Originally Posted by
pax2908
On the French speaking web site, they have published the details of an incident which occurred "a few months before" AF447. In that case, maintenance have found that the three probes had the water drainage holes blocked. My question is again a naive one: in such a case, the problem is considered to be solved once the drains are cleared and the pipes flushed (as per the Airbus procedure), OR is there a mechanism to at least trigger more frequent inspections? For sure if maintenance is done correctly, then it should NOT be normal to find all 3 probes with the drains blocked?
I think we can find an AESA air worthiness directive from 2003 whose purpose is to increase the maintenance frequency on the Pitot probes. Another AESA paper describes manufacturing problems on the drain of certain AA probes resulting in a rapid obstruction, poor water drainage and poor performances in case of heavy rains or icing conditions (even if you have an efficient heater). Maybe we see now the difficult aging of these AA probes. But whatever, when the French Air Force lost a Mirage 2000 five years ago, the military did not wait for a similar problem to reoccur: the AF conducted a large study on its entire Mirage 2000 fleet to get complete statistics over a period of time, to analyze the risk and its evolution, and to adapt the maintenance. Has it been done on these airliners ? Jeff