New Icing Rules And Definitions For Carriers
Effective in 60 days, the FAA will require carriers operating aircraft of less than 60,000 pounds (MTOW) under Part 121 rules to change how they deal with icing and observe a clear definition of icing conditions. Operators will have to install ice-detection equipment or update flight manuals "to ensure timely activation of the airframe ice protection system." The action is intended to address circumstances that have led to accidents and eliminates crew guesswork by setting a definition for icing conditions. Documents submitted during the rule's comment period included some from private citizens who, according to the FAA, stated the agency "had not done enough, early enough."
The rule identifies icing conditions as the presence of visible moisture in temperatures of 5 degrees Celsius or less static air temperature, or 10 degrees Celsius or less total air temperature -- unless the AFM defines it differently. The final rule is identical to the proposed rule and gives the flight crew primary ice detectors, specific visual cues and air temperatures to check for while flying. Aircraft that are not equipped with primary ice detection or an advisory ice detection system are required to take specific measures. Flight crews in those circumstances must activate and continuously or cyclically operate the ice-protection system when in icing conditions. The FAA estimates the cost of compliance at $12.7 million for benefits estimated at $27.2 million. Read the full document online (PDF).