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Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll
- Filligree 2y agoThis just isn’t Boeing’s decade.
- BoredPositron 2y agoFeels like IBM or Oracle.
- dotancohen 2y agoUntil the McDonnell Douglas management retires, Boeing will not recover. It's not a matter of an unlucky decade, it's a matter of replacing engineering with MBAing. It's just that the latency between cause and effect are long on the engineering side of this industry.
- fred_is_fred 2y agoThe merger was 27 years ago. While it may have been the cause at the time, there’s no more McD to blame. Anyone who was a senior leader in 1997 has long since retired. This is Boeing and only Boeing’s problem.
- warcher 2y agoThose guys are top tier you have to admit— tank their company, get acquired, keep their jobs, eventually wrangle their way into managing their acquirer, tank the acquiring company… this is god tier MBAing.
- abdellah123 2y agoHorses are very stable
- betaporter 2y agoI hever never once heard of a dutch roll occuring to a train.
- shdon 2y agoAm on a Dutch train right now and there is a distinct lack of roll, Dutch or otherwise. That said, I wonder where the term Dutch Roll comes from. Perhaps the oscillation is reminiscent of the motion of a ship rocking side to side. The Dutch were a major sea power.
- koliber 2y agoWhen it happens, it's catastrophic, and then it is not called a dutch roll.
- HPsquared 2y agoThe rail equivalent is called hunting oscillation. https://en.m.wikipedia.org/wiki/Hunting_oscillation https://en.m.wikipedia.org/wiki/Hunting_oscillation
- rootusrootus 2y agoOne of my first horse rides as a child made me pretty much swear off ever getting on one again. Stable it was not...
- blakesterz 2y ago"Dutch Roll is a coupled out of phase movement of the aircraft as result of weakened directional stability (provided by the vertical tail and rudder), in which the aircraft oscillates around its vertical as well as longitudinal axis (coupled yaw and roll)." That sounds pretty scary. I wonder why it wasn't bigger news when it happened last month?
- deleted 2y ago[deleted]
- jamesholden 2y ago[flagged]
- kcplate 2y agoI know the humorless HN is downvoting you but I gave you an upvote. Farts and fart jokes are always funny.
- doctor_eval 2y agoIt’s being downvoted because it’s technically incorrect. They are describing a Dutch Oven.
- raverbashing 2y agoSounds like a Yaw Damper failure? https://en.wikipedia.org/wiki/Yaw_damper https://en.wikipedia.org/wiki/Yaw_damper Not dangerous per se but very annoying for passengers
- maxxtrawl 2y agoI will walk, thanks!
- rootusrootus 2y agoI wonder what the odds of injury or death are if you walk those 768 miles vs fly. I think I'd fly.
- 0x445442 2y ago#NothingWorks
- notfried 2y agoThis is what a Dutch Roll looks like: https://www.youtube.com/watch?v=Zmjam1evDD4 https://www.youtube.com/watch?v=Zmjam1evDD4
- ceejayoz 2y agoThis seems to really under-sell the severity; the real-world example someone else linked is much more dramatic. https://www.youtube.com/watch?v=2tgfkGiHhxs https://www.youtube.com/watch?v=2tgfkGiHhxs
- giantg2 2y agoWow that's an intense example.
- rootusrootus 2y agoThat's not real world, though, that is a demo flight where they induced a strong dutch roll on purpose.
- deleted 2y ago[deleted]
- ragebol 2y agoFor anyone else (besides me, being Dutch) wondering about the name: https://en.wikipedia.org/wiki/Dutch_roll?useskin=vector#Name https://en.wikipedia.org/wiki/Dutch_roll?useskin=vector#Name TL;DR: it's from ice skating where there's a similar move. But no idea why it's called that in ice skating.
- shdon 2y agoIce skating... Interesting... My guess was it having to do with ships rocking side to side. Maar waarom een schaatsterm?
- ragebol 2y agoMaybe the ice skaters took it from ships, also an old Dutch tradition I suppose.
- AnimalMuppet 2y agoI'm not sure if this is relevant, but: I have read that back in the day (1500s-1700s), the Dutch built flat-bottomed boats that could carry a lot, and the English built round-bottomed boats that handled better in the ocean. Maybe the way a Dutch boat handled in heavier seas is the origin of the term?
