Encontrei o seguinte texto numa discussão online, que me pareceu séria, sobre o assunto da queda do avião da Air France:
Quote: “OK, a bit more information has come to light. One of the French TV stations has obtained, and broadcast, the list of messages that the ACARS (Aircraft Communications Addressing and Reporting System) sent out before the flight was (presumanly) lost. Here’s a copy of it, from another forum:
Now, here’s where I earn my pay as “resident expert” – although I’m not familiar with the Airbus systems in detail. I’m also using info gleaned elsewhere to fill out the gaps in my knowledge, of course.
The columns in the data are:
1. ATA Code & Part Identifier
2. Message Type
3. Date and Time
4. Actual message – numeric code and english text
5. Date
6. Flight #
ATA code – a two digit code which identifies the general system affected. The ones of interest here are:
21 Air conditioning
22 Auto flight
27 Flight controls
34 Navigation
Note that there is NO ATA 24 – which is the electrical one. Starting to look like no electrical systems were lost (or at least, none reported as lost)
Message Type : FLR is a Fault Report WRN is a warning that would have been displayed to the crew. (So FLR are things the crew wouldnt have warnings for)
Date and Time – Note that the first message is at the BOTTOM of the page
Message Codes – I’ll get to those
Date – straightforward
Flight – Note that the first two messages (bottom of first set) are AF444 and thus not the accident aircraft.
Ok, to the messages. I’m going to group them by time. Note that we don’t know the order they actually occurred in – ACARS reporting order my be random for simultaneously reported events. So each group could be shuffled. But 0210Z is before 0211Z at least.
0210Z
We have 14 total messages. 2 fault reports, and 12 warnings. That would have lit the cockpit up like a christmas tree.
The two faults are ATA 34 EFCS2 and ATA 27 for EFCS1. EFCS is the Electronic Flight Control System.
The warnings include AUTO FLT AP OFF and AUTO FLT A/THR OFF. Those indicate that the automatic pilot and autothrottle were both off – due to failures, not crew action. The F/CTL ALTN LAW message indicates that the fly-by-wire system has dropped into the secondary “Alternate Law” where the full protection of the “Normal” Law isn’t available. One consequence is that you can stall inAlternate Law – Normal Law prevents stalling. The various FLAG ON PFD messages indicate the precence of warning “flags” on the “Primary Flight Displays”. The F/CTL RUD TRV LIM FAULT one indicates that the “rudder travel limiter” has a fault. (It’s used to prevent pilots applying too much rudder at high speeds) NAV TCAS FAULT refers to the Traffic Collision Avoidance System (which is used to warn of other aircraft).
So, what’s going on? What it looks like is that the aircraft Air Data and Inertial reference Units – and especially the Air Data part, which is the box that calculates the airspeed and altitude – were failing. Loss of accurate and consistent data from the three ADIRUs forces other systems to revert to simpler modes of operation. hence Alternate Law, and the automatics dropping offline. TCAS needs to know your altitude to avoid other aircraft. The Rudder Limiter needs airspeed to know where to set the limits. Its also possible that angle-of-attack information was being lost too.
Layman’s terms: At 2:10 GMT, the aircraft quite suddenly lost a significant amount of the data necessary to fly it safely – almost certainly airspeed and altitude information. The crew would have been presented with conflicting information between the pilot and co-pilot, and won’t have known what was correct. At the same time there’s a dozen warnings lighted up, a bunch of bells and horns sounding, and suddenly the automatics have handed control back to them.
At dead of night, in a a massive thunderstorm.
0211Z
5 more messages. All ATA 34 – Navigation. Another two Flag messages, which dont tell me much (but the detail info will to the Airbus guys). NAV ADR DISAGREE – This means that of the three ADIRUs, not only has one been lost, but the other two disagree so much that the systems relying on them now have no idea what to use. This locks in Alternate Law, as well. ISIS refers to the Integrated Standby Instrument System. That’s the backup, completely independent, system used to provide airspeed and attitude information if the main data systems fail. Well, now it’s got problems as well. IR2 is part of the inertial reference system.
Layman’s terms.
Less than 60 seconds later, not only have the crew got confusing indications on the main system, but the standby – which you’d turn to first to find out which of the main systems was still trustworthy – just went tits up. At this point the crew have, in effect, lost all reliable indications of airspeed. They are now flying the aircraft – at least in terms of flying the correct speeds – literally by the seat of their pants.
0213Z
“only” two messages. F/CTL SEC 1 FAULT and F/CTL PRIM 1 FAULT refer to faults in the SECondary and PRIMary flight control computers. Its conceivable they might have been dropped now out of Alternate Law and into ‘Direct” Law where there is NO system protection for the crew. They may even have been forced into some kind of reversionary mode, with actually no control over the main controls. (Though I think not).
Layman’s terms:
Now, in addition to unreliable indications, the control systems (perhaps due to the same unreliable airspeed info) are also starting to shut down. It’s getting pregressively harder to fly the aircraft.
0214Z
Three messages. Our first and only ATA21 – Air Conditioning – message. This is likely to be the source of reports of “cabin pressure warnings” that have been mentioned – with access to the manuals you could decode to the specific fault. Likely means that the cabin was depressurizing. The ATA 34 message is actually, I’m told, also related to the cobin conditions. The ATAT 22 one I don’t know.
Layman’s terms.
There’s really only one way to generate these kinds of messages that I can think of – the airframe had started to break up under load and the cabin explosively decompressed. (Note that “explosive” here means “fast”, and is nothing to do with a bomb)
So, my previous scenario was largely off base.
This looks like a case of loss of the significant flight instruments – likely due to the storm – perhaps ice or hail damage to the probes, or maybe a lightning strike or two as well – and then the crew either stalled or had an overspeed due to the turbulence in the storm and not really knowing their speed, which caused the aircraft to break apart as it departed controlled flight in extreme conditions.
Nasty”
Enfim, vale o que vale…
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