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Added to that question is why radar data showed it to be airborne at 93 kn ground speed. I have no idea what the wind speed and direction were but that’s an astonishingly low speed, especially at the airport elevation.

It makes me wonder if they had a faulty airspeed indication, I think that was a problem on the Lion Air flight.

Edit: There’s no way I’m reading that chart correctly. It couldn’t have been airborne at 93 knots, that quickly. Maybe that airport runway has a hell of a hump in it...


Last edited by javadog; 03-15-2019 at 04:56 PM..
Old 03-15-2019, 02:24 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #181 (permalink)
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200 hours total?

as in flight time?

as in not very much more than necessary to solo a Cessna 172?
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Old 03-15-2019, 03:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #182 (permalink)
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Quote:
Originally Posted by David View Post
A question to pilots: how many planes nose up when you throttle up?
It's a function of where the thrust line is in relation to the pitch axis. You can see that on virtually all commercial jets, the engines are the lowest thing under the airplane when in flight. They are well below the pitch axis, so thrust will make the airplane pitch up. Pilots just adjust trim for the long haul to maintain level flight, or give it some down stick if its temporarily pitching up more than desired. Software takes care of that today.

Quote:
Originally Posted by Neilk View Post
So apparently Boeing is going to roll out a software fix in 10 days.

I am curious how are airplanes updated, I imagine it is more than a USB drive?
Speaking of software, it may be as easy as downloading the fix from Boeing's My Boeing Fleet customer service website. That can be done right there in the cockpit. Technology can be so cool...

If the fix requires any hardware changes, it could take awhile to implement. Some avionics components are about a five minute swap, "plug and play" with a big ass multi-pin connector on them, just like your car. With some components, you're done right there. Others need calibration to their various input sources, or with other components.

I don't think these particular components, if some indeed need to be replaced to accept the new software, will be all that easy. These communicate with the "where am I and what am I doing" external and internal sensors. These would include the AOA sensors we have already discussed, plus the airspeed indicators (these are the little pitot tubes seen in the photos right next to the AOA sensor), altitude sensors, nav gyros, and that sort of stuff. This all requires calibration and verification.

That calibration was one my jobs on site. I was responsible for those tasks as the Tooling and Equipment Engineer. Not just performing those tasks on site, but designing the equipment with which we performed those tasks. Any time we worked on the airplane in such a way as to have disturbed the nav gyros, the AOA sensors, etc. we had to re-calibrate those components. Think about it - what is "straight ahead"? What is "level" (both pitch and roll)? How do you "tell" the airplane all of that? What is your baseline for measurement?

Seat tracks. They do far more than just hold seats (and lavs and galleys) - they serve as the "zero" for yaw, pitch, and roll. These are some of the most carefully aligned components in the airplane, but not because we mount seats to them - we mount a lot of our alignment equipment to them. In this case, the very equipment that tells the aircraft what "straight and level" is.

Here is a quick high level overview of just one of our alignment procedures. This is for the nav gyros. We start by mounting an electronic gyro (of my design) to the seat tracks on the centerline of the aircraft, somewhere near where the front or rear main spars of the wing would meet (if they actually extended all the way to the center of the fuselage - they don't). We mount targets both forward and outboard of the gyro, in the seat tracks. Kind of like surveyors' targets. We then use lasers to align the gyro housing to those targets. Once physically aligned, we then turn on the gyro and let it find "straight and level".

Once aligned, we dismount it from its housing, quick scurry out the door and down the stairs, and head for the forward EE (electrical equipment) rack, located up by and accessed through the nose gear wheel well. The gyro is electronically "spinning" this whole while, and the clock is ticking. We only have so much time before it starts to "drift", so we have to work fast.

Once in the forward EE bay, we mount our gyro to a shelf that will be mounted on the EE rack. This shelf is loose - it is not yet hard mounted to the rack. Once the gyro is mounted to it, we can begin aligning this shelf to the rack. Once the gyro tells us that shelf is "straight and level", we hard mount the shelf to the rack and remove the gyro. This shelf will then hold the nav gyros.

AOA sensors are easier. We align these optically all from the outside of the aircraft. Hopefully you guys kind of get the idea, though. If it's not just software, depending on which hardware, it could mean a fair amount of fiddly-dicking around, which would lead to delays.

So, hopefully, it's just software.
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Last edited by Jeff Higgins; 03-15-2019 at 04:07 PM..
Old 03-15-2019, 04:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #183 (permalink)
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Someone got in very, very big trouble. Might have even lost their job. Probably reduced to being a burger flipper, or an architect, or some other equally unrewarding job.
Just about shot Merlot through my nose! lol!
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Old 03-15-2019, 04:07 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #184 (permalink)
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So the Seattle Times has an article about Boeing's cozy relationship with the FAA and 737's flawed certification process (link) .

