This fish wrapping slease rag and the Speagle are spreading crap.

Report: Pilot "not in cockpit" when Air France plane ran into trouble - Monsters and Critics

Tail chutes are not fitted to production aircraft because of cost.

A BAC 111 was also lost during flight testing through a deep stall.

BA carried out a study with a water sprinkler system in the cabin after the airtours/manchester disaster - although it would save lives it wasn't fitted due cost.

Same as smoke hoods for pax.

money money money

AoA "input"
 

What kind of implications for this? Software, training, philosophy?

Stall Recovery
 

The relevance to AF447 is toward the end:

1979 was a bad year for the DC-10, and it was almost worse.

May 25, KORD: Engine came off AA DC10-10; all fatal.

June-July: Entire DC10 fleet grounded due to overraction to pylon mount cracks.

Aug, XMEX: WAL, Western Airlines DC10-10 landed on closed runway and collided with truck: 50 fatal.

Nov, Antarctica ANZ DC10-30 KSSU config hits Mt. Erebus; ~260 fatal; Recovered data exonerated the plane.

What didn't hit the mass media was this incident:

Aug, climb out from Frankfurt; AeroMexico DC10-30 at gross cleared to 31K feet. A/P in 1500 fpm climb mode until 27K feet, where the engines couldn't maintain 1500 fpm, so pitch increased into a full stall. In spite of stick shaker, Capt failed to recognize the extreme vibration as the overhead panels were coming down in the cabin, etc. Capt declared Mayday, and then decided to pull power on #3 engine, believing that to be the cause.

Pulling power to #3 put the plane in a spiral, which the Capt recognized, and recovered at 10K feet. He canceled Mayday and continued on to KMIA, where they discovered damage to ailerons, and the elevator counterweight horns were missing.

Departure may have been Madrid, but either way, it might have ended in a deep sea search.

So, the question: will pulling power to one engine of a big twin in deep stall help?

GB

Software Engineering/Reliability, Peter Mellor
 

DozyWannabe,

Thanks for very interesting info.

A Near Loss
 

I recall hearing about this incident a long time ago. During the testing/certification of the A-320, one of the test aircraft was almost lost. The pilots were doing some sort of testing at an altitude between 30-33K. For some reason, they got into a pitch up, wings level situation and couldn't get the aircraft to roll or the pitch to come down. Finally, they retarded the throttle on one engine to idle and the other to max thrust. The aircraft then started to roll and the nose came down. They got control of the aircraft at approximately 10K, not much room left.

GB "...So, the question: will pulling power to one engine of a big twin in deep stall help?..."


Won't that depend on how the Thrust is "Pointed"? Rudder, Elevator? As I recall, the DC10 that lost (sic) number one on TO had ample airspeed to fly its commanded AoA (By F/O). When the Captain took over flying, He could have reduced thrust on #3, and mitigated the a/c's obsession with rolling (over) to the left. As it was, Thrust was left full, and the a/c had insufficient Yaw authority to prevent its rollover to the left. There is a rumor that Captain's foot slipped a split second on takeover (The Right Foot), allowing a smidge of left Yaw, sufficient to unrecover.

This was at 500AGL on a clear day, with TWO engines left. It would at least seem after all this time that the flight crew (447) were surprised, and possibly unable to pull things together, for reasons we'll soon know.

************************************************************ ***


Beyond a certain threshold, doesn't Thrust (even power to keep 'flying') simply make things worse?

Apology for the previous interjection to a good on going discussion, but news media give me the willikers.

In a stall with a tri engine configed craft, the tail engine oomph will work wonders.
We need 411a back.

Airbus FBW EMI-resistance testing (including lightning)
 

Quote from RR_NDB:
A test 787 (ZA001) was hit by a lightning bolt and survived. (landed). During the Test phase or Certification process, the airliners are "lightning tested"?

Response from DozyWanabee:
I don't think so, but the laws of probability suggest that many a FBW Airbus model has been struck by lightning in one form or another in their 23 years of airline service and not one has fallen from the sky because of it.

This is way outside my expertise, but those of us who were the first line pilots to fly the A320 had naturally taken some interest in the subject.

My recollection is that they had parked one on the military airfield at Istres (engines running) and bombarded it with radiation on a wide range of frequencies. The flight testing had also involved flying into deliberately-selected Cu-nims on a number of occasions. The story was that there had been one or two FCC trips, but that a normal reset had been achieved.

