By Scott Hamilton
Jan. 30, 2020, © Leeham News: Boeing appears preparing to produce around 220 737 MAXes this year.
Spirit AeroSystems announced this morning that it reached agreement with Boeing to supply 220 fuselages in 2020.
The actual number of MAXes Boeing produces this year may vary from 220. It could well be that some of the 2020 fuselage deliveries spill over into 2021 deliveries.
Boeing said this week and last week that it will resume production “a couple of months” ahead of recertification of the MAX and that it will be a slow and deliberate restart and ramp up.
Spirit also said it doesn’t expect to produce 52 fuselages a month until late 2022. Fifty-two was the production rate before the MAX was grounded. Boeing planned to go to rate 57 by the end of 2019.
Coupled with Spirit’s announcement today, it is now possible to plot a ramp-up scenario that is critical information for Puget Sound employees and the more than 600 Boeing suppliers.
The Wichita (KS)-based company has about 100 MAX fuselages in storage.
From what we now know, it is also entirely possible the production system is shut down again toward June/July if in fact a mid-year recertification doesn’t happen.
There are really 3 possibilities at this point;
1. Boeing does what it has indicated.
2. Boeing does not re-start after 90 days the production system.
3. Boeing re-starts it all, begins to ramp up, and then future events require them to shut it down again.
FAA have told airlines that re-certification is likely abt April. BA are just trying to put their past errors behind them with overcautious statements. Looks like they are aligning production with the FAA’s comments.
Isn’t “restart a couple of months BEFORE” certification the same as “we’ll restart pushing FAA”?
No. It just means the production process needs a ‘warm start’ to have it going once certification comes through, being a few weeks out on the date the FAA ticks the completed box is neither here nor there if there is another delay. FAA doesnt care if theres 5 or 15 planes of the slow start ready when the final go ahead comes
There are about 400 finished frames available for “5, 10 planes for a slow start.”
Restarting production before a Re-certification has solidified is another imbecile act of pushiness from Boeing.
Nobody in Boeing management has experienced an epiphany. They are still in “(rinse repeat)^infinite” mode.
it seems that irony is lost on some people.
One word of encouragement from the FAA and it’s all over.
Aluminium can be recycled.
Dont be silly …thats definitely not going to happen. Its just a ‘process’ now left to go through.
@dukeofurl ‘just a process’ – I can not suppose you mean that RTS, as foreshadowed or rather forepurposed by the re start in production publicity, is as simple as producing a few fuselages
My take is that everyone has held off, in fact, from BA while waiting for FAA re certification, at which point BA will be even more vulnerable to time delays and more disposed to deal – lawyers for victims, overseas regulators, pilots and airlines and workers unions of all sorts, both airline and BA, banks, insurance companies etc etc
Is it impossible to imagine legal challenges to FAA re certification ?
It seems the worst possible outcome for BA is un coordinated and isolated FAA re certification (un coordinated with airline indemnity deals etc, overseas RTS) followed by…..having to go through the same whole process overseas
I think it far from impossible to imagine such difficulties. I imagine that a lot of overseas regulators are keeping quiet for now because any public negativity not backed up by fact would have a significant consequence in the financial markets. That’s something that they’re not going to do.
What that means is that they’re waiting for facts to be presented to them. Which means they’re waiting to see what Boeing and / or FAA presents to them. And, whilst we roughly know what that is going to be (a software patch), we’re not party to all dialogue (if any) between BA/FAA and other regulators.
What we do know is that EASA didn’t seem to be impressed by the patch idea… And Transport Canada are likely wanting MCAS removed… And Boeing haven’t said they’re doing anything but a software patch plus sim training.
Actually we know that EASA is involved in the software audit, and likely is involved in all the testing. I think their being quiet is in deference to the FAA being the regulator of record.
But all the regulators that responded to the FAA invitation, will need to be on the same page prior to RTS. If they aren’t, then I’m sure RTS will be deferred again, as it has been before.
I know I’m being silly. Recycling aluminium would cause dividends to be cut. Can’t have that.
Don’t count on it… We know that the EASA is deeply unhappy about the lack of AoA integrity on the MAX, and wary of the as yet not publicly known raw aerodynamics of an MCAS-less airframe. The JATR report also seems to have a lot of recommendations which, AFAIK, are being mostly ignored by BA for the moment at least.
In short there is a decent probability that FAA is going to disagree with the likes of EASA, CAAC, etc. If that happens, what then?
I do wonder what FAA has told Boeing about its influence overseas? The FAA cannot guarantee their recertification will automatically be honoured abroad; the complete opposite in fact.
So much critically depends on what Boeing has understood about the situation internationally, yet all the public news I’ve seen is mostly negative in this regard. Has anyone seen anything at all recently about how the EASA, CAAC, Transport Canada, etc. sees the proposed software fix? I know that they don’t do their work in public, but even so.
To be serious, it’s an intriguing situation. We are being told that the FAA are doing some kind of audit. My understanding of an audit is that it’s done AFTER design, build and test. Actually, I know it’s done after design, build and test. I should do after a career spanning 45 years.
But design, build and test seem to be ongoing. So the audit is subject to fluidity, moving goal posts.
If the audit is not subject to fluidity, why haven’t EASA performed flights as part of the audit with MCAS on and off? The same applies to the FAA?
The American Airlines pilots union, said the interview given by Boeing’s CEO was too optimistic. Further evidence that design, build and test is not complete.
An intriguing ‘process’.
N7201S has been in the air again, on Monday, and again yesterday 30th January.
Have Boeing completed the changes, are they just verifying that all is well, or are they still making modifications based on their testing ?
