Cessna Citation 500, Beverly, Mass., March 17, 2007–The NTSB determined the probable cause of the Air Trek Citation icing accident was the inadequate guidance
Fuel starvation caused by accumulated ice crystals was apparently responsible for the engine power loss on British Airways Boeing 777 G-YMMM, according to an interim report issued by the UK’s Air Accidents Investigation Branch. The power loss and subsequent nonfatal crash occurred on G-YMMM’s approach to Heathrow on January 17.
As I prepared to write this column the television and radio news programs were reporting on the recent spate of business aviation accidents. One of the widely reported accidents that caused considerable concern at the NTSB was the November 28 crash of the Challenger 601 in Montrose, Colo. In this accident the NTSB is investigating airplane performance issues, including the possibility of upper-surface wing ice contamination.
As a result of its ongoing investigation into the November 28 fatal takeoff accident of a Challenger 604 in Montrose, Colo., the NTSB has issued a special alert involving the detection and effects of ice accumulation on aircraft wings.
Last month the FAA issued a Special Airworthiness Information Bulletin (SW-08-03) containing “recommendations for rotorcraft during icing conditions.” The SAIB describes “procedures to reduce the probability of an engine in-flight shutdown due to ice and snow ingestion,” including special precautions during winter pre-flights and ground power settings.
Sikorsky’s S-92 has successfully completed the artificial icing requirement of the FAA’s icing-certification program, thus preparing the aircraft for its final all-weather-operations certification phase. It has already completed more than 80 percent of the requirements for icing certification and begun natural icing trials, with several successful natural icing events flown to date.
The FAA last month released a final rule governing certification of transport-category (Part 25) airplanes for operation in icing conditions. The new rule, which takes effect October 9, effectively added new material to Part 25, Appendix C, the section that details the so-called icing envelope.
The FAA yesterday released a final rule governing certification of transport-category (Part 25) airplanes for operation in icing conditions, effective October 9. In publishing the new rules, the FAA added new material to Part 25, Appendix C, the section that details the so-called icing envelope. The new Appendix C material, however, does not address the NTSB’s desire for the icing envelope to be expanded to include larger icing droplets.
Summer is almost upon us in the northern hemisphere, but the FAA is embroiled in two significant icing-related issues: a proposed new rule for when de-ice systems are activated and a new interpretation of the term “known icing.”
Comments are due today on an FAA draft letter of interpretation released April 3 on the meaning of the term “known icing conditions.” At press time, 82 comments had been filed, mainly by individuals.