rubik101,

Why do you keep saying the "B" word? There is no evidence at all of that. There is, however, evidence of severe convective weather on the route. There is, however, evidence of the aircraft being rather High in Coffin Corner early in the flight (FL350 candidate for jet upset.) There is radar evidence of an enormous mature cell (and almost all, mature cells have associated lightening contained within them whether or not a lightning detector on a spacecraft or a weatherman in Atlanta can see it is unimportant.) All of us who have penetrated them can tell you they are full of lightening, St Elmos fire, extreme turbulence, massive up/down drafts, ice beyond normal design limits... etc, and when you exit a big one don't just punch out at a 90 degree angle or you might break the wings off. It is my humble opinion, as a guy who flew before wind shear was even a word, that you should exit at a 45 angle to the cell wall.

Naturally, don't penetrate and you won't ever have to make that choice. But riding around on autopilot all the time pushing buttons does nothing to sharpen your hand flying skills for a possible situation like this when you will need it the most. I am simply appalled by the autopilot-dependent culture in many flight departments.

Crunch

ADFS,

This is probably one for a new thread anyway and there is every chance this ppost will also be deleted. However, the seemingly arbitrary removal of perfectly reasonable postings speculating as to the cuase of this accident gives the impression that the mods are exerting editorial control.

It would appear, at the moment, that the wreckage trail is pointing towards a sudden and catastrophic failure in the airframe. The ACARS message indicates an sudden depressurisation but this may have been triggered by factors other than that which has been suggested by a senior AF pilot. A lightning strike that may also have disabled the radar and comms could caused a breach in the fuselage which would iniate an explosive decompression.

It is assumed that the crew were unable to broadcast any mayday and it was therefore a sudden event that caused the loss of A/C and all on board. If Comms were damaged by lightning the crew may have had no means to relay a message in any event. Even with the highest workload, there were three crew and it is inconceivable, in my mind, given their location over the sea and hundreds of miles form the nearest landfall, that communication would not have been one of the highest priorties, irrespctive of what else was going on. Only recovery of CVR will confirm actual circumstances.

Everything here points to a freak accident caused by a confluence of events - the perfect storm. The sooner that the variuos theories are ruled out and the causes are identified the better for everyone.

Why 14 mins? The first and last messages have been reported 4 mins apart.

ACARS
 

I have worked on installing the latest ACARS system in my airline and the amount of information that one can get from ACARS is mind boggling. In fact I would dare to say that is as good as FDR , but obviously lacks the CVR capability of recording voice.

ACARS works with VHF or SATCOM , there is also a HF data solution but it is not common and only few airlines use it.

As far as the AF A330 is concerned , I have no doubt that they had SATCOM as the postion of the A/C over the ocean was away from any ground base recivers . hence MCC or Operation Control could get all the messages from the stricken aircraft.

One thing that remains to be seen is how Air France has selected to operate the ACARS on this route. Transmissions using SATCOM are expensive, many airlines are selctive in the amount and the frequency of information that is transmitted by ACARS using SATCOM. Some configure the system to collect all the data and when they reach a VHF station , it dumps all that data to base using the much cheaper rate.

A very good question was raised about the G force . YES , ACARS can send this information as well and it will be quite helpfull in the crash analysis. Whether the G force was recieved by Air France or not is not clear.

ACRAS is the primary tool for Aircraft Tracking with many airlines operations control centers. However , again it depends on how the airline has configured the system. Obviousley it is a waste of money to send postion fix every five minutes (specially under SATCOM) , neverthanless ACARS is second best flight tracking system after Radars with an added advantage that a Radar has certain range while ACARS is not necessarily bound by range limitation.

.

Because the messages from the computer are relevant, not the chance of some occurrence. De-pressurisation was the very last, along with vertical speed. There was 4 minute spread of computer and system failures before that.

I'm sure he has also flown those same number of years without a bomb on his aircraft. But there has been system failures before, as well as bombs. So you must look at just the information on this crash.

