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Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed

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Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed

Old 20th Mar 2019, 20:15
  #301 (permalink)  
 
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FCeng84,

Would an improved stick nudger as per the 747s on the UK register, in the clean configuration, do it?
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Old 20th Mar 2019, 20:34
  #302 (permalink)  
 
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Seattle Times report

FBI joining criminal investigation into certification of Boeing 737 MAX

March 20, 2019 at 12:55 pm Updated March 20, 2019 at 1:16 pm


The FBI has joined the criminal investigation into the certification of the Boeing 737 MAX, lending its considerable resources to an inquiry already being conducted by U.S. Department of Transportation agents, according to people familiar with the matter.

The federal grand jury investigation, based in Washington, D.C., is looking into the certification process that approved the safety of the new Boeing plane, two of which have crashed since October.

The FBI’s Seattle field office lies in proximity to Boeing’s 737 manufacturing plant in Renton, as well as nearby offices of Boeing and Federal Aviation Administration (FAA) officials involved in the certification of the plane.

The investigation, which is being overseen by the U.S. Justice Department’s criminal division and carried out by the Transportation Department’s Inspector General, began in response to information obtained after a Lion Air 737 MAX 8 crashed shortly after takeoff from Jakarta on Oct. 29, killing 189 people,
Bloomberg reported earlier this week, citing an unnamed source.

It has widened since then, The Associated Press reported this week, with the grand jury issuing a subpoena on March 11 for information from someone involved in the plane’s development, one day after the crash of an Ethiopian Airlines 737 MAX 8 near Addis Ababa that killed 157 people.

The FBI’s support role was described by people on condition of anonymity because of the confidential nature of the investigation.


FBI joining criminal investigation into certification of Boeing 737 MAX

Sorry about the formatting, need more PPRuNe text tools...
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Old 20th Mar 2019, 22:33
  #303 (permalink)  
 
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This is starting to look very ugly. Boeing have a long way to go before the grounding is lifted.
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Old 20th Mar 2019, 22:39
  #304 (permalink)  
 
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Here is the text of the story re the FBI

FBI joining criminal investigation into certification of Boeing 737 MAX https://www.seattletimes.com/busines...oeing-737-max/
March 20, 2019 at 12:55 pm - Updated March 20, 2019 at 1:29 pm By Steve Miletich
Seattle Times staff reporter

The FBI has joined the criminal investigation into the certification of the Boeing 737 MAX, lending its considerable resources to an inquiry already being conducted by U.S. Department of Transportation agents, according to people familiar with the matter.

The federal grand jury investigation, based in Washington, D.C., is looking into the certification process that approved the safety of the new Boeing plane, two of which have crashed since October.

The FBI’s Seattle field office lies in proximity to Boeing’s 737 manufacturing plant in Renton, as well as nearby offices of Boeing and Federal Aviation Administration (FAA) officials involved in the certification of the plane.

The investigation, which is being overseen by the U.S. Justice Department’s criminal division and carried out by the Transportation Department’s Inspector General, began in response to information obtained after a Lion Air 737 MAX 8 crashed shortly after takeoff from Jakarta on Oct. 29, killing 189 people, Bloomberg reported earlier this week, citing an unnamed source.

It has widened since then, The Associated Press reported this week, with the grand jury issuing a subpoena on March 11 for information from someone involved in the plane’s development, one day after the crash of an Ethiopian Airlines 737 MAX 8 near Addis Ababa that killed 157 people.

The FBI’s support role was described by people on condition of anonymity because of the confidential nature of the investigation

Representatives of the Justice Department, the FBI and Transportation Department declined to comment, saying they could neither confirm nor deny an investigation.

A Seattle Times story over the weekend detailed how FAA managers pushed its engineers to delegate more of the certification process to Boeing itself. The Times story also detailed flaws in an original safety analysis that Boeing delivered to the FAA.

Criminal investigations into the federal oversight of airplane manufacturing and flight are rare, in part because of the longstanding belief that a civil-enforcement system better promotes candid reporting of concerns without fear of criminal repercussions.

Those criminal cases that have occurred have focused on false entries and misrepresentations.

In 1998, Transportation Department and FBI agents, acting on a whistleblower’s allegations, served a criminal search warrant on Alaska Airlines, seeking evidence of maintenance irregularities.

The investigation expanded to include the January 2000 crash of Alaska Flight 261 that killed 88 people, which the National Transportation Safety Board later blamed on the airline’s faulty maintenance practices and poor FAA oversight.

