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Message
re: 737max crashes in Ethiopia. Killing 157
Posted on 3/11/19 at 8:47 am to dewster
Posted on 3/11/19 at 8:47 am to dewster
quote:Business Insider
I imagine their share prices are going to crater today.
quote:
The second crash of a Boeing 737 Max 8 aircraft in five months has caused has sent Boeing shares down 12% Monday morning, wiping out nearly $28 billion of the company's market value.
The sell-off in Boeing, which commands a weighting of more than 10% of the Dow Jones Industrial Average, has wiped out nearly 340 points from the index.
This post was edited on 3/11/19 at 8:48 am
0
Posted on 3/11/19 at 9:06 am to GEAUXmedic
quote:
JUST IN: Ethiopian Airlines grounds Boeing 737 Max
well yeah
Posted on 3/11/19 at 9:08 am to LetzGeaux
quote:
Just got off of one about 30 minutes ago. Flown internationally on them for the last 7 months. About 20 flights. This Russian roulette is getting old lol.
quote:
Only 350 or so have been delivered to airlines worldwide on a book of 4,700 orders.
Your chances of being on 2 out of those 350 or so is much higher than any chance I would like to take. Best of luck in the future - hopefully this issue is not with the plane itself. Are aircraft recalls a thing?
Posted on 3/11/19 at 9:27 am to darnol91
Something I found interesting from the PPRuNe thread; they are discussing the MCAS, and this guy makes an interesting point about the reliability of the quality of the sensors (obviously everyone is speculating that the cause of this crash is related to the MCAS issue due to the similarity to the Lion Air crash, which has not been proven).
quote:
MCAS is reacting to sensor data- the same data that the instruments in front of your eyes are relaying to you. If your AOA indicator goes haywire, or your ASI is showing lower than stall speed, then you'll have a difficult situation. What MCAS does... it controls flight surfaces to prevent a stall that is likely to occur given the sensor inputs that it's receiving. If you're flying you'll usually trust the instruments- the same instruments as MCAS. Maybe other MCAS interventions haven't been noticed or reported because the rest of the time it's actually functioned the exact same way as the pilots have operated anyway.
If you've just taken off on most other aircraft, if you get a low reading from ASI, or even stick shaker, your first priority is to try to control the aircraft, stabilize flight, level off if at a safe altitude, call a pan and go through the checklists... whereby you eventually should discover that the ASI sensor is bad, Air speed is fine and switch to the alternate input and go on your merry way. Why MCAS is scary is that it 100% relies on sensor data- you're now in the exact same situation as described above, with the exception being that your aircraft has just trimmed nose down by itself, any breathing space you had to troubleshoot has been eroded by MCAS nose down, and any time you could have used to figure out the problem is now spent trying to pull back on the yoke as hard as you can.
It's very easy to say "just pull a couple of CBs, disconnect trim switch, everything will be fine", but in those circumstances, you're on climb out of airport XYZ, suddenly the stick-shaker goes, the ASI in front of your eyes IS showing a reading that's abnormally 'low', the aircraft just trimmed itself nose down to prevent stall, before you have any chance to diagnose the problem you're fighting against the MCAS nose down attitude, your right hand man has 200 hrs all-in and is panicking.
Again, like I said earlier, absolutely not jumping to conclusions as to what caused this tragedy. Again, just re-examining the MCAS issue that has been brought up. Again, stating that MCAS in and of itself should not be a problem- providing the inputs are 100% reliable the software goes unnoticed and may even act as a safety net in the manner it was designed to be. Again, the problem that I see that I haven't seen highlighted previously is the hardware! MCAS relies on data, sensors are the source of the data, why are the sensors so fallible?? Why can't they spend more money on the hardware- ensuring sensors are foolproof with adequate redundancies that can always be relied upon?
Again, Southwest knew the problem and had a quick fix for their own 738 MAX orders, providing an additional AOA indicator for crew to easily cross-check if needed. Note that their statement on 738 MAX listed above is qualified- they're happy with 'their fleet' Possibly their quick & simple solution might be sought by other 738 MAX operators, or even demanded of Boeing to retrofit.
