Avionski udesi i nesreće

[namenski]

OK.

Samo, ako nisi primetio, ja fotografije i nisam postavio kao vest, nego kao zezanje uz tekst koji se i odnosio na period razvoja B737MAX...

[namenski]

@Pegin Hoces li barem da kazes nesto kao 'jao, da, zeznuo sam se...', 'izvini' ne moras, nasi smo   

[Pegin]

Sorry.

Malo sam intolerantan na humor kad su avionske katastrofe u pitanju.

U avijaciji sam preko 35 godina što sportski što profesionalno i možda imam malo drugačiji pogled  na forumske komentare od ostatka populacije.

I zato izvini još jednom ako si stvar primio lično, nije mi bila namera.

[namenski]

2 hours ago, Pegin said:

Sorry.

Malo sam intolerantan na humor kad su avionske katastrofe u pitanju.

U avijaciji sam preko 35 godina što sportski što profesionalno i možda imam malo drugačiji pogled  na forumske komentare od ostatka populacije.

I zato izvini još jednom ako si stvar primio lično, nije mi bila namera.

Ma daj...  

Malecki je problem sto u mom postu nije bilo ni naznake humoristicke namere.

Ako je tako moglo da se shvati - izvinjenje.

[אַף אֶחָד]

https://www.theguardian.com/business/2019/mar/16/boeing-how-big-is-crisis-two-disasters-five-months

[Shan Jan]

Ako sam dobro shvatio iz svega ovoga - nakon sto se Lion Air avion srusio pre par meseci, izdata je direktiva aviokompanijama da posade obrate paznju na ovaj problem. Nije mi samo jasno da li je dodat neki trening/manual ili je samo ostavljeno na stranu aviokompanijama da se snalaze kako one hoce?

 

Sas druge strane, Boeing je razvijao u medjuvremenu patch za ovaj problem i sada je pod jos vecim pritiskom da ga isporuci sto pre. Bojim se samo da i ovo ne dovede do zbrda-zdola resenja patch-a pa da se problem samo prebaci na drugi deo sofvera/hardvera.

 

Boeing je ocigledno odlucio da rizikuje sa kratkim testiranjem i velikom komplikovanoscu sistema zarad ustede u potrosnji i - izgubio je. Nadam se da ce ovo biti dobra lekcija svima da malo olade sa komplikovanjem softvera i hardvera u svojim konstrukcijama. 

 

"Dobra" stvar je sto nesrece u avioprevozu su uvek katastrofalne, sa stotinama poginulih pa uvek stizu na vesti i prave pritisak da se nesto promeni. Npr. autosaboracaj ima dnevno mnogo vise poginulih ali za to nikoga nije briga. Da se tako ozbiljno pristupilo autosaobracaju imali bi smo mnogo manje nesreca, ali to je vec neka druga prica...

[Peter Fan]

@namenski je na bio na tragu necega glede tehnoloskog limita koje nabudzavanje platforme stare 50 godina moze postici. Potreba za efikasnijim motorom je uslovila premjestanje pozicije istih na krilima, koje je prouzrokovoalo promjenu aerodinamickih svojstava cijelog aviona, koji je onda kompenziran softverski:

But the LEAP engines required an even bigger change. Boeing redesigned the pylons, the structure that holds the engine to the wing, extending them farther forward and higher up. It gave the needed 17 inches of clearance. The company also put in a higher nose landing gear.
The change, however, affected the plane’s aerodynamics. Boeing discovered the new position of the engines increased the lift of the aircraft, creating a tendency for the nose to pitch up.
 
The solution was MCAS, which ordered the stabilizer to push down the nose if the “angle of attack” — or angle that air flows over the wings — got too high. The MCAS depends on data from two sensors. But on the Lion Air flight, the MCAS relied on a sensor that was erroneously reporting a high angle of attack when the plane was nowhere near a stall.

 

https://www.latimes.com/local/california/la-fi-boeing-max-design-20190315-story.html

---
 dok je @dragance bio u pravu glede "boranije".

 

Oba 737 MAXX koja su pala su imale samo jedan sensor (standardna, jeftinija verzija), za razliku od skuplje opcije koja ima dva. 

 

On both ill-fated flights, there was a:
* Sensor problem. The AoA vane on the 737MAX appears to not be very reliable and gave wildly wrong readings. On #LionAir, this was compounded by a

* Maintenance practices problem. The previous crew had experienced the same problem and didn't record the problem in the maintenance logbook. This was compounded by a:

* Pilot training problem. On LionAir, pilots were never even told about the MCAS, and by the time of the Ethiopian flight, there was an emergency AD issued, but no one had done sim training on this failure. This was compounded by an:

* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.

All of this was compounded by a:

* Pilot expertise problem. If the pilots had correctly and quickly identified the problem and run the stab trim runaway checklist, they would not have crashed.

 

https://twitter.com/trevorsumner/status/1106934362531155974?s=20

[radisa]

Platite za ekstra sigurnost, ako ne platite, ko vas jebe...

 

Barve new world...

[burekdzija]

4 hours ago, Peter Fan said:

* Economic problem. Boeing sells an option package that includes an extra AoA vane, and an AoA disagree light, which lets pilots know that this problem was happening. Both 737MAXes that crashed were delivered without this option. No 737MAX with this option has ever crashed.

