Use of unnecessary Anti-Ice
Going a bit off topic here, but I well recall as a young First Officer a Captain telling a story AGAINST HIMSELF of using Airframe Anti-Ice when unnecessary.
He claimed to have been flying very high in very low temperatures, well below the iceing temperature range in cirriform cloud, where the only water present would have already been ice crystals. He turned on the Airframe Anti-Ice, and proceeded to ACQUIRE wing ice as a result.
His theory was that if left alone, the ice crystals would have bounced harmlessly off the cold airframe, but in turning on the Anti-Ice, melted them, whereupon the water ran back over the unheated portion of the wing, and froze.
I always thought it a good story, but doubted it's credibility over the past 30 years or so, I remain curious.
Can anyone lend any credibility or at least good theory to this story?
Anxiously awaiting a solution to a 30 year mystery,
Old Smokey