Philip, I suspect they are talking about the software audit. How close they are to RTS may be related to what exactly is meant by software audit. Is this an audit of the logic for the code, or is this an audit of the actual software itself that demonstrates that the code implements the logic correctly ?
How far does this software audit go, is it just MCAS code, or does it encompass STS, or any other part of the software that could have any effect on MCAS ?
I’m still shocked that MCAS 1.0 made no allowance for AOA readings that made no sense at all. I don’t get how a programmer wouldn’t flag up that they didn’t have a valid/non-valid range of input. I don’t get how whoever signed off the specification didn’t also call a halt when they found out the range of AOA input was not specified.
I agree with you. I think we have discussed this between us a number of times and we agree.
I don’t know the answer to your questions, except an audit takes place once testing is complete and the OEM declares that it is working. Not before. An audit is not part of testing.
The audit is both logic (design) and build (software/code). This comes back to sloppy software/code or sloppy engineering. With regard to MCAS1.0, Bjorn said software/code, I said engineering. We never agree.
MCAS1.0 worked according to it’s logic (design). So there was nothing wrong with the software/code. So it was sloppy engineering. The logic was wrong the design was wrong.
Will MCAS2.0 be better? The FCCs do not do failure isolation such as AoA out of range, which would have prevented both crashes. Failure isolation is a requirement of dual/triple/… channel fail over/fail safe redundancy. So the FCCS are not dual channel.
My best description is that the FCCs are master/monitor configured. The master is the left seat (captain), the monitor is the right seat (first officer). The left sensors are still the master. The right sensors are used by the right seat/FCC to call disagreement. But that’s it. It just calls disagreement. If the left seat/FCC fails then the right seat/FCC.
It’s better but still dumb as per the true definition of dual channel.
I think the new software will work. But I don’t think the logic or design will. I don’t think it will be able to safely control the pitch instability using the trim stabiliser.
Let’s see what EASA say. The ‘process’ is to say the least weird. Audits are not part of testing. An audit begins when testing is complete. But further, the logic or design should have been audited before the software was written! That’s another story.
Yes I did note they were flying again. A yo-yo kind of trajectory. A lot of up and down, at least to begin with.
“”I’m still shocked that MCAS 1.0 made no allowance for AOA readings that made no sense at all. I don’t get how a programmer wouldn’t flag up that they didn’t have a valid/non-valid range of input.””
Shouldn’t be difficulft to pay some indian programmers to give this software a cold.
Not difficult to pay some corrupt maint in Ethiopia and Indonesia.
Not difficulft to pay the Florida AoA repair shop.
$1m invested … MAX grounded and Boeing lost over $20b.
Jakdak, according to the reporting, the software audit is of the software documentation. This is to make sure the software development process was done properly and according to standard industry practices.
It checks for integrity and consistency and completeness, and for errors in naming or calling or branching. It doesn’t check for function. That is done in separate flight and simulator testing.
The scope of the audit is the entire FCC, not just MCAS. So it could not begin until the software development was mostly complete in October.
The audit is a requirement for certification. It was a necessary step before formal flight testing by the regulators. Boeing has continued to test the function of the software separately, in their own testing.
The software audit might not catch things like bounds checking, that were missing from the first MCAS, unless they were a flow or branching error. I’m sure the regulators are looking at things like that as well, but probably more during simulator testing.
I can’t follow the technical discussion of what MCAS 2.0 will do with the FCCs. It still seems to me that it is little more than an idiot light. If the pilot is still an integral part of the system, wouldn’t it have been easier to rig an idiot light alerting the pilot to a AoA failure and then give them access to an on/off switch for MCAS?
Your are more technical than you think. Boeing are now paying $20 billion for an idiot light and an on/off switch for MCAS.
But perhaps they are paying $20 billion for something else. I wonder what that is. Maybe it’s got something to do with instability.
“”We are being told that the FAA are doing some kind of audit.””
So Obama and Trump cut funding the FAA for years and there should still be software freaks left within the FAA who are able to write an software audit? Give me a break.
If the software audit were the job of the regulator, EASA wouldn’t have asked for it, EASA would have done it themselves.
Also because of some clowns inside the FAA (the FAA is part of the TAB, who said that MCAS2.0 follows regulations and is safe), because of these FAA clowns I can’t imagine the FAA is independent enough to write an software audit.
Because of all this FAA garbage in the past, foreign regulators don’t accept FAA certifications anymore. Why should they accept an FAA software audit. The FAA are Trump’s soldiers nothing else and Trump is unhappy.
If certification of the MAX is close, EASA flight testing without MCAS should be close too. End of the game for Boeing to hide, EASA will uncover what MCAS is.
They all know it already, Boeing, FAA, Trump. The FAA will certify the MAX alone, same as the FAA wrote a garbage audit alone for the first time (the FAA guys are so experienced doing software audits).
US kindergarden, nothing has changed, same as it ever was.
Good Luck producing 45 MAX in december, I wonder who wants them.
Intriguing and at the end only outcome counts – I expect that outcome will address all flaws, not only MCAS, will be solid and not soft because it’s Boeing. At least on EASA side, if FAA wants to take another shortcut for Boeing, I wouldn’t be surprised but once again very disappointed.
For me talking about restarting production months before RTS is quite inappropriate. They should restart only after all the flaws being addressed well. For me – a Wall Street talking by Calhoun.
For software you do (A) the audit for the tools then (B) for the “conceptual how to” Der Plan :-), then (C) for the implementation. … before you even load it into the target system.
Where does this put the tail end of orders delivery dates relative to their proposed delivery dates before the whole malarkey started?
