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Posted

The technical advisory board now says the plane is safe to fly, with one or two things still left to do, which they have not detailed.

 

Two are training and documentation. Given what happened I would have thought that training and documentation were top priorities and would have to be done before release for service.

 

 

  • 2 weeks later...
Posted

Not a 737max but an interesting insight into modern aircraft and why runaway trim is a memory item.

 

 

 

 

  • 2 weeks later...
Posted

Stabiliser trim action is so strong it's not capable of being counteracted by elevator. Fast speeds have more nose down trim required. It can Jamb  or run away. The usual trim brake is like throwing a back axle into a spoked flywheel and is usually actuated byopposing elevator application which is a natural reaction. followed by disconnecting the power to the trim,( manually switching it off).. Manual trim is very slow and if there's a lot of force being applied to the elevators, it's got a lot of resistance to being moved. (High load on screw jack). . It can also freeze at low temps if an unsuitable grease has been applied. It's about minus 60 C at cruise levels. Nev

 

 

Posted

Just watching the programme about ‘Boeing’s killer aeroplane’ and it occurs to me that their comment about turning off the electrics to the trim jack could have saved the plane is a bit erroneous in as much as, if the trim has already moved full nose down, switching it off will not return the trim jack to neutral so the cockpit crew would be faced with struggling to pull back the yoke with enough force to get the nose up and wind the manual trim at the same time. I am pretty sure that I would not have succeeded.

 

 

Posted

 Not you or most others. That's why the plane is still grounded. I wasn't too impressed by that show last night. It was a bit light on with the real information. Manual trimming is slow and the force to move it is high when there is a big load on the trim jack and if you are looking ot the ground the speed goes up real fast, making the situation rapidly worse. The stab has a lot of authority and the elevator cannot overpower it. Nev

 

 

Posted

I heard that with the horizontal stabiliser jack-screw in full nose down, the forces are so strong that the manual trim wheels need to be forced back by both pilots whilst “porpoising” the control column forward to un-load those forces momentarily! Not really intuitive with the ground rushing up at you.

 

Of course pilots were meant to recognise the fault long before the jack screw gets to that extreme - sadly two crews didn’t.  I believe that part of Boeing’s resolution of the problem will now limit the travel of the jack-screw into the nose down direction.

 

 

Posted

Well. why give it more than it will ever need, but there's no simple fix to this or it would have been back in service months ago.  The forward location of the engines is the real problem as they provide lift forward of the wing at high AoA.. They had to go there as they were too low to allow a bigger diameter engine to fit. Nev

 

 

  • Agree 2
Posted

Another part of Boeing’s remedy involves software changes to limit the envelope so less nose down jack-screw will be required!  It’s becoming obvious that this re-vamp to an existing airframe has been a “dogs breakfast” from start to finish!

 

 

Posted

It will be a long time before I consent to fly on a Max8. I always avoided airlines that operated DC10/MD11s I will do the same with these even if it means driving rather than flying! (Might have to buy an amphibious car!!!)

 

 

Posted

Sage advice.

 

I will never unless a absolute emergency get on a 737 

 

Max. Just not trustworthy to me. Even with a top airline, they can't trust the aircraft. Why would I?

 

Jet flights are a rarity for me, I am selective. I vote on ethics,safety and integrity. None apparent at Boeing.

 

 

Posted

The 737 has had it's issues The rudder jamming opposite to demand was knocking them out of the sky for years till they cooled the actuator  then tested it again and found it was seizing up when cold and working in the wrong sense. I managed to dodge it during my career. BOEING were ONCE the best . 707, 727 and 747. Now they have absorbed all the others  and Airbus freaks them out when it gets about 1/3rd of the Market. They have been developing a new ethic to increase profit. You can research it if you care to.. It started at least 10 years ago .  Nev

 

 

  • Informative 1
Posted

Can we be sure Airbus is more ethical? VW(European)  seemed ethical untill caught out by some uni students. 

 

 

Posted

Sure the VW crew got caught.

 

But the EU cracked down.

 

People got jailed, billions on fines, consumers were compensated in Europe. Management took a bit hit. Not perfect but a far cry from the USA.

 

In Europe if found out you generally get punished and systems change. I the USA unless politicians want your head, you get a raise.

 

 

  • Like 1
Posted

I can't see what connection there is between Volkswagen and Airbus except where they are made,( sort of) and it's a consortium of manufacturers, Their design(s) has/have more height of the fuselage from the ground to provide more space for the engines.. You can visit their website anytime.  I don't know anything about their financial structure re shareholders etc. Shareholder expectations affect Company policies and the FAA's role in this is under examination as well . This is not something that's just happened recently .Boeing's policy has been clear for a while to those who cared to look. Nev

 

 

Posted

Todays news is that FAA have fined Boeing $3.9 million for fitting faulty tracks to 737s including the Max.

 

What will they do for money?

 

 

Posted

Doubt that amount would make any difference. It's a pittance in the amounts that are involved  in this matter. Looks as if they are doing something . Slap on the face with a wet lettuce leaf at two paces. FAA are involved in this too. They allowed the lazy"B" too much rope. No oversight. That's their reason to be . Nev

 

 

  • Agree 1
Posted

I heard yesterday that a whistleblower has come forward. He was a production line manager for a few years at the Boeing plant, He says that there was a big push to increase production and it led to a lack of safety. After the first Max crash he talked to Boeings CEO, but nothing was done, after the second crash he talked to the FAA and again little was done. Now it seems he is talking to congress.

 

 

  • Like 1
Posted

Remember the SBS doco on Boeing whistleblowers in 2011. They got the sack, the problems were ignored, 3 x 737 NGs broke apart on landing overruns & all was pushed under the carpet. At least the latest whistleblower  has already retired from Boeing & has had his say at an inquiry. The Boeing "Profit before Safety" culture has been exposed but has it been eliminated? Dennis Muilenburg is saying all the right things now but he was in this up to his neck all the way through. This saga has a long way to go yet.

 

Scrapping the Max & moving on to a new design would be the best option but the timeframe to do this is huge & the cost is prohibitive. Maybe they could redesign the wings to have taller landing gear, then the engines could be moved back to where they should be.

 

 

Posted

This seems to be the behaviour we can expect from big business nowadays.

 

Just look at the banks, Telstra and mining to see what the trend is. Pay the top dogs more, pay the workers less and just hope that all goes well. Whatever happens don't take responsibility and if necessary denigrate anyone who gets between you and your money.

 

 

Posted

The recriminations are becoming louder. Boeing has temporarily halted production of the Max. There are now more than 380 new Max's in storage. The FAAs Steve Dickson chastised Muilenburg this week for pursuing an unrealistic date for the return of the Max to service which is now pushed out to an unknown date in 2020 after he (Dickson) was grilled by the House over FAAs decision to allow the Max to continue flying after the Lion Air crash. With no production the 600 companies supplying parts have to decide what to do with skilled workers. If many go elsewhere for work then that leaves a vacuum when production does start again.

 

https://www.stuff.co.nz/travel/news/118252923/boeing-considers-halting-production-of-737-max

 

 

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