What should operators do when they face the prospect of ice forming on aircraft and flying controls? The most obvious course of action–applying anti-icing fluid– might prove the worst, according to the European Regions Airline Association (ERA), which warns that, paradoxically, the use of thickened anti-icing fluid can lead to creation of a frozen gel that can affect all aircraft.
Cessna Caravan 208B, Bellevue, Idaho, Dec. 6, 2004–The NTSB blamed the fatal accident of the Salmon Air Caravan on the pilot’s failure to maintain aircraft control while on approach for landing in icing conditions. Inadequate airspeed was a factor.
Apparently, it’s just a time-honored myth that the Inuit language of native Alaskans has as many as 400 different words covering all forms of frozen precipitation. In fact, there are about a dozen, just like in English.
Sikorsky’s S-92 equipped with the OEM’s new rotor ice protection system (RIPS) has been FAA certified for flight in known icing conditions. Sikorsky is seeking S-92 RIPS certification from the EASA and Transport Canada. A Cessna Citation involved with the S-92 icing program in Alaska on September 30 flamed out in icing conditions and made a deadstick landing with no serious injuries to the four people on board.
A University of North Dakota (UND) Cessna Citation II icing research aircraft made a successful deadstick landing near Beaver, Alaska, about 70 miles north of Fairbanks, after both engines lost power on September 30. In IMC at 9,200 feet, the Citation accumulated about seven-eighths of an inch of ice on the wing’s leading edge.
A proposed AD would require the installation of de-icing boots on the landing-gear struts and cargo pods, as well as other changes to deicing equipment and procedures, on nearly 750 U.S.-registered Cessna 208 Caravans. The directive stems from the FAA’s investigation into nine icing-related incidents within the past few months and six accidents in the previous two icing seasons.
Two recent fatal accidents in icing conditions involving Cessna Caravans prompted the NTSB to issue more recommendations for the turboprop single. The Safety Board wants the FAA to require that operators maintain at least 120 knots when flying in icing conditions. The NTSB also wants Caravans to be prohibited from operating in more than light icing conditions and flown manually when in icing conditions.
Beech King Air 90, Rawlins, Wyo., Jan. 11, 2005–The NTSB said the air ambulance accident was caused by “the pilot’s inadvertent flight into adverse weather [severe icing] conditions, resulting in an aerodynamic stall.” A contributing factor was the pilot’s inadequate planning for the forecast icing.
Eleven years after the October 1994 crash of American Eagle Flight 4184 in Roselawn, Ind., the FAA proposed a revision to Part 25 certification regulations that aims to prevent such icing accidents. The comment period for the notice of proposed rulemaking (NPRM) closed on February 2. Now the new rules will begin to wend their way through the FAA rulemaking process.
Concerned about the growing number of Cessna 208 Caravan icing accidents, aviation authorities in the U.S. and Canada have issued a bevy of new recommendations, airworthiness directives and restrictions. Caravans continue to be plagued by icing accidents–more than 34 to date– and the number of lawsuits against the manufacturer is mounting.