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AF447

Old 9th Jun 2009, 15:20
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@cesarnc, thanks.

I'm hoping the report will clear up the question of how they got the information that the plane was in 'hard turbulence'. If it was via ATC, then they must have been in turbulence a bit before 02.00, I think? If it was via ACARS, should that have been part of the ACARS report that was leaked, or do pilot-entered transmissions get dealt with differently? If it was, in fact, an AF department informing the crew of 'hard turbulence' ahead, wouldn't AF have expected them to change course to avoid?

[Edited to correct time.]
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Old 9th Jun 2009, 15:30
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Thanks, ELAC.
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Old 9th Jun 2009, 15:35
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Originally Posted by Dysag
LUALBA posted this morning what purported to be a dispatch from Airbus.

It included:

The data available at this stage of the investigation:
- does not suggest any loss of electrical power supply,
- does not suggest a loss of instrument display.

If this is genuine, it seems they missed an opportunity to clarify (if they know from the ACARS) the serviceability or not of the weather radar. Or do I have to decode the above? i.e. "instrument display" includes the radar?

I think far too much importance is being put on these ACARS messages.

ACARS is not required to be onboard an aircraft. It is a handy feature to have, and can be quite useful, but it is also subject to errors and failure itself. At this point in the investigation, there is no way to know how accurate these messages are.


Just so you all know:

1) Many jet airliners do not have ACARS installed or the airline chooses not use the system at all. (cost factor)

2) Many jet airliners that do have it installed do not have SATCOM capability and the system is useless over water.
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Old 9th Jun 2009, 15:40
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@DC-ATE

How about sticking to what you know?

At FL350 and 210 tons my A330-200 (slightly different engines) would have had a barberpole at M.86 of 292 KIAS and a Vls 1.3G of 241 KIAS, a spread of 51 kts. A M.80 cruise would have been at 272 KIAS and the recommended TAPS would have been 260 KIAS. At either speed there would exist an approx. 20 KIAS margin to the nearest limiting speed, let alone the nearest actual buffet speed. That's a pretty wide margin to operate within and hardly anything like a coffin corner. How much more room do you think they should have had? I'd be willing to bet your fine Deisel 8 probably didn't have as much a of margin at the altitudes you routinely chose in similar conditions, unless you liked flying around in the 20's. And if you did, I'll bet you saw a lot more bouncing around than most of your colleagues.

One could make the argument that, possibly, the incident might have been avoided if only the aircraft was flying at a higher level. FL370 would have been well within the aircraft's operating capabilities and if reports here are correct another aircraft following the same route just 10 minutes behind at FL370 reported making no more than normal deviations to avoid weather and no encounters with unusual levels of turbulence.

Was flying lower at FL350 in the junk versus in the clear at FL370 a factor? Who knows, but it's a better theory than suggesting, without evidence, that a 50+ kt. window between limiting speeds at FL350 was an insufficient margin of safety.

ELAC
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Old 9th Jun 2009, 15:44
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preliminary report

to overthewing:

the preliminary report is expected towards the end of this month, according to a BEA statement.
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Old 9th Jun 2009, 15:50
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Dont know about the 330 but on the 320 series all the power for the pitot/static and window heat is channelled through one switch on the overhead panel. Could a simple internal switch failure render all the heating to these components inop.On the B737 the same items are controlled by 4 switches.
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Old 9th Jun 2009, 15:50
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The fact is, we know from previous experience and from Airbus admission that the fin is very sensitive to excessive sideloads.
WAY back when I was flying the KC-135 (the old water-wagon in the early 70s), the dash 1 cautioned against strong inputs to the rudder noting it could induce significant loads.

It doesn't take but a casual glance to see it IS the largest control surface and thus it can create huge forces. When we were doing hard-over rudder training, it was eye-watering to see how quick a hard-over could roll you through 90deg. BIg surface.. big forces.
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Old 9th Jun 2009, 15:53
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Weather radar

LUALBA posted this morning what purported to be a dispatch from Airbus.

It included:

The data available at this stage of the investigation:
- does not suggest any loss of electrical power supply,
- does not suggest a loss of instrument display.

If this is genuine, it seems they missed an opportunity to clarify (if they know from the ACARS) the serviceability or not of the weather radar. Or do I have to decode the above? i.e. "instrument display" includes the radar?
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Old 9th Jun 2009, 15:58
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As most carriers use averages for baggage weight & passenger weight but actuals for the AirCargo units, the most likely area for weight error is not the air cargo (Frt, mail) load but rather in the bgge / pax weights. I know there is a fudge factor built into the W&B but have always wondered how close the average wt was to the actual all up load (Pax, Bgge & Cgo).
Actual cargo weights that are usually provided by the shipper.

If they are off, then the mistake goes un-noticed. I just learned of a recent air cargo shipment (on a pax carrier) that was reported under by 1500 lbs and not noticed until customs on the recieving end flagged the shipment for inspection because the wt was off.