But no criminal charges were filed, although the FAA, in a separate administrative review, ultimately found that Alaska and three of its managers had violated safety regulations, fining the carrier $44,000, revoking the mechanic licenses of two of the managers and suspending the license of the third.

Federal criminal charges were brought over the May 11, 1996, ValuJet Flight 592 crash that took off from Miami International Airport and plunged into the Everglades minutes later, killing 110 people.

Federal prosecutors in Florida filed a 24-count indictment against SabreTech, an airline maintenance contractor, and its workers over alleged violations in the handling of oxygen containers blamed for the crash. SabreTech was found guilty on nine counts but was acquitted on conspiracy charges, according to news reports. An appeals court later overturned all but one of the counts, the improper training of employees
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Old 20th Mar 2019, 23:10
  #305 (permalink)  
 
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Originally Posted by Denti View Post
I know the 737 does not have a stick pusher, but, at least in the NG, it did increase stick power approaching a stall. That seems to be insufficient in the MAX, or not included in its systems. Below an excerpt from the NG FCOM, latest version i flew which is by now a few years old. If i understand it, there is now a fourth system with MCAS to aid in that situation.
Denti, that's pretty much what I had in mind. In my day we used a system called "Q feel" (AV-8) to provide some artificial force feel to the stick and it was fail passive.

As to FCEng's comment about the aircraft needing to have something already in place, the priority must be to make it safe for worldwide operators. If there is a better way to provide the required control force transfer function already in place then great. Otherwise it needs to be introduced.

Boeing is not dumb. Why pick this MCAS kluge if all you need to do is straighten out a control force function. It beats me.
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Old 21st Mar 2019, 05:53
  #306 (permalink)  
 
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Originally Posted by Rollleft View Post
Juan Browne's YouTube Video LIon Air B-737 Max NCAS Update Is far more informative than Boeing Pres. Dennis Muilenburgs full page NY Times Mar 20 apologram declaring Commitment Dedication and Values.
Longer and more detailed video from veteran 777 co-pilot Juan Browne:

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Old 21st Mar 2019, 06:02
  #307 (permalink)  
 
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Originally Posted by Bergerie1 View Post
FCeng84,

Would an improved stick nudger as per the 747s on the UK register, in the clean configuration, do it?
I am not familiar with that stick nudger design so I cannot make an assessment as to whether or not a similar system added to a 737MAX would provide the certification compliance that is achieved via MCAS.
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Old 21st Mar 2019, 06:15
  #308 (permalink)  
 
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Originally Posted by FCeng84 View Post
Denti - thanks for your reply. I feel as if your words have finally drilled something into my thoughts that I had not been allowing in before. I think I was just too stuck on the classic notion of a stick pusher in the form of a new, external "muscle" of some sort. What I think you are suggesting is that because the pilot is already pulling the column when the AOA range of concern is reached, why not increase required pull force by stiffening the variable column feel gradually as a function of AOA? The 737 column feel system (both NG and MAX) already has functionality to provide a relatively sharp increase in column stiffness when passing through an AOA threshold somewhere beyond stick shaker AOA. It may be possible to modify this to provide a more gradual increase in stiffness that would address the issue for which MCAS was fitted.

I'll give this some more thought, but I feel you (and others making similar suggestions - my apologies for not recognizing those earlier) may be on to something here. I'll check with some people I know who are more expert on the associated requirements to see if this might be another approach that would satisfy the associated cert regulations.

Thanks, again - the value of the public square that PPRuNe is needs to be acknowledged and maintained.

FCeng84
Denti - Considering this further there are two probable show stopper issues that get in the way of using variable column / elevator feel as a means of providing the certification compliance that is achieved with MCAS:

1. The variable feel arrangement on 737MAX does not allow for continuous adjustment of the feel system pressure as a function of AOA. There are provisions to provide a step increase in pressure when an AOA threshold is exceeded as one of the layers of awareness to the crew that they are getting to high AOA, but it would require considerable additional equipment to turn that into a continuously variable feel pressure level defined as a function of AOA.

2. There is not enough column / elevator feel system adjustment range to provide the compensation that would be needed. This is particularly true at high Mach / speed where the nominal setting for the feel system is rather high to begin with. There is not enough range left in the system from there to max pressure to sufficiently offset the Cm-alpha characteristic that must be addressed to meet the FARs.

