National Transportation Safety Board
Office of Public Affairs
WASHINGTON, D.C. - The National Transportation Safety Board today issued recommendations to the Federal Aviation Administration aimed at preventing the kind of dual engine flameouts that have occurred on three Beechjet 400 aircraft in the last 2 years that the Board is investigating. The planes were equipped with Pratt & Whitney Canada (P&WC) JT15D-5 engines. One of the recommendations is classified as "Urgent." The aircraft landed safely in all three cases without injury. Two of the flightcrews were able to restart at least one engine; the third landed without any engine power. All the airplanes were operating at between 38,000 and 40,000 feet near convective activity when the flameouts occurred, and they all occurred after a power reduction. The flameouts occurred on July 12, 2004 near Sarasota, Florida; November 28, 2005 near Jacksonville, Florida; and on June 14, 2006 near Norfolk, Virginia. In addition, a similar case has come to light that occurred April 23, 2000 in Brazil.
Mark V. Rosenker, Chairman of the NTSB, said that "dual-engine flameout is an unacceptable risk that needs to be addressed as quickly as possible."
According to the FAA's specialist on engine icing, convective storms can pump significant amounts of moisture into the upper atmosphere, and the blowoff from the tops of these storms can contain significant amounts of ice crystals. A P&WC study concluded that with engine anti-ice turned off, it was possible for ice crystals to build up on the leading edges of the JT15D-5 engine's front inner compressor stator and that the buildup could lead to a compressor surge and/or flameout.
The Safety Board's urgent recommendation said that the FAA should require Beechjet 400 pilots to activate ignition and anti-ice systems at high altitude whenever they are in or near visible moisture, or near convective storm activity, or before any power reduction while in those conditions. The Safety Board believes that many pilots may not be aware of the risk posed by ice crystals at high altitudes.
The Board issued three other recommendations dealing with the kind of information provided to pilots and with research to develop an ice detector that would alert pilots to internal engine icing.
NTSB Office of Public Affairs: (202) 314-6100
The National Transportation Safety Board (NTSB) is an independent federal agency charged with determining the probable cause
of transportation accidents, promoting transportation safety, and assisting victims of transportation accidents and their families.