U.S. to ground Boeing 737 Max 8
businessinsider.com
businessinsider.com
The fact that Boeing cut as many corners as they did to bypass mandatory training just adds more smoke to the fire. When the dust settles on this episode I won't be surprised to learn that Boeing (and FAA regulators) is found completely at fault for engineering shortcuts to save costs on re-training.
And promptly given a pass by the FAA/regulators.
The A220-300 competes with the A319neo and 737 MAX 7 (and the A319neo isn't selling any better than than the MAX 7).
I don't think really an abandonment is on the cards: too many fleets are too heavily bought into the 737 family, and the cost of migrating away is real. By way of comparison, the A320(ceo) hardly had the best of starts to its life either with the Air France Flight 296 crash (which while different, still wasn't exactly good press!).
I agree. It seemed like the FAA was taking a position best described as "innocent until proven guilty." I think that's great for the US criminal justice system. I think a better approach for air travel safety is "abundance of caution." I have no direct experience in this field but it seems to me that the plane should be grounded out of an abundance of caution until we know more.
Edit: FWIW I used the phrase "abundance of caution" before I read it in the article.
Mileage will vary based on geography and beat though.
And... I'd admit we saw some charging documents we immediately dismissed from new officers, roughly like 'this guy seemed shady and was near a crime.' We'd lay into them for that though, they'd eventually seem to figure it out.
I am not a lawyer. If anyone is in doubt I suggest speaking to a lawyer!
But if there is nothing to back it up, the guy will be realeased very soon, and if you do it repeatedly, you'll eventually get problems (and rather quickly and seriously if you lied and it can be proven).
I guess the question here is what about him makes him seem shifty to you. One would at least hope his skin color would not be factoring into that and that your judgment would have been the same for anybody else exhibiting the same behavior.
Then again, in Guantanamo Bay there are people held in custody for many years now without any charges, so these rules can be bent pretty far in the right circumstances.
Planes aren't criminals or even citizens, though. But to translate this to the 737 Max situation, when something seems to be wrong it seems entirely reasonable to ground planes in order to investigate the situation. But there should be a limit to that grounding, and a permanent ban requires some actual proof.
Of course keep arresting people for no good reason, people lose their trust in them.
Remember how big of a deal the Toyota accelerator pedal recall was?
The way this particular glitch plays out sounds suspiciously like software, or a software-like function of the MCAS unit.
https://www.caranddriver.com/features/a15125313/its-all-your...
I'm not sure Boeing's software, even if not at fault, will be entirely flawless.
Some napkin math. 150,000 flights, each with 172 seats (based on the American Airlines 7M8 configuration, which is admittedly tight). That's 25.8 million journeys. Two accidents, let's that's ~350 deaths. Your chance of dying on any given journey is therefore 0.00135% (four nines to live).
You've got a 0.0167% chance of dying [1] for every 10,000 miles driven. Let's assume that each 7M8 journey averages 2500mi (generous, a transcontinental average). A linear projection tells me that's a 0.004175% of dying in an equivalent car ride.
You're still 3X safer on a 7M8 than you are in your car.
Now, by no means should this be taken to say the planes shouldn't be fixed or that Boeing should "get away with it." However, grounding all these planes and pushing people into a less safe form of transit may actually end up causing more harm than allowing the planes to fly with a fixed, short schedule to resolving the problem.
[1] https://www.seeker.com/how-common-are-skydiving-accidents-17...
The grounding and reaction may also shake people's faith in air travel in general, causing them to drive more even if planes were available. Bruce Schneier has a good write-up on this effect post 9/11 too. Humans are terrible at dealing with this kind of thing.
The reality is you're much more at risk in your Uber ride to the airport than you are aboard the 7M8.
[1] https://en.wikipedia.org/wiki/Boeing_737_MAX#Orders_and_deli...
Commercial flying is safer on average than driving, but that's because of, not despite the extreme approach to safety concerns. (General aviation is actually substantially more dangerous than driving)
If there are, they'll have to wipe the dust off of them, and send type-rated crews into territories they're not familiar with day-to-day.
That, or defer maintenance of the existing fleet.
I'm unconvinced that this is the safe resolution, but that's what will happen.
At least the US and Canada allowed planes in-flight to land, instead of making them turnaround and come back anyway via non-revenue ferry flights.
Mostly people will just cancel their holidays or agree a teleconference because getting flights on that route at short notice is too difficult.
Flying in/out of unfamiliar territory is a known risk. Whether the 737 MAX series is higher risk or not is an unknown risk because of insufficient sample sizes.
Hopefully some statistician will start tabulating P values so we can see if the confidence intervals overlap or not. Treat this situation like a new "better" drug for X where 2 users died in quick succession. Is there enough evidence to take it off the market or not? AFAIK, nobody has (yet).
>If the delay's long enough to actually see parked aircraft brought into service, it'll largely be the same crews flying older 737s anyway.
Sorta. On a Canadian airline, Westjet, the MAX is flying routes that are too far for the regular 737s without a fuel-stop (by my estimates). I'm booked for such a flight in 2 months. I'll get to learn what happens. I would have been happy to fly the MAX8 based on the current lack of evidence for grounding.
I would think at least some people are driving instead. US airlines run at a pretty high utilization, grounding dozens of planes isn't going to be easily absorbed into other flights.
Issues with new airliners and engines -specially engines- are not rare at all. So this sort of grounding is not rare: see 787 first grounding (battery issues), current partial grounding (Rolls-Royce Trent 1000 issues), or Pratt & Whitney ongoing issues with the A320NEO engine (PW1000G issues).
You can imagine the sort of clusterfuck when PW needs to produce 60 engines a month for Airbus, only manages to build 20 in its factory... but need to send these 20 engines to replace already delivered engines because they are defective. The situation has improved a lot lately, but 2017/2018 were tough...
Only the A350 introduction has so far been relatively event free. Probably because the Trent-XWB is a derived from the Trent 1000, so the 787 took care of the teething...
I am biased on this since I have spent a couple of years working on the development of A350XWB systems (and only marginally contributed to other programs) but I always had the feeling that, after the trauma of the A380 (rampant production issues, lengthy delays and management mishaps/stock fraud), the focus for A350XWB was put on accountability at all levels.
This might not be sustainable for a large corporation but retrospectively, that seemed to have had the desired effect at least for this particular aircraft program.
OR the planes doing the short-haul flights will now have to make these longer-haul flights, increasing the short-haul flight costs.
"I could drive or fly...oh, no, but what if they try to put me on a 737 Max? I better drive."
“The ones that fall out of the sky have been grounded, so that’s great”
I'm not sure that's correct. Let say there's 350 MAX aircraft in service, flying 5 flights per day on average. In 6 months, thats about 320,000 flights. So a 1 in 320,000 chance of a fatal crash. Let's say the average route length is 1000 miles. That's 1 crash per 320 million miles flown, or 3.125 crashes per billion miles flown.
If we assume an average of 150 passengers per flight, then it's 468 deaths per billion miles for the MAX, compared to only 0.02 deaths per billion miles across all aircraft. [1]
In the US, there are 12.5 deaths per billion miles driven, including pedestrian and cyclist deaths from motor vehicle collisions.[1]
If it crashed once every 6 months, the MAX would be around 37X more dangerous than driving, and 2340X more dangerous than an average commercial flight in the United States.
[1] https://en.wikipedia.org/wiki/Transportation_safety_in_the_U...
I imagine 1200 miles is short for an average 7M8 flight though, which could make it substantially safer. With 2500 mile averages you get back to that 3X number I cited. It's still no more a death trap than your average Honda Civic (10% safer by your metrics, more by mine).
To your point, it is of course riskier than a different aircraft.
My whole thesis was to ask what effect this will have across the entire population and how will humans react, irrationally, to this news.
Some trips may be made using older aircraft. Some trips may not be made at all. But I think assuming a 1:1 correlation with driving is a bit silly.
But compare spending 20 minutes traveling 10 miles on a local street, vs 10 minutes traveling 10 miles on a freeway. Both are considered equally safe using a fatalities-per-VMT model. But in the former, you’ve stayed safe for a longer portion of your life. (See http://pedshed.net/?p=1050)
Using that metric would make that Boeing far less safe compared with driving.
Airplane travel have fixed segments (takeoff and landing, ascent, descent) and variable segments (the coasting phase that varies by distance traveled). Car travel is only the variable segment. Hard to compare apples to oranges.
there's another issue, which is plane risk is uneven during their journey, so a type that does half the flights but twice the distance on average will end up almost 1.5 times as safe all other things being equal.
this source claim 45% crashes happening on takeoff and landing which are a minimal percentage of travel if you measure risk by mile or hour: https://eu.usatoday.com/story/travel/columnist/cox/2013/08/2...
a way to normalize that would have to use "number per flights" but then you'd get trains, with their multi-stop journeys, skewing the numbers the other way.
1) a teleporter with the exact same risk as driving 20min on local streets or 10min on the highway would be the worst thing ever invented. In reality, 100% of people would choose it unless they were intentionally wanting to spend time driving
2) A 100% safe ridable snail would be the ideal form of transit, given that you'd spend your whole life safely trying to get somewhere.
That is, the plane isn't inherently 100x safer if you just fly it empty.