- yurishimo 2y agoAt first I read that as `schatsterm` and thought it was cute, but then I looked it up to double check and it's still cool! But now I know that the word I thought it was is actually a `bijnaam`. Your language is fun and I have been enjoying learning it over the last couple of years. :)
- bell-cot 2y agoFor those unfamiliar with Dutch Roll - https://en.wikipedia.org/wiki/Dutch_roll https://en.wikipedia.org/wiki/Dutch_roll Noteworth there: The 2013 fatal crash of a Boeing KC-135R, after its rudder PCU failed. The article places preliminary blame (for the new incident) on the 737-8's rudder PCU. One might wonder about the design, components, and processes commonalities between rudder PCU's for the KC-135R, and 737-8.
- banannaise 2y agoThe 737 rudder PCU also had a defect in the 90s that caused a series of major incidents, although obviously that's been fixed since: https://en.wikipedia.org/wiki/Boeing_737_rudder_issues https://en.wikipedia.org/wiki/Boeing_737_rudder_issues
- n0us 2y agoHow does this impact the share holders?
- Havoc 2y agoThing is this could just keep going. There’s no telling how many bad apples Boeing put out there
- CoastalCoder 2y agoIf it's a software issue, I'd think owners would be pretty clear on its status on each plane. But for physical defects, yeah that's scary.
- rl3 2y ago>If it's a software issue, I'd think owners would be pretty clear on its status on each plane. Ha. I have some bad news for you: https://www.bloomberg.com/news/articles/2019-06-28/boeing-s-737-max-software-outsourced-to-9-an-hour-engineers https://www.bloomberg.com/news/articles/2019-06-28/boeing-s-...
- CoastalCoder 2y agoI can't read that article, but I'm assuming (hoping?) that even if the software is flawed, there's still clarity about which source code / build configuration is installed on a given plane. Contrast that to the allegedly faked test results, and known defects, of the planes' physical characteristics.
- rl3 2y agoThe source article was talking about how their software practices were so bad they’d hire $9/hr engineers to work on core avionics stuff. As for your point: There’s not much contrast. MCAS was software, after all. Only upside to software is because it can be updated (maybe), it’s at least more likely to be fixed instead of covered up.
- krisoft 2y ago> If it's a software issue, I'd think owners would be pretty clear on its status on each plane. That assume that it is a known software issue. If it is an issue with some unknown triggering factors how would they be clear on its status?
- justinclift 2y agoNot the incident from the article, but this footage of some other aircraft doing a Dutch Roll is illustrative: https://www.youtube.com/watch?v=2tgfkGiHhxs https://www.youtube.com/watch?v=2tgfkGiHhxs
- romanovcode 2y ago[flagged]
- deleted 2y ago[deleted]
- supportengineer 2y agoAfter a quick search just now, I could not find any tweets about it
- deskamess 2y agoAs one of the commenters to the video said: "That is the Noon Flight from Moscow arriving as usual!" Nothing to see here. Some bounce cars - others dutch roll planes. Personally, I am partial to the Swiss roll.
- everybodyknows 2y agoAirplane in the video is a Russian design, and the flight appears to have been done for demonstration.
- shepherdjerred 2y agoWas murder proven?
- kleiba 2y agoYou gotta love the first comment under that video.
- marcus0x62 2y agoYears ago, my father in law ( a heavy jet mechanic) got sent to China for two months as part of a team to diagnose and fix a recurring dutch roll complaint on a particular airframe. This was for a A300-series flown by a large freight carrier. The local mechanics couldn’t figure it out, so this team was assembled from the mechanics at headquarters to fix the plane. They inspected the plane and found no damage. They had the pilots make multiple test flights - they could not reproduce the problem. The pilots were adamant that the plane was broken. Engineers from Airbus ended up flying out to assist. They couldn’t identify any problems. After a few months of effort and a lot of very expensive dart throwing and parts swapping, they gave up. As far as anyone could tell, there was never anything wrong with the plane, and based on comments overheard from the pilots, they simply did not like this particular plane. It had been pulled from a boneyard and recertified, and they considered flying it beneath them. FIL did come home with some cuban cigars and really high quality counterfeit Fluke multimeters he got from the local market, though.
- Waterluvian 2y agoEek… I’d never want to fly a plane that’s beneath me. I’d prefer it to be at the same altitude.
- moffkalast 2y agoWell unless you're an air launched cruise missile operator.
- denderson 2y ago#UnexpectedDrStrangelove ?
- bigstrat2003 2y agoTechnically any plane should be beneath you. Also above you, but beneath you too.
- Two4 2y ago
- amarant 2y agoIt kinda bothers me that airlines are still placing orders for new Boeing airplanes. Taking delivery of old orders is one thing, since they can't really back out of those, but placing new orders implies that some level of trust remains for this company, and I just don't see how that makes any sense at all?
- masklinn 2y agoBoeings are still flying, and Airbus has no availability. On the neos, they have more than a decade worth of orders, and the order book A350 is not much shorter.
