunder Posted March 13, 2019 Share Posted March 13, 2019 Very informative video above. So when the auto pilot is disabled, the mcas system still operates? Manual control, but not REALLY manual control..... The simple answer is to disable mcas system when auto pilot is disabled? Also what is the go with the mks system reacting to only one erroneous sensor input? Why actually have multiple sensors and redundancy then? Pretty horrific thinking the pilots were trying to trying to get the nose up with trim and yoke inputs but the aircraft is driving itself into the deck! In the past we had pilots making mistakes and crashing aircraft with automation developed to save aircraft. Now we have the automation crashing aircraft and we are relying on pilots to save the aircraft... To my mind there is something very very wrong with this way of thinking. Yes, perhaps the pilots should of known how to disconnected the mcas system, but that doesn't address the fundamental issues behind this. The aircraft WANTING to crash itself. ..... 2 Link to comment Share on other sites More sharing options...
IBob Posted March 13, 2019 Share Posted March 13, 2019 So, if I have understood the video correctly: in the event that this MCAS system is erroneously trimming nose down, for whatever reason, the only workable crew response is to turn off the trim servos with the switches on the centre console, then retrim the aircraft by hand with the manual trim wheels? All of which supposes the aircraft is at sufficient height, and in a suitable flying attitude, to allow that to be successfully carried out............ 1 Link to comment Share on other sites More sharing options...
Downunder Posted March 13, 2019 Share Posted March 13, 2019 So, if I have understood the video correctly: in the event that this MCAS system is erroneously trimming nose down, for whatever reason, the only workable crew response is to turn off the trim servos with the switches on the centre console, then retrim the aircraft by hand with the manual trim wheels? All of which supposes the aircraft is at sufficient height, and in a suitable flying attitude, to allow that to be successfully carried out............ Yes, but they have to determine the problem first...... Link to comment Share on other sites More sharing options...
dsam Posted March 13, 2019 Share Posted March 13, 2019 The aircraft WANTING to crash itself. ..... Precisely! If there was an independently powered GPS failsafe system that over-rode all systems where non-landing automation was merrily flying into the ground, the GPS "terrain-floor failsafe" could stop it. Link to comment Share on other sites More sharing options...
Downunder Posted March 13, 2019 Share Posted March 13, 2019 Precisely! If there was an independently powered GPS failsafe system that over-rode all systems where non-landing automation was merrily flying into the ground, the GPS "terrain-floor failsafe" could stop it. We've come full circle. Automation stopping pilots kill people. Now pilots stopping automation kill people. Link to comment Share on other sites More sharing options...
poteroo Posted March 13, 2019 Share Posted March 13, 2019 Could some of these recent jet accidents be in part due to crew reluctlance to switch off the autopilot, or any other system and handfly the aircraft? How much practice does an airline crew get at hand flying on basic panel, ie, power x attitude? Does simulator time equate to actual flight time in these emergency systems? Things are a mighty lot more frightening when there is a large pitch change and it's for real! Several accidents, eg, the Air France one off Brazil, and the AirAsia one off Java have been simple failure to recover from a stall events which crew training/retraining in basics should prevent. But it seems Boeing have built the MCAS into its' 737 Max to avoid needing the pilot input? As said previously - we've come full circle. 1 Link to comment Share on other sites More sharing options...
kgwilson Posted March 13, 2019 Author Share Posted March 13, 2019 The pilots of the Max 8s were experienced high hours pilots & yet they failed to disable both Autopilot & MCAS systems. A couple of points to ponder are Why does the MCAS system continue to operate when Autopilot is disengaged? The pilots manually change trim (by switches on the yoke) & MCSA then takes over after 5 seconds to negate their input. They should know this but at the time their mind is in overdrive. Most of the flying hours of these pilots is sitting there while the autopilot flys the plane. There is probably only 1 takeoff & landing for each 3-5 hours of experience and most of that is assisted. I had more than 150 takeoffs & landings in my last 50 hours. Link to comment Share on other sites More sharing options...
