RR_NDB

Hi,

The System could also provide good news to the crew.

May be (the System) should ASSERTIVELY inform to a hard working crew submitted to uncertainties (as in Thiells B727 and AF447) IMMEDIATELY when the Air Speed (and related indications) became reliable again.

IMO UAS and Reliable Air Speed (RAS ) should not be programmed by Designers as a System "inside information". Better to communicate BOTH.

The anomaly came from just the sensors (OBSOLETE). Not even (caused) from ADM, etc.

The confidence in the System (of great importance) MUST BE PRESERVED!

("Good news" in Easter day )

Lyman

"Guarantee?" Yes, you'll want marketing, down the Hall, but they're out golfing.

AlphaZuluRomeo

@ RR_NDB:
While I agree that the system could also provide good news to the crew, I don't think your example is pertinent.
Indeed, the system has to be sure of itself to provide news (particularly good news such as: you now can rely on...)
The current logic is: The fact that the 3 airspeed sources give ~ the same value is an indication that this value is correct as long as no error occured.

As soon as an error occured (and until a system reset on the ground, with a check of its sources), the system is no more able to determine if what it "senses" is true or not.
You can easily imagine that 3 frozen/clogged pitots will at some time indicate ~ the same (incorrect) airspeed value. It would be very dangerous to rely on that (incorrect) value.
I know that ice eventually melt, but ice is not the only potential problem encountered by the pitots. What about volcanic ashes, for example?

Hence it's far safer IMO to let the crew do its job, as pilots: Assess the failure, eventually see that the values ​​seem correct again and decide to give them (or not) (limited) confidence. In the mean time, fly pitch&power, which can be done without relying on airspeed indications.

Regards.

Mac the Knife

Stunning discussion by some very smart people. Puts me in mind of "Dark Star".

"No, no, Doolittle, you talk to it.
Teach it Phenomenology, Doolittle."

CONF iture

As you know ... I sincerely disagree here, the sidestick vs control column argument is a serious one and cannot be discarded from the equation that helped to the final result.
I would agree the argument is not making a difference regarding the initial pitch up as the displacement of the sidestick was limited as would have been such displacement of a control column, but the difference is later on especially when the cpt came back.

Lyman

When he was telling Bonin (PF) CLIMB!, what was the other pilot seeing? BECAUSE, as we know, BONIN was holding NOSE UP, he said so. He was PF, and yet the other pilot said CLIMB? Didn't HE SEE THE DISPLAYS?

"But I have been holding NOSE UP". Tell us again the displays were working?

Why did PF have to TELL anyone he was commanding NU?

This tells us Number One: No one knew (except RHS!) RHS STICK POSITION.

NUMBER TWO, with the a/c commanded NU, how did the others not see this on the displays?

NO ONE knew the attitude. For THREE, BEA stays quiet after ""I have no displays" (When Captian enters). We must assume NO DISPLAYS came back, ever.....

PILOT A: "Climb, Climb"

PILOT B: "NO, Do Not Climb"

PILOT C: "But I have been holding NOSE UP for some while"

None knew attitude. What display?

These are discussions of what they should do with the CONTROLS. And they are clraerly confused. FOR ONE, they know they are plummeting down, For Two, they are guessing at which way to cammand the NOSE. How can PNF tell "CLIMB", if he know the a/c is PITCHED UP at 17 degrees? The displays are not working, and they are trying to suss anything that will stop the descent, without knowledge of NU, clearly.

roulishollandais

AT THE TOP OF THE EVEREST OF MAN-MACHINE INTERFACE , I pay tribute to TEST-PILOTS , and TEST-INGINEERS who offer their lifes to improve Air Safety, and I also pay homage to TEST-PARACHUTISTS WHO TEST THEIR ZERO-ZERO EJECTABLE SEATS at price of their own health.

Maybe it is the worst fault of Airbus to have used airline pilots to test A330 also killing the test-pilot Nick Warner, and passengers confronting stall in AF447.

1994 A330 test flight crash - Wikipedia, the free encyclopedia

AlphaZuluRomeo

roulishollandais,

I cannot distinguish many similarities between the crash of 1994 and AF447. Care to elaborate?

I sincerely hope I misunderstood your point, and that this is not (airbus) bashing disguised as a tribute (to test crews).

PS: Do humans still test (0/0) seats? Last time I checked, dummies ruled.

RR_NDB

Quote:

I don't think your example is pertinent.

I will comment reasons to mention these flights in the example:

1) PF's stalled their planes

2) Pitot's issue triggered the sequence of events

3) Stall caused LOC or (non recoverable situations)

4) They didn't identified AS issue (due icing)

5) Redundant indications were not enough. Result: Confusion and misleading

(In Thiells case a misleading was obvious. In AF447 "lack of minimum understanding" seems a fact. (based in what we have) Confusion seems to be resulted. When you are fed with REDUNDANT erratic indications a "misleading" occur: Reduce (or destroy) your confidence in the System you is operating. And open new possibilities.

Yes, there are some (imo minor) differences, i agree: 727 heater off, 447 obsolete Pitot's, 727 stall then LOC, 447 full stall: net result, an amazing* LOC. This 2 crashes has IMO more commonalities than other possible examples. Yes, every accident is unique.

AZR, i am "technically oriented". But, this "non technical value" (confidence) is of extreme importance. I don't like the scenario of a crew with no confidence on the "interface" (even partially). This is very dangerous and can led to "dramatic" possibilities.

It would be very interesting to understand the current approach in "detail" (algorithm). Can be in "managerial" level. An outline. Maybe A33Zab could also help on this.

