Three Incidents In Past Two Years; Another In 2000

Three Beechjet 400 aircraft have experienced dual engine flameouts in the past three years... a number that is more than a little disconcerting. After investigations into all three incidents, the National Transportation Safety Board Friday issued recommendations to the Federal Aviation Administration aimed at preventing those flameouts. One of the recommendations is classified as "Urgent."

The planes were equipped with Pratt & Whitney Canada (P&WC) JT15D-5 engines. In all three cases, the aircraft landed safely and 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 July 12, 2004 near Sarasota, FL; November 28, 2005 near Jacksonville, FL; 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.

In addition to the urgent recommendation, the Board also 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.

Recommendations

• Immediately require Beechjet 400 pilots to activate the engine 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 unless the pilots can verify that the airplane is not in or near visible moisture or near convective storm activity. (A-06-56) Urgent
• Require Raytheon to incorporate the information regarding anti-ice operation and ice formation contained in Safety Communiqué' No. 269 into the Beechjet 400 airplane flight manual. (A-06-57)
• Incorporate the information regarding anti-ice operation and ice formation contained in Raytheon's Safety Communiqué' No. 269 into the airplane flight manuals of other JT15D-powered airplanes. (A-06-58)
• Work with engine and airplane manufacturers and other industry personnel as well as the appropriate international airworthiness authorities to actively pursue research to develop an ice detector that would alert pilots to internal engine icing and require that it be installed on new production turbojet engines, as well as retrofitted to existing turbojet engines. (A-06-59)

FMI: Read The Full Text Of The NTSB's Letter