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AF447

Old 23rd Jun 2009, 07:29
  #2181 (permalink)  
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Weapons_hot and Woodja51

While most certainly a lot of colleagues may agree rather silently with your outspoken assumptions, this is not solely a longhaul problem. On short- and mediumhaul the situation is very similar. However, the nature of short- and mediumhaul allows for a more quicker build-up of "hands-on" experience.
There was, while aviation was definately something different as it is today, the rule in the major field players manuals that the way to longhauls office chairs has to start on shorthaul and with a visit for some time on the mediumhaul fleet.
Things have changed and may not everywhere the same anymore.

Comming to the point of this, with the unease you mentioned in your post, would anyone expect to find the captain in bunk while crossing the most challenging part of the journey?
Guess not!

Let's wait for the boxes to tell us more.
 
Old 23rd Jun 2009, 07:41
  #2182 (permalink)  
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I would opin that the unease experienced by 'experienced' captains is not due to a perceived lack of experience in their FO but from their own lack of experience in temporarily handing over their responsibility.

An analogy might be when you let someone else drive your car no matter how experienced they are.
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Old 23rd Jun 2009, 08:50
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If the posts of Woodja51 (#2199) and Weapons Hot(#2205) turn out to be on the mark, then it would show a major flaw in the “Cruise Captain” concept for long haul flights. In fact, in many airlines, cruise captains have almost zero experience of manual flight from the left hand seat, and that manual flight experience would very likely be only in the simulator.
Perhaps at the time of dividing up and allocating “on seat” and “rest” periods among the pilots for the flight, that part of the flight which eventually proved to be most critical was not considered to be likely to be the most challenging.
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Old 23rd Jun 2009, 08:56
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But a spokeswoman from the BEA, the French air accident authority, noted that many sounds were picked up on the sea bed and investigators were not sure that what they had detected was from the flight recorders.

"It's not the first time sounds have been heard and we will be verifying this with all the equipment we have at our disposal," she said. "The search is continuing and we haven't found the recorders."

An Air France spokeswoman also said she could not confirm the newspaper report.

Le Monde said French naval vessels had picked up a weak signal from the flight recorders and that a mini submarine had been dispatched on Monday to try and find the "black boxes" on the bottom of the rugged ocean floor.
Not yet, not yet !
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Old 23rd Jun 2009, 09:03
  #2185 (permalink)  
 
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thanks for info

To those who threw me the info on the copilots experience, thanks - perhaps lost in translation but I was not casting aspersions merely observing what seems to be a common trend in modern aviation.

That is, the lack of hands on time when it really matters. Be it SOPS and automation, modern aircraft being so good etc etc.

I see that I may have some followers in what I was trying to say albeit poorly.

In as much as when something goes wrong it sometimes is better to 'wind the aircraft clock' as the memory item/checklist....then action the event... ( ooops can't wind the Breitling any more .. all GPS updated.. but you get the idea.)

Sorry for a bit of thread drift , By the way, here at EK they have just increased the experience levels for command. But as some of the F/Os have pointed out it seems that in our case we can have cadet pilots get command status ahead of other chaps based purely on hours with the company - and that experience gained from the school of hard knocks be it G/A or military is soon to count for very little. Some are excellent pilots, no mistake but have not had the benefit of lots of hands on/sectors etc.

It is this perception of hours actually meaning something that is the root of some of the problems aviation faces.

To the uninitiated, having 10 000 hours must mean that you are twice as good as someone with 5000 hours.

Guess reading 'fate is the hunter 'gives a better sense of what experience really means?

A pilot doing the same thing for 10 000 hours is not the same as doing a different thing for an hour 10 000 times .. you get my point.

As far as inflight rest goes, (at least in EK )the captain is not allowed to rest in first class when there is a bunk - located in the aft of the aircraft too....( yes I know captains prerogative and all)

But if I think that the F/Os are not up to speed to do an Atlantic crossing at night, avoid weather etc, it is time to chuck it in.

Anyway, I hope that some light is shed on the cause ( maybe B/B's found?) as otherwise nothing will be learned from the loss of so much life.

W
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Old 23rd Jun 2009, 09:37
  #2186 (permalink)  
 
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Questions and answer about pings in water

Please be aware that the pings are acoustic (sonic waves) and not electromagnetic (radio waves). Water is not an ideal isolator, any electromagnetic emission is absorbed within very short distance.

Sonic (audible) pings have a carrier frequency in the low kilohertz band, ultrasonic waves may go up to 100 kHz. Modulation of such a "carrier" is physically possible but technically not feasible, since the "carrier" signal is far too weak to carry any useful and detectable modulation. In the deep sea, sonic waves do not propagate easily, they get deflected and echoed by changes in water temperature and density anomalies. But even if that problem would could be overcome, any modulated data transmission rate is intrinsically limited to a fraction of the carrier frequency, in an underwater application to something like a morse or telex transmission.

