...when many similar situations have been successfully handled by other crews.
Statistically speaking ONE case of COMPLETE lack of understanding after trigger (3 Pitot's then UAS) among other < 40 cases reccommend attention to EVERYTHING. (HF, man machine interface, etc.). We must remember similar conditions (no visual references, turbulence, etc.) could occur again.
My point is:
1) Considering "frequency" of UAS cases traced to the use of now obsolete Thales probes.
2) Considering some cases were related to the use of competitor probes, currently and still in use.
3) Considering they became "rapidly lost" and "increasingly confused"
4) Considering Pitot's data (simultaneous failure) are still today not adequately processed (NO REDUNDANCY AT ALL) by System
5) Considering identification of UAS presently has to be done by scan and feeling (as linked paper put)
6) Consider PF was caught in surprise and acted almost immediately (by "lack of speeds" as you observed)
I ask:
Why not to provide an instantaneous (even non causal, before an eventual Law change) indication to the crews (Airbus SAS, Boeing, Embraer, etc.) (PRECISELY) of UAS?
Complementing: The point is, everything SIMPLE and PRECISE the System (through the man machine interface) provide to the crew, if possible (UAS is) IMO increases the safety of the plane operation.
Surprises (coming from her
) better to avoid.
The
mentioned paper (i am considering still valid and "official") led me to this point.
AF447 case was not "triggered just by "tiny ice crystals" affecting "obsolete AS probes" in a System operating without redundancy (Air data).
AF447 case was triggered (it seems to me) by a "lack of understanding" of what was really happening. UAS as everyone know, causes erratic indication in several indicators as mentioned in the linked paper. The Pitot data (considered GARBAGE by the System designers) during a transient phase are still fed to pilots (they receive this "input") that need to rush the scan in order to
just identify UAS. As the paper points.
If the System tells you (on UAS) you save time (precious) and could act MUCH more precisely and fast.
IMO, the "interface" should be reviewed. Why? Because in my opinion can be easily improved with
good cost benefit relationship.
BUSS could still be an optional. (STD in 380);
An UAS indicator could be Standard. At least before we solve the Pitot's issue.
I do find it "a bit of a stretch" to blame the systems
Evolution (stepwise) is not based in "blaming". Sometimes "a tweak" (as you know) "makes a difference"
Ultimately what was done right/wrong and by whom boils down to bad CRM associated with as yet undetermined Human Factors.
I agree. But remember:
CRM and HF "becomes critical" under extreme difficult conditions. In Portland the crew had time to digest the surprise (gear problem). F-GZCP had few seconds and apparently never
understood and realized the "benign" problem: Simply an UAS. That shortly "dissipated".
