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Old 03-19-2019, 06:29 AM   #1531
hoveringuy
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As an engineer at a major US aircraft OEM, I feel like quality is going down. The constant push for competitiveness and emphasis on stock performance puts a lot of pressure on suppliers to constantly find ways to do things cheaper. Methods that were tried-and-true are revised to a new process that should work as good but are cheaper. We end up with expensive Service Actions to fix those things because the old way was the right way.
Messier-Bugatti, which had previously only manufactured wheels and brakes, was given the 777X main gear contract because Goodrich didn't participate in the race to the bottom and maintained standards. I'm sure it will be fine...
Our major customers won't RON the new jets until after the first 3 months because there are too many production bugs to work out.
We've been firing all the QA inspectors, but the Air Force won't accept tankers because they're full of FOD. I could go on...
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Old 03-19-2019, 06:51 AM   #1532
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And is it so hard to build a tough, completely reliable AoA sensor? We've been making these for what, 90 years? Or two that check each other constantly?
.
the 737 has a really noisy cockpit. the shape of the front fuselage was designed in the 1950's or so. technology wasn't so good. you can see there is a pretty steep rake where the windshield meets just above the nose cone. those vortex generators are an afterthought to help reduce some of the godawful wind noise when sitting up front.

the E-145 i used to fly had a really noisy cockpit too. like the guppy drivers, we wore our headsets for the entire flight to preserve our hearing. in the airbus, everyone pretty much just takes their headseats off and turns on the radio speaker above 18k so we can listen to all that beautiful silence.
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Old 03-20-2019, 02:50 PM   #1533
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We have a few older NG's without the vortex generators, and they do make a big difference. Nevertheless, I'm keeping my Bose A20's on. The noise level is high enough to cause fatigue after a full day. The silence on the 787 flight deck is unreal, I've had Airbus 330 pilots comment that it's quieter than their cockpit.
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Old 03-20-2019, 07:05 PM   #1534
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yes. i have sat in the cockpit of the 78 a few times. omg! when the packs shut off for the take off roll, its like you can hear a pin drop up there.
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Old 03-25-2019, 11:50 AM   #1535
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"Boeing defends 737 MAX’s cockpit add-ons, begins new pilot information sessions"

https://www.seattletimes.com/busines...kpit-displays/

" “There are no pilot actions or procedures during flight which require knowledge of angle of attack,” Hamilton added."
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Old 04-05-2019, 04:14 AM   #1536
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The preliminary report is out http://www.ecaa.gov.et/documents/204...2C(ET-AVJ).pdf

We'll probably never know exactly why one of the AOA sensor outputs began to read very high erroneously, but at this point it's apparent that the system didn't have sensor redundancy sanity checks and that it should not have had full stabilizer trim authority given that fact. As far as I know, Airbus systems have multiple (3?) AOA sensors feeding the flight computers, which will disregard a high reading of one sensor and indicate AOA disagree.
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Old 04-05-2019, 12:20 PM   #1537
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I think Boeing is in deep shit.
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Old 04-05-2019, 01:13 PM   #1538
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I didn't know this - If you know about the MCAS and know how to shut it off when it overreacts, it turns itself back on each time and dives the nose down!

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Old 04-05-2019, 02:52 PM   #1539
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Well it trims in increments repeatedly until it 'thinks' the aircraft is not at a dangerous AoA, but if you move the electric trim switches to cut out it is physically disabled because electric trim is disabled. The reason this crash appears to have happened after the crew initially turned the electric trim off (page 11), stopping the 'runaway', is the crew turning electric trim back on (page 12). This is likely because of the fact that they failed to retard power after the first descent, causing the aircraft to reach a very high airspeed, eventually exceeding VMO. At these high speeds a dangerously out of trim aircraft will have very high control forces, and timely manual trim adjustment with the wheel could also be difficult, especially with both pilots trying to fight to keep the nose up by pulling the yokes. In a panicked state, turning electric trim back on to allow retrimming with the yoke switches may have seemed like the only solution, when it's really a fatal mistake.

I have heard from a couple of pilots that there is a trim force reduction maneuver for runaway nose down trim practiced in sims which consists of allowing the nose to drop temporarily and trimming while it drops. In this case they did not have enough altitude to make any mistakes or to do this maneuver.
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Old 04-06-2019, 03:00 PM   #1540
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^^ wow, yeah, a last ditch desperate attempt to save it. Such a shame.

Question - When a plane is diving, can you slow it down with just throttles? Or is it out of control if overspeed?


From a Seattle Times piece yesterday:

"Two failed sensors at Lion Air, both on the accident flight and on a previous flight, followed by the failure of another just over four months later on the Ethiopian jet, is troubling.

