Originally Posted by
lomapaseo
...
AFAIK the ice crystals at high altitude do not adhere to blading (unlike low idle conditions at low altitudes in freezing rain).
I would add that some engines have been affected by the effects of probe blockage which affected the FADEC control on stall recovery which of course affects power.
A good reference on this, which has been posted here before :-
http://airs-icing.org/AIRS_II/AIAARe...06-206-739.pdf
...Of course an upgrade of pitot systems is probably still warranted based entirely on past history.
Err yes, but the Thales AA probe in use was known to be deficient on this type of aircraft before this event, (ref Air Caraibes for example), and the replacement Thales BA probe not as good as the best Goodrich probe - hence the ADs around the world in September 2009.
But the now preferred Goodrich probe also failed in the Guam October 2009 incident, and if you read the report and the recommendations
Unreliable airspeed indication - 710 km south of Guam, 28 October 2009, VH-EBA, Airbus A330 202
your comment probably still applies!