Boeing’s big advantage before these issues started were the earlier delivery slots,
Ignoring any cancellations, I would estimate that the production stoppage plus the subsequent gradual ramp-up will push most of the delivery dates (later on in the queue) another 12-18 months out. That will pretty much even out the A/B delivery capabilities.
See this post, “Adjusting the Skyline” section within: https://leehamnews.com/2020/01/15/boeing-hasnt-hit-bottom-yet-neither-have-suppliers/
When would this make the go/no go date? And what flexibility would Boeing have to absorb the 220 if restart gets pushed back by (not too many) months? Essentially, is the rate of increase driven primarily by how quickly Boeing feel the line can recover or is it driven primarily by the how many airliners it believes it can hand over reliably in 2020?
The EASA is not a by-stander and set out their requirements. JATR published a report with recommendations on the 737MAX.
If Boeing feels it still somehow can shortcut, exempt, move goal posts, push Washington, make things go away like they are used too, things could get ugly.
When will be the 737MAX stall testing by EASA with MCAS activated? Or is Boeing redesigning / certifying it as anti stall instead of as Characteristics Augmentation system? The control forces for trimming, confusing emergency warming system, redesigning it? I hope so.
For stall it needs three of each, computers, sensors and power units in fail-safe/fail-over triple redundant configuration. It doesn’t. Why is three of esch necessary? If MCAS as an AoA disagreement of more than 5.5° it switches itself off. To give an example:
Left FCC and Left sensors are still master. Right FCC and Right sensors are used to monitor Left.
Left AoA is 11.6°, right AoA is 6° then MCAS switches itself off. If left AoA is wrong and right AoA is right then it doesn’t matter. But if left AoA is right and right AoA is wrong then it matters, the airplane is in stall territory; but MCAS has shutdown because the disagreement is greater than 5.5°.
So no, can’t be a stall protection system.
It should be remembered that MCAS is still a single point of failure. Specifically, if sensor disagreement occurs it turns itself off. So a single failure of a sensor causes MCAS to shut down. That means MCAS cannot be relied upon.
But to go further. I don’t think MCAS checks MCAS. So right MCAS doesn’t check left MCAS to see whether left MCAS is acting properly. Left MCAS is the master. I haven’t been able to verify it. I’ve scoured Peter Lemme’s work. Anybody know?
I’m sure EASA will tell us what Boeing are doing, one day.
Fear not, as MCAS has turned itself off, your next level of safety is the pilot.
If the aircraft is actually in the area where you do need MCAS, and it’s pitch black outside the aircraft, no moon, over completely dark featureless terrain..
Your pilot will be able to decide which of the AOA sensors is giving the incorrect reading, determine what his airspeed is, possibly ignore the stick shaker, stall warning etc. and save the aircraft…
I know people quote AF447, but I would still rather have 3 sources of input, and a solid algorithm that votes out the invalid value. (We’ve learnt from AF447)
I would imagine, and of course I am guessing here, that MCAS even in 1.0 configuration would trim the stabiliser ANU as well as AND, to reset trim once the AOA had returned below the trigger angle.
I’ve been wondering just what effect MCAS would have had on Lion Air, or Ethiopian if the AOA reading had gone the other way, i.e. was the software written only to correct for too high an angle of attack, or if due to AOA sensor failure in a negative direction, MCAS had decided that it needed to pitch the aircraft nose up for a number of seconds.
I would expect the facts to become clearer IF any of the lawsuits isn’t settled before they reach the courts, and discovery comes into play.
From a safety point of view, I’d like all of the facts to come out, purely so that we learn something from the crashes, and don’t make the same mistakes again !
Jakdak, you have to keep in mind that for MCAS to be needed, the pilot has pulled back on the column and entered a climb angle outside the range usually encountered in flight. He has intentionally taken manual control to do this, and has intentionally put the aircraft there.
If MCAS shuts down at that moment, and does nothing more, nothing will materially change for him. The correction has already been made.
If MCAS is either inoperative prior to that moment, or it backs out the correction it had previously made, then he will experience softening of the column forces upon attaining that climb angle. That softening is the effect that MCAS removes.
So there is no dire emergency. The dire emergency was precipitated in the accident flights by MCAS not turning off. So turning off is a good thing, not bad.
This is the issue I have with Philip’s comments. He’s trying to present the fixed MCAS as being equally risky to the non-fixed MCAS. That is just not true.
If the failure had gone the other way on the accident flights, nothing would have happened, MCAS was not active for a descent angle.
Based on the design of the sensor, if the vane is removed, the counterweight causes rotation off-scale high. So that is the likely failure mode.
I agree turning MCAS off is a good thing, and I agree that the latest version of MCAS is quite different to MCAS 1.0 or whatever was installed during the crashes.
How do we know for sure that in the original version of MCAS, it was not active for a descent angle ? I would expect that it would have been programmed to only trigger for a positive AOA above the threshold, but I don’t have much confidence in that software at all !
Jakdak, we know that because there is no regulation or requirement for column force behavior in descent. The regulation only exists for ascent because of the potential to further lead into the stall regime. And MCAS is only there to comply with the regulations.
I understand that, but the requirements, and what was implemented in MCAS 1.0 don’t fill me with confidence to the point where I would state that it’s known that MCAS 1.0 wasn’t active for a descent angle.
I’m sure the newer versions of MCAS will have been subject to far more scrutiny than the original version.
“we know that because there is no regulation or requirement for column force behavior in descent. The regulation only exists for ascent because of the potential to further lead into the stall regime”
Which regulation are you referring to that MCAS designed to apply to? A column force only in accents and not in descents?