@BOAC, I can't remember where I saw it, but there was a report that other flights were in the area at the time, both ahead, behind and parallel - if memory serves, one was a DHL freighter. The report also said that none of the flights that might have heard from AF447 picked up anything. It does seem a little puzzling that the crew sent out an ACARS message but no radio traffic was heard, although the fact that the first ACARS message was sent on the hour suggests it may just have been a SOP-scheduled message.

For you Airbus 330-200 drivers out there (or anyone else who actually flies for a living at the higher flight levels)....

FL 350 and still heavy with weight of 8 hrs of fuel plus reserves remaining for the trip.

Autopilot disconnect (for whatever reason, the ACARS says this was the first event) , now hand flying in Alternate Law. No overbank or (my understanding) buffet protections. Moderate, or possibly severe turbulence in the mix if that's what kicked off the Autopilot in the first place due to pitch or roll overlimits. Now your prime consideratoin is to keep the aircraft within the aerodynamic buffet boundaries.

Have any of you hand-flown an Airbus (or other aircraft heavy with fuel) at those flight levels even in smooth air? What about in rough air and may have to maneuver...or outside forces are doing the maneuvering/airspeed fluxuations for you and you're fighting to stay withing the (small at FL350) flying envelope/Q-corner?

The problem with > moderate turbulence when you're high and heavy isn't about shearing off parts of the aircraft that in turn cause it to come down, it's about being able to keep it flying especially if the Autopilot gives up due to conditions exceeding it's capability to keep up with changes of axis/and or airspeed and suddenly hands control over directly to the pilots, where that pilot may have little or no experience controlling his wallowing aircraft in that high-altitude, small margin for error realm of fight on a good day, let alone a dark and stormy night.

Perfectly good airplanes have succumbed to the Laws of Aerodynamics with no faults, structural failures before the fact, lightning strikes, b-word events, etc. etc. etc. in the mix. Just because in normal conditions we don't run up against the boundaries of those Laws doesn't mean they disappeared...they're still there waiting to bite. And we are paid NOT to run up against those boundaries and avoid situations where we might, and this is what we routinely do as professionals.

Take a jet aircraft and put it high, heavy, and run it through rough enough air and the Laws of Aerodynamics are waiting. I assume they still teach these things for those that haven't experienced it. They really aren't kidding.

It seems many people here are looking at the weather as a probable cause.

I have flown the A340 (but not A330) for many years in similar tropical weather on the other side of the world , Africa , Far East and India where the same weather pattern exists.

Towering CB's , Massive CAT's , rain and precipitation of huge magnitudes are quite common. No pilot in his right frame of mind will attempt to penetrate the worst of such weather and in this day and age , the pilot has plenty of information and warning to prevent him from going through such weather.

If , and I say a BIG IF , weather is considered as a major factor , then surely there must have been a failure in the cockpit mainly the weather radar, that sent the crew into a very active cell. OR , the radar failed to pick up these activities !!!!

Our old A 340's ( no more flying) had a problem with weather radars. If I can remember rightly , we had problems with the shallow band of vertical coverage of the radar. It could not pick up the significant weather when it was tilted beyond certain degrees , up or down. Apparently it was a software issue , which was supposed to be fixed in the newer generations of A340 and A330.

MikeAlpha7

does the ACARS "know" whether the SATCOM uplink is working, and would it buffer the mesages if it "knew" the link is unservicable for the moment and sent them at a later point in time when it "realises" the link is up again?

Or in other words: If messages are received during a four minute period of time by the operator, does that necessarily mean, the technical incidents which triggered the messages did happen also within a four minute period of time?

Can messages be lost during transmission, such that the message set received by the operator is actually only a subset of what was sent by the a/c?

Probably that kind of questions is what people in Paris are trying to sort out in the the moment.

Punch through!
 

Quote;
"I still think people are losing sight of the fact that when transiting the ITCZ, sometimes there is NO ideal way through. You've gotta punch your way somehow and that route depends on what looks better on the radar and outside."

