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AF447 wreckage found

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AF447 wreckage found

Old 30th May 2011, 19:25
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The missing cvr transcript

"Unless I missed it, nobody seems to have mentioned that the original worst-case theory--that the airplane flew into the mother and father of all ITCZ thunderstorms because it was radar-blanked by a line of cells between it and AF447--no longer seems to hold water.

Certainly 447 flew into weather that created an unusual kind of supercooled, high-altitude icing that suddenly affected the Pitots, but the CVR transcript doesn't mention anything that might be interpreted as turbulence upset--only the apparent impossibility of dealing with multiple fault warnings and anomalous displays. "

Does anybody really believe that there wasn't a lot of chatter going on in the cockpit? Especially, "What's it doing now?"

We've been given only minimal information and so far no indication that the CVR was not intact.

Another notable absence: Any reference whatsoever to the number one item: THE CHECKLIST! With everything going "off " nothing re "reset".
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Old 30th May 2011, 19:27
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An Airbus Programming Error?

Doomed Flight AF 447: Questions Raised about Airbus Automated Control System - SPIEGEL ONLINE - News - International
Gerhard Hüttig, a professor at the Institute of Aeronautics and Astronatics at the Technical University in Berlin, considers the high angle of the horizontal stabilizer to be a failure of the Airbus' electronic flight control system. Hüttig, a former Airbus pilot himself, calls it "a programming error with fatal consequences."

"No matter how hard the crew tried to push down the nose of the aircraft, they would have had no chance," Hüttig says. He is demanding that the entire fleet of Airbus A330s be grounded until the phenomenon is adequately explained.
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Old 30th May 2011, 19:35
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@DozyWannabe. TCAS doesn't receive any speed input whatsoever. It calculates closure rates based on comparing time it takes to send a signal and receive it back at the antenna.

Post amended because of bad wording

TCAS does have one air data input for Mode C (barometric altitude) coming from the Static Port. It would be very unusual for a Static Port (which is flush on the fuselage) to ice over.
So as a source of failure for the TCAS I think not likely.

Last edited by Shaka Zulu; 30th May 2011 at 20:52.
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Old 30th May 2011, 19:48
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Originally Posted by Shaka Zulu
@DozyWannabe. TCAS doesn't receive any speed input whatsoever. It calculates closure rates based on comparing time it takes to send a signal and receive it back at the antenna.
No Air Data Input.
I stand corrected - cool.

Right, so that being the case there are two questions. If TCAS doesn't require air data itself, is the way it's plumbed into the A330's avionics something to do with it? Also, at what point in the ACARS sequence did that message fire? Early on, it might raise some questions. Later, as more systems began to fail it might be a moot point.
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Old 30th May 2011, 19:53
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TCAS computation needs altitude to assess threats and should receive barometric and Radio Altimeter inputs! yes/ no?
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Old 30th May 2011, 20:19
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For those pondering lessons from this accident:

Its probably been said before in the last 55 pages but,

If you lose sensible airspeed and altimeter indications, disregard all and fly attitude and zero bank angle for normal cruise flight with relevant manual throttle setting. Been there, done that.

Try it in the sim.
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Old 30th May 2011, 20:19
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Autopilot and autothrust disengage and a/c reverts to Direct law giving immediate pitch up due trim and a/c gains circa 3,000 ft and then enters dynamic stall.
With the few precious facts that we have a this moment, why make stuff up that even contradicts those?
At the beginning of the climb:
- alternate law
- THS 3 deg up
- nose up input from PF
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Old 30th May 2011, 20:25
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If the airspeed data was erroneous/unavailable for 50 seconds or so and then became available why the aural "STALL" warning was not continuous since? I think an audible "STALL" and "SINK RATE" would be more than enough to get the crew aware. The question is: why there were no such alarms? Or why it sounded only when the sidestick was pushed forward, supposedly breaking away from the stall, or at least relieving it? Maybe I'm missing something...
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Old 30th May 2011, 20:33
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According to common logic and some data on the net, the answer must be "YES". So yes, the TCAS must have failed due to bad (inconsistent?) altitude data, but whether the data was really wrong or the source of the data just stopped functioning, is impossible to tell.

When searching the net for this topic, I came to this youtube link called "Part of the series of 32 training videos of the A320. [17] IR 1 Fault IR Dis" This video is not for the faint of heart. Captain and co-pilot are going through FIVE MINUTES of checklists related to the failure of the system providing flight data... Maybe this checklist is doable in the safety of the simulator & VFR conditions when one can see the horizon... But I don't believe such a checklist can be completed over the ocean at night, with thunderstorms around, the plane out of control, multiple other alarms and the captain not in the cockpit!!!