How much of a component is airspeed in the lookup table for MCAS? If a 737-MAX runs into a flock of birds, blocking the pitot tubes, or some bug, or other foreign object stick in the tube, giving a false lower value, will the MCAS input values be thrown off by a large amount? I assume the reset parameters also take into account airspeed or is it just AoA?
Richard, I researched this a bit more. The FAR 25.173 requires the average push/pull force on the column to be not less than 1 lb per 6 knots airspeed increase/decrease resulting from the push/pull.
The latest FAA guidance for the test procedure is at the link below. Example test data are shown in Figures 7-1 and 7-2. Note that the gradient can vary locally as long as it doesn’t reverse.
For the MAX, the engines being below the wing mean that at high positive AoA (ascent), the nacelle effect is more pronounced than at high negative AoA (descent). So I believe that MCAS would not be required for descent.
I also searched extensively and found no reference to MCAS having any other than nose-down action. That was also explicitly stated in the Boeing documentation.
Of your comments I find the column force comment without precedent in the history of humanity.
You are saying MCAS moves the stabiliser to move the stabiliser pilot tubes to change dynamic pressure in order to change the column force.
If Boeing are doing that, they need to have their rights to build airplanes withdrawn.
As Richard said a long time ago, column force is controlled by feel computers. So column force is synthetic. Just recalibrate the feel computers to adjust the column force. Deeeeeeer.
Physically moving the stabiliser just to change pilot feel. Deeeeeeeer.
Of course, the stabiliser only goes up. Deeeeeeer.
Philip, not sure where the stabilizer pitot tubes reference is coming from. I have never said that.
The feel systems are designed to accurately represent the aerodynamic forces on the aircraft, and also to center the control surfaces for various trim conditions. By MCAS applying a force to the airframe, that force is also represented to the pilot through the feel system, if it’s accurate.
You are suggesting that the feel system introduce a force synthetically, so as to meet the regulations by artifice. That would only mask the unwanted behavior.
It’s on memory. My understanding is the stabiliser has pitot tubes to provide more accurate dynamic pressure readings to the feel computers. But I’ve read so much, my mind may be playing games.
The feel computers must provide a synthetic force because human beings do not have the strength to move the control surfaces manually. Hence the use of hydraulics at 3000 psi. The calibration of the synthetic force mimics the rise in dynamic pressure. If the calibration is wrong, just recalibrate. You don’t actually have to move the control surface. That’s just silly.
Airplanes are not flown according to how much synthetic pressure is applied to the column. Despite your assertion to the contrary.
Philip, it’s not a matter of the calibration of the feel system being incorrect. It’s a matter of the aerodynamic performance of the aircraft. That’s why it was discovered in wind tunnel testing, with no feel system present, and confirmed in the simulator.
ANU and AND.
We only know that MCAS understands AND, to cause the stabiliser to produce an upward force to counter the forward lift of the nacelles.
We don’t know whether MCAS understands ANU.
You wonder what I wonder! It may be a one way train to hell.
Is it a bird, is it a plane, It’s super pilot
Richard, I don’t know how an airspeed unreliable error would affect the MCAS system. MCAS now has access to data from both sensors. I’m sure it would have some mechanism to deal with this, as it does also for AoA. In the worst case, we know that MCAS authority is not sufficient to overwhelm the elevator.
Philip, the two FCC results are compared, so it is a fully redundant two-system comparator. When you say MCAS checks MCAS, that is not in the literal sense, but the result of MCAS should be the same on both sides, if not an error is flagged.
There is no need for triple redundancy in a system where pilot has full authority. Triple redundancy was introduced with FBW because the computers have full authority. Triple redundancy is not required for stall identification or prevention systems either.
MCAS is not a single point of failure. Like other trim systems, it will now turn off if a problem is sensed. That doesn’t make them single points of failure, as they are not critical to flight. Nor does it make them unreliable.
Please read the definition of redundsncy. For yours is unique!
Redundant would mean that if one AoA sensor failed the other would take over. But, how do you determine which failed and which didn’t? With Three AoA sensors, you have a ‘vote’, whereby the Two (presumably good) AoA sensor’s out vote the One (Presumably bad) AoA sensor.
The pilot has full authority, if he can turn off MCAS. But, from what I know, the only way to turn off MCAS is to disable the entire electric trim system. (the One, and only One trim motor).
If MCAS fails, then how do we know that MCAS will turn itself off? It’s all software. It depends on where the software failure is. If in logic, or in the FCC hardware or in the buss, or wiring? We have no other redundant Off switch in series with MCAS, except for again, the stab trim cutout, for the entire electric trim system. For the manual yoke switch, you have the column cutout switch, and if that was stuck, you can override the column cutout by the override switch. From what I hear, MCAS 1.0 was wired through the override switch, in able to bypass the column cutout switch. I wonder if that’s still the case.
One thing that bothers me is the non mirror ability of MCAS 1.0. Only the Left (Captains side) AoA sensor being used. Pilots instinctively think that there are dual systems, and sensors. Only one stick shaker going off, may point to only one AoA being bad etc.
I’ve seen mention of “only the F/O column limit switch activating the FCC” in the training manual of the 737-8 (Max). I’m assuming that’s a misprint or it has been changed with the MCAS 2.0 changes?
(search for MCAS, and page 27-41 is reprinted from the training manual (Jan 2017), with the last sentence referring to the “F/O column limit switch” in the link below).
why only F/O column limit switch activate FCC?
to amplify on the non mirroring of the 737’s Left side (Capt) and Right side (F/O). Is the Left Radar Altimeter still the only input to the AutoThrottle on 737’s or is that changed also with the dual channel, and how does it now ‘vote’ with only two Radar Altimeters or disable the AutoThrottle if the RA’s differ?