I was thinking about the crash last night and as flawed as the MCAS implementation appears to be, I have to agree with their statements in the article

Quote:
No training, no information
After the Lion Air crash, 737 MAX pilots around the world were notified about the existence of MCAS and what to do if the system is triggered inappropriately.

Boeing insists that the pilots on the Lion Air flight should have recognized that the horizontal stabilizer was moving uncommanded, and should have responded with a standard pilot checklist procedure to handle what’s called “stabilizer runaway.”

If they’d done so, the pilots would have hit cutoff switches and deactivated the automatic stabilizer movement.

Boeing has pointed out that the pilots flying the same plane on the day before the crash experienced similar behavior to Flight 610 and did exactly that: They threw the stabilizer cutoff switches, regained control and continued with the rest of the flight.
With all the focus on control issues with the Lion Air flight, I can't believe the Ethiopian Air pilots did recognized the issue and at least disable MCAS. These are supposed to be trained professionals, or maybe they were just professionals. But if I were a 737Max pilot, after the Lion Air crash, I certainly would have familiarized myself with the process. Boeing certainly appears culpable, but poor piloting, at this point, appears to be the cause of the crash.
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Old 03-18-2019, 06:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #185 (permalink)
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I am fairly certain that the pilots will get their fair share of the blame for this. It's hard to not notice the trim wheels spinning away next to your knee. If nothing else, they should have seen that.

Poor training is almost certainly going to be an issue too, but that captain needed someone in the right seat with more than 200 hours. That's on the airline.
Old 03-18-2019, 07:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #186 (permalink)
 
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Quote:
Originally Posted by flipper35 View Post
From the article.
Quote:
Boeing is now faced with the difficult task of explaining to the media why pilots must know how to intervene after a system failure. And also to explain that airplanes have been built and certified this way for many decades. Pilots have been the last line of defense when things go wrong.
Thank you for posting the article, the 737 Max still seems like a pit-bull that can turn on it's owner/operator at any moment. As with pit-bulls, proper training seems to be essential.
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Old 03-18-2019, 07:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #187 (permalink)
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I disagree. If a pilot sees and hears the trim wheels spinning and he hasn't activated the trim switch, he should recognize he has a problem. Never mind what caused the trim wheels to spin, the fix is the same.

It's not hard to notice them.

https://youtu.be/ULCrAZyNk34
Old 03-18-2019, 07:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #188 (permalink)
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A useful summary of what's transpired:

Crash: Ethiopian B38M near Bishoftu on Mar 10th 2019, impacted terrain after departure
Old 03-18-2019, 07:56 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #189 (permalink)
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FWIW:

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Old 03-18-2019, 08:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #190 (permalink)
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Quote:
Originally Posted by javadog View Post
That's weird. I caught part of a show over the weekend with some scary similarities.

the show is called air disasters on the Smithsonian channel. Pretty good show.
https://www.imdb.com/title/tt9838136/?ref_=ttep_ep_cur

It described several incidents involving airbusses where the altitude reading was confused with the AOA reading and caused the controls to go 10 degrees down instantly.
Note that the passengers did not go 10 degrees down, they went up into the ceiling. Lots of serious injuries.
the same thing happened on a few other identical planes, almost all off the west coast of Afrika.

They never did figure out why the hardware mislabeled the altitude readings as AOA readings, but they wrote a software fix to prevent the plane from over-reacting.

IIRC they didn't pull breakers either

And before you go sayin' i don't know nuthin about the subject, I sat right seat in a Citation business jet once. I remember it because he kept telling me not to touch ANYTHING.




Last edited by sammyg2; 03-18-2019 at 12:09 PM..
Old 03-18-2019, 11:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #191 (permalink)
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And that's another thing: why do people take off their seat belts on a plane?

I never do that unless my bladder is bursting.
if I'm not heading to the lav or on the way back, I'm always belted in.

But apparently others do not do that and tend to get hurt by turbulence. Prolly the same people who get runned over by trains.
Old 03-18-2019, 12:07 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #192 (permalink)
 
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Quote:
Originally Posted by javadog View Post
I am fairly certain that the pilots will get their fair share of the blame for this. It's hard to not notice the trim wheels spinning away next to your knee. If nothing else, they should have seen that.

