Quote: Will Fraser
... this accident suggests the reason all prior incidents had acceptable outcomes was merely that the (447) flying pilots had no horizon, no a/s, etc. and were in weather at night.
Will,
How have you come to this suggested conclusion?
From the pattern of Failures and Warnings in the ACARS messages it is reasonable to conclude a loss of airspeed information, but nothing more.
Extracting from the last posted summary of ACARS messages (assuming it is correct) the failures reported only lead to 3 items of information: Airspeed; Flight Director, and; Flight Path Vector being removed from the PFDs. Likewise the failure message related to the ISIS is for the speed/mach function which itself should only produce a red SPD flag on the ISIS, not a failure of the entire unit (which would display an OUT OF ORDER flag and related maintenance code). There is no information available to us that would lead to the conclusion that attitude or altitude data was lost, either on the PFDs or on the ISIS.
The problem with this discussion is that, in the absence of any further facts, it has drifted so far off base that we've come to the point of discussing the merits of plumb-bobs of all things. The contributions now seem to fall into the categories of: Declarations regarding the certainty of some critical flaw in design or concept; Various home-brewed plumb-bob solutions to said flaws; Validation of same by anecdotes or experiments in a Cessna, and; Occasional efforts to bring things back to the known facts about the aircraft and the accident.
It would all be quite humorous were it not for the fact that it is actually setting back efforts to understand what did happen to AF447, which is a very important question to those of us who fly the aircraft as pilots or as passengers. All one has to do is read the articles appearing in various media sources (such as those posted here from The Times and The Australian) to see the reverberation effect of inaccurate conclusions stated here becoming magnified and reflect back to us as "consensus opinions of professionals in the field". That's a fault of the media as much as anything, but it does shape perception of what happened and it should be a reminder that this is a "Professional" forum where there's an expectation that what you suggest in your posts is at least a speculation informed by knowledge of the aircraft/crew/accident and supported by the facts available.
The suggestion that the AF crew lost all PFD and/or ISIS data and that this was a or the reason for the accident is not one that is supportable given the known information to date.
0210 22-83-00-2 WRN FLAG
LEFT PFD SPD LIMIT
Rejected ADR still feeding data to PFD
If there is valid ADR, it's not being selected for LEFT seat.
0210 22-83-01-2 WRN FLAG
RIGHT PFD SPD LIMIT
Rejected ADR still feeding data to PFD
If there is valid ADR, it's not being selected for RIGHT seat.
0210 22-83-00-1 WRN FLAG
LEFT PFD NO F/D
Automatic Flight System (AFS/FMGC) loss of 2 ADR sources.
Safety mechanism, prevents erroneous F/D for pilot to follow
0210 22-83-01-1 WRN FLAG
RIGHT PFD NO F/D
Automatic Flight System (AFS/FMGC) loss of 2 ADR sources.
Safety mechanism, prevents erroneous F/D for pilot to follow
0211 34-12-00-0 FLR ISIS
ISIS (22FN-10FC) SPEED OR MACH FUNCTION
SUSPECT LOSS OF ADIRU1 AND/OR ADIRU3 FOR ISIS MACH
Suspect Loss of ADIRU3
NAV DISAGREE CONCLUSION DELAYED - ADDITIONAL FAILURES - RECOMMENCE FAULT ISOL
0211 34-12-00-1 WRN FLAG
LEFT PFD NO FPV
0211 34-12-01-1 WRN FLAG
RIGHT PFD NO FPV