Talking Airplanes!

Planes have gone violently into the ocean again in the past, at some instances vertically into the water at great speeds and in one piece, other times in scattered pieces following a mid-air break up through either an explosion/decompression or as a result of violent physical forces on the plane following the free fall; but in all those cases i've studied, the wreckage didn't lie at such a great depths and more importantly, debris and traces of the crashed plane were found at the point of crash, on the surface instantly, the very day of the crash or maximum 1-2 days afterwards.

Wow, there are too many variables in this equation: the condition of the black boxes, the currents, the depth of the area, the difficult task of seeing a little trail (kerozene, oil), locating a remain of the wreckage that may be miles away of the actual crash point,....it´s gonna be a titanic search.

Those are the only known FACTS so far; the ACARS messages, to explain, are electronic messages that airbus' planes transmit periodically through their on-board flight computers, and automatically back to the airline on the ground, informing the people on the ground about the flights' process and status. The above are the last automatic electronic messages received from the flight prior to the crash.

To put them in plain words, here's a simplification of their meaning for everyone to understand:



Means that the plane no longer controls the level of engine thrust automatically; the pilot either called for a manual control of the engines or something caused the autothrust to disengage by itslef.



The plane's on manual flying. The flight controls are now onto the hands of the pilot, either through his will, or via uncommanded disengagement.



FBW stands for "fly by wire", which is an AIRBUS patent of automatic electronic manipulation of several parameters of the plane's control and behaviour in flight, which are controlled by the plane itself, through its flight computer, regardless of pilot input. An example, if the plane stars loosing air speed dramatically, FBW will automatically engage one or more of its automatic programmed functions in order to avoid getting into a stall, i.e. dropping the nose and maximizing engine thrust in order to regain speed, etc etc. The way the FBW system works and interacts with the pilot is dictated by what "law" (i.e. mode) is selected each time, and for Airbus' FBW there are three modes. One of them is "alternate law" and the above message means that the mode of FBW's function was changed from its previous one, to "alternate law".

It's a rather technical issue, for more if interested, see this article here:
http://en.wikipedia.org/wiki/Fly_by_wir … ol_systems



A problem with the plane's vertical flight control surface called rudder and which is located in the vertical wing of the plane in the back.
http://en.wikipedia.org/wiki/Aircraft_rudder



Traffic Collision Avoidance System - The Traffic alert and Collision Avoidance System (or TCAS) is an aircraft collision avoidance system designed to reduce the incidence of mid-air collisions between aircraft. It monitors the airspace around an aircraft for other aircraft equipped with a corresponding active transponder, independent of air traffic control, and warns pilots of the presence of other transponder-equipped aircraft which may present a threat of mid-air collision (MAC).

The error message means that the TCAS stopped working due to its sensor (antenna) malfunctioning.



Problem with the plane's flight computer.



Pitot static ports are tubes on the front of the plane's exterior that measurement air pressure in order to measure fluid flow velocity, which gives us airspeed, attitude, altimeter and various other situational indications in the cockpit. With the pitot static ports blocked or failed, the plane (its flight computer and autopilot) doesn't have a clue where it is, in what situation it is (vertical, horizontal etc etc), at what height and speed it is flying, where it is flying etc etc. Now, if the pilots don't have visual references (the horizon and surroundings) in order to determine the plane's situation, then they might fall into the loss of situational awareness situation which is very, very dangerous. Sadly, the night of the accident they couldn't see anything 'cause it was dark and they were in a thunderstorm. However, it is not know at this point if the failure of the static ports was caused PRIOR of AFTER some incident that might have 'caused or started the crash chain of events.



As a result of the above; from wiki: "The Air Data Inertial Reference Unit (ADIRU) is a key component of the integrated Air Data Inertial Reference System (ADIRS), which supplies air data (air speed and altitude) and inertial reference (position and attitude) information to the pilots' Electronic Flight Instrument System displays as well as other systems on the aircraft such as the engines, autopilot, flight control and landing gear systems.[1] An ADIRU acts as a single, fault tolerant source of navigational data for both pilots of an aircraft."