"Lawrence Sciortino, a West Seattle-based retired pilot with 35 years experience flying for Eastern and United airlines in both Boeing and Airbus jets, said that angle-of-attack sensors are historically extremely reliable, and this failure rate seems much higher than normal.

" “In my career, I don’t remember ever having a single angle-of-attack probe send an erroneous signal,” he said. “After all, it’s a simple device. Why are we having so many failures?” "
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Old 04-06-2019, 03:45 PM   #1541
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Depends on the rate of descent. In an all out dive, no, it won't slow down, but it also won't gain speed as fast. According to the data available now the plane wasn't really "diving" until the very end. It climbed and descended multiple times over the duration of the flight and was accelerating for most of the flight, it passed VMO over 2 minutes before the crash. There's a nearly 3 minute period where no electric trim action took place between the cutout and the trim events right before the crash which suggest they turned the electric trim back on. Seems that if in this period of pitching up and down while fighting the airplane they may have had more luck manually trimming the airplane out and reduced control forces if they had reduced power. The data indicates that the throttles weren't retarded until the final dive.

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Old 04-06-2019, 08:36 PM   #1542
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^^ wow, yeah, a last ditch desperate attempt to save it. Such a shame.

Question - When a plane is diving, can you slow it down with just throttles? Or is it out of control if overspeed?


From a Seattle Times piece yesterday:

"Two failed sensors at Lion Air, both on the accident flight and on a previous flight, followed by the failure of another just over four months later on the Ethiopian jet, is troubling.

"Lawrence Sciortino, a West Seattle-based retired pilot with 35 years experience flying for Eastern and United airlines in both Boeing and Airbus jets, said that angle-of-attack sensors are historically extremely reliable, and this failure rate seems much higher than normal.

" “In my career, I don’t remember ever having a single angle-of-attack probe send an erroneous signal,” he said. “After all, it’s a simple device. Why are we having so many failures?” "

a jet airplane can reach the point where it is going so fast that the controls will not have the athority to recover. part of the cause is the phenomena known as mach tuck. center of lift moves aft on the wing to the point the elevator does not have the authority to overcome it.

in that situation, i would throw out the landing gear and speed brakes and hope for the best. if you are going fast enough, they will probably all just shear off.

this reminds me of this shitty ass cargo operation i used to fly for many years ago. it was owned by a certain straight line race car driver that i will leave nameless here. as a first officer, i had the misfortune of being the guy at the top of the rotation on the day that i wound up flying with said asshole.

a 20 series learjet has a maximum mach of .82 which is in itself pretty fucking fast by airliner standards. once we reached cruse altitude of 41,000ft, this shitstain of a man pulled 4 circuit breakers on the panel in order to disable some of the aircraft's systems. they were....oh...minor little things like Mach overspeed warning horn, Mach overspeed puller.....you know....the kind of stuff that is supposed to be a last resort before the airplane kills you.

being the cowboy that he was with complete disregard for any sort of rules, he apparently thought it would be a good idea to fly the airplane from detroit to colorado at about .85/.86 the entire time we were in cruise. i will say that we made it to our destination uneventfully and without incident. i will also say that pretty much the entire flight i was shitting my ass off i was so fucking scared.

the reason why this was so dangerous is because(i presume) we were right up against the threshold were just a little bit faster and we most certainly would have been a grease spot in a Kansas field. a very un-recoverable mach tuck situation pretty similiar to what we are talking about with the boeings in this conversation. the only difference is that at fl410, i would have had a lot more time to think about my asshole being the last thing going through my mind as my face hits the windshield.

i would be a really senior 747 captain had i stayed and not left for the regionals. fuuuuuck that! i would rather suck a gallon of shit out of rosie o'donnel's asshole than work there for another day longer than i had to in order to build the experience required to move on.


sorry, i guess i could have just answered latefan's question with "yes". carry on....
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Old 04-06-2019, 10:59 PM   #1543
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Brian does this asshole run service you speak of happen to based out of Willow Run????
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Old 04-07-2019, 03:22 AM   #1544
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While I think MCAS in the current form should never have passed the safety study phase, I think it's a stretch to say that the pilots did everything right, reading the initial report. They did not at all perform the unreliable airspeed memory items (which call for a certain attitude and thrust which would have kept them a long way away from both the ground and the never exceed speed), and they apparently switched the trim cutout switches back on, which allowed the MCAS to start trimming the nose down again.

Boeing does have a point that if you'd follow the memory items "by the book" a crash would not be the result. I'm not saying it's acceptable for the aircraft to be designed in such a way that it presents you with a very stressful non-normal situation as a result of a single failure, though.
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Old 04-07-2019, 03:25 AM   #1545
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Brian does this asshole run service you speak of happen to based out of Willow Run????
Registrations ending on CK?
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