Alaska Airlines flight forced to make an emergency landing... 82

[Alistair_Heaton]

F35 is a designed to be an unstable aircraft.

if the electronic crap fails it is known that a human does not have the capabilities to fly it unassisted.

like it or not the progression away from analogue human monitored system has resulted in a colossal improvement in the accident stats.

the max is a magenta line aircraft. Just with 1960's crew alerting systems.

 

[LittleInch]

Magenta line??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Alistair_Heaton]

Its developed over the years to indicate a reliance on automation.

The magenta line is on the NAV display indicating what has been programmed into the flight management system and is the currant active leg.

https://www.youtube.com/watch?v=5ESJH1NLMLs&t=9s

 

[Alistair_Heaton]

As an example approach into Geneva flown by me.

Magenta is my current leg. White is what it's going to do if I don't do anything.

Notice it has vertical profile as well. And indicates terrain. If the plan was to get near the ground it would trigger an alert and make that leg invalid. We would still need to change the selected alt to allow it to descend on the profile.

 

[Alistair_Heaton]

I can give you more technicality's of the NAV performance and ATC separation requirements and why it really throws a spanner in the works if your not able to meet them. Which you can hand flying but its extremely high workload and liable for emails to start flying before you have even landed. If you want. But it really doesn't add to the thread topic and would be suited to somewhere else.

BTW at that time we were 10 meters horizontal NAV performance and 25 meters vertical. Once we get below 10 000ft the SBAS stuff kicks in and vertical comes down to 15meters. But everything remains on BARO vertically until the final approach fix doing a LVP approach on GNSS.

 

[dik]

another type of craft?

"Checks are to be carried out on a second Boeing aircraft model following the blowout of an unused door on one of its planes earlier this month.

The US Federal Aviation Administration grounded more than 170 of the 737 Max 9 fleet after a cabin panel broke away thousands of feet above the ground.

On Sunday, the agency said airlines should also inspect older 737-900ER models, which use the same door design.
The FAA described the move as an "added layer of safety".

It said there had been no reported issues with the 737-900ER, but that it uses the same style of panel to "plug" an unused door as the plane involved in the terrifying 5 January incident."

https://www.bbc.com/news/world-us-canada-68052160

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Alistair_Heaton]

It's the same.

They will have reused the same door certification.

Absolutely anything that's been used in the past that's certified all the way back to the original has been used so they can use grandfather cert rights.

Hence it only having 2 x AOA sensors and some nonsense that is good.

 

[3DDave]

Triple redundant AoA sensors on an Airbus sent it out of control when ice blocked two of them, voting the working one off the farm. The plane lost 4000 feet before the pilot realized the continuous nose-down trim was happening and pulled the circuit breakers on the related flight computers to get it back to a single sensor system. See 2014, Lufthansa flight 1829

The EASA response:

As a result of this incident an Airworthiness Directive made mandatory the Aircraft Flight Manual amended by the procedure the manufacturer had described in the FOT and the OEB and a subsequent information of flight crews prior to the next flight. EASA issued a similar Airworthiness Directive for the aircraft types A330/340

just like Boeing did.

Turns out having a crew not nod off during the aerodynamics portion of the class saves lives when unreliable sensors are not detected by shoddy software rushed to market.

Such attention to quality:

https://www.reddit.com/r/aviation/comments/bnm8ai/til_airbus_a330_in_2008_suffered_multiple_sudden/

 

[Alistair_Heaton]

That was a pitot blockage not AoA

They have two at the front and one on its tail AoA on old school AB

Pitot static Boeing and old school AB have the same 3 voting, AB has 4 to meet fbw cert think the 4th is the standby instruments but don't known

A220 has smart probes which does everything. Plus two old school AOA vanes. So we have 6

 

[3DDave]

"The Aviation Herald learned that the loss of altitude had been caused by two angle of attack sensors having frozen in their positions during climb at an angle, that caused the fly by wire protection to assume, the aircraft entered a stall while it climbed through FL310. The Alpha Protection activated forcing the aircraft to pitch down, which could not be corrected even by full back stick input. The crew eventually disconnected the related Air Data Units and was able to recover the aircraft."