Let's then also assume that people are not commontly drive transcontinental distances. Your calacluations are interesting but all over the place. E.g.:
> How many more people will take connecting flights — the > danger is in the take off and landing after all
So in this case distance does not matter. How does car safety compare to airplanes in terms of number of trips?
Anyway, the biggest problem is assuming that all grounded flights will be replaced by driving. Either the flight will use different aircraft or the trip is cancelled in majority of the cases.
Reacting strongly when those procedures seems to have missed something is important not because of the crash itself but because the process is important. Could the same oversights lead to additional fatalities is the question, the robustness of the boeing is a minor point.
Flying is only as safe as it is thanks to regulations written in blood. I don't think flying today versus driving today is the right comparison to make, rather flying today versus flying in a decade. If we allow leniency on the basis of alternatives to flying being more dangerous now, improvement of flight safety may be squandered so that the safety of future transport as a whole is reduced.
I also think these regulatory bodies have to make grand gestures, at times, to reassure the bags of blood and bones that get on planes in a way that statistics do not.
And even if they fix the problem and pilots get more training, it's still likely to hurt 737 Max sales; it seems likely they cut those corners because having the Max count as "just another 737" that didn't require extra training, was a major advantage to airlines. When airlines need to retrain their pilots anyway, they might choose different planes in the future. And they may be less likely to trust Boeing and the FAA when they claim a new plane model won't require extra training.
Then again, I don't know the airline industry. Maybe it just blows over with no long term effects.
Following that, the problem is not finding who is at fault but how to prevent it from happening again. The first step to getting the aircraft ungrounded is often to update the flight manual and decrease inspection time so it can be flown safely with reduced capabilities. The root cause is fixed later.
Aviation regulatory bodies are normally not into finger pointing. Traditionally, the customer pays for everything, even if it is not their fault. The reasoning is that it is one less incentive for the manufacturer to hide defects. No doubt that legal battles will ensue but care is taken to keep lawyers out of the technical process.
After the flight data recorders are recovered from the Ethiopian Airlines accident they could reevaluate if it turned out to be something else. But this seems like a rational safety first position given what we know today.
Hopefully Boeing's April patch and mandatory additional training mitigates the issue well enough to resume normal flight operations.
I know I will look twice next time going on a trip which plane I end up on, I'm not sure I will go with a 737 Max anytime soon.
"an a320 crashes every two years" sounds quite different than "a brand new 737MAX crashes during take off every 6 months because of the faulty sensor thingy".
Also a320 family of 8605 aircraft took the life of 1393 passengers in 30 years, 737MAX is at %30 of that in two years and 350 aircraft.
737MAX accidents look very brutal and specific. It doesn't look like "ironing out imperfections" but more like "this plane is broken, it falls off on take off" - regardless if that's the case, people see a pattern here.
Not really fair to blame the plane in that case.
Two crashes within six months is very abnormal. Abnormalities are evidence of problems. Airline regulators are tasked with keeping people from dying, not with protecting manufacturers' feelings.
You need more information than just a calendar and a model number to make determinations of flight safety.
You do realize they redesigned the plane after 9/11 to prevent that from happening again, right?
My (apparently very controversial) opinion is that we don’t know enough to predict that now, because we don’t know what caused the Ethiopian Air crash yet.
People are avoiding the 737 MAX because given the current information it definitely could be a problem with the plane, in fact the information we already have from the first crash makes it look like it's very likely to be a problem with the plane.
You option is not controversial, it's just wrong.
Again: the topic here is predicting long-term damage to consumer confidence. I understand what is happening right now.
The entire 787 fleet was grounded not more than a few years ago due to battery issue. How many people actively avoid 787s today? Long-term consumer trust depends not just the root cause of an accident, but also the perception of how it was addressed. As the GP correctly points out, the 767 (and all other planes, and security screening procedures) were redesigned to protect against the type of attack that succeeded on September 11.
These two crashes have one thing in common: brand new planes.
Unless you know of an islamist terror organization that has a grudge against Ethiopian desert wilderness, I don't think terrorism is a more likely common cause than the brand new airframe.
I'd say "unless you have some indication that it was the plane's fault". Otherwise, agreed: 2 crashes per se tell you nothing about the safety of the plane; it could've been a terrorist attack or a suicidal pilot or a missile.
It's two crashes under similar circumstances, with no indication of such an external event, that justify suspecting the plane.
Since we aren't talking about assigning criminal penalties to the plane (for one, because its fairly well destroyed, and for another because it wasn't the kind of thing subject to such penalties in the first place), the criminal standard of proof ("beyond a reasonable doubt" -- which still falls short of actually being sure) is inapplicable. In fact, given the minimal consequences of blaming the plane in the discussion in this thread, its probably fair to do so if there is any reasonable basis for belief that that the crash was the plane's fault. Its certainly to do so if the preponderance of the evidence as yet reviewed by the person doing the blaming suggests that, even if it is a fairly weak conclusion that a very small amount of additional evidence could reverse.
Edit: Max-8 had first flight in 2016 is in service since early 2017, so the crash rate over that period is roughly identical with the rate for the first 5 years of the A320. We just have a set of two closer together recently. Not enough data to form a statistical basis of course.
Time is not a very usefull thing here, as number of active aircraft and flights will be very variable.
If you cherry-pick the time interval, you can say that basically all planes crash once every hour.
Boeing used software to override and reinterpret pilot inputs so that the airplane behaves as if it were a 737, in order to cut costs on retraining. When that software fails, the pilots are suddenly flying a totally new airframe that would normally require additional certification with 0 experience.
This layer inbetween where the computer goes "actually what I think you REALLY meant to do is..." is novel in the 737 Max.
And all the various layers of protections in fly by wire airplanes do that - they second guess certain inputs to prevent edge cases. But in any case the input is going through software abstraction. Any apparent directness is part of that software behavior.
I'll be interested what the software update due at the end of April entails exactly. I think every airplane should get the angle of attack sensors disagree indication, standard.
That said, I prefer either the older boeings, with minimal computer interference when hand flying or the Airbus approach. Because Airbus at least appear to know what they are doing.
This Boeing-Airbus chimera isn't really working.
Lift from the nacelles is the issue.
There are a ton of planes with a better flight/crash ratio.
380 A340 where build since 1991 almost exactly as much as the number of 737 Max built (376). Not one fatal accident in almost 20 years for the A340 versus 2 fatal accident in 2 years for the 737.
The earliest reports said that pilots could avoid this runaway trim issue by knowing to disable the electric trim. Now it sounds like doing that may also eliminate all ability for pilots to trim the aircraft.
Inability to trim make airplanes extremely difficult to fly, the control (yolk) pressures required can quickly become too high to maintain control. Pilots would have to hold something like 1 lb of continuous backpressure for every 6 knots out of trim for the entire flight.
That’s partly true, but it’s not the whole story. MCAS and its use to make the MAX 8-9 fly “more like the 737” is part of a longer trend of manufacturers coddling pilots instead of expecting them to behave as competent professionals and treating them as such. They’re effectively opting for a more familiar normal aviating experience, with the tradeoff being longer emergency/exigency checklists and so much more to manage/remember/process when the system malfunctions. With the end-result being that even more experience is required to safely and reliably pilot modern aircraft.
Side note: Disabling trim should only be done as part of a problem remedy, not as part of normal flight.
(Disclaimer: I’m not a pilot. I’ve read for many hours on these issues.)
I can’t legally be the PIC (pilot in command) in a Citation 525 (“CitationJet” or CJ) despite it being nearly identical to the 550 (Citation II or Bravo) I can, in most ways that I can tell matters. I have copilot time in both and PIC in the 550 (and related models). The newer plane is even easier to fly, frankly, and has some nice safety features for engine failures. I have to get the training and certification (and recertification every two years) to legally be PIC in the newer Citation, though.
My limited understanding is that the aerodynamics and flight characteristics of the 737 MAX are quite different than the older 737-800 - let alone the even older second (or even first) generation 737s. The memory items may be different. That alone should have mandated a new type certificate in my non-regulatory expert perspective.
I'm certainly concerned whether MCAS is both working as intended, and also failing safe. But my more immediate concern is like yours: when MCAS is effectively disabled in the normal course of troubleshooting runway trim by setting stab trim to cutoff, now you have a plane that has different stall behavior than you're type rated for! Flip those switches, now you need a different type rating! Of course pilots can learn different stall behaviors and avoidance for a new type, we don't need abstraction to do that for us when we know about it and have trained for it. Stall avoidance is fundamental make+model knowledge, but it can be non-obvious and making it obvious and deliberate is what the type rating is about.
So yeah we might actually end up in the very curious case where either Boeing, or FAA or NTSB are all: this is going to require a type rating afterall. The very thing the airlines in particular want to avoid.
It seems to me the in-cockpit "aoa disagree" option needs to become standard by AD. MCAS only takes input from one of the two alpha vanes, so if it gets bogus data it has no backup source. Meanwhile the pilots have no indication the two vanes disagree unless they (apparently) bought that indication feature. Which I think is pretty fucked up if that turns out to be true and relevant as to either cause or solution in all of this.
Eh, I googled it for you people. It was air france 447: https://en.wikipedia.org/wiki/Air_France_Flight_447
https://techcrunch.com/2019/03/13/boeing-requests-faa-ground...