I may ask: Why? Frankly, IMO there are better approaches. This "long latch" (long outage) and "reset on ground" tells me: Room for improvement.

DSP techniques (very common) and good algorithms solve this easily. Typical engineering problem that instrumentation (industrial) engineers has full capability to deliver "State of the art" implementation. No problem! Remember, you process the signal (normal), the onset of "garbage generation and the recover of the Pitot's normal operation. (447 case). In Thiells 727 perhaps plane crashed with 3 tubes frozen. (we don't know). An interface probably never would provide "good news".

Good question. Before clogging (i mean, during transitory) DSP easily detect. Probably tubes will be no longer operational, thus creating a more serious scenario. Fortunately NOTAM's solve this. There is no "instant" ash. like 447 crew faced after entered WX. So, ash, no problem: Same DSP, same approach. (long latch for other reason)

I will continue (editing) in few minutes. But i anticipate: "Globally speaking" i.e. looking to all factors (reliability, crew "workability" on the issue (assessment, cross checking (as mentioned paper put) my feeling is: Better to review current approach.

As lomapaseo IIRC well put (as i understood his post). WE could, should (quasi must) post our engineering POV. Safety is our ultimate goal. (It's my agenda, my reason to think, to analyze, to read, etc. here in PPRuNe)

* The AF447, LOC seems unique in (commercial airliner) aviation history. No abnormal attitude, and only a long and slow RH turn. (Even "G protected" during the zoom climb), Indeed unique? I don't remember nothing similar. (Unless the ROD is considered an abnormal attitude, may be of a new type )

Organfreak

This link shows much more detail about what went wrong. Draw your own conclusions as to what Mr. Hollandaise had in mind:

ASN Aircraft accident Airbus A330-321 F-WWKH Toulouse-Blagnac Airport (TLS)

RR_NDB

Hi,

Mac the Knife

"Dark Star"

CONF iture

Thanks for your PM Lyman.
I can't tell there was an issue with the attitude indicator(s) but it is a possibility there was one or they thought there was one as they choose to manipulate the ATT HDG switch or is it the way it is teached at airfrance to turn simultaneously both AIR DATA and ATT HDG switches ...
For sure there was confusion, big time, and those invisible sidesticks just contributed to that confusion.

CONF iture

It has been suggested by the BEA that On n’a pas une bonne annonce de… et … de vitesse were going together but most probably they don't as they are separated by 4 seconds and the translation made is incorrect : Usually une annonce is not a display but an announcement made through a public aural system.

Annonce furtive ou persistante "STALL" (Appendix 3 in IR3)

IMO the PF was telling that the STALL WRN that came up one second earlier was a false one.

jcjeant

Hi,

This is not the first time differences (significant) were detected between the versions (English and French) in the preliminary report No. 3 and cause confusions
Announcing and displaying are two different things with different meanings
So .. what is the true word ? the one in the french version or the one in the english version ?
It does not add anything positive to the professionalism of BEA when it comes to communicating
It seems amazing that BEA can't ensure the service of a translator familiar with the aeronautics language as they have sufficient funds
It will be interesting to scrutinize carefully the two versions of the final report (if it is translated into English)
BTW .. stay that the BEA is french and so the original publishing (in french) must be considered like official release

RR_NDB

Hi,

CONF iture:

I will comment on that (well observed and likely) probable fact on:

Man-machine interface and anomalies thread, on the ramp "being fueled".

Mac

I hope the improvement of "interface" crew currently use in "advanced planes" (all types) in the aftermath of AF447 HOW, WHY, analysis and subsequent "works".

* Albert Schweitzer

AlphaZuluRomeo

CONF iture, jcjeant,

"On n'a pas une bonne annonce ... de vitesse" cannot imply anything else than a display AFAIK. What do you have in mind, regarding an "announcement" ??

I agree that the term is not the more common in french ("on n'a pas une bonne indication" seems better suited) but remember it was the middle of the night and the beginning of troubles. Using "une annonce" in place of "une indication" doesn't surprise me that much (french is my native language).

I really don't think the BEA is to blame, here, unless wanting to quibble about everything it writes.
I insist on here, because sometime translation issues are real, and may lead to misunderstanding and/or nonsenses.

RR_NDB

I hope this is being addressed by BEA with the right* emphasis.

"but the difference is later on especially when the cpt came back."




* right means, IMO relevant

roulishollandais

May be they no more do. I thought in the 90's it was already the case., But I had to wonder one of my friend, CLAUDE JOHARY, had to test a Mark-IV (type to be confirmed) from the ground. After what I had some problems with his back, and could no more apply as astronaut. He died in 1995 as passenger.
MS.760 Paris 11 Octobre 1995 - Uzech - Arostles

The ONLY similaritie I want to point out is the non adequate man on the non adequate place ; and that concerns HMI.

A33Zab

If i understand your question correctly,

'Good news' is if ECAM message/action is properly handled, understood and cleared by crew.

VERY good news is if ECAM message or FLAG is cleared by the system itself because that means the anomaly is not present anymore.

For the speed indication it is more difficult:
but they are in view (ADR 3 standy/isis and selectable to show on any PFD)
so if they are consistent again after anomaly the crew will know UAS is not present anymore.

HazelNuts39

An 'annonce' can be in writing, e.g. the small ads in a newspaper. Good point, nevertheless.
Found this in the "Lexique-bilingue" on the Dassault-Aviation website:

ANNONCIATEUR DE MODE DE VOL: FLIGHT MODE ANNONCIATOR (FMA)