Not that anyone would know more than a pilot.

 

[Alistair_Heaton]

yes two out of three.

Boeing none Fly by wire you have two and have to go third regression after one goes which puts you in the same situation stick the nose down to known performance attitude.

And that's it all protections gone after one sensor failure. On the max original it would then drive you into the deck anyway unless you spotted it. You do that as per qrh and memory items and something else is still messing with your control inputs.

 

[Alistair_Heaton]

BTW most of my current lot would follow the flight director on departure even if it commanded a 30 deg nose pitch up.



Us old farts stick the pitch attitude in the same place every time and ignore the speed... But apparently we are dinosaurs. Funnily enough the the unreliable airspeed checklist says to pitch to the same pitch attitude... Funny that....

 

[3DDave]

"On the max original it would then drive you into the deck anyway unless you spotted it."

At this point that is simply wrong. Not sure why continuing to be wrong about it, but there it is. There was the initial really bad speculation about how it worked and then the clear algorithm was made clear.

It only makes a single change unless retriggered by a pilot making a trim input with the trim switch. It won't drive anyone into the deck without pilot involvement. I know this. Why is this not obvious to anyone who looked at the FDR graphs from the accident reports? Maybe people aren't looking for facts when using false information as a bludgeon is so satisfying.

The problem with redundancy is if they depend on the same thing they are no longer redundant. They are duplicate. That is, they can all duplicate the failure exactly the same way at the same time.

 

[1503-44]

Are we not talking about independentcy, rather than redundancy?
If I substitute "unnecessary" in place of "redundancy". I can't makes sense of it.
The problem with unnecessary is if they depend on the same thing they are no longer unnecessary.
Eliminating the double negative...
The problem with unnecessary is if they depend on the same thing they are necessary.
The following makes sense to me, but i'm not sure if its still what you intend to say.
The problem with independency is if they depend on the same thing they are no longer independent.



--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[SWComposites]

1) please take all of the endless and off topic and beaten to death discussions about flight controls and previous Max issues and what not into a separate thread.

2) some supposedly inside comments about the door plug issue:

https://leehamnews.com/2024/01/15/u...nspection-procedure-at-boeing/#comment-509962

 

[3DDave]

Well, SWC, that writeup on leehamnews is quite the cold slap in the face for anyone working on aircraft, particularly the allegation about Spirit falsifying a repair record.

 

[Murph 9000]

This doesn't seem worth a new thread, and the mainstream media are already conflating it with this incident. It seems to have been picked up by pretty much everyone from the usual western press, to TMZ, to the Hindustan Times.

Virgin & Airbus must have been feeling left out of the media storm, and now have their own little "quality escape" with 4 missing fasteners on an A330. Not on the same scale as the Alaska MAX 9, at least for now, but maybe does have a bit of "something rotten in the State of Denmark" about it for the industry.

https://www.independent.co.uk/news/world/americas/flight-canceled-passenger-wing-issue-b2482980.html

 

[Murph 9000]

Juan Browne's latest on the 737 issues. The spotlight has turned to the 900ER for the same door plugs, although just recommended precautionary checks, rather than an airworthiness directive and mandatory grounding.

blancolirio - B-737 900ER DOOR UPDATE! 22 Jan 2024

 

[1503-44]

Every manufacturer has an opportunity to learn something here.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

SWC,

That's quite some apparently insider view and makes total sense. The door is not supposed to be simply opened then closed but "removed". If it's not "removed" then it skips a work package for someone to do a QA check to sign it off. Also it looks like Spirit employees are in the Boeing factory fixing things. It's perfectly reasonable that they will want to limit their work compared to what Boeing people do.

Also makes it possible that the replaced seal wasn't totally sealed hence the door might well have been in position and looking ok, but with a poor seal.

Some things I guess we'll never know.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.