In 14 years on the A320, I was struck by lightning on about six occasions. The worst case was on the approach to Bilbao Rwy29. We lost both Radar transceivers, and after landing there was a hole in the radome you could have pushed your head through. However, at the time of the strike, we had no noticeable electrical transients, and no failures of EIS or FCCs.

Chris

PS
DozyWanabee's post indicates that the A320's 2 ELACs (Elevator-Aileron) use the Motorola 68000, and its 3 SECs use the Intel 80186 (this was the late 1980s and PCs were in their infancy). As DW says, ELACs and SECs each have a command channel and a monitor channel. I think the software engineers writing the command channels were segregated from the team doing the monitor channels. My (no-doubt simplistic) layman's understanding was that each team received the requirements from the flight-control designers in the form of logic diagrams, using "and" gates and "or" gates. Instructions in plain English/French/German were strictly avoided.
The other key part of the A320 flight-control architecture are the 2 FACs (Flight Augmentation), which, among other things, calculate V-speeds and manage all the rudder (yaw) functions.
In my 14 years, I never experienced an FCC failure.

jcjeant,
Fair enough. What is the basis for the whole trial, then ?

And the experts are basing their findings on what ?

Ah ! And how many times that hadn't happened ? Pray tell.
The investigation is so expensive and needs to be so thorough that the BEA report is in all cases the main exhibit, as the NTSBG is in the US and the AAIB in the UK.
At the trial, parties are quite allowed to show their own evidence, but we are, after all in France and the system here is that most of the discovery has been done by all parties with the help / assistance / supervision... of the court : the instruction judge generally.
Now, whether you like that system or not is irrelevant and far better peoiple than you have accepted the French way of judicial procedures and found it fair... See for instance the people at Bielefeld University.
Of course, with an agenda and some prejudice, everything is possible.
What should be possible , too, is that people could grow up.

PJ2:
Help me here (or not).

If the ALT 2 command is already full nose down in a stall, nose down sidestick does nothing additional and nose up sidestick just perpetuates the condition??

Once again sorry if covered before.

I am intrigued by French Law. I hope that soon there will be a thread in R&N about the trial.

Evidence at Trial in the US, (US Law is based on English, "Queen's Bench"), is submitted (entered) ultimately by the Court, regardless the proffer. 'Special' or 'Expert' testimony is likewise allowed if any challenge by counsel should fail. Subsequent testimony rests on the evidence, which stands on its own.

I can't quite get what the report from BEA has that affects its proffer, and any subsequent determinations. Of course it is admissable, yes? I cannot imagine what either side would have against it. At Court it will be massaged by both, and even though the Final Report is strictly forbidden from assigning Blame, rest assured counsel will have no such sanction.

OK465 Does the Nose Down command rely on Manual trim wheel ? I recall that to reject a/c command for nose up, the sidestick has to be pushed fully forward to trip it? Then manipulated in concert with a recovery ?

Speculative thoughts about a gyro-stabilized a/p reversionary mode.

I find it interesting that (if I understand things correctly) if two of three air data units malfunction, the autopilot disconnects and demands that the plane be hand-flown, just when the essential airspeed data is unreliable.
What if the autopilot in that case would revert to use inertial (gyro) data as autopilot input?
(As the quote above illustrates, a dangerous pitch-up could be eminently noticeable by anyone in the plane - except the pilots, who potentially may be so fully concentrated on deciphering the ECAM messages that they fail to notice the g or pitch increase.)

It would not be rocket science to design an inertial data driven reversionary a/p mode, which might even be automatically activated in case of an unreliable airspeed indication. Just to keep the plane on a steady pitch angle while the crew sorts out the problem.

Those modern inertial data units or "gyros" measure both turn rates and linear accelerations with high precision along all three axes, so it seems at least theoretically possible to have such a unit drive a stable 1-g flight path also without airspeed data.

I realize turbulence may lead to potentially dangerous airspeed over/underspeed excursions, as a pure inertial system would try to keep the speed over ground stable. The most obvious remedy to that which I can think of would be to descend to a slightly lower altitude using e.g. GPS as altitude source, to get more speed margin. If necessary e.g. due to weather ahead, do a 180 turn.

It seems that most (all?) serious unreliable-air-data incidents have to do with iced-up pitot tubes, which however is usually a temporary condition. This reversionary mode could help keep the plane in control until the ice melts and air data comes back.

Any thoughts? Or is this capability already existing?