Which means that the plane had no idea of its situation at the time.



...and therefore the plane was producing counter-cancelling, wrong information about the flight.



Major, massive flight computer errors occurring one after another.



This means that the cabin pressure wasn't controlled anymore. Maybe a decompression occured, as a result of either an explosion or a mid-air break up due to excessive external physical forces, or a mid air-break up as a result of an explosion.

BEAR IN MIND THAT THESE ARE THE ONLY KNOWN FACTS SO FAR, and are known through the automatically transmitted electronic messages generated from the plane and sent to the ground, at the airlines' offices. There was no actual, verbal communication of any kind with the pilots regarding any incident; the last communication they had with the atc, was to notify of thunderstorm situations and turbulence.

Eerie.

They might be the result of ANYTHING. A lightning is the less probable of all, don't believe the media crap that tries to awe people; it's not excluded, but by itself it can't cause that damage; planes are being hit by lightnings everyday; now in combination with something else, it might have contributed, but a stall and loss of controlled flight, or loss of situational awareness if the systems failed and a stall / free fall / mid air break up / ocean plunge as a result of that combined with the fact that the pilots didn't have visual references are way more likely to have happened; in this time though, everything is speculation. There's also the possibility of something way more complex, 'caused by the plane itself, suspected by some computer navigation problems 'caused unexpectedly and without finding the reason so far, by this type of plane, the a330 during the last couple of years, in separate independent incidents:

Although a remote possibility, everything is on the table of a professional and thorough investigation and nothing can be excluded if not contradicted by confirmed facts. Everything could have happened 'till the black boxes are found and start telling us the truth.


http://avherald.com/h?article=40de5374
http://avherald.com/h?article=412a7663
http://avherald.com/h?article=41386e6c

But bear in mind that all plane crashes are essentially a cause of a chain of events; nothing, ALONE, can bring a modern aircraft down.

Can you tell more about the Flight Envelope, PRIM and SEC computers? Why the failures are so massive?

Thanks for the updates and explanations, D.
BTW how on earth do you know so much about aviation?

Studying. Aircraft manuals and books, aviation books and professional aviation forums (except for meteorology and / or complex technical data that only professionals who work with or fly planes can understand) studying for countless hours countless official air crash investigation reports, documentaries, flying the simulator for 5 years now. I am nowhere near a pro on this one of course as i wasn't formally trained at any of these and can't understand the deeply technical stuff, naturally, but it's always been a very fascinating topic for me to which i dedicate many hours each day.

Onto the topic, here's a very informative post from pprune.org from someone who's obviously into the industry, which further explains what i told you above about the ERROR MESSAGES received:

As for the question on why they didn't send out a message to the atc, here's the self-explanatory rule of all pilots:

1.NAVIGATE
2.AVIATE
3.COMMUNICATE

My vision and hearing are perfect. I was considering it as a main career choice up until 16 when life became more realistic

Now that is SUPER-COOL!

Mel also had a similar experience to that while flying with Lufthansa....9/11 has put paid to all that

Life's a bitch isn't it? Being a family of 4 children back then, it'd be impossible to raise the money needed for 3 years of basic studying in the UK or US, plus 2+ years of specializing in passenger jet(s). Back at the time, only the studying fees, without all the other living expenses calculated) for UK, were at around 30 000 pounds per year.

Where can I read about the whole electronic "background" of flying? It seems fascinating. The computers you mentioned, Flight Envelope, PRIM and SEC don't have their respective Wikipedia entries.

Demetris, could the level of inputs received by the aircraft's systems control during something like turbulence swamp the computer systems and result in anomalous readings that the computer tries to correct - which leads to abnormal stresses placed on the airframe?

I know very little about this so I may be talking about something that is obviously not possible to the knowledgeable!!

One of Polish news websites broke the news that some bodies have been retrieved. Other sources confirm that?

It's official:

"Forca Aerea Brasileira (FAB) have announced today (Jun 6th), that they have found two male bodies today as well as a rucksack, which contained a ticket for flight AF-447. The bodies and rucksack were found about 1200km off the coast of mainland Brazil."

original source here