FAA Requires Ice Protection Changes for Transport Aircraft
The agency's review of aircraft in-flight icing safety began after two crashes in the Midwest in 1994 and 1997 that killed 68 and 29 people, respectively.
Acting because of accidents and incidents in which flight crews did not operate the airframe ice protection system (IPS) in a timely manner, and also because of concerns over crews' workload when they must manually cycle an IPS when they see ice accumulating, the Federal Aviation Administration issued a final rule yesterday requiring that transport aircraft certificated for flight in icing conditions have a system that operates continuously, a system that automatically cycles the IPS, or an alert to the crew each time the IPS must be cycled.
The final rule will take effect Sept. 2, 2009; it will ensure crews have a clear means to know when to activate the IPS and will reduce the workload, FAA said.
FAA said it began a review of aircraft in-flight icing safety after two accidents, one in 1994 and another in 1997, that caused the National Transportation Safety Board to issue recommendations A-96-56 and A-98-91. This final rule partially addresses those safety recommendations.
A-96-56 was based on an Oct. 31, 1994, crash of American Eagle Flight 4184 near Roselawn, Ind., where the plane was in a holding pattern because of weather delays at its destination, Chicago's O'Hare International Airport. The plane nosedived while descending from 10,000 to 8,000 feet, and all 64 passengers and four crew members were killed, according to NTSB's online database. This recommendation asked FAA to revise its icing certification testing regulation so crews would have a means to positively determine when they are in icing conditions that exceed the limits for the aircraft's certification. A-98-91 was issued after a COMAIR Airlines plane crashed on Jan. 9, 1997, near Monroe, Mich., en route from Cincinnati to Detroit. All 26 passengers and three crew members were killed. This recommendation asked FAA to require turboprop aircraft manufacturers to update the icing information in their manuals and training programs, emphasizing that leading edge deicing boots should be activated as soon as the airplane enters icing conditions.
FAA said it received 14 comments when it proposed the rule, and some minor amendments were made as a result. The Airline Pilots Association, NTSB, BAE Systems Regional Aircraft, and The Boeing Company expressed support for the rule; NTSB and other commenters suggested specific improvements or clarifications.
The final rule includes this language: "The FAA acknowledges that it is not a simple task to design and certificate an ice detection system. However, ice detection systems exist today that meet the reliability requirements of part 25. Section 25.1309 ensures the degree of reliability of an airframe IPS is commensurate with the hazard level associated with the failure of the airframe IPS. In response to the contention that an ice detector would not be economically feasible, the FAA notes that on recent part 25 airplane certifications manufacturers sought and received approval for installation of ice detectors without an FAA requirement for such a system. Therefore, the FAA infers that these manufacturers consider the installation of ice detectors economically feasible."