I have to disagree with Farfrompuken's comment above. In extremis if there is no way through then you have to divert or go back if you can't go around the storm. That is what we are paid to do if necessary.

Not when your ports are frozen over and only to a degree - remember Aeroperu 603? Granted, that was a B752, but you can only do so much with conflicting info... I had mentioned pitot-static failure before AF did, purely based on ACARS messages, but nobody paid any attention to it...

AMF, aggree with your view
 

As an ex 340 "operator" and now a happy -400 "driver", I must aggree with AMF's post...
Put all that together, and now add "dual input" as both guys upfront grab the stick, as the autopilot kicks out, and try to correct the jet upset!!
As you know, "dual input" doubles, or cancels out the actual stick position

A bad day for all.

RIP.

"advisory regarding cabin vertical speed"
 

For the A330/340 rated - a question.
This will be the next A330/340 sim LOFT session once the facts come out!
Is this "advisory" an ECAM message also?
Looking at all these ACARs messages prior - what electrical power losses would cause the Controllers to default/fail?
If for example all power is removed - does the system enter in FAILSAFE closed position for the valves (operating the Ditching Valve)?
Is there an situation you can think of where the Outflow Vlv/s would not close fully to control the cabin altitude - perhaps causing this vertical speed advisory?
Meaning if the sequence of events, ECAM warnings, etc. has the 3 cockpit crew dealing with all the previous issues, now comes an eventual CABIN HIGH ALTITUDE.
The next problem for the Crew would have been a "controlled" expeditious (2-3000 ft/min) or maybe even an emergency descent (shy of MMO with Speed-brakes)?
As we know that would make it extremely difficult to avoid and very easy to literally drop right into even more severe weather and the eventual turb., icing, spacial orientation and performance issues.

AMF,

How much above `optimum` do you think he was at the time?

On the 767 entering an area of severe turb you are recommended to be 4000` below optimum for max comfort away from stall mach buffet etc...What is it on the 330?

I remember in the early days of the 76 some of the older chaps would go as high as possible- sometimes 4000` above optimum- used to feel like being on a knife edge. Doesn`t happen on my flt deck I can tell you!!

The "failure" of the Captains TAT probe would cause a double ADR fault.

The result of this is the disconnection of the autopilot and a reversion to Alternate (2) Law.

This was quoted in an earlier post as the first two symptoms transmitted via ACARS.

As I understand it, the health of the said TAT probe is not monitored, so this would not be evident.

Until they (hopefully) get the FDR and CVR who knows?

However we do have a proven a/c (ok yes there have been a few incidents as with any type), an experienced and mature crew who presumably were well familiar with long haul ops across the ITCZ and the hazards associated with large CBs working for an established company with a good track record.

My opinion on the scant evidence we have so far is that something happened extremely quickly - no distress call was apparently made.

So if I was a betting man I would go with the bomb theory. I just hope and pray they get the recorders from the ocean.

Well, what will knock off a/p, switch the opmode of FbW and lead to a stream of ADIRU failures? If you're gonna dismiss ideas, at least do that constructively...

Purely based on what we have on this thread, the first possible indication of 'difficulties' at 11:00?

I am not convinced that this opinion is the only explanation. Several posters have already expressed that in the case of extreme trubulence and/or an upset they would be busy trying to fix it and not make distress calls a priority. Just a few posts back someone pointed out that when you are in the cruise with headsets off you might not be able to find the hand mike. And frankly at three hours from the nearest land I don't see what an urgent distress call could do. It is different close to landing where you need ATC help.

Where
 

Hi,
does anyone know where the accident happened (lat/long) ?

Hand flying: rarely done at altitude, but not a problem at all.

ITC: seemed stronger 15, 20 years ago, but still well worth keeping an eye on.

Radar: can be difficult to interpret. Remember, radar shows essentially water.
Water falls down when the sun goes down (mostly). What remain are weak
echos of possibly still strong turbulence.

Satellite-pics: not available in real time in the cockpit. Don´t know if
they were available to the AF-Crew before departure.

Best, Klaus