facthunter Posted March 13, 2019 Share Posted March 13, 2019 The comparing of U/L's to these planes is not valid to any great extent. You, in your plane don't have any control system other than your basic direct coupled wires and rods and you can feel the air load on the control surface, always. All feel on a hydraulic or fly by wire control system is artificial.. You have no complicated flap schedule or spoiler ratio mixers. or flying tail that has enormous power in the pitch plane. Imagine you have fitted an autopilot that didn't disengage when you asked it to. but most don't have one of those even. It's NOT just a matter of plugging the autopilot in and reading the paper. That's the common perception though. If you get near vertical you are coming down at 9 miles a minute vertically. Stalled at 2 miles a minute vertically.. You are always flying close to a stall at high altitudes and can't really fly manually and hold altitude to normal limits. above FL 310 You REQUIRE extra vertical separation if autopilot not serviceable' Crew awareness and training are always potential factors but in this one the manufacturers have perhaps neglected to give full attention to the differences of this to the last models underplaying the significance of the new system. Saying they have been in service for 50 years and have built "X" number of them is a bit irrelevant as the early ones bear little resemblance to the latest in flight management systems engine thrust and cruising levels and efficiency.. 2 near new Planes have gone down with no survivors and the plane is effectively grounded world wide. That's probably appropriate in the circumstances.. Nev 1 Link to comment Share on other sites More sharing options...
Downunder Posted March 14, 2019 Share Posted March 14, 2019 Worldwide fleet now grounded. Ethiopia crash now linked to Lionair crash.... Boeing recommends entire global fleet of 737 MAX aircraft be grounded http://www.abc.net.au/news/2019-03-14/donald-trump-boeing-737-max-8-grounded-faa-ethiopian-airlines/10899102 Link to comment Share on other sites More sharing options...
APenNameAndThatA Posted March 14, 2019 Share Posted March 14, 2019 The terrifying, and overwhelmingly problematic fact remains, that two virtually brand new 737 MAX's, with experienced pilots at the controls, have flown straight into terra firma/ocean in recent months, and this is a situation for grave concern - for all concerned. It simply means that technology must be overwhelming the pilots, and that there are automation conflicts that were never envisaged, or thought through, simply because of the vast number of possibilities, multiplied by the number of components in the systems. Sensor errors are common, and every failure in the chain should mean the systems automatically revert to a simpler, fail-proof system, for backup. It appears the automation designers are designing electronic systems that are falling back upon reliance on other electronic and electrical backup, thus compounding information errors. Donald Trump said pretty much the same thing. (I actually don't mind The Donald. Unlike GWB, he didn't start an illegal war and kill 500 000 civilians and counting. And unlike Hillary, he is capable of intimidating China.) Link to comment Share on other sites More sharing options...
kgwilson Posted March 14, 2019 Author Share Posted March 14, 2019 Donald Trump said pretty much the same thing. (I actually don't mind The Donald. Unlike GWB, he didn't start an illegal war and kill 500 000 civilians and counting. And unlike Hillary, he is capable of intimidating China.) You are of course entitled to your opinion. Someone who has an overbearing narcissistic personality and has made 9014 false or misleading claims in 773 days to 3/3/19 since taking office is not particularly trustworthy in my book. Neither China or N Korea are in the slightest way intimidated by Trump. He got nothing from the last so called summit & Kim is now rebuilding his armament capability. 2 4 Link to comment Share on other sites More sharing options...
kgwilson Posted March 14, 2019 Author Share Posted March 14, 2019 The truth begins to surface . See this report published in the Washington Post. https://www.stuff.co.nz/travel/travel-troubles/111297163/boeing-pilots-fume-at-being-left-in-the-dark-over-changes-after-lion-air-crash Link to comment Share on other sites More sharing options...
Teckair Posted March 15, 2019 Share Posted March 15, 2019 Donald Trump said pretty much the same thing. (I actually don't mind The Donald. Unlike GWB, he didn't start an illegal war and kill 500 000 civilians and counting. And unlike Hillary, he is capable of intimidating China.) How dare you have an opinion about Trump that is not bad! Shame on you! Everybody knows the best bet was Hillary?? Link to comment Share on other sites More sharing options...
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