Lightning bolts to "electronic" a/c´s
 

Hi,

The lightning generates a broad spectrum of RF. We can "hear" it in the NDB and in the VHF, etc. The EMI/EMC issue is important and we can easily imagine the intrinsic susceptibility of circuitry to "interference". The Istres testing was for this. Also observing, FADEC. This was for radio "interference".
The ACARS (now two, after mm43 post) perhaps indicating a buss fault warned me to remember a training i had in PHX area on this subject. Don White also told about Tempest, a classified content. The EMP (electromagnetic pulse) of the lightning has a steep rise of energy in time. Worse is the nuclear blast. It´s EMP could destroy the "front end" of a HF receiver (connected to an antenna) hundreds of miles from the blast.
But the lightning also carries "high current". We can "see" it in the flash.
My comment was about the current in the nose of a highly electronic a/c is like when we was in a C47 hit by a cloud-cloud bolt (i remember the ozone odour and the noise) at FL 080. The theory is that the "static current" flows outside the fuselage. But the holes we did see in the skin (thin for high currents) may suggest some energy "enters". And there is some "induction inside" the fuselage. (the fuselage like a coaxial cable receiving current in it´s shielding). I respect a lot this issue. High energy involved. I did see a gas station pump, knocked out by a bolt. And the road ahead a car of a friend "melted" before raining, etc. How many times displays "flickers" when crossing electrically charged space? Anyway the design (shielding, spatial redundancy, etc) and the statistics like commented earlier are an important argument that the issue is "under control".
Theoretically this would not occur. So...Better to stay away the phenomena when possible. After the "testing" the 787 was "reinforced" in this aspect. I heard of IIRC a F28 that lost hydraulics after a bolt. (with currents flowing in the "wrong circuit") And big planes crashed as a result from ignited vapors in fuel tanks. (L188, 707 and a 747)

The "testability" of this kind of susceptibility is a problem. No "man made generators" available. New designs, "composite intensive", requires attention.

Sure they are. Every high tension test site has them, since high voltage surge protectors need to be tested too. The general lightning bolt shape with rise and fall times and current range 10kA to 100kA is well understood. There is a physical mechanism in place which limits the rise times and the bandwidth of a lightning bolt. So testing is not that difficult but might be a bit destructive on the airframe.

Positive Lightning
 

That would not be sufficent to test the effects of positive lightning on an aircraft , it is up to ten times more powerful than negative lightning (95% of lightning is negative lightning)
NWS JetStream - The Positive and Negative Side of Lightning

They got control of the aircraft at approximately 10K, not much room left.

Occasionally it is apparent that death is looking the aircraft's crew in the face .. at which stage to try anything with a chance is better than putting one's head between one's legs ...

This is the characteristic of the traditional pilot .. not to give up and wave arms around in frustration... even when it is obvious that the die is cast with no chance of rectification ...

stick technique
 

Chris Scott's notes on sidestick technique are worth a read even for non-FBW pilots.

Well I don't know about +ve/-ve lightning [actually I do ;)], but in an Airbus context, I clearly remembering watching test/development aircraft MSN2 fly directly into an intense squall line shortly after take off and receive 5 visible strikes before it was enveloped in the cloud....... 43°39'1.63"N 1°20'6.37"E....

which I guess was the point!

'twas a cold, humid evening coming from a warm afternoon...

bearfoil:

Automatic pitch trim is available in alternate law.

Are there are exceptions to this in alternate law? Somewhat ambiguous in syntax as the word 'always' is not used. If there are times when it is available and times when it is not, you could use this phrase. If it is always available you could also use this phrase. (Could it be available and not active?)

Assuming it is always 'always available' you bring up a good question.

When the low speed stability function is progressively commanding nose-down elevator, what flight condition is the THS being automatically trimmed for?

I'm pretty sure in ALT 2 with dual ADR failure in a stall when the pilot manually rotates the pitch trim wheel it will remain where the pilot leaves it. (Would you get a USE MAN PITCH TRIM on the PFD like in Direct Law?)

But I'm willing to entertain the "you don't have a clue" inputs from more knowledgeable Airbus experts. I have a thick skin and learn from my mistakes.

Search Area Refinement
 

Additional to 'noske's post 1915
Anyone interested in the detailed analysis used to refine the search area should see:

http://wwz.ifremer.fr/lpo/layout/set...A9mentaire.pdf

OK465

Thick skin also, but the brain has some catching up to do. I know the pilots of A330 here are top notch, and most of this is well above my head, but I get the definite feeling that if not completely conversant with the Law, a guy could get real behind, real quick, and perhaps not even be aware of how far behind until the thinker goes to overwhelm. I'm sure it's just me, and my archaic skills.

