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US refuses to ground Boeing 737 Max

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Re: US refuses to ground Boeing 737 Max

#151

Post by raverbashing »

Grue3 wrote: post #147
raverbashing wrote: post #144

Earlier quoted context omitted.

That reasoning logic is the kind of strawman that we can expect from frequentists :) Both crashes have been explained and it's bleeding obvious that they do not relate to the plane in itself.

Have they been expained within days of the crash? Last I heard the exact circumstances of 370's crash is still unknown. 17 took several years for the official report to come out.

Yeah the exact circumstances are not known but it was clear after a couple of days that MH370 did not fly its designated flight plan and instead flew a different path and actively avoided detection.

Re: US refuses to ground Boeing 737 Max

#152

Post by rnx100 »

_cerv wrote: post #45

Some points from personal experience from working at Boeing, family working at Boeing, and a close friend on the flight line for the 737-8; - not everything is back from the Lion Air incident, but internally there was strong confidence that a lack of pilot familiarity with the adjusted mechanics of MCAS contributed to the disaster - reproducing these failures has been extremely hard and has required a lot of cooperat…

What are insider's views on the MAX being the new MD11 cargo, which had a similar software solution for stretching-induced aerodynamic instabilities?

https://www.pprune.org/rumours-news/619272-ethiopian-airline...

Re: US refuses to ground Boeing 737 Max

#153

Post by anoncoward111 »

lb1lf wrote: post #150
Grue3 wrote: post #147

Earlier quoted context omitted.

Have they been expained within days of the crash? Last I heard the exact circumstances of 370's crash is still unknown. 17 took several years for the official report to come out.

In the case of MH17, there were strong indications it had been shot down within days at most, and once the Russian-backed rebels let investigators into the area, one found pieces of wreckage showing shrapnel damage. Hardly consistent with a defect in the airplane. Official doings take time; if I went out in the street and killed someone in plain view of lots of witnesses, it would still take years for a final verdict…

In fact, potentially for political reasons, an intercepted communication between Russian rebels in Ukraine and Russia based military was released within hours of the crash on youtube

It was released so quickly that some even thought it was Western propoganda, but all evidence points to the plane being shot down by a BUK

Re: US refuses to ground Boeing 737 Max

#154

Post by Angostura »

briandear wrote: post #93
Legogris wrote: post #56

Earlier quoted context omitted.

> The sudden rush to judgment on this case is unjustified by the evidence. If it turns out this was not Boeing's fault, a lot of people are going to have to eat their words, and millions of dollars will have been wasted for nothing. The prudent thing would be to err on the side of caution and suspend it until we know. What's millions of dollars (which I think is way exaggerated for a temporary suspension until the ev…

Did the E.U. ground the A320 when the Germanwings suicide pilot crashed the plane in the Alps, killing 150? Investigators didn’t know what brought that plane down for several days. Wouldn’t the prudent thing to do be to ground all Airbus A320s until the cause was confirmed? Did they ground the A320 after the Egyptair crash? They still aren’t sure what brought that plane down. But they didn’t ground the fleet. How abo…

> Did the E.U. ground the A320 when the Germanwings suicide pilot crashed the plane in the Alps, killing 150?

Was there a similar-seeming crash of the same model a few months before?

Re: US refuses to ground Boeing 737 Max

#155

Post by jpatokal »

agumonkey wrote: post #134
_lbaq wrote: post #77

Earlier quoted context omitted.

>Ethiopian Air are near the bottom This is ignorance, Ethiopian have been flying for 70 years and have an excellent safety record on par with most western airlines.

Could there be more non fatal incidents that only manufacturers and safety regulators are aware of ?

Aviation doesn't work that way. If a moving plane screws up in any way (too close to another plane, wrong taxiway, botched takeoff/landing, etc) it will be noticed. The US also has the widely used ASRS system for confidentially reporting safety issues/lapses of any kind for everybody's benefit, and most other countries have similar systems now, although I can't vouch for Ethiopia specifically.

https://asrs.arc.nasa.gov/

Re: US refuses to ground Boeing 737 Max

#156

Post by anoncoward111 »

_cerv wrote: post #45

Some points from personal experience from working at Boeing, family working at Boeing, and a close friend on the flight line for the 737-8; - not everything is back from the Lion Air incident, but internally there was strong confidence that a lack of pilot familiarity with the adjusted mechanics of MCAS contributed to the disaster - reproducing these failures has been extremely hard and has required a lot of cooperat…

Spare me. The pilots themselves have stated that they were completely unprepared to fly the plane safely in any condition with 0 training or warning.