Something is terribly wrong when the regulator that's supposed to keep people safe is less willing to do that then the company that stands to lose the most from the bad image of a product.
Compare and contrast with Johnson & Johnson's handling of the 1982 Tylenol poison incidents. Tylenol immediately pulled the product off the shelves everywhere out of an abundance of caution and earned a lot of credit with the public. Boeing... yeah.
https://www.theguardian.com/society/2018/nov/27/vaginal-mesh...
https://www.nytimes.com/2010/08/27/business/27hip.html
https://www.bloomberg.com/news/articles/2012-06-11/j-j-said-...
As an aside, do you know who actually owns most of the jets for an airliner? Banks like wells fargo and chase. They still expect leasing payments regardless if the plane is flying or not.
Flydubai is the biggest loser - over 20% of their fleet grounded.
Airlines typically fly many sizes and shapes of planes. And usually more of the smaller planes.
But You can’t just drop in a Dash8 q400 twin turboprop for your grounded MAX.
And the MAX could fly further than the 737; so it opened new routes that the 737 could not do.
Those airlines clearly think the probability of this is pretty low or they would have make the call to ground those planes on their own, but a jet that smashes itself into the earth and disintegrates because of a faulty sensor is probably even worse than a grounded jet.
But the reason why I'm not a day trader is that I have no idea why they rebounded so quickly haha
Personally I never want to be that guy.
I'd say a spotty record is probably worse...
Gotta get ahead of that PR curve!
Supposedly the profit margins for discount airlines are pretty slim, so if they can't fill all the seats what's the point? What's bad is that they had to wait for that to happen before they took action. It just makes it look like they'd choose profits over safety every time... as long as they can keep making profits.
I certainly couldn't have been the only one to look at the airline I'm about to fly on and check that they didn't have any of the Max 8 variants in service.
After two crashes in such a small amount of time, the investigation doesn't need to be complete. The planes should be grounded until proven safe, not flying until proven unsafe.
Is your position that any grounding of the planes is unjustified until the full root cause is determined, or that "only" two crashes isn't enough to justify this action?
While I would always rather understand root cause -- and it's absolutely essential to get there eventually -- the world is full of imperfect information and assumptions are sometimes all you have.
Regarding the 737 MAX now, the prior Lion Air crash is reasonably well understood. It has exposed some fundamental weakness and questionable design choices, but the plane was still deemed safe to fly.
Thus, what we have is one unexplained crash. Why should it be grounded?
(Having said that, I'm avoiding the MAX as far as I can. But that's based already on the Lion Air crash. So, I argue that it should've been grounded after Lion Air became understood, or not at all.)
I don't understand how they could build MCAS on the basis of one (!) AoA sensor.
... i mean, honestly all we're doing out here is sitting back with a bag of popcorn and channel flipping between the UK parliament on Brexit, and Trump on twitter. And they say there's nothing entertaining on TV any more...
Also, the FAA makes precautionary changes before it knows everything, it has routinely issued emergency airworthiness directives before investigations have been complete.
Here: https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-...
It's not immediately clear, at least from my skimming of the report, whether a similar situation exists for nose-down trim, since in that case thrust will help the elevator with pitching up.
Of even more significance is that is currently unclear if it is even possible for a pilot, once it has disengaged the trim motors (following faulty commands from MCAS) to manually correct the trim as per Boeing procedure [1].
The problem lies in the fact that it makes a lot of sense to haul back on the yoke as hard as you can if the nose starts dropping. Elevator upwards deflection loads the tailplane aerodynamically in such a way that it becomes harder to trim the tailplane in the required direction. Called colloquially a yo-yo maneuver, you are then require to "offload" the tailplane (think - push yoke forward..) in order to be able to manually correct the runaway trim.
Plane going nose down, push yoke forward at 500ft? I do not envy the crews at the pointy end of those flights. My heart breaks just thinking about it.
The Lion Air pilots must have been pulling back on the sticks until their tendons break, to no effect. I hope there is a special place in hell for Boeing execs.
[1] 737 Flight Crew Training Manual, chapter Non-Normal Operations/Flight Controls, sub heading Manual Stabilizer trim:
"Excessive air loads on the stabilizer may require effort by both pilots to correct mis-trim. In extreme cases it may be necessary to aerodynamically relieve the air loads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually."
This was recently brought to the attention of members of a certain pilots forum that does not welcome lurkers, hence not adding a link.
1. The confuser commands a nose down trim, this means that the leading edge of the tailplane is raised. In actuality, this represents a decreased angle of attack (think of tailplane as a upside-down wing).
2. Pilots haul back with all their might. This means that the elevators (the trailing control surfaces at the trailing end of the tailplane) deflect upwards in order to increase the angle of attack and create more "downforce" from the tail, raising the nose.
3. Think of the trimmable tailplane [1] as moving around a pivot. In reality it is a jackscrew/hinge combination.
4. The elevator deflections (the intuitive response) "creates a twisting force" the tailplane around the "pivot point" and against the desired direction that you want the trim to travel.
5. Unload the elevator pressure to make it easier to trim it. The key is that elevator deflections, despite intuitive are not sufficient. Luckily, it is a trained manoeuvre.
[1] https://i.stack.imgur.com/9RQY4.jpg
Note the UP and DOWN markings on the airplane's skin.
Some planes have little cutouts on the back of the elevator that move, thus deflecting the wind. Other planes, the whole back wing moves (stabilator).
To keep the nose pointed up or down, it can get tiring to constantly apply force on the pitch control. So now we can "trim", which changes the neutral position of the elevator to be higher/lower.
Some planes have little cutouts on the elevator or stabilator for trim. Other planes, the whole elevator / stabilator moves for trim.
Some times, when the whole elevator / stabilator moves up/down for trim, you need a lot of force to move it back down/up, especially if its neutral position has changed.
Occasionally, under high loads due to wind/pressure, you just can't. So you have to go to it's current neutral position (no matter how high or low) so you're not fighting a loosing battle. Then you have to reverse the trim. Then you can apply the opposite force.
The elevator is the little wing at the back of an aircraft that tilts up and down to make the nose go up and down. When the pilot is flying, this up-down is what moving the yoke forward/back does.
The elevator also has a tab (the trim tab) part of the wing that can move independently from the main part. This trimming movement allows for adjustments to the plane's up/down movement that don't require the yoke forward/back (this is useful to "lock in" the current desired climb/descent/level flight so that pilots don't have to be constantly pushing/pulling on the yoke to get the plane to be climbing/descending/level the way they want it).
The 737-MAX has a system that automatically uses this trim tab to pitch the nose of the plane down when it senses certain conditions, without notifying the pilots. In this case (plane inexplicably pitching down), the natural response from a pilot is going to be to pull back on the yoke to counteract.
This can cause issues because the act of pulling back on the yoke increases the pressure on the elevator (because physics - the more the elevator deflects in an attempt to change the plane's attitude, the more force the airstream flowing over it exerts. This "catching the airflow" is why it can change the plane's attitude at all). Apparently on this plane if the trim tab is way out of line even if disconnect the erroneous system that was automatically adjusting the trim tab and try to reset the trim to a safe position by hand, the airflow over the "loaded" elevator (which is trying to counteract the position of the trim tab and keep the plane from crashing) is too strong to physically allow the manual control to move the tab. So the "correct" procedure is to push the yoke in (allowing the nose to go down/lose altitude) to reduce the airflow that's hitting the elevator, while frantically spinning the manual trip wheel to get it back to neutral. Then, once you've reset the trim manually, you presumably pull back on the yoke to get the nose up and pull the plane out of the dive.
The issue with that is that the ground can get in the way in between when you've let off the yoke and you've spun the wheel enough to get the trim tab back to neutral.
I seem to recall some tail draggers I flew had no trim tabs too.
The only airliner I can think of that uses trim tabs is the DC-9 and its derivatives (MD-80/MD-90/Boeing 717). Some, like the L-1011, went in the completely opposite direction and use an "all moving tailplane" where the functions of the elevator and stabilizer were integrated into one piece.
I think the basic procedure for how to undo the excessive trim based on too much force to move the tailplane still is accurate though...
I just read this great article (https://www.skybrary.aero/bookshelf/books/2627.pdf) linked lower down in this thread for more details.
Like, how long does it take to determine the exact problem, spin the manual trim wheel to get to the point where you can recover from a nose dive in this case?
How does that number (in seconds I'm guessing?) translate to altitude levels?
- in 3 seconds when in cruise
- in 1 second when on approach
- when in the landing phase - immediately!
Such a system would be certifiable.
Most modern airliners have ~10 "memory items" that are procedures that are to be recalled and applied immediately without consulting any checklists. Runaway stabilizer is such a memory item. But first you need to recognize the issue as such..
It bears to mention that the 737 is riding on it's "grandfathered" certification status from the 60's, getting a free pass on many newer requirements that are subjected to airliners designed today. This is why it doubly makes sense for the bean counters to not design a new aircraft.
That is pretty frightening about the grandfathered rules.
I don't know much about cars but I do know they have a similar thing. Suddenly because you have a car 1 year before a point in time it can be obnoxiously loud but today it wouldn't be street legal. I almost can't believe the same thing happens with planes.
So there’s an incentive to not just make the type backwards compatible to keep the common “type”, but also not introduce too many new features that might bring into question the grandfathered training.