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Old 21st Mar 2019, 10:28
  #309 (permalink)  
 
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Runaway! Stop and think what that's really meant to 737
pilots over time. Whrrr...Whrr... of the trim wheels
spinning away without input. EASY, we have a recall to
fix that.

This is DIFFERENT! Because of the component fault situation
AOA, the stick is shaking.... a whole different and scary event,
especially because the plane seems to be in a routine flight
condition. Nobody would really notice that in such an unexpected
time the trim wheels are ever so discretely moving, and PAUSING...
due to inputs, but then relentlessly resuming their travel. Very
sneaky while a another perceived crisis is unfolding.

No reasonable person should just casually roll off their tongue,
This is a runaway stab, they should have selected cut out.

Don't know about the Boeing factory, but out in the real world there
are NO 737 Max flight simulators where this could have been
observed/trained. (and in some airlines NO pilots knew their
familiar 737 had been changed enough to include an unknown
automatic flight control input)

It's NOT a runaway stab... for most normal 737 pilots out there!

The stick shaker is still going, with the attitude and power this
should not be possible. Who would be thinking stab trim at this
time? Remember that in daily life those Whrr.. wheels are so
often doing their thing in the background. It's not abnormal if
one is otherwise stressed out.
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Old 21st Mar 2019, 10:58
  #310 (permalink)  
 
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From my reading of the B-737 MAX’s problems, the problems originated when the new larger diameter LEAP engine had to be placed more forward and higher than previous engines, due to the Fan’s large diameter and ground clearance issues. MCAS was a by-product of this compromise. It seems that Boeing’s version of the LEAP engine even has a smaller N1 fan than Airbus’ version, for the same reason.
Why not then hang the LEAP engines on variable position pylons, that would have a ground position, used during take off and landing, and a flight position, where the engines would be moved to an optimal position for flight ? Connect the feature to the landing gear lever.
We have variable wing aircraft like the F-111 and the B-1, folding wing aircraft like the B-777 and the Grumman E-2, so I don’t think that a variable position engine pylon would pose a great engineering challenge to Boeing engineers.
But it would need time, time for design, manufacturing, testing and certification, a luxury Boeing may not have. And the FAA would be hard presssed to continue certifying such an aircraft under the original B-737 type certificate.
Over the years, the B-737 went trough several engine upgrades, a full wing redesign and several avionics upgrades and still mangaged to retain the original type certificate with Supplementary type certificates to cover the modifications. Will a variable position engine pylon still allow it to be considered as a modification of the original 1967 model ?
My Canadian pilot’s licence say « B73C », meaning I am only rated on the NG version of the 737 (the -600 through the -900 series). It’s the same with EASA licences. But my FAA pilot’s licence just says « B737 », so I am theoretically rated on all 737 aircraft. Can Boeing continue to stretch the myth that the B737-100 is the same beast as the B737 MAX ?








Last edited by Gilles Hudicourt; 21st Mar 2019 at 13:42.
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Old 21st Mar 2019, 11:14
  #311 (permalink)  
 
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Originally Posted by derjodel View Post
Good point. In the situtation like the recent Atlas crash where pilots tried to pull up last second, it would probably trim agains them, right?
How about a case where the pilots, after having been trained about the perils of spurious MCAS activations, would get an airspeed indication failure (unreliable airspeed) followed by real stall warning (generated by the AOA vane), and a justified MCAS activation, but that they would misinterpret as a spurious MCAS activation. They would do the runaway trim drill, meaning trim against the down stab, and turn off the stabilizer switches and pull on the stick.
Would they be able to recover from the stall that would follow ?
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Old 21st Mar 2019, 11:45
  #312 (permalink)  
 
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Great video, although before you spread it, I think it has some important details wrong:

- He thinks the problem MCAS try to solve is that thrust produces pitch-up moment. It's not, it is a surface (nacelles) which produces no lift at low AOA but some at high AOA. If say surface is not at the center of gravity longitudinally, say it's forward from it, this added lift will create a nose up moment that wasn't there at low AOA, and as long as it's not "compensated" by anything extra in the rear will reduce the pull force at the controls. Additionally, in frontal view, the nacelles drag COP also raises so that reduces the nose down moment induced by it (more than with the previous engines position).

- He said MCAS advances throttles to full.
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Old 21st Mar 2019, 11:53
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Everyone is talking about fixing MCAS.

But the fundamental problem is the position of the engines relative to the wing.

Why is no one talking about fixing that? I suspect I know the answer!