Last edited by ap08; 30th May 2011 at 20:48.
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Old 30th May 2011, 20:53
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@ Aeromech, post corrected because of course you are right and I should not have used no ''Air Date Input'', just no input from the Pitot probes
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Old 30th May 2011, 21:43
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@ST27
The aircraft pitched up steeply and decelerated from cruise speed to a virtual standstill in the first 30 seconds or so
There is no way an a/c at 38000 ft is going to decelerate fron Mach 0.82 to a virtual standstill in 30s. Imagine the forces on the flightcrew: why would they proceed? If they try, it'll stall well before the standstill.

The BEA report simply doesn't contain much information. Don't read too much into it.
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Old 30th May 2011, 21:51
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Undiagnosed emergenzy check-list?

I just wonder if there exist such a thing as a "stall checklist" or even a "general catastrophic -check-list" that is designed to reveal - to the perhaps bewildered crew the true state of the flight.

I'm talking about a checklist that designed to be used in the situation where the captain returned to the cockpit in this flight. The situation that he may not have realized the true state of the flight.

Take a lesson from emergency medicine (where I have some expreience) . Whenever a traumatized patients is hospitalized something called Triage is performed. To help the doctors cope with the situation a simple A-B -C -D -rule is performed. This procedure is trained regularly - so it will pop up in the minds of all involved and also direct the treatment of the patient. So here goes:
A -- Airways - - Are the airways open and and not threatened (as by unconciousness or blod - swelling /injury etc) --> if yes continue --> if No - Intubate - open airways - cricotomy --once fixed-- go to B
B: Breathing : Is patient breathing good - if yes go to C -- If no -- clear the situation --> tension pneumothorax? Collapsed lungs ? -Chest Xray- Apply chest tube
C: Circulation --> Stable blood pressure? - Signs of major bleeding?Substitute fluids/blood. Stop any major bleeding --> emergency surgery to control bleeding.
D: Disability - Severe injury? - fractures? wounds? Neurological damage? CT-scans - X-rays - surgery to treat fractures etc
E: Minor injury - can wait to diagnose and treat

This rule was invented when one realized that patients died in CT-scan- machines etc because of bleeding - instead of being brought directly to surgery when indicated

So what would be the analogue within aviation? Please notice that in this checklist A-B-C is concerned with stabilizing the patient - so he will not die within minutes. D: is only performed when A-B-and C (stability -at least temporal ) is achieved. Pleas also notice that this procedure is done with with the full attention of all involved. If the patient is stable (not severely injured)- A-B-C will not take long time to establish - it its a critically ill patient surgery for A-B-C may take lot of efforts- lot of surgery - lot of time.

May I suggest : A- for Angle of Attack?

Last edited by Ask21; 30th May 2011 at 22:08.
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Old 30th May 2011, 21:52
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Many moons ago I had a LHS pitot heat failue in an F50.
We were near top of descent when it happened, it was daylight, and I was aware of the consequences if we flew into icing.
We were in clear air, but I gave control to the F/O.

On descent we encountered a thin layer of cloud. We had no alternative - it was a continuous deck.
Within seconds of entering the layer (we went IMC) my airspeed suddenly rocketed upward toward VMO. It oscillated there for a few seconds then rapidly returned to an about normal reading.
Although I expected it, although I knew what was happening, although I had a good ADI in front of me - still - every fibre of my piloting instinct was screaming at me to pitch up to prevent the overspeed I was witnessing.

Of course, I didn't.
But - I was in daylight (even if IMC) and in relatively smooth air.
My excellent F/O was flying, and had normal ASI indications from a good pitot. Nothing had happened in terms of pitch/power changes to justify this abnormal lurch in speed, so my experience over-ruled my basic piloting instinct to react.

And we were in VMC in a minute, with normal ASI readings restored on my side.

But believe me - until you have experienced this - you will never understand the shock and disorientation it can cause.
At night, at high altitude, in heavy turbulence, with complex failures cascading through the systems and shutting down flight control functions - God help any pilot faced with this scenario. Do all the rationalising and armchair deconstructions you wish, but being in the hot seat at that fateful moment is an entirely different matter.
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Old 30th May 2011, 21:58
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Instrumentation error is less likely than stall

Jollin said
Quote:
Doesn't it seem intuitive that if a 200t jet transport has an IAS of < 60kts (and WOW says the plane is in the air), then it MUST be stalled, regardless of the AOA reading?
"No, it is just as likely (or more so) to be an instrumentation error. "

This sentence is frightening : a pilot that doesn't believe his instruments because he doesn't believe he could have made a mistake is a fool, nearly dead.