This 737 Max added this new “safety feature” without telling the pilots (because it’s the “same type”). And that feature seems to have an unfortunate interaction with other systems in some circumstances.
Is this in anyway akin to drivers counter-intuitively steering into a skid in order to regain traction?
[1] http://aerossurance.com/wp-content/uploads/2015/03/737-contr...
Elevator upwards deflection loads the tailplane aerodynamically in such a way that it becomes harder to trim the tailplane in the required direction.
so I'm not sure what you mean by "matter of aerodynamics", because that comment suggests that it only gets harder due to the forces exerted by the air on the control surfaces, and so could be overcome by applying more force --- which a hydraulic system could be engineered to do.
I'd settle for a special place in prison.
That is different then stating the probability of it being as safe as the average airplane, which you can't do as easily without additional modelling/priors and bayesian statistics.
Lies, damn lies, and statistics. The NH is that a plane has 1/10 [M * flights] failure rate. The odds of 2 failures in 20M flights falling in same (random) stride of 150K flights are 150K/20M = 0.75%.
[E: fixed numbers] [EE: yes, I admit this calculation is incorrect]
If we assume that accidents are rare and independent per mile, then the correct distribution is a Poisson distribution with a parameter of 150,000/10,000,000 = 0.015. In which case the odds of no accident should be 98.5111939603...% and the odds of one accident should be 1.47766790940...%. The odds of 2 or more accidents is 100% minus those, which is 0.0111381302891...%.
It gets even worse when you consider the fact that both crashes happened while the plane was in the air. Nearly half of all accidents happen at takeoff and landing. This makes the per mile, just flying along failures even less likely.
If I understand correctly, that's the probability for 2 crashes within any span of 150 kiloflights. I'm curious if it makes sense to ask about the first span of 150.
The assumption is that for the average plane all accidents happen independently from one another. Under such an assumption, the probability for any span of 150k flights is exactly the same as the probability for the first span of 150k. So it would not change the answer.
If you roll a die a 1000 times, the odds of landing on a 6 on roll 999 is the same as it landing on a 6 the very first roll.
This is more revealing than they’d like, I think.
A company is recommending to their regulator that the regulator take action against them. That is a pretty solid indicator that the lawyers have a rough idea of potential liability and are now trying to mitigate damages.
> Early Tuesday, Dennis A. Muilenburg, the chief executive of Boeing, spoke to President Trump on the phone and made the case that the 737 Max planes should not be grounded in the United States, according to two people briefed on the conversation.
And for the record, I made the same call. It's not easy but I'm certainly not judging Boeing for weighing their options and moving forward with a strategy that gives the company the best chance at recovering from this mess.
They also have thousands of outstanding orders for this model plane that are, at best significantly delayed and perhaps in jeopardy.
https://www.faa.gov/news/updates/media/Emergency_Order.pdf
[ sound of stampeding lawyers intensifies ]
I hope they find out the cause & make sure it never happens again.
[0] https://www.dailysabah.com/africa/2019/03/13/ethiopia-cannot...
Even if Trump were to give a phone call along the lines of 'Ground the Plane or else I'll write an executive order' , the optics of the situation would be so much better if Chao (Secretary of Transportation) or Dan Elwell (FAA Acting Administrator) were to give the announcement instead.
Personally involving himself unnecessarily is Trump's MO. "Only I can fix it." was one of the themes of his 2016 RNC speech.
If the President is requiring it then the proper mechanism to do that is an order.
You're suggesting a side-channel phone call and a threat so that he's still deciding but it's recorded as someone else's decision for PR purposes, and you think that's better? That's a terrible idea.
I disagree with GP, but this is basically how firings are handled at high levels.
It's very rare for a POTUS or a corporate CEO to actually fire a direct report. Instead, they say "you have X days to resign before I fire you" via a side channel, and most of the time the report opts for the resignation.
(funny thing is, at the first company I worked for, the CEO did this to the VP of Engineering... and the VP assumed he was bluffing, waited out the whole 30-day period he was given without resigning, and then got walked out of the building one morning in front of everyone who was there that early... and the guy who was in charge of walking him out was one of the people who was promoted to replace him)
I actually don't believe this is true - I can look up citations in a bit, but the FAA is an independent body whose directors are appointed by the president.
The Federal Aviation Agency was an independent agency, but the Federal Aviation Administration, which it became, is a subordinate agency within the Department of Transportation. It has an Administrator, but it does not have directors, commissioners, or some other multimember voting governing body.
more to the point, who told the FAA bods not to pull the plane? Was this the President too?
Because of how this has been handled by the Trump I think Boeing now have a 'Samsung Note 7' on their hands, i.e. a product that isn't going to be re-released as it is poorly engineered and can't be fixed by just changing a supplier or two. It was a hack with another hack to keep the hack okay. There will be a who knew what and when scandal. This won't be like the Dreamliner teething issues due to two lost planes. People can forgive teething issues but a scandal is a different beast.
> In August 1989, a Trump Shuttle flight arriving in Boston incurred a nose gear failure upon landing due to maintenance errors by Eastern personnel prior to the acquisition. Trump personally flew on the next Trump Shuttle flight to Boston in order to manage the media reaction to the incident.[3]
[0] https://www.cnbc.com/2019/03/13/boeing-shares-fall-after-rep...
Yes, but it'd not be unusual for the agency's director to check in with the president on a course of action or vice versa, verbally or via memorandum, without the president formally invoking his presidential authority via executive order.
To put the whole thing in perspective, the number of EOs issued annually by recent presidents Bush and Obama was very modest, averaging 36.4 and 34.6 respectively.
The words he used was "emergency order" and "we", not "executive order" and "I". CNBC is reporting it (not quoting any official source which says that, and citing only the President's "emergency order" public statement) as an "executive order", but other news sources are not, and Boeing is saying that they recommended the grounding to the FAA.
My initial impression is that this is an FAA action based on Boeing's recommendation that the White House wanted to take the press attention for.
That would make me feel better if this were true. It seems to match my expectations for who is in charge of various decisions, as well as the politics that Trump likes to play. So it makes sense at least.
> Early Tuesday, Dennis A. Muilenburg, the chief executive of Boeing, spoke to President Trump on the phone and made the case that the 737 Max planes should not be grounded in the United States, according to two people briefed on the conversation.
https://www.nytimes.com/2019/03/12/business/boeing-737-groun...
Maybe Boeing changed it's mind in between yesterday and today?Or that reporting was inaccurate?
Or, that's exactly what happened, but then today either Trump or Boeing or both of them realized this wasn't gonna fly (no pun intended), and that they had to be grounded, they talked to each other again, Trump decided he wanted to make an announcement about it because he likes being on TV about whatever he's thinking about at the moment. (I'm not sure an "emergency order", which Trump said it was, is even a thing?)
I mean, really, who the fuck knows. This administration doesn't tend to make a lot of sense, and it's kind of kremlinology trying to guess why they do what they do.
Well, the link to the order has that in its title (but is also a dead link right now):
[page with link] https://www.faa.gov/news/updates/?newsId=93206
[target of link] https://www.faa.gov/news/updates/media/Emergency_Order.pdf%2...
[EDIT: Oh, they f-ed up the URL in the link with a trailing space, and didn't verify it before posting: https://www.faa.gov/news/updates/media/Emergency_Order.pdf ; It is indeed an "Emergency Order of Prohibition", and an FAA emergency order is an actual distinct legal thing under 49 USC Sec. 46105(c) https://www.law.cornell.edu/uscode/text/49/46105 ]
But either way, this is symbolic and shows the stance of the government to the world and internally. The highest office in the US is grounding the planes like the rest of the world is, the administrative nuances are irrelevant. Boeing and the airlines would be the ones to challenge it, way to go for PR.
The question is how the public should have been informed by the event. Dan Elwell, the acting director of the FAA, is both a military and commercial pilot. If he made the announcement, it would have carried far more weight than Trump (who likely doesn't know much about airplanes).
I don't actually think Trump is doing anything wrong in trying to take responsibility for the action, and suspect the decision was reached through appropriate channels rather than by him reading something by a pilot on Twitter, but having a president known for more being capricious than his understanding of aviation safety as the figurehead behind the decision does make it look less like a reasoned decision to the average person, especially if they have strong anti-Trump priors.
Trump owned an airline with a fleet of 17 Boeings. He also used 2 large Boeings as private jets.
Very likely he knows a thing or 2 about airplanes.
I predicted two days ago that this would turn into a shit storm of hysteria, justified or not. The President exerting his authority is similar in that sometimes these events turn too emotional and fearful. He made the right call for that sake.
Surprisingly, I am not a botanist.
Also important: he's a lobbiest for the airline industry.
It made the news when he was confirmed because of his ties to the industry. He is the Ajit Pai or Betsy DeVos of the FAA.
Why not the Tom Wheeler of the FAA?
That seems to be a closer fit to the kind of industry ties he has had then either Pai or DeVos. Pai's industry ties was as a lawyer for Verizon, whereas Wheeler's were as head of first the cable trade association and later the wireless trade association, and having been involved in several telecom companies. That seems a much closer match to Elwell, who was VP of a major aerospace trade association and a pilot and an airline executive.