That's why the black boxes cannot transmit any data.
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Old 23rd Jun 2009, 09:39
  #2187 (permalink)  
 
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Pt probes question. In this AF note we read [my own rough translation] "March 2009 [...] Airbus recalls the procedure for maintenance and verification of the probes". The note does not say what anomalies (if any) were ever found during these checks. Could someone explain the procedure? In particular, can the drain holes be inspected visually on the ground, and how often is this done? Somebody mentioned the possibility of obstruction caused by corrosion; so this problem - if present - should persist long enough that it is detectable on the ground.
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Old 23rd Jun 2009, 09:45
  #2188 (permalink)  
 
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Hi,
PJ2:
Now it makes sense to talk about a "cabin rate of climb/descent" and one can readily see now why a cabin rate of climb of "1800fpm" up or down, is not only excessive, it is an indication that the CPC is not able to control cabin pressure, for whatever reason.
[...]
We cannot know the full meaning, (ie, was this a depressurization, a CPC fault or...?) of the advisory but we do know that at some point the fuselage/cabin structure was compromised/breaking up, at some point between 350 and sea level.
[...]
ACLS65:
Do you know if the ACARS msg corresponds to the Max Differential Pressure Limiter Function limit being hit or Cabin V/S 1800+-fpm?
Unless I have missed the interpretation of the ATA code somewhere, no, I don't think it corresponds to anything except the advisory message. Someone?
This item is described by Eurocockpit.com (they have the full ACARS headers and content) as being a CABIN VERTICAL SPEED advisory.
Check this page (scroll down for the English text):
Eurocockpit - Archives

I don't fully understand why Goodrich would say that the pitots probes are also sending data for the cabin pressure controler (and for engine monitoring) when I understand that such system would use the static pressure instead of the total pressure in order to control the pressurisation (Cabin delta P). Moreover, the pressurization schema is pointing ADIR 1+2+3 for the controler data.

It looks like each pitot probe is coupled with two static ports, then if the pitot probe is faulty, the static ports data are considered faulty also?
Or, not only the pitots probes were frozen but also the static ports?
In fact, if the static ports were considered faulty, all the sequence would make much more sense. In the Air Caraibes case, the sequence start with the TAT probes freezing before the AIS, Altitude, ADRs went nuts.

S~
Olivier
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Old 23rd Jun 2009, 10:09
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How deep?

Propagation through water provides more attenuation horizontally than it does vertically, due to amongst things, the lensing effects and characteristics.
The Box's can be deeper than the horizontal range and this is why the search is aided by a submarine and has better chances than a surface vertical.
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Old 23rd Jun 2009, 10:11
  #2190 (permalink)  
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takata - not familiar with the AB system, but I suspect something is 'lost in translation' on this. I would expect the CPC receives a digital 'static' input from AD1/2/3/ and thus if they are either shut down by crew action or isolated by software the source may be lost? Whether there is a backup?

Incidentally, did I see someone claiming the ACARS message could also be cabin alt >8.8k? Is this a revision of the 'definite' claim that it was only an up or down rate signal?
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Old 23rd Jun 2009, 10:26
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An explanation?

Takata said (post 2219)
I don't fully understand why Goodrich would say that the pitot probes are also sending data for the cabin pressure controler (and for engine monitoring) when I understand that such system would use the static pressure instead of the total pressure in order to control the pressurisation (Cabin delta P). Moreover, the pressurization schematic is pointing ADIR 1+2+3 for the controler data.

It looks like each pitot probe is coupled with two static ports, then if the pitot probe is faulty, the static ports' data are considered faulty also?
Or, not only the pitot probes were frozen but also the static ports?
In fact, if the static ports were considered faulty, all of the sequence would make much more sense. In the Air Caraibes case, the sequence starts with the TAT probes freezing before the AIS, Altitude, ADRs went nuts.
For a possible explanation/resolution of the confusion about static pressure sourcing, see this post by OVERTALK:
link
.
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Old 23rd Jun 2009, 10:32
  #2192 (permalink)  
 
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"That's why the black boxes cannot transmit any data."

I know this is going to sound pedantic, but the black boxes are sending a datum, as in the ping. They could easily be modified as you intimated to morse a fleet ID, which under ideal conditions would be helpful, but under poor conditions could be next to useless. However, the idea of a morse modulation would parallel the SETI model of looking for intelligence amongst noise, which seems to be the situation ATM.
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Old 23rd Jun 2009, 10:35
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BEA Press release

"Aucun signal émanant des balises acoustiques des enregistreurs de vol n’a été validé à ce jour. Des travaux sont régulièrement entrepris dans le cadre des recherches en cours pour lever tout doute sur des bruits perçus et tout fait établi sera rendu public."



No emanating signal of the acoustic beacons of the flight recorders was validated to date. Works are regularly undertaken within the framework of researches in progress to raise any doubt about perceived noises and all established fact will be made public.

Bureau d'Enquêtes et d'Analyses

Last edited by Squawk_ident; 23rd Jun 2009 at 10:51.
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Old 23rd Jun 2009, 10:44
  #2194 (permalink)  
 
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Tech Data on Dukane Underwater Locator Beacon.