Poor training is almost certainly going to be an issue too, but that captain needed someone in the right seat with more than 200 hours. That's on the airline.
I’m not so sure, there was zero training on the system, no override, and no manual on it available to crews according to what I read.
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Old 03-18-2019, 04:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #193 (permalink)
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Grand jury has started looking at the certification process. I recall (un)fondly what it was like to receive a grand jury subpoena at Boeing. Sends everyone into ass-covering mode.
Old 03-18-2019, 04:17 PM
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Quote:
Originally Posted by stealthn View Post
I’m not so sure, there was zero training on the system, no override, and no manual on it available to crews according to what I read.
Actually, I think it is described in the manual. There are not very many simulators for the Max 8 yet, but...

I’m fairly certain that a competent pilot would recognize the fact that the stabilizer trim is being manipulated without pilot input. That is something that they do train for, it really doesn’t matter why the stabilizer is moving uncommanded. The fix is the same and it’s been that way for 50 years.

I don’t mean any disrespect to the pilots that crashed these two jets but I truly believe that that would not of happened with the frontline pilots we have here in this country.
Old 03-18-2019, 05:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #195 (permalink)
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Originally Posted by madcorgi View Post
Grand jury has started looking at the certification process. I recall (un)fondly what it was like to receive a grand jury subpoena at Boeing. Sends everyone into ass-covering mode.
Yikes. I never had the pleasure. FAA, JTSB, and other regulatory agency audits were enough for me.

Boy, you know, it's getting harder and harder to defend these guys. There were a few pretty big scandals while I was there, and a few folks went to prison over them, but none involved loss of life and airplanes auguring in. I really hope they get to the bottom of this and, if there were any behind the scenes shenanigans regarding quality, suppliers, training requirements, certification requirements, etc., heads really need to roll.

I feel for the engineering, technical, and mechanical folks at the company. In the past (and I bet once again) these kinds of colossal FUBARs consistently emanated from the "business" end of the business - the money men. The ones trying to cut corners and "maximize shareholder (or is that "stakeholder"?) value". The guys constantly telling the guys who design and build the damn airplane to find a cheaper way. Such were the bane of my existence. If this proves to be another one of their cost cutting mandates, I hope everyone involved gets their just deserts.
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Old 03-18-2019, 06:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #196 (permalink)
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It's always a lot cheaper to modify an existing design than come up with and get a new design through the certification process. When you start modifying an original design it can and does profoundly change the flying characteristics of the airplane. The original 727-100 was a good handling airplane. The -200 was stretched and many say didn't handle quite as well as the -100. Not terribly bad but just different. I flew the original 747-100 design and it flew much better (like flying a huge Beechcraft) than the -200 imho. The -200 was a better airplane but didn't handle as nice as the original design. The worst example of this was the DC-8. The original design flew quite nice. They even flew one supersonic ON PURPOSE!! I flew the stretched -71 and -73 models and it was the most difficult airplane I have ever flown. It had been stretched more than once, re-designed wings and re-engine a few times. I don't think the original 737 design needed MCAS. If this was an MCAS software problem I surely hope it can be fixed properly. Soon.
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Old 03-18-2019, 08:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #197 (permalink)
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Originally Posted by Fly Mach .86 View Post
It's always a lot cheaper to modify an existing design than come up with and get a new design through the certification process. When you start modifying an original design it can and does profoundly change the flying characteristics of the airplane.
Reminds me of this fiasco below.

2013
Coast Guard to decommission troubled 123s
https://www.militarytimes.com/2013/03/20/coast-guard-to-decommission-troubled-123s/
Quote:
The eight vessels were the produced under a contract to convert the Coast Guard's 49 110-foot patrol boats into 123-foot vessels.
I don't know who else caught the pilot union representative on NPR yesterday afternoon/last night, but the Boeing self-certification process didn't serve the public or the pilots very well this time.
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Old 03-19-2019, 07:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #198 (permalink)
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https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/
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Old 03-19-2019, 07:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #199 (permalink)
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Quote:
Originally Posted by javadog View Post
Actually, I think it is described in the manual. There are not very many simulators for the Max 8 yet, but...

I’m fairly certain that a competent pilot would recognize the fact that the stabilizer trim is being manipulated without pilot input. That is something that they do train for, it really doesn’t matter why the stabilizer is moving uncommanded. The fix is the same and it’s been that way for 50 years.

I don’t mean any disrespect to the pilots that crashed these two jets but I truly believe that that would not of happened with the frontline pilots we have here in this country.
From news reports, and I'm sure this will get clarified later, the Maneuvering Characteristics Augmentation System (MCAS) pre-Lion Air crash was not in the manual. Pilots did not know of it's existence (allegedly).

After the Lion Air crash it became a supplemental addendum, and some are arguing that was not sufficient, that additional simulator time and training should be required as the 737 Max is certainly different than the 737 that came before it, something Boeing downplayed in order to sell aircraft and obtain certifications - or so current theories hypothesize.

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Old 03-19-2019, 07:32 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #200 (permalink)
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