People criticized Trump for putting a non-scientist at the head of the Department of Energy, however, where is the criticism of Obama for putting a non-pilot as the head of the FAA? When Trump does something wrong, sure, criticize him, but Elwell is an experienced, relevant choice to head the FAA -- especially compared to Huerta. Reducing Elwell to "Lobbyist" is silly, if one actually looks at his background.
His ability to directly influence, and damage, the executive branch's operation in service to the people to what he wants is thus limited.
Do you know what the Presidency is? It's the head of the executive branch. By definition, Chief Executive of the United States. The law specifically are for the President being CEO -- that's exactly what being president is. The one who signs bills, runs the organizations who enforce the laws, and runs the military that defends the country. The president is 100% in charge of the Executive Branch and all of its agencies -- that's exactly what the job is! He could fire every head of every non-independent executive agency tomorrow and it would be 100% constitutional.
That is...unclear, at best. The only account of the decision making I've seen in any news source that comes from anyone involved (e.g., excluding CNBCs unsourced claim of an "executive order") is Boeing's claim that they recommended the action "in an abundance of caution" to the FAA which acted on it. (EDIT: Actually, the FAA has just tweeted that they made the decision, based on evolving evidence from the investigations, so that's another narrative.)
Of course, the White House can assume the privilege of announcing any decision from anywhere in the executive branch, and the President announcing it as an "emergency order" that "we" are issuing is factually correct where "we" refers to the Executive Branch.
Well, it does seem to spend a lot of time on Twitter. Perhaps he saw something convincing there.
Violating that tradition is rather stupid for a President. Not only are FAA decisions now tainted, he is putting himself square at the center of blame for anything negative happening from now on. It’s even worse considering there aren’t really any symmetrical opportunities to shine with a job well done in aviation safety comparable to a crash.
It is an analogy, which is why I used the word analogous, and it still fits.
The power of the Executive Branch is vested in the President of the United States, who also acts as head of state and Commander-in-Chief of the armed forces. There isn't any framework to have a rebuttal to that, this is as succinct as it gets.
SOME agencies are independent of this structure. They are called independent agencies.
Other agencies are not.
The President's primary role in this capacity is to steer the executive branch, and this is done using rather mundane executive orders which are usually merely plans, again ANALOGOUS to a companies quarterly or annual goals. A CEO lays out the mission and the organization follows that.
The job title is a 3-part job. Head of executive branch, head of state, and commander-in-chief of armed forces. The celebrity status and reliance on The President's every move and stance on everything is merely happenstance, but a byproduct of the constitutional government becoming involved in every aspect of American society, having subsequently created all these "not-companies" with millions of employees, and perpetual armed conflicts around the world.
So finally, head of the executive branch, for agencies not independent of this structure, the President is ANALOGOUS to the Chairman/CEO and has ultimate say in steering them. There is no tradition that was violated.
Anyway, on the topic at hand, the FAA followed the order and indications from the President and issued their own.
Unfortunately Trump didn't start this trend but I really hope whoever is next stops it.
I disagree. Bureaucracy is a good thing. This smacks of a President that looks a) desperate for attention and b) incapable of delegating.
FAA has an acting administrator: Dan Elwell. He was appointed by Trump to be Deputy Administrator.
http://www.msnbc.com/rachel-maddow-show/why-hasnt-trump-nomi...
First of all, there is a backlog of higher priority nominees. It wouldn't be good to distract congress from those.
Second of all, the constant harassment of this administration must be having a huge impact. A person has to be slightly crazy to accept a nomination. They and their family will be facing physical danger, legal danger, and more. Lots of competent people are thus unavailable as choices. The constant harassment has had a real negative effect on the quality of our government.
Put yourself in their shoes. You have a normal family and could earn millions of dollars per years in a nice comfortable corporate executive position. How insane do you have to be in order to take something like $150,000 while living in the expensive DC area and being unable to simply go out to eat in public? What normal parent would subject their kids to the abuse?
Scaring away qualified people does not improve the government. You don't do that unless seeing Trump do badly is so important to you that you are willing to sacrifice the wellbeing of the country itself.
Actual qualified people like Mattis and Tillerson faced little trouble. Even Gorsuch, who was the embodiment of a stolen seat, did just fine.
What's scaring away qualified people is the proud ignorance and naked corruption of the administration.
And it's the same when we're considering nominations in general. What happened to Kavanaugh could happen to any nominee, no matter the branch.
He initially tried to nominate his own pilot for the job (the same who screwed so much that FAA had Trump's plane grounded).
I can conjecture about Boeing being a big US manufacturer, etc, but is there any evidence at all for why the US held out on this one? My initial reaction was that there must be a good reason for the holdout, given our safety record, but on reading more about it, I've not seen one. (Again, relative to the stance of excessive caution).
1. Ineptitude 2. Corruption/Greed 3. US planes don't have the same issues that is suspected to be the root cause of other crashes.
From what I've read so far, there's absolutely no clear indication at this point it was solely pilot error, and common sense dictates you ground the planes before more crashes happen.
5 times as many people died on Aeroflot than any other airline during the Soviet Era.
I mentioned it because when I first heard that there were so many other regulatory bodies grounding the fleet, I was surprised about the FAA. When it was pointed out that many of those regulatory bodies represent countries having a handful of these planes to begin with, I was still surprised, but it made a little more sense that the FAA might have more to lose if the decision proved rash.
Not a trivial number for either fleet, but I imagine it won't significantly impact their business either.
While it certainly sounds like there is a flaw in how the system handles erroneous sensor data, or that the interface promotes incorrect actions, the independent groundings of 737 MAX 8 planes probably are not independent in sense of each authority coming to its own determination based on their professional opinions alone. It would be politically foolish to be the lone holdout in your region.
There is a real cost to grounding these aircraft, and I'd imagine that if they are grounded without specific questions that need to be answered or problems that can be fixed, it becomes even more difficult to un-ground them later.
I don't usually make libertarian-style arguments, but until there's evidence pointing to a specific safety of flight issue from the latest crash there's no justification for the government effectively "taking" airplane owners property by preventing its use.
At the moment there is specific evidence, I have no doubt the FAA will act swiftly.
Thus, more evidence is required to ground an airplane (that has, after all, gone through the certification process), than two crashes.
As someone pointed out in this thread, there were three B767 hull losses between September and November 2001, but two of those were caused by 9/11 terrorists and don't tell you much about the airworthiness of the aircraft.
The fundamental question is this: should the plane have been grounded immediately after the second crash? Many here seem to think that yes, obviously. I think that no, one unexplained crash of a certified plane does not warrant grounding. Once details and circumstances emerge that are indicative of some fundamental design flaw, or multiple unexplained crashes (as with the comet), of course ground it.
Is that a substantive disagreement, or "pedantry"?
On 24 March 2015, Germanwings Flight 9525, using an Airbus A320, flying from Barcelona to Düsseldorf crashed near Digne in the Southern French Alps, killing all 150 on board. They didn't know it was a suicide pilot until after they investigated. Yet, A320s kept flying in the meantime.
On 29 March 2015, Air Canada Flight 624, using an Airbus A320, flying from Toronto to Halifax carrying 138 people crash landed short of the runway. The aircraft was badly damaged and 23 people were injured.
On 14 April 2015, Asiana Airlines Flight 162, an Airbus A320 with 82 people on board, lost height on final approach to Hiroshima Airport in Mihara, Japan, struck an antenna, and skidded onto the runway on its tail, spinning 180 degrees before coming to a stop. Its main landing gear collapsed and the aircraft suffered damage to its left wing and left engine. 27 of the 82 people on board were injured.
Three incidents, on respectable, high-safety airlines within 3 weeks of each other all with the Airbus A320. Yet, those planes weren't grounded, not even for five minutes. Three serious incidents within 3 weeks of each other is "empirical evidence" that the A320 is unsafe.
But we have a crash from Ethiopian Air, on a plane where the first officer had only 200 hours of total flight experience. And another crash months ago on Lion Air (a ridiculously unsafe airline) and that's "empirical evidence" that the airplane is bad?
Read About Lion Air's "safety" culture: https://www.nytimes.com/2018/11/22/world/asia/lion-air-crash...
Lion Air should be grounded. Ethiopia shouldn't be flying planes with student pilots in the right seat. There may be issues with the 8 Max, however, it's a fact that inexperienced pilots, bad maintenance, inferior safety processes and negligence will exacerbate any potential flaws in the aircraft. The fact is that in the case of Lion Air, if it were Southwest Airlines operating those flights in Indonesia, flight 610 never would have crashed. Lion Air had days of reported issues before the crash and they ignored them. Look at Lion Air's incidents and accidents: https://en.wikipedia.org/wiki/Lion_Air#Incidents_and_acciden... It seems that can't even taxi a 737 safety, let alone be trusted to fly one. And right now we're complaining about the FAA? We should be complaining about airlines that are being allowed to operate with this slipshod respect for safety.
The US, Canada and Europe hasn't had any 8 Max incidents -- the incidents happened in organizations that were operating in ways that would never be allowed in US, Canada, or Europe. That fact seems to be getting ignored in favor of complaining about the FAA or Boeing. The US flies a lot more 8 Maxes than Ethiopia or Lion Air, yet not a single crash. Is that just coincidence or does the US/Canada/Europe just do a better job?
