Captain Flame posted:
Let's put this one to rest once and for all !
The message F/CTL RUD TRV LIM Fault is justified by the loss of the ADR data.
As said previously in this thread, the rudder travel is then limited to 10 degrees and full deflection is only recovered at slats extension.
An Air Caraibe A330 incident report is circulating (in french) which describes a (survived) event sounding very similar to the AF447 event.
In the air Caraibe event (which I will try to find in english)....icing over of the Ptot probes and TAT probe at FL 350, in transoceanic equatorial WX, with severe turbulence, occured.
The following ECAM messages, flags and system reversions are consistent with the ones reported ont the AF447 ACARS report.
As decribed earlier in this thread, the TAT increase from -14 to -5 degrees typical of an iced up probe measuring the ice temperature instead of the Ram Air.
At some point in this event the CAS, MACH and ALT go respectively from 274Kts, M0.80 and FL350 to 85kts , M0.26 and FL347.
At the same time the cascade of ECAM warnings and cautions include NAV ADR Disagree, F/CTL ALT LAW, F/CTL RUD TRV LIM, ENG EPR mode faults (different engines there), Speed Flags on PFDs, loss of FDs, A/THR, etc....Including at some point STALL STALL audio warning (no protection in ALT LAW)
Summarily, the PF flew "pitch and power" with PNF on QRH unreliable speed indication, disregarding the STALL warning and using backup info of GPS Ground speed and Altitude (ND and FMGC).
Air Caraibe has modified all the 330 probes earlier this year.
Again, the Air caraibe report is VERY similar to what is now known of the AF447 troubles. (Weather, turbulence, airspeed data problems)
Guys I'm on the other side of the world, so while most of you are posting and moving on to other subjects, I'm counting sheep and then still responding to the "resolved" posts the day before! Forgive me if I'm five pages behind.
I hadn't read this A330 report earlier even though I downloaded it. Even though it is in French, It's clear most of the "events" logged about the accident/incident are almost identical. As the good "Captain Flame" stresses the engine EPR differences are moot, they are just airline customer engine selection options: For example on the previous gen aircraft the A310, you could order with Pratts w/EPR or GE's w/out EPR. In the latter case, since all you have is N1 for thrust settings you wouldn't get EPR (engine pressure ratio) errors logged (since you don't have those gages), you wouldn't see those EPR faults or warnings into the mtc computers. The aircraft system then reports these conditions to ACARs, and ACARs would then bundle this information into a data packets and beam it to the satellite or HF if, that service was paid for.
To oversimplify for non aviation types: ACARS is a telephone. If the Cable Guy (Installer) has problems with your TV/black box, he's going to ask you to use your telephone (ACARS) to report the faults to somebody back at his company (AOC/Maintenance Control) who is smarter than he is. Previous posters asked where the location coordinates for the last 0214z acars report came from since it didn't show up in the acars report. This is a good question. It appears the images on the first few pages of this thread from Channel2 France, are of a finished "environmental" report constructed for AF maintenance. We are not seeing the actual data packets (which would have sat broadcast coordinates,) which are broadcast line-of-sight to the satellite in a different computer language.
Here are excerpts from Wiki on ACARS:
SATCOM and HF subnetworks
SATCOM provides worldwide coverage, with the exception of operation at the high latitudes (such as needed for flights over the poles). HF datalink is a relatively new network whose installation began in 1995 and was completed in 2001. HF datalink is responsible for new polar routes. Aircraft with HF datalink can fly polar routes and maintain communication with ground based systems (ATC centers and airline operation centers). ARINC is the only service provider for HF datalink.
[edit]Datalink message types
ACARS messages may be of three types:
Air Traffic Control (ATC)
Aeronautical Operational Control (AOC)
Airline Administrative Control (AAC)
ATC messages are used to communicate between the aircraft and Air traffic control. These messages are defined in ARINC Standard 623. ATC messages are used by aircraft crew to request clearances, and by ground controllers to provide those clearances.
AOC and AAC messages are used to communicate between the aircraft and its base. These messages are either standardized according ARINC Standard 633 or defined by the users, but must then meet at least the guidelines of ARINC Standard 618. Various types of messages are possible, and these include fuel consumption, engine performance data, aircraft position, as well as free text data.....
(Each airline must tell its service provider(s) what messages and message labels their ACARS systems will send, and for each message, where they want the service provider to route the message. The service provider then updates their routing tables from this information.) Each type of message sent by the CMU [Communications Management Unit - CC] has a specific message label, which is contained in the header information of the message. Using the label contained in the message, the DSP looks up the message and forwards to the airline’s computer system. The message is then processed by the airline’s computer system.
This processing performed by an airline may include reformatting the message, populating databases for later analysis, as well as forwarding the message to other departments, such as flight operations, maintenance, engineering, finance or other organizations within an airline. In the example of a delay message, the message may be routed via the airline’s network to both their operations department as well as to a facility at the aircraft’s destination notifying them of a potential late arrival.
Those who claim that the ACARs data doesn't mean anything, are incorrect.
These messages are the best information we have thus far and they appear nearly identical to other A330 known mishaps. If history is any guide, since billions are on the line in Aircraft Ops and Sales, it may be years before the findings of this investigation are made public.
All my posts are just my opinion only.
CC