The FAA issued a Notice of Proposed Rulemaking (NPRM) last week that, if enacted, would require manufacturers of newly certified transport-category aircraft (Part 25) to incorporate an ice-detection system. The proposal is part of an ongoing effort by the FAA and NTSB to reduce accidents as a result of icing, and it comes on the heels of an NTSB recommendation that aircraft boots be activated immediately upon the first sign of airframe icing. If adopted as proposed, the rule would create FAR Part 25.1419 e through h. Manufacturers would be required to develop a system that either alerted the crew to the first sign of airframe ice or alerted the crew to the presence of conditions conducive to icing. Then the aircraft would either have to automatically and continuously activate the de-icing system or alert the crew to do so. Comments on the NPRM are due July 25.