Asiana Airlines Flight 162 was an Airbus A320-232, manufactured in 2007
Air Canada Flight 624 was an Airbus A320-211 manufactured in 1991
Germanwings Flight 9525 was an Airbus A320-211 manufactured in 1990.
The Asiana and Air Canada incidents were similar, but the aircraft were of different models, one was 7 year old and the other was 24 year old. The German Wings and the Air Canada aircraft were similar models, but both planes were 23-24 year old, and the incidents were completely different.
Compare that to the 737 MAX 8. Two fatal crashes, during the same stage of flight, with identical models, of similar age. 2 out of 350 planes crashed, where the fleet is barely one year old on average.
...its use for transporting OTHER people/stuff in air over OTHER people's property (and lives). I'd be surprised if the FAA licenses didn't have clauses that basically allowed explicitly this.
Regardless, I don't find your arguments persuasive. The FAA didn't wait for "evidence" before banning cellphones, e-readers, etc on flights; they've grounded planes before investigations were complete before...which was why I asked my initial question: What was different this time.
I'm not saying they can't do it, they obviously can (and just did.) All I'm saying is that there has to be some evidence that the crash is for a reason that implies other aircraft are affected. And obviously the standard for transport category aircraft is higher than for smaller airplanes. But it can't just be "we gotta be sure", because then you can't let anything fly at any time.
Imagine if every time someone had an accident in the same model car you own, the DOT prohibited that model car on the roads "out of an abundance of caution" until it was proven that it was not a design fault in the car. While there arguably would be an improvement in safety, it would also be incredibly disruptive.
What standard of risk would you apply? Because you have to draw the line somewhere.
Separate question - and your arguments are all logical. My question was "given the standard of risk that HAS been applied, why was this time different?"
The safety record of car travel in the US is dramatically different than the safety record in air travel.
This of course is insane when you are talking about a for profit business.
[1] https://youtu.be/vWxxtzBTxGU 20min in.
FAA Delegated Organizations
Page: https://www.faa.gov/other_visit/aviation_industry/designees_...
"Regular FAA oversight of an ODA is accomplished by a team of FAA engineers and inspectors to ensure the ODA holder functions properly and that any approvals or certificates issued meet FAA safety standards."
List of delegated organizations: https://www.faa.gov/other_visit/aviation_industry/designees_...
Spoiler: there's a lot more than Boeing on there.
I don't know about the specific concerns in that video, just replying to the insinuation that Boeing has some strange deal that exempts their planes from oversight by the FAA. They don't.
1. Ground the MAX after the reasons for the Lion Air crash had became clear, as it's not airworthy.
2. Do not ground the MAX, as it's sufficiently airworthy.
This new crash had not provided enough information initially to conclude otherwise.
However, the FAA is sort of arguing that there is now enough new information from the second crash to support the decision to ground it.
If that was determination was done correctly, then there is no reason to ground every plane of that model, just because another one crashes shortly thereafter.
The FAA obviously is inclined to believe that they did that determination correctly. Of course, they could be wrong.
It will be very interesting to see how the Ethiopian investigation turns out. If the cause was the same as Lion Air, then the FAA will come under tremendous pressure to reconsider what constitutes "safe to fly".
(IMO the industry in general will come under hard questioning about the role of software in compensating for aerodynamic issues. Yeah the military does it, but we have different standards for airlines.)
But if it turns out that some other factor caused the crash, unrelated to the Lion Air cause, then the FAA will come off looking insensitive but ultimately justified in their determination.
https://www.vox.com/policy-and-politics/2019/3/13/18263719/b...
https://www.militarytimes.com/news/your-military/2019/03/13/...
What's problematic with 737 MAX is that the stability assist was obviously installed as an after thought, and even worse, it's dependent on instrumentation that does not have several layers of fault tolerance as would be the case if it was actually built with the care that planes actually require to be as dependable as they are.
So the instability is not a problem. That boeing tried to get around it with a cheap patch of jury rigged software that is depending on input from non-fault-safe instrumentation, is.
For military purposes, I agree. There is an end objective to fighter jet development. To own the sky at all costs.
With civilian aircraft, there is too much to lose. You can't have an unstable air frame for civilian commercial mass purposes.
https://duckduckgo.com/?q=maple+seed&t=ffab&iax=images&ia=im...
maple tree seeds resemble auto-rotation in a helicoptor, not powered flight.
It's a nice mental model as to why you won't fall out of the sky necessarily with a loss of power in a heli, though.
The reason you don't see it in nature is that macroscopic organisms never evolved a continuously rotating joint. It's a hard problem for evolution to solve; how would blood vessels cross that boundary?
But of course machines have no such constraints, and the wheel and axle is hardly a new (or scary) invention.
Is it possible we're talking about two different things? Making a circle with your arm isn't the same as rotating it, and just making a circle isn't particularly useful for flight or locomotion. Imagine attaching a wing to your arm and making a circle -- half the time isn't going to be attacking the wind the wrong way. This wouldn't work to, e.g., fly a helicopter. You need real rotation.
Swap out "instability" for "drab paint jobs" and see:
> I disagree that "drab paint jobs are not a problem". In military aircraft that have drab paint jobs it's common for everyone in the plane to be in an ejector seat or to have a parachute. Can you provide statistics on how many (or what proportion of) military planes with inherent drab paint jobs routinely carry passengers without parachutes?
In this case the argument is not that a is evidence of b, it is that a ameliorates b. And that the risk of b is therefore priced differently where a is also present. So where a is not present, we must price the risk differently.
How that assertion relates to the historical record may be of interest.
To blithely say "oh well, military planes do X so X must be fine for civilian aviation as well" is either intellectually dishonest or fundamentally naive.
E.g. higher redundancy of HW & SW, stricter testing/checks/validation of flight envelopes, more feedback to the pilots about why a computer is performing certain actions, etc... than military aircrafts using the same systems.
Do any modern military non-fighter jets have bail out capabilities? It was my understanding that you couldn't even put on a parachute in flight to jump out. You either had an ejection seat, or no capability at all.
Fehrm, a former jet-fighter pilot and an aeronautical engineer: https://www.seattletimes.com/business/boeing-aerospace/faa-e...
That said there are airliners out there which are unstable in the longitudinal axis and require a yaw damper to prevent Dutch roll.
My intention was not to claim 737 MAX had the same aerodynamic nature as, say, F-16, but in the scope of the discussion point out that fixing instabilities with flight software can be made to work reliably.
The main argument was that it was inherently a bad idea to require computer assist to maintain stability and decades of military planes demonstrate that you can engineers such systems to be more or less fault safe.
There was a sibling comment somewhere in this post that stated that airbus doesn't introduce a layer between the pilot and the aircraft. This couldn't be further from the truth (assuming normal control laws). Applying full back stick on an airbus will hold the aircraft right on the edge of a stall. Applying full left or right on the stick will neatly roll the aircraft to 60 degrees of bank. Releasing the stick at this point will roll the aircraft back to a perfect 30 banked turn in the same direction. This isn't normal behaviour by any stretch.
If anything I think Boeing are suffering from not going to fly by wire control earlier. That would have made this whole subsystem irrelevant. You'd just apply the desired behaviour in the response curves in the control software.
https://en.wikipedia.org/wiki/Accidents_and_incidents_involv...
Having an unrecoverable stall mode is not a desirable flight characteristic, for sure, but I don't think it's unheard of. For sure it's nothing like inherently unstable airframes as used in fighter jets.
My rather limited understanding is that the airframe certification path Boeing used was one meant for fast-tracked recertification of minor configuration changes of the same hull. The main idea being that the manufacturer need only prove that the reconfiguration meets the same or similar flight characteristic requirements as the hull it was derived from.
This lets them produce/sell a technologically refreshed product without having to pass the rigorous testing normally associated with type-certifying a new airframe. The important characteristic of this is that the onus for this certification is left to the manufacturer. I do not know if the FAA actually independently confirms the recert is justified, or just plays it via honor system.
Old 737 hulls definitely didn't have this characteristic onstability, or do-or-die reliance on functioning AoA sensors, so while I agree there isn't anything wrong with incorporating instability into a design to satisfy some specifications per se, I'd still contend that the addition of that instability should disqualify an airframe from being recertified as a reconfiguration of an older one, and should require more extensive testing/training before pilot's are cut loose on it.
If anyone else has more accurate understanding of type certification, I'd be thrilled to learn the specifics.
> [It is] unconscionable that a manufacturer, the FAA, and the airlines would have pilots flying an airplane without adequately training, or even providing available resources and sufficient documentation to understand the highly complex systems that differentiate this aircraft from prior models
> The Flight Manual is inadequate and almost criminally insufficient
But we hear your "third world" and "idiot" dog whistles loud and clear.
We're nowhere near having gathered enough facts to put forward claims like that.
As long as humans are involved, human error is involved too, especially with a new system. This could happen anywhere.
What new information??? Or maybe “the taste of egg on our face?”
"On March 13, 2019, the investigation of ET302 crash developed new information from the wreckage concerning the aircraft's configuration just after takeoff that, taken together with new ly refined data from satellite-based tracking of the aircraft's flight path, indicates some similarities between the ET302 and JT610 accidents that warrant further investigation of the possibility of a shared cause for the two incidents that needs to be better understood and addressed"
Side note: I tried finding a site that would let me link out to a chart showing the full price history of BA. It's surprisingly difficult to find.
