Correct, FD needs 2 airspeeds. (FE for speedtargets calculations only 1)
@ 02:10:42 FD was transitonary available; IMO ADR2 was increasing and crossing the ADR 3 airspeed (~transitonary).
@ 02:10:47 it was consistent with ADR1 and FD returned.
I interpolated Vs1G (205t, FL350) ~ 185kts, VLS = 1.23Vs1g ~ 225kts.
anyway both airspeeds
below VLS.
BEA didn't have an answer in IR#3 either:
4.3 Recommendations relating to Flight Recorders
Analysis of the FDR parameters and audition of the CVR provide
information that is essential to an understanding of the event.
However, it is difficult to reconstruct the indications that were available to
the crew on their instrument panel, especially the instructions given by
the Flight Director crossbars when they reappear.
They will know about now!
The latest FCPC mod 2K?* / software may be a result of this.
Ref.
AD 2011-0199R1 and
AD2010-0271