Posted on 3/11/19 at 10:19 am to When in Rome
MCAS is only " supposed " to be active at flaps fully retracted with A/P disengaged. It was incorporated because the nacelles of the new engines extended forward of the aircrafts c/g, causing lift, increasing the AoA.
A friend at SWA said the FAA wouldnt certify the aircraft unless MCAS was applied to the software. Disengage MCAS youre not legal. Pilots in initial MAX training were never told about MCAS.
A friend at SWA said the FAA wouldnt certify the aircraft unless MCAS was applied to the software. Disengage MCAS youre not legal. Pilots in initial MAX training were never told about MCAS.
Posted on 3/11/19 at 10:21 am to OchoDedos
Yeah, I was reading about that too. It seems like they are relying on software to correct for what is essentially a physical design disadvantage.
This post was edited on 3/11/19 at 10:24 am
Posted on 3/11/19 at 10:22 am to When in Rome
quote:
MCAS relies on data, sensors are the source of the data, why are the sensors so fallible?? Why can't they spend more money on the hardware- ensuring sensors are foolproof with adequate redundancies that can always be relied upon
Air France flight 447 had a failure of all three speed sensors. All three pitot tubes were clogged with ice. Airbus had warned of this issue as there were 9 previous pitot tube failures in the preceding year.
Pilots failed to recognize the issue and crashed the plane.
Sounds sadly exactly what is happening right now. In the AF447 case, they were flying in the dark and in thunderstorms.
In this crash, they were flying in broad daylight and clear conditions. They were recently made aware of the trim issue and how to handle it.
All they had to do was either turn off autopilot, retract the flaps or disable mcas. At that point they could have flown the plane at a set power and they had visual view of the outside world.
Posted on 3/11/19 at 10:30 am to BHM
quote:
All they had to do was either turn off autopilot, retract the flaps or disable mcas. At that point they could have flown the plane at a set power and they had visual view of the outside world.
Stab Trim from Override to Manual
Posted on 3/11/19 at 10:56 am to BHM
With AF447, they had the failure of the three sensors, but the bigger issue was that once the autopilot disengaged, one pilot initially reacted with nose-up inputs and then continued to respond with nose-up inputs throughout the stall, which were being counteracted by the other pilot's nose-down inputs, because Airbus side stick controls operate independently and give little feedback to the other pilot. It seems like if the pilot hadn't input the nose-up inputs, they could have recovered from the stall by nosing down and recovering/flying manually. This final cause was primarily a communication issue.
What seems to be happening (speculation) in these recent cases is that the MCAS engages when it thinks that the plane is nearing a stall due to the faulty airspeed readings, automatically edging the nose down for the pilots so that the plane doesn't stall. But if the plane isn't stalling, the pilots would want to return to a normal angle of attack. So what I think I understand happened to the Lion Air flight is that rather than disengaging the MCAS at this point like they should have, they tried to fight the auto-nose-down caused by the MCAS by pulling up on the stick and could not overcome it.
So while both issues stem from faulty sensor readings, the final actions causing the crashes differ (although both are related to pilot error).
ETA: I can see Southwest's decision to add another AoA sensor to its 737 MAX fleet being the protocol followed by the other airlines after these incidents. I've seen criticism that the MCAS relies on two AoA sensors; so if one sensor goes out then it has to rely on only one with nothing to corroborate it. The odds of two going out are significantly lower than the odds of one going out, so three sensors (a la Airbus) makes way more sense. The system just takes the reading from the two sensors that read the same AoA and discounts the faulty sensor.
What seems to be happening (speculation) in these recent cases is that the MCAS engages when it thinks that the plane is nearing a stall due to the faulty airspeed readings, automatically edging the nose down for the pilots so that the plane doesn't stall. But if the plane isn't stalling, the pilots would want to return to a normal angle of attack. So what I think I understand happened to the Lion Air flight is that rather than disengaging the MCAS at this point like they should have, they tried to fight the auto-nose-down caused by the MCAS by pulling up on the stick and could not overcome it.