Make sure you use a log Y-axis when looking at historical data. Steady compound gains (even just from inflation) will make any chart look like a 'hockey stick' otherwise. You're almost always more interested in relative price movement, not absolute.
Gains from 2016 have been good, but that likely reflects the clear success of the Boeing over Airbus's new aircraft.
The current fiasco certainly will put a damper to their stock，but there's simply no other choice for new planes. They will bounce back.
Disclosure: I shorted/put BA yesterday morning
What? They have the A330neo and A350, the only wide-bodies they don't really compete with are the 747-8 and 777-9X.
The 737-MAX-8 crashes occurred within 6 months of each other, both on a brand new airframe on a new aircraft with a new control and sensor system that produced VERY similar profiles in rapid climbs and descents that point to an issue with said new autopilot.
The MAX-8 and the 200 are VERY different aircraft, even if they're fundamentally built around an original ancestor.
NYSE: BA $373.96
Seems to be 'discounted'.
Source: Career spent as a Wall Street Trader
There's every reason to believe a) Boeing will take a hit for this and b) Boeing will not go out of business because of this.
Isn't the A320neo _also_ new engine lipstick on a 30 year old airframe?
If you wanted to find the "fair value" price of BA you have to discount its future cash flows to the present. If BA planes are perceived as unsafe - what does this mean for future purchase orders? Does Airbus edge up ahead over time? Do people diversify their fleet with the new China-made jetliners?
From today's perspective, the stock is still in the middle of a crisis that is unfolding. It is impossible to know how much further down it will go as new data-points are revealed. How long will a fix take? Have commercial jetliners ever been recalled en masse?
Short-term trades are more fun than fundamental positioning, in this case, IMHO. Betting on continued high volatility via the options market is probably the safest way to go - as opposed to betting on directionality of the stock. Timing is everything. Happy trading...
Yes, all the time. They're called "airworthiness directives" and you can find them all here: https://www.faa.gov/regulations_policies/airworthiness_direc...
They're basically like car recalls: You take the plane to maintenance and they swap out the bad doodad. Boeing had a very public one like this with the 787 batteries when it first launched; they made some changes and now it's an incredibly popular plane. But in general, they're happening all the time for basically every plane, just not catching much public attention.
What do you mean civil disobedience? It’s not like there is a law forcing you to board the plane if you don’t want to.
https://pbs.twimg.com/media/D1j5YuBXQAATWlk.jpg
"March 13, 2019 | 3:00 p.m. ET
STATEMENT FROM THE FAA ON ETHIOPIAN AIRLINES
The FAA is ordering the temporary grounding of Boeing 737 MAX aircraft operated by U.S. airlines or in U.S. territory. The agency made this decision as a result of the data gathering process and new evidence collected at the site and analyzed today. This evidence, together with newly refined satellite data available to FAA this morning, led to this decision. The grounding will remain in effect pending further investigation, including examination of information from the aircraft's flight data recorders and cockpit voice recorders. An FAA team is in Ethiopia assisting the NTSB as parties to the investigation of the Flight 302 accident. The agency will continue to investigate"
Their previous one, less than 24 hours ago, had: "Thus far, our review shows no systemic performance issues and provides no basis to order grounding the aircraft. Nor have other civil aviation authorities provided data to us that would warrant action."
Here's my understanding/analysis of the situation: 1. Boeing was under pressure to create a more fuel-efficient version of the 737NG to compete with Airbus's A320neo. The 737MAX was the result. 2. In order to be lower investment for airlines, it was critical that the 737MAX share a type rating with the 737NG. This meant that a pilot certified ("checked out") on an NG would be able to fly on the MAX without further certification. 3. To gain fuel efficiency, the MAX has larger engines. To first order, larger engines result in more efficiency: by accelerating more air by a smaller amount you leave less energy in the air that's exiting the aircraft. The larger and more efficient engines results in 14% less fuel burn. That's a major improvement! 4. The larger engines and their placement resulted in a "pitch-up moment" during certain flight regimes. What this means is that when you add a lot of power to climb, and/or during steep turns. 5. To compensate and – this is critical – to maintain the same type certification, Boeing added something called MCAS (Maneuvering Characteristics Augmentation) which nudged the nose down by trimming the stabilizer (the horizontal bit of the tail) down (which pushes the tail down and therefore the nose up). It appears to be activated without pilot input. 6. There are other mechanisms which also "trim the stab down" and there has always been a mechanism which disconnects them: pulling back hard on the yoke. This is a natural motion for pilots because in all flight regimes pulling back on the yoke pulls the nose up, which is what you want to if the nose is going down. There is a backup mechanism as well which involves flipping a pair of cutout switches and manually taking over. 7. My speculation is that because MCAS was considered critical to making the MAX fly "like" the NG, the first disconnect mechanism was removed on the MAX. This is critical bit #2: the obvious/intuitive mechanism to disable something pushing the nose down was removed. 8. Because MCAS was so important, two (?) Angle of Attack sensors were added to the MAX. These sensors appear to fail more often than they should. In aviation terms that might mean they work 99.99% of the time, not 99.999%. 9. So now you have a situation where an aircraft has a required mechanism to fly/feel like another aircraft in order to maintain a consistent type rating but which is reliant on a shaky sensor. And when the sensor fails, the mechanism has – purposefully – been made more difficult to disconnect. From what I can tell, this entire set of decisions was driven by this type certificate/rating decision. That's the key mistake. I understand why this was done from a business standpoint, but if you're going to rely on manipulating flight characteristics it had better be bulletproof. Note that I'm not against the philosophy: Airbus has been doing it successfully for 25 years starting with the A320. But this isn't bulletproof. As it stands today, I wouldn't fly on the aircraft. Pilots are following this stuff pretty closely and are incredibly well-trained, but in a high pressure, low altitude, high wingload, high AoA situation, having them fiddle around looking for switches is a huge mistake. I have never said this about an aircraft before. I expect Boeing to re-enable the yoke disconnect and for the FAA to require recertification and a new type certificate for pilots to fly the MAX. Unfortunately, for Boeing, this will make them far, far less enticing to buy.
You reversed that.
MCAS is designed to force the nose down (that part is right) to counteract an upward pitching moment. That requires the leading edge of the horizontal plane to trim upwards, increasing lift at the tail, which pitches the craft's nose downward.
I think.
Edit: I was dead wrong. They had more 737 Max 8's than any other airline in the US.
Nothing concrete about the latest crash, could be 100% software related.
They also train their pilots using a 737max specific curriculum.
But also kind of like "if a customer had some suspicions about some avionics weirdness or training, why aren't you as a responsible vendor understanding or addressing it holistically?"
Huh? Says who?
That allows the system to have at least one failure and still operate.
With just two sensors any fault is an unidentifiable failure - how does the system know which is correct when there are just two votes?
It may be there's a third input from some other sensort, but then technically we're back to at least 3 sensors voting on the issue.
Functioning alpha vanes are critical on the MAX and NG.
With two sensors you can compare, and if they disagree beyond some epsilon of tolerance you can fail safe by deactivating the system.
With three sensors, you can compare them, and if one is out of bounds vs the other two, you can fail operational by continuing to operate the system while also alerting the operator to the needed maintenance.
I don't blame Southwest though, after all the FAA and Boeing gave the green light for these jets. It would be interesting to see where Southwest is going if 737 Max is discontinued after this.
So, 'just disable the trim' that has been throw around really sounds like they're disabling a critical feature, safety-wise, and while it's possible to fly the plane successfully without it, someone somewhere determined it was less-safe to do so.
Maybe not given that only 130 737-Max aircraft have been delivered to airlines.
Does anyone here know how aircraft leasing works in scenario like this? e.g. grounding of an aircraft model for an unknown duration, do airlines have the option so "switch out" currently leased aircraft?
In the UK the equivalent CAA is half-jokingly called "Campaign Against Aviation" for its merciless regulation.
The FAA seems to have veered in the opposite direction, inviting manufacturer staff to lead certification processes etc
Max 8s come equipped with a sensor that reads the plane's angle relative to the wind flow, prompting MCAS to automatically trigger the plane's nose to angle downward if it gets a specific reading.
However, problems could arise if the MCAS system gets erroneous sensor readings. The system automatically pushes the plane's nose down, potentially surprising pilots who are unfamiliar with the system and overriding their commands.This is what investigators believe happened to Lion Air Flight 610 before it crashed in October
more details https://www.cbsnews.com/news/boeing-737-max-8-boeing-737-800...
Umm, a little confused here, if the center of gravity shifted forward, why will the pitch up tendency increase?
The Center of thrust is offset down and somewhat in front of the CG, this means high thrust imparts a pitch up moment. Small, but present.
The bigger problem is the nacelles shape though, they create body lift at high AoA; imagine a vacuum bubble trying to suck the wing/nacelle backwards forming in the airstream, "pulling" them back.
Combine both of these characteristics, and you have an airframe demonstrating near stall positive pitch instability. I.e. you get a moment that if left uncountered will reinforce itself until the plane ends up stalling; behavior completely unprecedented in the airframe.
So in order to "counter" this behavior an automated system was introduced which supposedly restored the pilot relative flight characteristics in line with the old airframe's specs.