I am so waiting to hear from the pros here when the data hits the fan instead of the s. Perhaps at that point we can truly appreciate their (your) presence here. TurbineD, PJ2, Hazelnuts39, takata, Chris Scott, gums, Machinbird, Smilin Ed, Tubby Linton, mm43, y'all know who yar.

No bear, a telling post indeed, considering what has already [supposedly] been revealed of the flight deck composition, pre disaster.

My Wild Speculation
 

Basically everything working well: the radar and crew spot a wet cb and avoid it, perhaps even begin to think they have gotten through the ITCZ.

The radar and crew do not see a humongous dry/ice crystal updraft and fly into it. The temperature is so much warmer than standard that the a/c stalls somewhere in the updraft. Pitots may or may not be clogging while this is happening.

I am waiting for the BEA to learn how this or a different situation was handled by the crew.

Once both engines stall because because of high alpha, pulling one back to idle will not induce a roll.

.

AFAIK this is untrue. The last report I have seen they have not be able to duplicate the anomalies. They do not know if the ADIRU was a dud, if there was some outside interference, or what.

Radar capability
 

Barely detectable?
Simple model!

Not familiar with the cockpit door position of the A330 WRT the galley, but given the FOs were reasonably experienced, hearing the cabin call and/or loud banging/shouting on the cockpit door could easily have prompted one of them to open it normally. The A330 is a big aeroplane: it wouldn't have been being thrown around like a Pitts (it would have come apart before then). Is it conceivable the FOs let the captain in as soon as he arrived at the door and created a ruckus (assuming that they didn't think a hijack was also in progress...)?

It is true. Read the reports. Why ADIRU 1 put out spurious signals is irrelevant: the system didn't isolate it and the pilots could not control the aeroplane... twice.

Lightning
 

Hi,

EDLB

For components test, not an entire a/c. Do you have example(s)?

I prefer destroy It during testing than in real operation. And you can increase the pulses adaptively observing the test results. I suspect the a/c manufacturers just check compliance to rules, etc. I don´t like this.

donaldt

Impressive information; In one mission of STS they studied the phenomena with impressive findings. Very long bolts, etc. Frightening.

Some interesting info. on lightning in a/c:

triple whyskey dot niar.wichita.edu/agate/Documents/Lightning/WP3.1-031027-043.pdf

Posting just to close the issue unless something related is reported by BEA.

It's false. I went back and read the reports to refresh my memory. I don't know where you get the idea the the design of the ADIRU was supposed to isolate the spurious signals, but that's wrong too.

As for whether the ADIRU was a dud the 2nd Interm report clearly states it was not.

As outlined in the first Interim Factual Report, the ADIRU (serial number 4167) and an exemplar unit were subjected to a range of tests and examinations, and no faults were found that provided any information relevant to furthering the understanding of the accident.

http://www.atsb.gov.au/media/1363394...8070_ifr_2.pdf

NWR
 

Thanks for posting the link to the Ifremer report.
Quite technical but pretty interesting.

That's another evidence to which length the BEA was ready to go to find the wreckage (sorry for our beloved conspiracy theorists who are sure that the BEA / AF /AI do not want the wreckage to be found :ugh:).

bearfoil

Presume you are referring to the DC10 at Chicago.

If my grey cells are still functioning correctly...

The DC 10 had no protection on the slats for hydraulic failure.

When the engine disappeared over the wing it took out the hydraulic lines which allowed the slats to retract.

The crew had no knowledge of this and rotated the aircraft to obtain V2+10 which was below the stall speed of the wing on the side where the slats had blown back into the retracted position.

Not very dissimilar to the Trident captain who didn't notice that the droop had been retracted and after stick push recovery went back to try and fly V2+10.

Another question. In the 80s there was talk of fitting A of A indicators to civil aircraft - did it ever happen?

Phew!...after reading a lot of rubbish on prune over many years this thread of 100 plus pages is the biggest load of nonsense I've ever read on prune... this has to take the cake!
A complete waste of space from technical nerds who haven't got a clue what the hell they are talking about!
A load of nonsense from ancient aviators who flew F14s, Vipers or other military types that have NO RELEVANCE WHATSOEVER to this prang!
Chris Scott, an A320 driver, is one of very few current pilots on this thread who knows what caused this prang... as most current professional pilots do!
Wannabe pilots who never made the grade, and want to tell pro's who did cut the mustard how to do it, should listen to what Chris and his fellow professional airline pilots have to say!