Dukane model DK120 and DK100 Underwater acoustic locating beacons
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Old 23rd Jun 2009, 10:58
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Woodja51

Congrats on the excellent, no BS posts.
After 16k hrs including 13k plus hrs PIC on 737/67/320 and 777 make us see things clearer.
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Old 23rd Jun 2009, 11:35
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barstow, fully agreed, any 'intelligent' signature that can be correlated would make detection of the pingers easier, as long as it does not weaken the signal strength significantly.
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Old 23rd Jun 2009, 11:39
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weak signals

suspect you have in mind a correlation detector (like gps) which can pull a signal out of noise. still need bandwidth and unfortunately water is a very dispersive and stratified medium.
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Old 23rd Jun 2009, 12:04
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Mrs 22/04 said to me last night; why don't the recorders float; they could then be recovered with the seats bodies etc.

Set me thinking- put them in a box that it triggerd to release or eject by presence of water and pressure (depth) - is this a viable idea?
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Old 23rd Jun 2009, 12:05
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Jun 23, 8:04 AM EDT

Official: No black box signals from Flight 447
BY ANGELA CHARLTON
Associated Press Writer


PARIS (AP) -- French military ships searching for the black boxes of Flight 447 have detected sounds in the Atlantic depths but they are not from the Air France plane's flight recorders, French officials said Tuesday.
The official and French investigators denied a report on the Web site of the French newspaper Le Monde that French ships had picked up a signal from the black boxes.
The two recorders, key to helping determine what happened to the plane, which plunged into the ocean May 31, will only continue to emit signals for another eight days or so.
French vessels in the search area have picked up noises regularly, but subsequent investigation has revealed no link to the black boxes, French military spokesman Christophe Prazuck told Associated Press Television News.
"The black boxes have not been found. The black boxes have not been located. We're still looking for the black boxes," Prazuck said in English.
"Regularly they have alerts. They hear noises that could be related to the black boxes so they have to investigate these noises," he added, saying the French authorities "never" have had confirmation that any of the sounds detected were related to the black boxes.
The Airbus A330 plane came down in the Atlantic after running into thunderstorms en route from Rio de Janeiro to Paris. All 228 people aboard were killed. The cause of the crash remains unclear.
The French air accident investigation agency, BEA, said in a statement Tuesday that "no signals transmitted by the flight recorders' locator beacons have been validated up to now."
The BEA said work is continuing "aimed at eliminating any doubts related to any sounds that may be heard, and any findings will be made public."
Last week, BEA director Paul-Louis Arslanian sternly warned against any unconfirmed leaks in the investigation, saying they could mislead the public and unnecessarily worry or encourage the families.
Le Monde said a mini research submarine, the Nautile, dived Monday to search for the boxes based on a "very weak signal" from the flight recorders picked up by the French ships.
Searchers from Brazil, France, the United States and other countries are methodically scanning the Atlantic for signs of the plane.
French-chartered ships are trolling a search area with a radius of 50 miles (80 kilometers), pulling U.S. Navy underwater listening devices attached to 19,700 feet (6,000 meters) of cable. A French submarine is also searching.
The black boxes send out an electronic tapping sound that can be heard up to 1.25 miles (2 kilometers) away.
Ten of 50 bodies recovered from the Air France flight have been identified as those of Brazilians, medical examiners said.
Dental records, fingerprints and DNA samples were used to identify the bodies. Investigators are reviewing all remains, debris and baggage at a base set up in Recife, Brazil.
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Old 23rd Jun 2009, 12:23
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to woodja 51 and followers like Fullworward...

could you please stop this crap about poor handling/decision making of FO/SFO flying the plane while CPT is in his rest.

"lack of hands on time when it really mathers" do you think your FO is learning less on his leg being PF than you when you are PF?

So the AF FO/SFO spent thousands of hours learning nothing what really mathers? what do you really think about your fellow pilots? Only captains gain valuable experience when flying and somebody who sits in the same plane flying next sector doesnt?
If this is the case, you should maybe check why you dont give your collague chance to do so?

"But if I think that the F/Os are not up to speed to do an Atlantic crossing at night, avoid weather etc, it is time to chuck it in"

So what do you do? stay awake or have a nightmare in your rest that the youngsters cant handle the heavy at night past 10W. Yeah, i have been flying with these CPTs too, really seldom, but a few times. I can tell they were not the sharpest knife in the drawer. Usually lack of selfconfidence and below average pilot skills make them feel unconfortable in the cockpit. they fear loss of control and therefore over react to any situation what they cant totally foresee. this makes them believe, only them can handle the plane and generates a distrust towards younger collegues.

if you have doubts about the skill and experience level of your crew, feel free to contact your training department

poor copilots will become poor captains and poor captains were poor copilots before the upgrade. i have encountered both, cross your fingers they dont fly together when the **** hits the fan...

in the AF447 there were professional collagues trying their best, which for sure had enough experience but maybe not enough luck that night...

back to fact finding...

L
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