Re: US refuses to ground Boeing 737 Max

#157

Post by _0nac »

somecontext wrote: post #145
FartyMcFarter wrote: post #123

Earlier quoted context omitted.

When was the last time that two brand new Airbus planes of the same new model crashed in similar ways?

I don't know whether this is "the last time", but perhaps others might find this example informative. The A320 first crashed on literally its first passenger flight "(in service for two days)". https://en.wikipedia.org/wiki/Air_France_Flight_296 Later, an A320 crashed less than two months after delivery. https://en.wikipedia.org/wiki/Indian_Airlines_Flight_605 These two crashes, as well as a third flight later, Wikip…

That initial A320 flight was a demo flight for journalists where the pilot was intentionally pulling stunts like flying very low in front of spectators. Turns out he was flying lower than intended and basically plowed into the forest at the end of the runway. There was a long, still unsolved debate about where the A320 reacted correctly to the pilot's eventual commands to rev the engines and pull up, but ending up needing to do that was definitely not the plane's fault.

Re: US refuses to ground Boeing 737 Max

#158

Post by raverbashing »

av_throwaway_19 wrote: post #68
stirlo wrote: post #15

It’s scary to think how complicit the FAA was in granting Boeing’s wish that this 30 year newer plane with substantially larger engines only required 2-3 hours of new training and said training was able to miss covering entire systems like MCAS. Now 350 people are dead, all the FAA can be thankful of is the dead are foreigners so it’s unlikely they’ll be held properly accountable.

It isn't just the FAA and Boeing. Where I work many of us have a "common type rating" between the A330 and A350 (-900 and -1000). While I commend Airbus for making them similar they are in no way common enough to justify the minuscule training course. Flying the A350 you get lots of brilliant features like brake-to-vacate, auto wing leveling during a crosswind landing (when you de-crab), differential flap setting in…

> However, coming back to the 330 after lots of 350 flying it's very easy to forget just what you have and don't have.

Yeah that seems to be an important issue. You easily "get used" to a feature and I wouldn't be surprised if a pilot used to the 350 got in a bad situation on the 330.

Are those error rates taken from FOQA? And is the company raising the issue?

Re: US refuses to ground Boeing 737 Max

#159

Post by agumonkey »

jpatokal wrote: post #155
agumonkey wrote: post #134

Earlier quoted context omitted.

Could there be more non fatal incidents that only manufacturers and safety regulators are aware of ?

Aviation doesn't work that way. If a moving plane screws up in any way (too close to another plane, wrong taxiway, botched takeoff/landing, etc) it will be noticed. The US also has the widely used ASRS system for confidentially reporting safety issues/lapses of any kind for everybody's benefit, and most other countries have similar systems now, although I can't vouch for Ethiopia specifically. https://asrs.arc.nasa.g…

I'm not sure we understood each other. I understand aviation is heavily monitored by the field, but maybe only a few (when fatal or grave) sample of incidents gets to the public eye.

Unless walkingolof is also in the field and by 'track record' he meant even 'up to the slightest faults'.

Re: US refuses to ground Boeing 737 Max

#160

Post by verytrivial »

Can someone with flight experience help me with this question?

So, MCAS is watching the AOA sensor and dipping the nose to prevent aerodynamic stall. When activated (and altering the pilots loudly) what would happen to airspeed in the valid-AOA and borked-AOA sensor states? I would have thought in the bogus-AOA case, airspeed would be increasing MUCH faster? Is this factored into regarding validation of the AOA input? Or are airspeed indicators unreliable near aerodynamic stall? Or ..? It just feels like MCAS should be able to detect the contradiction state from other variables without requiring the pilot to act.

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