From a Flight Global article on the Turkish 737 crash
“What is not in Boeing 737 documentation and training available to pilots is that the autothrottle always gets its height information from the left radio altimeter,” it says.
“The knowledge available through training and pilot documentation is so under specified that it in fact can create a false or buggy mental model about the inter-relationships between the various automated systems and their sensor input.”
In its final report the Dutch Safety Board did reference this peculiarity of design on the aircraft involved in the crash.
“This is a relic from the Boeing 737, certificated long ago, which in the original design prioritised the provision of information to the [captain, seated on the left side],” it stated.
“It is noticeable that this subject cannot be found in any of the Boeing 737 manuals or training documents for pilots. Pilots therefore do not have the correct knowledge about links between the control systems and data input for their own aircraft.”
Risks of single-point failures are highlighted by the human-factors analysis.
“The only defence against a designed-in single-failure path [is] the pilots who are warned to mistrust their machine and to stare at it harder,” it says.
“Such a reminder, oriented only at the human operator in the system, is hardly credible after three decades of in-depth research into automated airliner flying and the subtle and pervasive ways in which automation on the flight deck – and particularly its subtle failure – affects human performance.”
Crews would not have been insulated from the “automation surprise” which emerged on the Turkish Airlines, it adds, owing to an absence of sufficient training, written guidance or documentation, or line experience.
The Dutch Safety Board insists its final report “clearly” shows the “main responsibility” for the loss of the Turkish aircraft “lies with Boeing”.
The similarities with Turkisk 1951 are striking. The lessons (not) learned a topic of investigation.
I don’t believe there is physical wiring from Left to Right except between the FCCs. So the Left sensors are not wired to the Right FCC, and the Right sensors are not wired to the Left FCC, as required by dual channel.
So if the Right FCC fails the Right sensors are lost with it. If the Left FCC fails the Left sensors are lost with it.
In short, the FCCs are cross wired but not the sensors.
Also look up SMYD. Remember the stick shaker with regard to the two crashes was asymmetric. No cross wires.
Philip, the reporting on the FCC change is that sensor data is available from both sides, to both sides, through the FCC communication channel.
However that may not mean that a fault can be isolated, if there are only two values. In some cases (known off-scale high or low, open circuit, short circuit), it may be possible to isolate the bad sensor. I don’t know the extent to which this logic is being used, but it’s commonly done as part or normal bounds checking.
If a sensor or computation result doesn’t agree but has no obvious source as above, then it’s raised as an alarm to the pilot, but not used for control functions.
I give up.
Both FCCs have access to each others sensor through each others FCCs. Not by physical wiring as required by dual channel.
Never going to agree. Your writing your own definition of dual channel.
Philip, I can’t find any reference to what you’re saying. The dispute appears to be whether FCC’s have access to the opposite side ADIRU through direct connection, or through the data channel between FCC’s.
The difference would be that with the data channel, if one FCC fails completely, the remaining FCC would have access to only its own side of ADIRU data, it would lose the opposite side ADIRU. That is true in the 737, and always has been, unless they have now changed the bus architecture, which seems unlikely.
With direct connection, the remaining FCC could still see both sides of the ADIRU. I agree that would be better, but probably not possible in the 737.
“the two FCC results are compared, so it is a fully redundant two-system comparator”
Maybe in 1930′ or 1960s that would be deemed as redundant but not in 2020s., now redundancy requires more.
“MCAS is not a single point of failure.”
Interesting is what you say… but when first AoA disagrees with second AoA – MCAS stops functioning properly. Same was during JT610 and ET302.
“There is no need for triple redundancy in a system where pilot has full authority”
You assume that MAX could be safely & easily flyable without MCAS, will see…
All your doing is proving you don’t have the knowledge. I’ve asked that you look at the logic of redundancy using a Boeing airplane. I did not say that Boeing must implement ARINC 629.
Boeing can cross wire the sensors on the MAX. But it needs hardware changes and changes to the software. That costs money.
To generalise, Boeing can make the MAX safe through hardware and aerodynamic changes. They know how to do it. But it costs money. They have been diligent in trying not to spend money. But it’s now cost them $20 billion. I think it will cost them twice that, maybe three times that.
Remember Bowing expected the MAX to return in April, at the cost of a few $, then May at the cost of a few $. And so on. They thought like you they would get way with it.
Your the one making the errors, not me and definitely not the pilots.
I do hope your employer and prospective employers don’t know who you are. You’ll be stacking shelves in a supermarket if they find out.
Sorry, your posts, including the last two posts, show you are making the errors, nobody else. Your facts are not facts. They are just very prejudiced views.
Have a nice day!
I know. At night, no moon, and an ice storm. Flight deck in meltdown. In other words, no instruments.
Is it a bird, is it a plane, It’s a super pilot.
People, pilots, need a reference point. I said that in the aftermath of the Lion Air crash. No reference point, people die.
No instruments means you apply known pitch and power, to achieve stable flight. All pilots know this, and train on it. It wasn’t relevant to the accident flights. There was no point at which they didn’t have a reference. No meltdown in the cockpit.
Pilots don’t know the pitch because of instrument failure. But anyway it’s not what pilots are taught.
Philip, pilots are taught to apply settings for pitch and power, among other things, if they have unreliable instruments.
Pitch can be approximated by adjusting trim while sensing column force, if no other secondary method is available. Similarly power can be approximated by throttle settings. Tables of these settings are provided by the manufacturer.