So while both issues stem from faulty sensor readings, the final actions causing the crashes differ (although both are related to pilot error).
quote:I think MCAS only operates when autopilot is disengaged.
All they had to do was either turn off autopilot, retract the flaps or disable mcas.
ETA: I can see Southwest's decision to add another AoA sensor to its 737 MAX fleet being the protocol followed by the other airlines after these incidents. I've seen criticism that the MCAS relies on two AoA sensors; so if one sensor goes out then it has to rely on only one with nothing to corroborate it. The odds of two going out are significantly lower than the odds of one going out, so three sensors (a la Airbus) makes way more sense. The system just takes the reading from the two sensors that read the same AoA and discounts the faulty sensor.
This post was edited on 3/11/19 at 11:26 am
Posted on 3/11/19 at 12:50 pm to cubsfan5150
quote:
Oldest plane I've ever worked on was from '62
Our gunships at the base I was at were all Vietnam era
I'm assuming Hurlburt field?
Posted on 3/11/19 at 3:02 pm to RedRifle
Passenger just misses flight
Article on the only passenger that didn't board. They closed the gate as he was walking up and he argued to let him on but they refused.
"When I arrived, boarding was closed and I watched the last passengers in (the) tunnel go in. I screamed to put me in but they didn't allow it," he wrote.
Article on the only passenger that didn't board. They closed the gate as he was walking up and he argued to let him on but they refused.
"When I arrived, boarding was closed and I watched the last passengers in (the) tunnel go in. I screamed to put me in but they didn't allow it," he wrote.
This post was edited on 3/11/19 at 4:12 pm
Posted on 3/11/19 at 3:22 pm to When in Rome
quote:
It seems like they are relying on software to correct for what is essentially a physical design disadvantage.
Most fighter jets could not fly without software tweaking things constantly during flight.
Posted on 3/11/19 at 3:23 pm to BHM
Have they released the names of the US victims?
Posted on 3/11/19 at 3:25 pm to Shiftyplus1
quote:
This could be because of anything. Pilot error, terrorism, shoddy maintenance....
Ethiopian adopted strict American, Israeli, and British maintenance standards. It’s considered one of the better global airline carriers despite the Ethiopian name. Would be very surprised if it was maintenance.
Posted on 3/11/19 at 3:34 pm to BHM
quote:True, fighter jets need to be unstable to allow for rapid maneuverability and therefore rely heavily on software to tweak systems during flight. I'm not saying that software enhancements are bad (obviously they are generally good); it just seems like, in this case, they might have compromised a level of airworthiness of the airplane structure in relying so heavily on something like the MCAS to offset the tendency for the airplane to pitch up due to the engines moving forward in the latest design.
Most fighter jets could not fly without software tweaking things constantly during flight.
This post was edited on 3/11/19 at 3:42 pm
Posted on 3/11/19 at 3:34 pm to fr33manator
quote:
I’d say the problem probably rested with Ethiopian airline maintenance.
They’re a good airline that flies world wide and iirc africas largest
Posted on 3/11/19 at 4:17 pm to MrLSU
quote:
Ethiopian adopted strict American, Israeli, and British maintenance standards.
Ethiopian is something of an offshoot of TWA, which managed the airline for 20 yrs. The FO with a grand total of 200 hrs is disconcerting.
Posted on 3/11/19 at 4:38 pm to redstick13
quote:
They only show one in their current fleet.
They have 4 in fleet, and 25 on order.
Posted on 3/11/19 at 5:20 pm to MrLSU
quote:
Ethiopian adopted strict American, Israeli, and British maintenance standards. It’s considered one of the better global airline carriers despite the Ethiopian name. Would be very surprised if it was maintenance.
This means very little if they are only using locals because they are paying only for locals. There are countless industries that try and do this and fail if they use locals only. If you wanna be one of the top airlines in the world you have to pay for the best and bring in the best. I'm not doubting they have some great people, but I also would bet they have some real slouches that would never be touched by a domestic carrier or the other top airlines in the world.
Posted on 3/11/19 at 5:44 pm to AUTimbo
Cannon and deployed with Hurbie guys
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