If the certification regime for the 737 Max is so fundamentally flawed, what else has been 'approved' that should not have been?



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Old 21st Mar 2019, 12:16
  #314 (permalink)  
 
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That video states (at 21 min) that MCAS pushes the throttles up to prevent stall. I was not expecting that.
Edit: ecto1 answered it already.
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Old 21st Mar 2019, 12:39
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Originally Posted by SLF3 View Post
Everyone is talking about fixing MCAS.

But the fundamental problem is the position of the engines relative to the wing.

Why is no one talking about fixing that? I suspect I know the answer!

If the certification regime for the 737 Max is so fundamentally flawed, what else has been 'approved' that should not have been?
This 737 Max problem could be the tip of the iceberg. Since the FAA has allowed Boeing to self-certify critical systems perhaps the rot is more than we think. And I thought the speech by Boeing CEO Dennis Muilenburg was quite lame. The usual self serving crap.
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Old 21st Mar 2019, 13:22
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Originally Posted by SLF3 View Post
Everyone is talking about fixing MCAS.

But the fundamental problem is the position of the engines relative to the wing.

Why is no one talking about fixing that? I suspect I know the answer!

If the certification regime for the 737 Max is so fundamentally flawed, what else has been 'approved' that should not have been?
I just did, post #311
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Old 21st Mar 2019, 13:40
  #317 (permalink)  
 
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Originally Posted by ecto1 View Post
Great video, although before you spread it, I think it has some important details wrong:

- He thinks the problem MCAS try to solve is that thrust produces pitch-up moment. It's not, it is a surface (nacelles) which produces no lift at low AOA but some at high AOA. If say surface is not at the center of gravity longitudinally, say it's forward from it, this added lift will create a nose up moment that wasn't there at low AOA, and as long as it's not "compensated" by anything extra in the rear will reduce the pull force at the controls. Additionally, in frontal view, the nacelles drag COP also raises so that reduces the nose down moment induced by it (more than with the previous engines position).

- He said MCAS advances throttles to full.
Yes, I picked up those points immediately (thanks to this forum). YouTube is aimed at a broad audience, and subtle technical details may be hard to convey (not sure he is aware of the difference).

The key points I noted were human factors, the ability of the jump seater to objectively diagnose, and other insights. Many people on this forum still cannot accept that those pilots could not see the 'obvious' solution.

I posted the link in this specific thread, because a search showed a post of one of his previous videos earlier in the thread.
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Old 21st Mar 2019, 15:21
  #318 (permalink)  
 
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Originally Posted by SLF3 View Post
Everyone is talking about fixing MCAS.

But the fundamental problem is the position of the engines relative to the wing.

Why is no one talking about fixing that? I suspect I know the answer!
I don't this is as big a deal as you're making it out to be. Mechanical augmentation of undesirable flight characteristics has been with us at least since the yaw damper on the B-47, and this is no different in principle.

The real issue is getting it done properly.
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Old 21st Mar 2019, 15:44
  #319 (permalink)  
 
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Question

Originally Posted by Deepinsider View Post
. (and in some airlines NO pilots knew their
familiar 737 had been changed enough to include an unknown
automatic flight control input)

.
Isn't that one of the REAL REASONS Boeing could be found culpable of negligence ?

... and points to indifference and a lack of aviation oriented 'What If'.thinking.

Has no one at Boeing today read 'Fate is the Hunter' ?
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Old 21st Mar 2019, 16:18
  #320 (permalink)  
 
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Originally Posted by FCeng84 View Post
Denti - Considering this further there are two probable show stopper issues that get in the way of using variable column / elevator feel as a means of providing the certification compliance that is achieved with MCAS:

1. The variable feel arrangement on 737MAX does not allow for continuous adjustment of the feel system pressure as a function of AOA. There are provisions to provide a step increase in pressure when an AOA threshold is exceeded as one of the layers of awareness to the crew that they are getting to high AOA, but it would require considerable additional equipment to turn that into a continuously variable feel pressure level defined as a function of AOA.

2. There is not enough column / elevator feel system adjustment range to provide the compensation that would be needed. This is particularly true at high Mach / speed where the nominal setting for the feel system is rather high to begin with. There is not enough range left in the system from there to max pressure to sufficiently offset the Cm-alpha characteristic that must be addressed to meet the FARs.
Thanks for that, always nice to get some direct feedback. That said, i currently fly a plane that is essentially without any feedback at all, save for a few springs that always offer the same resistance increase as a function of stick displacement.
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