- rootusrootus 2y agoBoeing has many years of backlog, too, this is really normal with airplane manufacturers. The airlines commit ahead, they wouldn't actually want to take delivery today anyway, so the manufacturing system is designed to work this way.
- masklinn 2y agoBoeing does not have a decade of backlog.
- Sakos 2y agoSeems like you haven't seen the latest news. https://www.washingtonpost.com/business/2024/06/11/boeing-sales-orders-drop-max/928418bc-2805-11ef-835a-2a6acac1f8a6_story.html https://www.washingtonpost.com/business/2024/06/11/boeing-sa... New orders are significantly down. Old orders will rarely be cancelled even if possible simply because there's no alternative. Airbus's backlog is longer than Boeing's. And while currently Airbus's manufacturing rate is much higher currently, it won't make a difference if everybody switches to Airbus.
- rootusrootus 2y ago> New orders are significantly down. For Airbus, too.
- omgJustTest 2y agoNot bigger news due to severity of issue, most likely. Safety report out today? Edit: yep, faa confirming today https://m.youtube.com/watch?v=Zmjam1evDD4 https://m.youtube.com/watch?v=Zmjam1evDD4
- Aldipower 2y agoYou can buy dutch rolls in a lot of spaces in the Netherlands called coffeshop.
- throw0101d 2y agoFour minute video illustrating a dutch roll: * https://www.youtube.com/watch?v=9Gt-IcCBiQ4 https://www.youtube.com/watch?v=9Gt-IcCBiQ4 Longer 15m video from Mentour Pilot with some more details: * https://www.youtube.com/watch?v=z2J_LUDWioA&t=1m https://www.youtube.com/watch?v=z2J_LUDWioA&t=1m
- qwertox 2y agoFirst video is very good for a clear explanation, second one to get a bit more comments from someone who knows.
- Tao3300 2y agoI was about to link the same video. It was fascinating and took some of the scare out, but if I'm ever in one, now I'm going to be sweating it that the pilot knows what he/she is doing and doesn't overcorrect.
- mlcrypto 2y agoThis is an aircraft worth taking great lengths to avoid. Cancelling important trips, meetings, etc.
- dboreham 2y agoStatistically it is not. Most of the time travellers don't know if they're on an Airbus or Boeing aircraft and hardly ever figure out that it's a MAX.
- mlcrypto 2y agoInfinite loss multiplied by small chance is still infinite risk
- ceejayoz 2y agoWhat daily activities don't have a small chance of the same risk? Eating has a small chance of choking to death. Walking has a small chance of getting hit by a falling tree branch. Pooping has a small chance of causing a brain aneurysm to pop.
- rootusrootus 2y agoYes, we will all die. Every last one of us.
- ectocardia 2y ago"Dutch Roll" in context: it's one of the dynamic modes of a plane -- a bit like the "phugoid" (e.g. when your paper airplane repeatedly speeds downward, pitches up, stalls, and speeds downward again on its way to the ground). In broad strokes, the dynamic modes can have natural frequencies -- in the same sense often used when speaking of resonance, transfer functions -- and there's a trade-off between (1) having low natural frequencies and (2) having a responsive control system. https://en.wikipedia.org/wiki/Aircraft_dynamic_modes https://en.wikipedia.org/wiki/Aircraft_dynamic_modes
- deleted 2y ago[deleted]
- VBprogrammer 2y agoThe 737, at least in classic guise, was traditionally very stable in Yaw. Unusually so because the swept wing jets usually require additional yaw damping because the geometry naturally means on yawing one wing gets longer and the other gets shorter as seen from the point of view of the airflow. So much so that the Yaw damper on the 737 was not on the minimum equipment list for dispatch. On other aircraft like the 757 having one of the two yaw dampers out of service limited dispatch to return to a maintenance base (from memory so it might not be exactly that). I'll keep my eye out for the report on this one because I'm not convinced the initial reporting tells the whole story. It's not unheard of for pilots to damage otherwise perfectly serviceable aircraft through in-proper rudder application - American Airlines Flight 587 being a horrible example.
- tekla 2y agoI'm going to to laugh at the bad takes on this thread, and await a more accurate report. Dutch roll is undesirable, but its a basic consequence of some converging aeronautical effects.
- zthrowaway 2y agoYes but the alarming thing here is the damaged PCU...