These should be memory items for pilots, they should have a rough idea of what settings are known to be stable for level flight, with a given wing configuration.
I still don’t know how pitch is set when there is alpha vane failure. Are pilots told to carry a pendulum?
They are taught to neutralise the control surfaces at a standard power setting. If the airplane is naturally stable it will fly straight and level. But it needs to be naturally stable.
“Pitch can be approximated by adjusting trim while sensing column force”
In the night? With no reference point? By adjusting trim? If you are in uncouncious little descent your trim feels quite similar to other positions… then you crash to mountain or ground.
Pitch & power means that you have known pitch and known power. You don’t have reliable pitch – you say start saying goodbye. Pitch and power is a remedy to unreliable airspeed, not unreliable pitch. So @Rob circular thinking.
Moreover you are missing a cognitive dissociation – when aircraft is going one way and pilots thinks is going other, when there is no reference point.
Philip & Pablo, Philip is right about neutralizing the control forces. This is what I said, I just explained the role of trim as well.
If the aircraft is trimmed for level flight, and then you lose instruments, you can approximate the needed pitch setting by increasing trim slightly while sensing the new neutral column force position. As you do that, you effectively increase AoA to meet the desired pitch and power table settings.
If the pitch setting in the table is the same as the level flight value, then you don’t need to use trim, but can just neutralize the column force, as Philip says. Trim just gives you options for setting other values of pitch if needed.
Thanks for telling me I was right.
With regard to the MAX crashes, both sets of pilots fought tooth and nail to achieve level flight. The basic training of all pilots.
MCAS refused to allow that.
Pilots must be trained for the airplane but the airplane must behave according to the training. For the MAX those words are demonstratively and evidentiably untrue. Boeing failed in training and in behaviour
Stop blaming the pilots. It’s evil.
“If the aircraft is trimmed for level flight”
Even then you need a point of reference, because 1 minute later or even less the aircraft can be in different position and pilot or will start to pray or will start to have a cognitive dissociation.
What you proposed is purely academic, in reality even much less.
Why don’t they put one of these in the MAX?
Philip, it’s not evil to acknowledge mistakes, or to understand the truth about what really happened, as demonstrated by factual evidence.
It’s not evil to examine what might have been done differently, unless those arguments are then used to persecute the pilots. I have neither done that nor suggested it be done. Yet we know that understanding of those mistakes can benefit others, by informing training going forward.
It would be evil if those mistakes were amplified or misconstrued so as to cover up or diminish the responsibility of Boeing. I’ve not suggested that, nor has it happened in reality. The Boeing errors with MCAS are very visible and open to the public, as evidenced by the extensive compensation by Boeing. None of that is diminished by pilot actions.
It is evil for the reverse to happen, to not look at other causes so as to focus responsibility solely on Boeing. The core principle of accident investigation is to examine every factor, not just the ones that you favor, or that are politically correct. This maximizes what will be learned from the accidents.
With that view, its appropriate to look at both pilot and airline mistakes. There is no diminishment of Boeing’s role by that happening. It’s just a matter of truthfulness.
Pablo, the assumptions given were no instruments and no point of reference. The pitch and power method would be the only option at that point, with pitch being approximated by column forces and trim. It’s far from ideal but better than the alternative loss of control.
What you say is factual evidence is not factual evidence. You change definitions, standards and regulations to suit your views and then call your view fact.
You can’t even get the definition/standard of redundancy right. To put it another way, you have changed the definition/standard that the world calls redundancy to offer your ‘facts’. They arn’t facts. You have just manipulated a well known definition/standard to suit your views. It’s called Orwellian behaviour.
You are a Web developer, an industry that is not regulated. Engineering is a regulated industry. Engineers must comply with accepted definitions, standards and regulations. Engineers cannot make up their own.
With the MAX, that’s what Boeing have done. Boeing made up their own definitions, standards and regulations. Consequence, the regulators don’t trust them anymore. I don’t, either.
Anyway I done. Just remember to me your words are evil.
“The pitch and power method would be the only option at that point, with pitch being approximated by column forces and trim”
Ufff… here we go again. Not factual info.
Philip and Pablo, you are welcome to provide evidence for your positions at any time.
Questioning someone’s background, insulting them, calling them evil, or arguing about definitions, is not evidence. Nor is just saying “you are wrong” as an example of the self-evidence of your own correctness. These are all ways of casting aspersions on the other person, in hopes of winning the argument without evidence. It doesn’t work.
And for the record, I’m a professional engineer, as I told you previously, but you choose to ignore as you do all inconvenient facts.
It’s difficult to blame the pilot for making mistakes in an unforgiving aircraft that they didn’t really know they were flying.
I think you said you were a consultant. But there does seem to be a difference in the quality of arguments. I’m not sure Philip is looking for things to be wrong with the Max. But it does seem you are looking for things to be right with Boeing. I am not trained as an engineer, but do have some training as a researcher, searching for connections that make all or most of the various facts make sense. And I do admit to a bias against the type of management Boeing has practiced. I guess, empirically, gathering in all of what I know and can understand, Philip’s arguments seem to gather and make sense of most of what we have been able to know — including the internal email messages. Most of all, his argument makes sense because most people have been forced to guess at things that should be known. This itself plays into how one makes sense of what is going on with the Max.
I am defending dead people as they can’t defend themselves.
Your ‘facts’ are not facts, they are opinion that denigrate the professionalism of dead people. As I said you can’t even get the definition of redundancy right.
I suggested you looked up IEEE communication protocols, data transmission protocols. I’ll give an example, ARINC 629. The Boeing 777 uses the ARINC 629 protocol. Boeing do get it right. Can it be used on the MAX. No, the CPUs are not big enough.