I'm probably oversimplifying, but it's the closest I can get to a visualization that makes some sense.
Because the center of thrust is also moved forward, and its effect is much greater than that offset by the center of mass. The 737 airframe was never designed to handle such powerful engines.
Sure it would. Here's a better explanation than I care to make: https://www.quora.com/Where-should-the-center-of-mass-lift-a...
"If the Center of Thrust does not act through the Center of Gravity there will be a moment causing the aircraft to pitch, yaw or roll about the axes of the aircraft and the moment(s) must be counter balanced by design (including provision for trimming when the thrust is varied)."
Boeing chose to counteract that newly induced pitch moment with software, so that they could sell the MAX 8 to airlines as not requiring any new training or type ratings. And now nearly 400 people are dead because of a marketing decision.
Source: Physics 101
It also could be with the engines moved forward from the wings a bit, their thrust tends to rotate the air frame "up".
Source: I am a pilot.
Please explain.
I'm not implying you're wrong, just very surprised to see this low a number. I would have guessed much closer to something like 45deg, maybe even more.
Let me know if that makes sense.
The bigger engines provide a lot of thrust and with the new position of the engines, it’s a lot easier for the plane to stall. So the plane was outfitted with a sensor and software that reads the angle of attack and it corrects it in case the plane reaches the factor of safety angle.
If the sensor malfunctions, the software would get wrong readings and try to correct something that doesn’t need correction. It moves the plane nose down. Pilots correct. Process repeats. Hence the elevation fluctuations seen in Lion Air and Ethiopian Airlines.
Just the one sensor?
reminds a typical enterprise software project - deep serious issues stemming from screwed up basic architecture are hastily patched up by software patches. Sounds like it was a money saving architectural decision as development of more deep modifications to the airframe to allow for those engines to be positioned safely would definitely cost more than a software patch. And after the Lion crash the Boeing is doing patches for the patch ...
https://www.cbsnews.com/news/boeing-737-max-8-boeing-737-800...
Now, I'm not an aerospace engineer, but common sense tells me that if you add something to a system that introduces a negative effect, you remove that something - not add something else to counter it.
But, that's me.
Regardless, I don't find the poster's logic to be unreasonable. However, Boeing was additionally constrained by available engine hardware. It's just a whole Charlie Foxtrot of a situation.
any kind of engineering - I did not want to "catch-all" everything.
How's this - "if you introduce a negative effect that can yield a catastrophic consequence..."
Remove it, or mitigate it?
I say remove it, and charge more for the flight fare. If people want more leg room, then pay for it.
The fact is at what point do you do this? What about an extreme. Like every time there is any crash just ground every single plane until the extensive investigation is done?
[1] And it should be irrelevant what has happened in other countries as far as grounding as well. Assumes they have concluded something and have more facts which of course they don't.
Edit: I love when people who comment on HN based on what they read feel that they know more about the actual risk than the people (per my reply to a comment) at Boeing.
Not sure why you jumped to the end there, as if asking "at what point do you do this?" is a ridiculous conversation to have. I think it's a reasonable question to ask. It seems like for most people the answer is somewhere between "ground all planes any time there's an accident" and "ground a new model that has has two accidents in six months".
Most of the world operates in shades of gray and nuance. Having the discussions about where the borders of nuance lie and why is valuable.
Please... go fly some 737 Max 8 planes to wherever you feel like it.
As a consumer, I simply do not want to, nor do I want the burden to worry about whether I actually am going to do so when I book a flight.
Lastly as someone in another comment made the other day not flying a 737 Max 8 means potentially flying an older plane or some other circumstance that in theory is more risky (even driving).
As a consumer who has flown on these plans many times, I'm glad they have been grounded until a fix can be deployed.
Based on what? News stories that have come out? Is that the highly accurate source?
[1] Which assumes the expert is even being quoted correctly which as anyone knows is not always the case.
Planes are grounded precisely because there is no information.
If we had information, then there wouldn't be a grounding (because we can rule out design flaws, etc).
When you are driving in a snow whiteout do you not slow down or even pull over? Or are you one of those people who would drive at the regular high way speed limit while not knowing what's in front of you?
-- Edit -- Apparently not. Now all the comments are blaming the FAA and saying it is fishy it took an executive order.
What's silly to me is how Boeing doesn't realize that another crash IN THE US would be disastrous, much, much worse than the position they find themselves in now.
I think it's a good move until we know the full picture though. Better to err on the side of caution when lives could be at stake.
Just because it's Africa doesn't mean the operators were lacking.
Without going into too much detail: there are many tradeoffs in airframe design, but one of them is fuel efficiency vs. inherent stability. Some airframe designs eke out a bit more miles-per-gallon at the cost of having ranges of motion where if the pilot gets the plane into that state, the feedback loops on motion become positive and the plane is likely to tip over, stall out, spin, etc. Boeing's Max-8 design makes this tradeoff, and the MCAS system is supposed to help compensate for this design by forcing the pilot to nose the plane down (to improve airflow over the wings and generate more lift) if the plane is pitched too high.
Problem might be that MCAS can malfunction and think the plane is pitching up when it's not, and if the pilot can't figure out how to disable it, they get very confusing signals--- they're pulling back on the stick to get the plane to climb, but MCAS is pushing the stick forward to avoid an expected stall that a malfunctioning sensor is telling it will happen. End result: pilot and the computer fight each other while the very important business of "keeping the plane in the air" isn't done and the plane crashes.
Taking into account the other sensor data is an obvious choice. A better understanding the quality of the sensor data in real field operation may also be required. Clearer stabilization problem indication, quicker manual disengage of auto pilot (several reports of nose down events) and MCAS are others. Decreasing the allowed tail trim for MCAS is another.
Then that leaves: Another one or two sensors. Independent review of the engine control laws (report of unexpected low thrust when climbing).
There is a lot to be done. The plane was rolled out too early and fixing the cut corners for real could take a while.
The conversation around this subject has degraded to irrational hysteria, but really: do you think Trump knows anything about airline safety? Is this really how we want the system to work?
Today it’s an airplane model, but tomorrow it’s banning travel from Africa because of an emerging disease, or capitulating to anti-vaxxers because of a news story.
Given his recent tweeting, he sure seems to think he does.
If Boeing requested it, it’s obviously a different thing, but it wasn’t clear at the time I wrote the comment, and the original comment was phrased conditionally anyway.
https://theweek.com/speedreads/828609/trump-claims-old-simpl...
Given the way that worked out, his having owned and operated an airline is certainly evidence that he had money, but not evidence that he knows much about even the business side, much less any other aspect other than the "being a passenger" side, of aviation.
Based on transcripts of him talking to airline industry executives[1] in the past, I'd say he actually knows less than nothing: i.e. he doesn't know what he doesn't know, much like the pointy haired guy who's too insistent he wants you to get the robots that write the computer programs to make a blockchain for cybersecurity to read your explanation of the bug.
[1]https://www.whitehouse.gov/briefings-statements/remarks-pres...
The rest engineers in Boeing, many are not longer first class, they got their jobs because of race and gender.
Your future heart doctor might be from the best medical school, but they might get in either by bribery or worse, by AA(affirmative action), they're not really up to the job, and they may kill you with good intentions without you knowing it.
Let the merited-based engineers do the most critical designs in this country please, people actually are different. For those who thinks everything should be absolutely equal, while that thought make you high whenever you think about it, you and many others may get killed by that ideology.
Many other thoughts...
-People, including executives, seem to have a very hard time thinking big picture. Q4 2018 financial results seem so important only in the time period around Q4 2018. History doesn't care about Q4 2018. History will care about the crashes (especially the second, more preventable one which happened while Boeing was working on software fixes "to make a safe plane safer")
-Overall, it is bizarre living through and watching these two crashes and the reactions to them in real time. I've often watched episodes of air crash investigation shows, the most interesting being series of crashes of the same aircraft models from decades ago (before I was in adulthood).
-No doubt that Boeing will be viewed negatively in historical light. Their culpability was sealed with their reaction to Lion Air, and only further worsened with their reaction to Ethiopian.
-I think the worst possible outcome for Boeing will be if it is determined that the MCAS issue is nonrecoverable even with the instructions that Boeing has repeated.
Still curious... what made the FAA and Boeing switch sides on this issue?
1. Was there new information? (Satellite data, etc)? -or-
2. In the inevitability of a ban, is it just a better look to seem "proactive" than to go down kicking and screaming?
More so, I hope there are subpoenas of Boeing's internal communications regarding this matter. Rumors I have read elsewhere indicate some real skullduggery if true.
Lastly, it really calls for the need of independent software auditing and compliance. There should be no proprietary software operating in regulated airspace.
If a business is using proprietary software that is found to have critical security bugs, they are 100% beholden to the vendor to get a fix. The vendor may decide to not fix that bug.
With free software, when (not if) a bug is found, the user has the right to fix the software.
While 'open source' might not be inherently 'more safe' than proprietary code (which we can't audit, so unlikely to be safe), it's inherently more safe due to the fact that the end user might actually be able to fix it, if required.
Lmao seriously??
# npm install boeing-aileron boeing-throttle boeing-flight-controls
let airbus.controls=Object.assign({},boeing.controls};
airbus.controls.yoke=undefined;
airbus.controls.headings=joystick;
airbus.controls.safety=basic_law;