Wiring fault
 

RR-NDB wrote and quoted one of my posts :

RR-NDB, there are two very different considerations related to this wiring fault. The first is why did it happen ? Your question. The second is what are its consequences ? My question.

As to your question, lightning was suggested quite early after the accident in June 2009 by Mr Feldzer. I do not believe it. Coincidence is too great. However, a software versioning compatibility issue would perhaps fit the bill.

As to my question, takata, in an uncharacteristically broadly sweeping answer, made a reference to BUS 2 and BUS 1. Takata, would you care to enlighten us on this BUS structure, please ? Just how many BUSes are there on them 'Buses ? And more importantly, how do they connect all relevant computers (ADRs, FCPCs) together ?

Takata, PJ2, Lemurian, mm43, and other knowledgeable individuals, please tell us, could multiple FCPCs retain their own personal flight law, differing with their "clones" ? What would a trio of clones become after a highly suspicious wiring fault affected only one of them ? What do you make of an airspeed probes fault appearing near simultaneously with a wiring fault ? What becomes of redundancy in this cr@ppy situation ? Why is there no "ADR 1(2)(3) FAULT" message in the sequence ? Why is there a PRIM1 FAULT and no PRIM2 FAULT ?

Best regards

PS : to all who take the time to read my modest posts, thank you for your patience. Please understand that my attitude here is about working with available first-hand evidence only. And so far, ACARS sequence is one very good source for such. Primarily, a maintenance sytem will not tell about crew deficiencies, only aircraft deficiencies. Thus, the reason why I appear strictly one-sided at this time.

...and I rest my case! :ok:

...and I rest my case!
 

Too bad. We thought you might enlighten us. :E

Mr Optimistic, I'd not be at all surprised if the BEA and other organizations have at their disposal a tool that "plays back" the FDR recordings into a video animation of the plane and the cockpit.

If they don't somebody should write such a tool.

QF72 interrim report 2
 

Cited from the report:
"As outlined in the first Interim Factual Report, two significant safety factors have been identified with the aircraft’s systems:
• an air data inertial reference unit (ADIRU) provided erroneous data that was not detected by the ADIRU itself
• the flight control computers did not filter spikes in angle of attack data in a specific situation.
The investigation is examining the context and origin of both of these factors."
It looks to me that the ADIRU is still suspect although the problem remains undetected..
However, more interesting, and perhaps relevant to AH447, is the fact that a program update brought an earlier unidentified bug into operation. There is a remote possibility that the software running on the computers on AF447 was a unique combinations of updated and un-updated programs leading to a unique system behaviour in comparison with other flights having speed-measurement problems.

Safety Concerns, your post brought me back to one of my hobbyhorses, the plane being out of communications.

Suppose the storm looked too large for them to go around without contacting DAKAR. That could lead to their trying to thread a hopeless needle and eventually going down.

Revealing such an assumption most likely will lead to an international incident. So it needs to be nailed down tighter than a drum before they release it in particularly delicate language.

This could be getting quite interesting to watch. DAKAR would no doubt point to Brazil's failing. Yet, DAKAR had the final responsibility here.

(I believe planes have dual HF radios. One should have been on Brazil with SelCal on. The other should have been on DAKAR with SelCal on after an alert to DAKAR they were coming but not in DAKAR's region of concern, yet. I tend to believe in "communicate early and often.")

Ref this post my limited knowledge of cutting code suggested that the sentiments were a bit optimistic. A specialist colleague provided the following commentary as an observation and invited me to post it for information.

"The contributor who goes by the name of syseng68k has a rosy, and, I fear, misleading idea of the quality of software and software development. It is not error-free, even in critical systems. There is probably no substantial system (of the order of tens of thousands of lines of code or larger, the size of all flight control systems in commercial aircraft nowadays) which has ever been built that was or is error-free. For the state of the art, see the last paragraph.

I have worked in the reliability and safety of software-based systems for a quarter century, am a member of my country's standardisation committe on functional safety of computer-based systems, have an international reputation in the field, and indeed shall be giving a keynote talk at a major international conference on the subject later in the year.