 

napraviti opciju od ovog votera je fundamentalno pogresno na toliko nivoa, da ih treba pozatvarati sve koji su svoj potpis stavili na to. softver ce uvek imati problema na novom avionu, ali zato je bog otac smislio nauku oko fault tolerance, za ovo se obara na ispitu, a kamoli da prodje u avion porucen u 5000 primeraka.

[Peter Fan]

8 minutes ago, burekdzija said:

 

napraviti opciju od ovog votera je fundamentalno pogresno na toliko nivoa, da ih treba pozatvarati sve koji su svoj potpis stavili na to. softver ce uvek imati problema na novom avionu, ali zato je bog otac smislio nauku oko fault tolerance, za ovo se obara na ispitu, a kamoli da prodje u avion porucen u 5000 primeraka.

 Posve je sumanuto da kriticna funkcija zavisi od jednog sensora, pogovto sto maltene svjetla u WC imaju redundancy, ali jebi ga, trka za profitom / manjak skrupula / odsustvu smislene regulacije.

 

The safety analysis:

• Understated the power of the new flight control system, which was designed to swivel the horizontal tail to push the nose of the plane down to avert a stall. When the planes later entered service, MCAS was capable of moving the tail more than four times farther than was stated in the initial safety analysis document.
• Failed to account for how the system could reset itself each time a pilot responded, thereby missing the potential impact of the system repeatedly pushing the airplane’s nose downward.
• Assessed a failure of the system as one level below “catastrophic.” But even that “hazardous” danger level should have precluded activation of the system based on input from a single sensor — and yet that’s how it was designed.

The people who spoke to The Seattle Times and shared details of the safety analysis all spoke on condition of anonymity to protect their jobs at the FAA and other aviation organizations

https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/
 

[Peter Fan]

Samo da naglasim da ovaj clanak iz Seattle Times treba procitati (iako u njemu kazu da avion ima dva sensora, ali da softver cita input samo sa jednog - sto meni nema smisla), jer daje odlican presjek i tehnickog I regulacionog problema. Oni su inace, kontaktirali Boeing prije nego je pao ovaj drugi avion, ali je Boeing iskusno iskulirao.

[3opge]

 

1 hour ago, Peter Fan said:

Samo da naglasim da ovaj clanak iz Seattle Times treba procitati (iako u njemu kazu da avion ima dva sensora, ali da softver cita input samo sa jednog - sto meni nema smisla), jer daje odlican presjek i tehnickog I regulacionog problema. Oni su inace, kontaktirali Boeing prije nego je pao ovaj drugi avion, ali je Boeing iskusno iskulirao.

Quote

Like all 737s, the MAX actually has two of the sensors, one on each side of the fuselage near the cockpit. But the MCAS was designed to take a reading from only one of them.

 

avion ima dva senzora ali samo jedan se koristi za MCAS sistem, nema poredjenja pokazivanja oba senzora.

 

[Peter Fan]

2 hours ago, 3opge said:

 

 

avion ima dva senzora ali samo jedan se koristi za MCAS sistem, nema poredjenja pokazivanja oba senzora.

 

Da, pa to I kazem da nema smisla. Sta ce im dva, ako se samo jedan koristi?

[Redoran]

4 hours ago, Peter Fan said:

Samo da naglasim da ovaj clanak iz Seattle Times treba procitati (iako u njemu kazu da avion ima dva sensora, ali da softver cita input samo sa jednog - sto meni nema smisla), jer daje odlican presjek i tehnickog I regulacionog problema. Oni su inace, kontaktirali Boeing prije nego je pao ovaj drugi avion, ali je Boeing iskusno iskulirao.

 

Treba ga pročitati nekoliko puta, i kod svakog čitanja se jedno deset puta vratiti na ovaj deo:

 

The FAA, citing lack of funding and resources, has over the years delegated increasing authority to Boeing to take on more of the work of certifying the safety of its own airplanes.

 

Early on in certification of the 737 MAX, the FAA safety engineering team divided up the technical assessments that would be delegated to Boeing versus those they considered more critical and would be retained within the FAA.

 

But several FAA technical experts said in interviews that as certification proceeded, managers prodded them to speed the process. Development of the MAX was lagging nine months behind the rival Airbus A320neo. Time was of the essence for Boeing.

 

A former FAA safety engineer who was directly involved in certifying the MAX said that halfway through the certification process, “we were asked by management to re-evaluate what would be delegated. Management thought we had retained too much at the FAA.”

 

“There was constant pressure to re-evaluate our initial decisions,” the former engineer said. “And even after we had reassessed it … there was continued discussion by management about delegating even more items down to the Boeing Company.”

 

 

Ovi su, jebotezec, ladno i opušteno sami sebi sertifikovali nov model putničkog aviona. Ja ozbiljno ne mogu da se u istoriji komercijalnog vazduhoplovstva setim bilo čega makar približno skandaloznog ovome. Da je ovo uradio Embraer ili ne daj bože neki ruski proizvođač, nijedan avion mu u narednih 50 godina ne bi sleteo na bilo koji aerodrom u civilizovanom svetu a ovi će sasvim izvesno nastaviti da sami sebe sertifikuju. Boeingove letelice su mi oduvek bile omiljene i totalni mi je bedak da su ovu megasvinjariju oni napravili.  

[jms_uk]

Zato sto FAA/EASA/bilo ko nema dovoljno obucenih ljudi da se razumeju u sve sisteme modernih letelica.


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