Anyway the protocol is used by the 777 to link sensors to the FCCs according to the right definition of redundancy as I explained previously. Does an airplane have to be FBW? No. The sensors on the MAX are already linked to the FCCs by wires not cables. So no.
Cross linking sensors requires more wires and more ports. But that’s a hardware change. It would also need bigger CPUs to process the significant increase in data. But that’s a hardware change.
Boeing refuse to do hardware or aerodynamic changes for the MAX. But be clear, they do know how to do it. The 777’s use of ARINC 629 is an example.
Do more reading and less writing.
So again, not blaming the pilots. Just pointing out things they did wrong or could have done better, so that we learn from them. Not denying issues with the aircraft or Boeing’s role.
“I’m not sure Philip is looking for things to be wrong with the Max. But it does seem you are looking for things to be right with Boeing.”
I have never heard a positive comment from Philip on the MAX. He thinks it should be scrapped, as he has said repeatedly. His viewpoints are entirely negative. You’ve heard both positive and negative from me. I’ve criticized things that were wrong with the MAX, but have not argued or concluded that therefore everything about it must be wrong.
“Most of all, his argument makes sense because most people have been forced to guess at things that should be known.”
This is exactly the problem, opinions are formed based on guessing and speculation and conjecture. They are not rooted in evidence or fact. And as per the above, all those guesses are negative because that is the preclusion that drives the guess. Only the negative is ever considered.
If you have training in research, you should be familiar with the need for objectivity. You try not to guess, you say you don’t know, and you try to find out, then you follow the facts. Or in the case where there are professional organizations overseeing the process, who choose not to speak or share details publicly, you trust that they are doing their job, and not sharing for a reason, unless you have cause to believe otherwise.
At the bottom of this thread, you made an entirely negative and political statement, based on what? There is no evidence for any of the things you said, nor would it make any sense for those things to happen. They reflect your personal frustration with the outcome of probable RTS, but they are not at all objective.
That’s why I try to post the balancing positive view. When I was a kid, there was a cartoon series called Gulliver’s Travels, and a character named Glum, who only saw the negative in any situation. I often think of him when I read posts here.
Philip. there is no comparison of the 777 FBW system to the 737 FBP system. You’re repeating what I had already said, that the external cross-connection is not feasible on the 737, but the internal FCC data channel is, so that’s what has been employed.
There is no need to employ the 777 bus architecture on the 737. The benefit would be small and related to the case where one FCC totally fails. Outside of that case, there is no functional difference between the external and internal connection. The data are available to both sides. In the failure case, the remaining side could see only it’s own data, as I said.
And for the record, the 737 FCC architecture is redundant, the loss of one side or the other permits the remaining side to continue functioning. That has always been true, it is not changed now. The aircraft could not be certified otherwise.
“Philip and Pablo, you are welcome to provide evidence for your positions at any time.”
1st of all thank you again for letting us know who is “a real boss”. 2nd – you have been given many reasons and evidence before, but you are repeating and repeating yourself and don’t expect copy & past from others every time.
And again when you don’t have arguments you are starting accusing everybody else for… not being factual.. or not being polite… A Jose Mourinho approach when he put finger from behind to the eye of Tito Vilanova.
“José Mourinho turned to violence against Barça to mask his own failure”
UTC’s CEO Greg Haine is assuming a 90 day delay on MAX which is consistent to what BOEING told them. For H2.2020, UTC has also halved production, from 42 to 21/mo (described as consistent with BCA’s plan upon MAX re-certification).
I don’t know the regular MAX cycle time upon receiving the empty hull and total fuselage inventory (BCA + the 100 in KS as Scott mentioned) + time to industrialize right-first-time all certified amendments by regulator(s).
To me – besides a lifeline to SPR + investor relation – this looks like BCA securing its Supply Chain (and a nervous SPR), avoiding disruptions and more layoffs at SPR before Renton’s industrial really kicks-starts assembly.
For all the damage Boeing did to Bombardier, I hope Canada delays certification. However most of that damage would be to Air Canada that cant fly its ancient A320 much longer.
So i doubt Canada will delay certification.
I would hope politics doesn’t get in the way of safety.
If, and when it’s safe, certify it. By all means make very certain it’s safe before you give the ok, but don’t play politics with safety.
@Scott I’m presuming that the production line workers that have been dispersed to the different MAX storage locations to prepare aircraft for delivery will be returned to the production line as Boeing re-starts production, or would this be a phased return ?
All things being political, when tRump is absolved of any wrongdoing, and stands on his pompous throne, one the next bits of his time worn rhetoric will be about saving this abortion known as the Max 8. It will come down to this. USA! USA!
analysts are waking up!
and what they see is ugly…
shocked by the rate of cash burn
and shocked by dividend Policy (borrow money to keep dividend …..)
1/subscribe to LEEHAM NEWS!
2/Do some serious analyst work, and not repeat -Parrot like- official Boeing com
Really sad to see the day Boeing is letting down the Warfighter . . .
The remote vision system is a tough nut to crack, for an operation as delicate as refueling. The system works well in 90% of cases. But the 10% are the ones more likely to occur under combat conditions.
Another issue is the incidence of undetected contacts. These are boom contacts with the fuselage not detected by either operator or pilot, but evident by scuffs or scratches or dents on the receiver aircraft. The Air Force wants that to be zero. If contact occurs, as it always has in refueling operations, the operators need to be fully aware of it.