Alway believe your instruments. An instrument IS more reliable than any pilot.

The A300 lost speed for less than one minute: all others instruments were available.
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Old 30th May 2011, 21:59
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Touch'n'oops you are reading the little bus control laws. Big bus does have alt 1 & alt 2 & does not necessarily drop into direct law with gear down.
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Old 30th May 2011, 22:04
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Alway believe your instruments. An instrument IS more reliable than any pilot.
JJFC - I refer you to my post (previous to yours) and point out that it proves your statment is WRONG.

I'll say no more than that.
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Old 30th May 2011, 22:54
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For god sake!

Thousands of technicalities trying to explain the unexplicable:

- why BEA (and Air France, Airbus and ultimately the French Government) are hiding the whole CVR/FDR transcript? Why only this thin and very filtered information? What they are so affraid off? This is probably the most intriguing air disaster of the latest 50 years!

- why the pilots were unable to recognize a fully stalled aircraft and apply immediately corrective measures (valid for either a Cessna 152 or a B777, A330, ATR, you name it)? Only two explanations: a total lack of adequate training and basic airmanship or an A330 big design flaw that turns almost impossible to recover from a stall like this.

And then we'll be dealing with criminal negligence worth some billions of dollars.
THEY already know the truth and are scared about the consequences.
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Old 30th May 2011, 22:57
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Instruments vs the pilot ?

@meccano

I said an instrument is MORE reliable than a pilot.

It is a very very confusing question :

Let's say :

- the instrument is 99.99% reliable.
- the pilot is 97% reliable

You have 0.01% chance that the instrument is wrong vs 3% the pilot is wrong.

All is a question of chance. Some pilots are more lucky than the others. It belongs to the pilot to cope with the 3% or the 0.01%.

I'm glad for you.

Sincerely your's.
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Old 30th May 2011, 23:10
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One day in a Lear Jet descending out of FL410 I leaned over to balance the fuel with the FO hand flying, that was in the days you could fly by hand, and when I looked forward I notice our airspeed was approaching red line, my attitude indicator showed a right 30 degree bank and increasing and we were turning right. I cross checked the other two attitude indicators and they agreed so told my FO I have it and leveled the wiings in the clouds and it took every bit of concentration to not follow my instinct to go back to what felt level. I was actually leaning sideways to feel right but still trusted the instruments. In this case however the IAS was wrong and needed to be disregarded. Recent Airbus Pitot static problems with other flights would not let me trust the airspeed instruments in this case. I can't believe anybody would certify an airliner that is stalled but the stall warning mutes because the pitot static system senses less than 60 knots. That is nuts.
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Old 30th May 2011, 23:28
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ST27 Quote:
The aircraft pitched up steeply and decelerated from cruise speed to a virtual standstill in the first 30 seconds or so
There is no way an a/c at 38000 ft is going to decelerate fron Mach 0.82 to a virtual standstill in 30s. Imagine the forces on the flightcrew: why would they proceed? If they try, it'll stall well before the standstill.

The BEA report simply doesn't contain much information. Don't read too much into it.
I was exaggerating somewhat, since the previous poster had suggested a constant deceleration throughout the incident, and that the ride might have seemed like horizontal flight.

The BEA report states that the IAS near the top of the ballistic path was 185 kts (about mach .59), and suggested that this was an accurate speed, since the indications on two instruments coincided.

Some simple physics calculations can be made to confirm that, given that when the aircraft started the episode, it was flying in level flight and at constant speed. As a rough assumption, it can be assumed that the energy needed to climb 3,000 feet will all come by bleeding off the energy of the forward motion of the aircraft.

The calculation suggests that they would have lost about 260 kts as a result of the climb, ignoring the effect of the TOGA power that was applied for a while during the climb. That puts us pretty close to the 185 kts that was recorded. So overall, they would have dropped from mach .82 to about mach .59 in about 30 seconds.

Perceived vertical acceleration would have been something like +1.5g near the start of the climb, and +0.5 g over the top. That certainly would have been noticed by both passengers and crew.

Last edited by ST27; 30th May 2011 at 23:56.
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