A famous study by Robin Lutz of Iowa State University twenty years ago on the source of about 200 mission-critical software failures for NASA showed that over 98% were due to the requirements not covering adequately the actual situation the system encountered. (syseng68k prefers not to call these "bugs" but most people working in ultrareliable software do.) A more recent study by Lutz and Mikulski from 2004, published in one of the premier journals for software engineering, may be found at http://www.cs.iastate.edu/%7Erlutz/publications/tse04.pdf

There is an enormous variety of problems with computer-based systems in aerospace contexts, the number of incidents is clearly increasing, and I fear will continue to do so. A check of Peter Neumann's "illustrative risks" Section 1.6, Commercial Aviation, gives some sense:
http://www.csl.sri.com/users/neumann/illustrative.html#9 The Risks Digest archive is also available on-line at http://catless.ncl.ac.uk/risks

Kevin Driscoll of Honeywell, along with Brendan Hall, Hakan Sivencrona (of Chalmers Institute of Technology) and Phil Zumsteg, published a paper recounting a so-called "Byzantine anomaly" with the FBW control system of a major airliner, that almost caused the airworthiness certificate to be withdrawn:
http://www.cs.indiana.edu/classes/b649-sjoh/reading/Driscoll-Hall-Sivencrona-Xumsteg-03.pdf
Driscoll gave a recent keynote talk at SAFECOMP 2010, "Murphy was an Optimist" on such kinds of failures, which are ongoing.

Estimates by colleagues who know put the general coding error rate in safety-critical software at about one error per 1,000 LOC (lines of executable source code). Obviously, this is a very general statement. How often behavioral anomalies are triggered by coding errors depends of course on the operational profile of the software. For example, the bug in the configuration control software on the Boeing 777 aircraft was present throughout the lifetime of the aircraft but only manifested after a decade of line service http://www.atsb.gov.au/publications/investigation_reports/2005/aair/aair200503722.aspx and recent anomalies, also triggered by issues with ADIRUs affecting the primary flight control, in Airbus A330 took a similar length of time to manifest : http://www.atsb.gov.au/media/1363394/ao2008070_ifr_2.pdf

There are some companies, such as Altran Praxis (formerly Praxis High Integrity Systems), who have instrumented their error rates and demonstrably achieve much lower rates, of the order of one error per 25,000 LOC. Altran Praxis have recently engaged on the Tokeneer project funded by the NSA, whose object was to develop error-free software http://www.adacore.com/home/products/sparkpro/tokeneer/
Despite apparent initial success, five errors were eventually found:
http://www-users.cs.york.ac.uk/~jim/woodcock-hoare-75th-final.pdf (note, this is a paper for a celebration of the 75th birthday of a UK pioneer in reliable software technology, Turing Award winner Sir Tony Hoare, co-inventor 40 years ago of the original method for mathematically proving that sequential programs do what they are supposed to do).

Summary: Five errors is as good as it gets in software with many tens of thousands of LOC. This is the order of the first civil aircraft flight control systems a quarter-century ago (Airbus A320, 1988, about 60,000 LOC). However, since then the size of the systems has increased by two orders of magnitude, and of course they are also very highly distributed, which brings many subtle additional sources of potential error into play (e.g., Byzantine failures)."

"Wiring Fault" ?
 

Svarin:

From BEA Interim ACARS report:

ATA: 279334
Source: *EFCS1
Identifiers: *EFCS2
Class 2, HARD
This message indicates that FCPC 2 no longer considers as valid the information that is
delivered to it by ADR 1 (via bus 2). The ATA code beginning with 27 indicates that the fault was not detected by any other FCPC during the three seconds that followed (otherwise this message would have been classified ATA 34). This message has not been fully explained at this stage of the investigation.


In my knowledge the slash "/" is used when an ambiguous fault occurs.
Up to 3 possible failures may be indicated with the most probable possibility on the left. (FCPC 2 FIN 2CE2)

A "+" sign is used when there are multiple faulty components involved.

No!, only 1 FCPC or FCSC is in control, this will be the FCPC(FCSC) which has the highest level of law (The Master), Normal order FCPC 1,2,3 FCSC 1,2.

The Master transmits it's deflection orders to the other computers, which executes these to their own sets of servo's.

A FCPC is able to engage Normal law(all protections), Alternate Law(reduced protections) and Direct law(No protections), FCSC can only compute Yaw alternate law and Direct Law.

After Loss of normal laws the reconfiguration of control laws is different for the pitch axis and for the lateral axis.