syseng68k, what use is a closed loop control of you do not know the sweet spot for applying the sensor and have a way of doing so without destroying the probe's calibration? I strongly suspect that presuming the entire probe is all at one temperature is a serious mistake.
Something changed in the last few years that is affecting the probes of at least one manufacturer rather adversely. It's not global warming, the time frame is wrong to declare that. We've been cooling this last decade. So let's look, instead, at things like probe maintenance, probe mounting, flight regimes used, and so forth.
That might be some worthwhile study even if it does not apply to the accident under discussion here. I've certainly seen no proof that this is what happened to AF447. "It's too simple," is the way I'd describe it as a cause. AF447 was more likely done in by a rather rare cascade of failures, perhaps improper radar settings (lack of training), perhaps asleep in the cockpit, perhaps distracted by preparations for the 4 hour crew change, perhaps it involved engine icing, perhaps any number of things mentioned here. (Maybe some of them can be surmised from noting the strange position at which the plane apparently hit the ocean with a very strong vertical velocity component. A really good "it went down here" position might sharply limit the flight (or spin) profiles that could have taken place. That would also require some good guesses at just how high a vertical velocity component was needed to cause such a breakup.)
Look to things that somewhat limits the probability that it's a daily event for other AF447 flights before this one. I note one, it was particularly dark with very little illumination from the Moon. That limits any visual horizon for orientation. That happens half or less of each month. Another is the somewhat exceptional storm. And, yes, icing on pitot probes seems to be an exceptional event. But is this enough for explaining why it's only happened once since A340s were flying that route at that time of day? (Does the flight more commonly have its 4 hour crew change happen at a different position in the flight? Could this have been caused by the captain being overdue in the cockpit leaving the F/Os preoccupied with "where is he?")
JD-EE