That's just one pallet of cargo. Add that to the high probability of pax and baggage weights being off and you have a potential beginning link in the accident chain for quite a few flights every day.

I've experienced quite a few Max Gross takeoffs that barely got off the runway with two engines operating. If an engine had failed after v1, the takeoff would likely not have been successful.

So yes, it is possible that AF447 could have weighed more than the crew thought it did, but so do many flights that are operating every day.
A contributing factor? Maybe.
A direct cause? Probably not.

Last edited by Futura Rider; 9th Jun 2009 at 18:03.
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Old 9th Jun 2009, 16:01
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I would imagine that by Display the dispatch means the DMCs (Display management computers)and associated CRT or LCD displays in front of the pilots.There has never been any suggestion that these failed only the data that would normally be indicated on the screens.
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Old 9th Jun 2009, 16:06
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Old 9th Jun 2009, 16:06
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ELAC -
How about sticking to what you know?
I'd be willing to bet your fine Deisel 8 probably didn't have as much a of margin at the altitudes you routinely chose in similar conditions, unless you liked flying around in the 20's. And if you did, I'll bet you saw a lot more bouncing around than most of your colleagues.
[Thank you for your reply, but it's actually DIESEL...picky, picky]

Well, I don't know everything, but I know/knew enough to avoid areas such as the one in question by enough margin that I never really had to worry about it. Did I burn a lot of extra fuel? You bet I did, and we all got home with a safe, smooth ride. And, I did NOT choose those altitudes that did not provide the margin I felt necessary. This is far from an exact science and the sooner some pilots realize that, the better off we'll all be.

As to the remark about flying in the 20's. I once flew from ORD to LNK (about 400 nm) at TEN thousand feet to avoid the chop that EVERYONE was complaining about at just about ALL of the higher altitudes. We never got a ripple. All ya gotta do is listen to others and experience it yourself to know.

And:
One could make the argument that, possibly, the incident might have been avoided if only the aircraft was flying at a higher level.
One could make the argument that, possibly, the incident might have been avoided if only the aircraft.....had avoided the area completely.
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Old 9th Jun 2009, 16:10
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Re: Discussion of ACARS w/ Honeywell Person

RE: message 842.

Two points of interest from the Honeywell person: The messages are sequential from when the autopilot disengaged. The Pitot errors occured after the main events and could indicate that the heaters went out (electrical) or blockage (ice).
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Old 9th Jun 2009, 16:14
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@ ELAC

How about sticking to what you know?

At FL350 and 210 tons my A330-200 (slightly different engines) would have had a barberpole at M.86 of 292 KIAS and a Vls 1.3G of 241 KIAS, a spread of 51 kts. A M.80 cruise would have been at 272 KIAS and the recommended TAPS would have been 260 KIAS. At either speed there would exist an approx. 20 KIAS margin to the nearest limiting speed, let alone the nearest actual buffet speed. That's a pretty wide margin to operate within and hardly anything like a coffin corner. How much more room do you think they should have had? I'd be willing to bet your fine Deisel 8 probably didn't have as much a of margin at the altitudes you routinely chose in similar conditions, unless you liked flying around in the 20's. And if you did, I'll bet you saw a lot more bouncing around than most of your colleagues.

One could make the argument that, possibly, the incident might have been avoided if only the aircraft was flying at a higher level. FL370 would have been well within the aircraft's operating capabilities and if reports here are correct another aircraft following the same route just 10 minutes behind at FL370 reported making no more than normal deviations to avoid weather and no encounters with unusual levels of turbulence.

Was flying lower at FL350 in the junk versus in the clear at FL370 a factor? Who knows, but it's a better theory than suggesting, without evidence, that a 50+ kt. window between limiting speeds at FL350 was an insufficient margin of safety.

ELAC
And you do know the weight was 210 t? Also you do know what the precise temperature was?

Could you just for fun do the math again with 220 t and ISA+15 ?

Last edited by Interflug; 9th Jun 2009 at 16:34.
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Old 9th Jun 2009, 16:14
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Thanks Dysag.

By the way, the bomb threat to an AF flight from BA to Paris has just been clarified. A former AF employee, fired a few days before such flight, called from his cell phone to Air France office and made the threat. I came up in the local news this morning. The guy will face charges.
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Old 9th Jun 2009, 16:15
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@Chicago567
The Pitot fault is the first event. In the sequence you should read the fault messages first and the warning messages after.
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Old 9th Jun 2009, 16:17
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BIg surface.. big forces.

