Agency Calls For Advisory System, Automated IPS Activation

The Federal Aviation Administration is seeking comments on a proposed rule calling for installation of systems on transport-category aircraft, to alert flight crews to conditions favoring the accumulation of airframe icing, and thus requiring pilots to activate anti-icing systems.

The FAA says such systems would remove any question of when pilots are required to activate such measures... which could reduce the number of icing accidents.

In its Notice of Proposed Rulemaking, available for download at the FMI link below, the FAA states its proposed standards would require a means to ensure timely activation of the airframe ice protection system on aircraft certified for flight into known icing (FIKI) conditions. The FAA proposes a warning system that would alert crews to low temperatures and the presence of moisture -- conditions that could lead to airframe icing -- and standards calling for the mandatory activation of deicing systems at that time.

Transport category aircraft currently offer several measures intended to assist pilots in determining if deicing equipment should be activated -- including outside air temperature gauges, and on many aircraft, ice lights that shine on a wing's leading edge to show the pilot the level of ice accretion. Those systems still rely on the pilots' discretion on proper deicing procedures from that point, however.

The FAA states such ice warning systems could conceivably activate an aircraft's ice protection system automatically... thus removing the pilot from the decision-making process. The FAA cites several icing accidents in which pilots either failed to notice icing accretion -- or did note such conditions, but then failed to activate the proper deicing systems -- as justification for the need to automate the process.

The big question in such a plan is one of cost -- to both aircraft manufacturers, and operators. The FAA estimates the cost of implementing an automated IPS system on a particular type or group of aircraft at $485,000; the cost to install such a system is estimated to be close to $15,000... per plane.

By comparison, the cost to design an advisory system -- which would still require pilot activation -- would be slightly less for manufacturers, at $447,500. Such a system would cost significantly less per plane at the operator level, however, at an estimated $7,250 per aircraft.

The FAA will accept comments on the NPRM before July 25, 2007.

FMI: Download The Full NPRM (.pdf)