If you are a "reasonable and prudent" pilot when it comes to icing, a new interpretation by the FAA should reduce stress in your winter operations. Where the FAA used to define "known ice" as any area where there were clouds and sub-zero Centigrade conditions, the new rule takes a decidedly more rational tack. True, enforcement of the "flight into known icing conditions" rule was usually limited to instances where the pilot actually encountered enough of the frost stuff to cause a problem. But the threat of enforcement action when flying in subfreezing clouds of any kind likely caused cancellation of some flights that could otherwise have been completed safely by a "reasonable and prudent" pilot. Experienced IFR pilots know that ice is where you find it, and the new rule reflects this. Known ice now means that if information readily available "indicates to a reasonable and prudent pilot that he or she will be operating the aircraft under conditions that will cause ice to adhere to the aircraft along the proposed route and altitude of flight, then known icing conditions likely exist." For more insight into the FAA's new take on known icing, click here to read our editor's opinion.