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Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

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Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#111

"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?

The question is how bad the oscillations were, and how long they lasted. Maybe for the passengers it was indistinguishable from "regular" turbulence?

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#112
post #57

Earlier quoted context omitted.

No fan of Boeing. But where are you going to go to buy something else? There is only Airbus. There isn't a huge competitive market, it is just 2 companies left standing. Perhaps a good argument for fighting monopolies? And, while Boeing looks bad, when sales go down, corporations adapt. The pesky customers want "Safety", and we aren't selling "Safety", got to get some of this "Safety". Guess we better do some re-orgs…

>The pesky customers want "Safety", and we aren't selling "Safety", got to get some of this "Safety". Guess we better do some re-orgs, some focus groups, some training to make sure everyone knows "Safety" is important. Maybe throw in some training on "Quality". Gah hahahaha. Oh God, don't make me laugh that hard. One does not merely add some more Quality to a product as if it were flour in a cooking recipe. Quality i…

It all starts when psychopaths on wall st install psychopaths in the C suite.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#113
post #81

"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?

Not as scary as flying upside down which is what I originally thought based on title alone. Most people are familiar with "barrel roll" but by comparison this just looks like wiggling. Counterintuitively though my understanding is that barrel rolls are generally safe even for large planes since it's a stable 1G maneuver (some jock irresponsible air force pilot used to regularly barrel roll B-52s until he did one too…

> barrel rolls are generally safe even for large planes since it's a stable 1G maneuver

Maybe "safe" here means that merely the stress of the maneuver itself wouldn't destroy the craft? But surely the loss of lift is likely to put it at significant risk, as in your example.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#114
post #49

"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?

> why [Dutch Roll] wasn't bigger news I think the name is a serious problem. Something like “uncontrolled aircraft orientation” is more descriptive. “Dutch Roll” brings to mind thoughts of “is it better than Swiss Cake Roll?” and “is this news-spam for Hostess brand emerging from bankruptcy?”

There are terms of art, jargon, in many fields that mean something different than the “obvious” reading of the term. I had a discussion with someone on Hacker News recently that just could not understand that “dynamic programming” was a very specific solution technique for a broad range of problems with a special structure, rather than any sort of programming with a dynamic aspect to it.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#115

This is an aircraft worth taking great lengths to avoid. Cancelling important trips, meetings, etc.

Statistically 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.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#116

As 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.

As 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

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#117

Four minute video illustrating a dutch roll: * 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

I 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.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#118
post #81

"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?

Not as scary as flying upside down which is what I originally thought based on title alone. Most people are familiar with "barrel roll" but by comparison this just looks like wiggling. Counterintuitively though my understanding is that barrel rolls are generally safe even for large planes since it's a stable 1G maneuver (some jock irresponsible air force pilot used to regularly barrel roll B-52s until he did one too…

That depends on what you mean by “generally safe”. Airline jets are not made to withstand the forces of an aerobatic maneuver and while they can do it in test flight conditions, each time requires pulling the jet out of service afterwards for a full structural inspection.

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#119

Not 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

[flagged]

After a quick search just now, I could not find any tweets about it

Re: Southwest Airlines Boeing 737-8 Max Experienced Dutch Roll

#120

"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?

E.g. wibble-wobble or the more pronounced wibbly-wobbly.
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