Acuity (currently 20/50 vision) and depth perception are both affected by projection onto a 2D screen. Even with 3D and VR technologies, it may not be possible to attain the same level as human vision. Then you also have dynamic range problems with glare and shadow, where again human vision is superior. And infrared vision also has inherently less resolution.
Boeing is saying this all can be resolved by real-time image processing and enhancement, and that as vision improves, the undetected contacts will as well. Hard to evaluate this claim.
Cameras on the boom itself, closer to the refueling junction, would help, also force-feedback sensors. But perhaps these are not permitted on the boom for safety reasons.
Also using goggles where the images for each eye can be separately manipulated, might help to enhance acuity and perception (true binocular vision). I guess we’ll see what happens.
“The remote vision system is a tough nut to crack, for an operation as delicate as refueling. The system works well in 90% of cases. But the 10% are the ones more likely to occur under combat conditions.”
It really is a Boeing “el cheapo” problem
as that “nut” has been cracked by others.
Uwe, it appears that Boeing chose to try commercial 3D technology using only glasses to resolve depth perception, as opposed to the earlier systems using helmet-mounted displays with true binocular vision, as I mentioned.
That may or may not work, if not they will have to go back to the binocular method. For now they are thinking it can be made to work, but the Air Force has concerns with that approach.. Well have to se.
Uwe, I looked into this and it appears that the Airbus MRTT Boom Enhanced Vision System (BEVS) already accomplishes what the Boeing KC-46 Remote Vision System (RVS) is trying to do, using the same commercial 3D technology and goggles. That system is already being certified for US aircraft.
Kappa Optronics, the German developer and manufacturer of BEVS, has won awards for innovation. So looks like Boeing/Collins have some catching up to do.
Airbus has moved on into automatic link up and fuel transfer. A high quality “round the clock capable” vision system is a basic requirement I’d assume?
I saw that too, I agree that Airbus is close to automating the refueling task. For now that will be used as an aide, but eventually could be fully autonomous.
The BEVS acuity is also not as good as 20/20, but the image processing and depth perception are enhanced. So seems like that is where the Boeing system is lacking. The Air Force must be aware of BEVS as it’s being certified to refuel US aircraft. So they will likely hold Boeing to the same standard.
There’s also the problem of undetected contacts, they need a better feedback mechanism to know when a contact has been made.
“letting down the Warfighter . . .”
less senseless global damage. This is OK.
Any reduction in (US) MIL forces readiness is a boon.
I wonder if Boeing is waiting until the final report from the Etheopean accident comes out, before they ramp up production again? It should be published in a month or two? I assume that the Etheopean investigation is difficult as what was left of the plane to investigate was quite damaged.
Good call. I think the same applies to the regulators
Ethiopia should have all the time to wait for EASA flight tests without MCAS.
I’m afraid Boeing and the FAA may stage their own Brexit.
The Max will get certified in the US, and then they will launch a PR campaign against world-wide regulators. We all know the rhythms of that campaign. The Max will be presented as the MAGA plane that is good because it is American — an example of Yankee ingenuity and know-how that fell victim to red tape; bureaucratic regulation; backward, incompetent pilots from the developing world; and the ineptness of simple minded stewards who can’t handle the demands of the modern Western technology left in their care. International regulators will be presented as unimaginative, jealous, self-serving, nationalistic, and driven by their hatred of the American way of life.
EASA won’t get to fly the plane without MCAS. The facts will get lost. And of course, the decision to to re-certify the plane despite serious questions about its airworthiness, will be like all such decisions that have an inevitable logic. The executives will draw their huge salaries, not-so-clever stockholders will be left holding the bag, and tens of thousands of workers will draw the miserly unemployment checks that they get in America, and maybe file applications to work at for an aerospace company with headquarters abroad but with American manufacturing plants.
“”EASA won’t get to fly the plane without MCAS. The facts will get lost.””
If FAA certifies alone the rest of the world can flight test the MAX without Boeing. Nothing should get lost, it’s important for the court.
What a disaster that would be for the US. America first.
“” 100 frames stored on site. “”
Do these frames count as “delivered to Boeing” ?
Doesn’t Boeing need to pay the frames in advance?
I think they are only stored there because Boeing has less space.
@Philip, @Rob, @Pablo: You guys are just going back and forth on the same topic. None of you is going to convince the other, so how about moving on? Furthermore, the topics you are beating to death are not relevant to production ramp up and restart, the subject of this post.
“”the topics you are beating to death are not relevant to production ramp up and restart, the subject of this post””
Hard to comment on topic because I think threads on page TWO are ignored, at least I ignore page TWO and further pages. It makes less sense to comment on page TWO if there likely won’t be a reply.
There is a need to talk off topic as we see in mostly every thread.
It would be different if an old thread on page FIVE would get a new comment and then the whole thread would move up to page ONE because of this new comment. Then we could post on topic very much.
You are right, totally, it’s useless. So I tried to be concise as possible and not to elaborate.
But blaming dead pilots to whitewash big flaws or mistakes of others just makes me sick!
@Pablo: Indonesian investigation did attribute the probable cause to something like 13 factors, including airline maintenance and pilot actions–as well as Boeing–if I recall correctly.
I see difference in (well balanced) critic and blaming (with unrealistic, ungrounded claims and multilayer theories). Because biggest fail was not telling to pilots what MCAS exactly was and it was enough to extend flaps to stop it.
I hope Ethiopian crash report will bring all facts and all factors to the light, and will balance them well without bowing to anybody.
Sorry Scott, I did not initiate but responded to Philip dragging his points about the MAX into this discussion, as he already has in your next article (today’s) on the 777x as well. But I won’t respond to him in that column or in future, in deference to your wishes.