The roll was due to yawing a swept wing - not the rudder. Left rudder, by itself, would tend to create a roll to the right since the vert is above the aircraft Cp, or cg. The resulting roll to the left is due to yaw, or un-sweeping the right wing - increasing lift on that side, and increasing the sweep of the left wing - decreasing lift on that side. Hence the roll to the left. Works subsonically and transonically.
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Old 9th Jun 2009, 16:23
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411A;
the above statement I suspect is indicitive of a present day general lack of swept-wing aircraft aerodynamic knowledge...IE: if dutch roll conditions should develop (especially, at higher altitudes), the last thing a pilot would want to do, is have pilot applied larger rudder inputs, because....this will make the dutch roll conditions much worse, not better.
A known fact, decades ago, but I now suspect...totally forgotton, or never taught.
Concur, 411A. Seen it in major carriers as well and not just the smaller outfits. It's barely bread-and-butter training all the way down. Along with instruction on high-altitude flight, more-than-basic met (thunderstorms, windshear, frontal analysis etc etc etc), anything on swept-wing flight (what's a 'yaw damper?") and how to do a proper visual approach in a transport aircraft, I have never seen a course on radar use either. In a recent conversation with colleagues, I am informed few know how to use the B777 radar either, with recent, "interesting" results in the same ITCZ.

The lo-cost mentality now embraced by all airlines, has taught passengers to expect and demand $1.49 fares in exchange for on-time, completely-safe transportation by highly-experienced, fully-trained personnel. Those illusions are coming home to roost.

Passengers can't have it both ways nor can airline owners or managements.

The industry has driven the airline-pilot profession into a place and into such a state of disrespect and relative poverty where nobody wants to come to it anymore when there are far greener fields elsewhere with far less risk and a more secure future. "Love of flying" just doesn't do it anymore.

The industry is hiring the relatively-inexperienced-and-basically-trained because, as I said two years ago, the pipeline is drying up, and is leaving the training of these issues which rightfully belong in every professional airline pilots' toolkit, to "home-study".

This is NOT a comment on the AF crew. This is a comment on where this profession has been taken/pushed by forces and priorities which do not comprehend aviation but which nevertheless manage large airlines. Back to the thread.

All we know is, the vertical stabilizer came off at some point during the accident sequence. The evidence is, (as I posted) extremely thin so nothing may be concluded except the VS is off the airplane and intact, with rudder, with slight damage to the bottom/rear of the structure and a possible, though not proven, presence of at least one fastening lug. Hopefully photos will emerge soon and that notion can be proven/disproven.

THAT said, the presence of the lug, (should it be there), proves nothing more than "the fin broke off the airplane". Possibly, as has been suggested, analysis of the failure modes (bent sheet metal, tear lines, telltale scratches, torsion and tension fractures) done by qualified engineers may inform us further. Until then, we only know that the fin broke away. We know nothing about pilot inputs or the severity of lateral loads sufficient to break the fin off. It happened and whatever did it had severe force way beyond the design limits of this and, I suspect, any transport aircraft.

In terms of conducting a search for the main wreckage, assumptions must be made in order to use resources efficiently in the large area under consideration so it makes sense to build scenarios and assess reasonableness then begin. It is logical and not merely speculative to expect that the fin's location, given last transmitted aircraft position, winds and currents will be in the main wreckage's proximity. A "radius of action" can be maximally and minimally determined, outside of which the location of the fin would not be possible and a search conducted rationally. One expects that these processes are already either underway or now even complete and a search begun with the advertised deep-sea robotic equipment.

There remains absolutely no evidence whatsoever of pitot or TAT icing, hot-rising-air-in-thunderstorms, (anectdotal testimony is interesting but if it was that hazardous, we'd be hearing a lot more about it) and no evidence whatsoever of "coffin corner" issues. I know that specialists have contributed a great deal of knowledge regarding interpreting the messages but the ACARS messages do not place such conclusions beyond reasonable doubt. All notions remain entirely unsubstantiated theories. There is nothing anyone can post that will change this state of affairs. Because we know so little and there is so little "trace", we must demand very high standards of any new evidence and be careful not to wander beyond what that evidence can tell us directly.

ELAC;

As usual, first class call - spot on.
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Old 9th Jun 2009, 16:24
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Pinger Problems

Just FYI, the recently released CVR report from USAir 1529 notes the CVR pinger did not activate as it should have when shorted by water.

The underwater locator beacon (ULB Dukane Model DK100, s/n DM1661, battery expiration date October, 2009) did not function when tested. After shorting the center electrode to the case, no sound was detected using a Dukane Ultrasonic Test Set Model 42A12. The beacon was also tested using a Dukane Test Set Model TS100, which indicated Open Probe/Batt.
Hopefully not a problem with those on AF447.

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Old 9th Jun 2009, 16:26
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WX and ACARS

as a AF B747 captain,i do confirm that we have a dedicated weather departement which occasionaly send some infos via ACARS in case of turbulence.
the last one i received (about turbulence)was when we were heading to FAI (AK, USA).
as long i can remember it was something like;
severe turbulence forecast from XXhrs valid till XX hrs.
position X N XW to Y N YW.
from FL 250 to FL 410.
RIP
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