- tekla 2y agoSure. but that's just like, OK, that by itself means very little. It could mean the standby PCU somehow activated by itself, maybe damage causing a un-commanded activation, maybe software bug, maybe God said fuck this plane in particular. The point is we have no idea since there are not enough details to know. But of course, on HN we have a army of people who think they know stuff because Wikipedia. https://trends.google.com/trends/explore?q=dutch%20roll&date=now%201-d&geo=US&hl=en-US https://trends.google.com/trends/explore?q=dutch%20roll&date... Yep, exactly what I suspected.
- exabrial 2y agoWhat the news about Boeing has done is make me pay more attention to commercial aviation in general. The number of aviation incidents is actually pretty crazy, and no, Boeing is not at the center of them despite what the media would have you believe. What is amazing though is the actual injury and fatality rate is really low due to well trained crews and measured responses by air controllers.
- FabHK 2y ago> the actual injury and fatality rate is really low due to well trained crews and measured responses by air controllers. It’s the crew and ATC staff, definitely, but also - the amazingly well engineered airplanes (despite recent Boeing hiccups - just goes to demonstrate the high standards) with many redundancies; - the archaic, but robust ATC system; and - last but not least the excellent safety culture, which investigates problems thoroughly to the root, but without blaming individuals.
- rvnx 2y agoBoeing could still argue "you see, it's safe, redundant systems worked, we haven't killed anyone this time"
- dotancohen 2y agoThe word that you are looking for is resilience I believe. Commercial and GA aircraft are highly resilient, and the procedures built around that industry are highly resilient as well.
- giantg2 2y agoAssuming one follows the procedures... Boeing...
- alistairSH 2y agoWhat really blows my mind in the number of near-misses on active runways (at least within the US). I don't know if the trend is up, as I don't have historic data, but certainly looking at Youtube (VASAviation, etc), there are a scary number of them (2 within the last 45 days at one of my local airports).
- rollulus 2y agoAs a Dutchman the endless list of apparent “Dutch” things never ceases to surprise me. Uncles, courage, ovens, double, going, etc., and a new one to my list: rolls. And none of them means any good.
- matt-attack 2y agoDon’t forget Angles.
- yurishimo 2y agoAs a new resident, I also find it surprising! It's a shame that most of the substitutions seem to be negative however. Lots of really great stuff and people in NL <3
- code_runner 2y agodutch babies are a pretty decent desert!
- kleiba 2y agoHalf of them refer to "German" things, where the word "deutsch" underwent some pronunciational variation.
- izolate 2y agoActually, a lot of these pejoratives are from the 19th century. By the 17th century, the word "Dutch" had begun to solidify its meaning around the Netherlands. This mainly stems from a time when tensions between the British and Dutch were at their peak, due to competition.
- bigstrat2003 2y ago> And none of them means any good. Dude, Dutch ovens are awesome. One of the most useful cooking tools imo.
- xeromal 2y agoDutch oven also means trapping your partner or kid under the blanket and farting. lol
- geekfactor 2y agoI didn't know what it was called, but I've experienced mild Dutch Roll enough on flights, usually on the approach or landing, that I didn't realize that it was all that rare or dangerous. I had come to think of it as a normal result of wind shear. I imagine it's a matter of degree, and I wish there was some mention of the magnitude of the Dutch Roll in this case vs what is considered normal or acceptable. (Edited to qualify my experience as "mild".)
- Out_of_Characte 2y agoHow did you tell the difference between dutch roll and the plane catching a glideslope?
- wkat4242 2y agoDoesn't it have yaw dampeners to prevent this? Ps didn't have time to read the article yet, sorry. But I thought this issue was mitigated on the 737
- outside1234 2y agoSo what you are saying is that we shouldn't fly the 737-8 MAX?
- outside1234 2y agoFor those of you that are more visual, here is a terrifying YouTube video of what Dutch Roll looks like: https://www.youtube.com/watch?v=2tgfkGiHhxs https://www.youtube.com/watch?v=2tgfkGiHhxs
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- crazytony 2y agoLooking at flightradar24, the only real upset I see is the turn over the southern Sierra Nevada range which is also ~55 minutes before arrival into OAK. Wonder if mountain waves play any part in this incident? It's the only thing I can think of that could possibly generate a dutch roll without continuing flight stability issues. (They could have also turned on/off something like the yaw damper in the cockpit but that's not specifically called out int he report) I can't imagine the standby PCU causing this incident unless there was some kind of electrical or pneumatic issue causing it to engage. But 737 + PCU issues (yes, I know it's been redesigned) is never a good day. Hopefully we'll get a NTSB report on this one.
- classified 2y ago> Dutch Roll is a coupled out of phase movement [...], in which the aircraft oscillates around its vertical as well as longitudinal axis (coupled yaw and roll). That sounds ... adventurous. What might cause something like that?