Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Norfolk, Virginia
Wednesday, June 14, 2006 16:15 EDT
NTSB Narrative Summary Released at Completion of Accident
The Raytheon Beechjet 400A was cruising at flight level 380 when both of the engines flamed out after the pilots had reduced power prior to turning on the engine anti-ice systems. The airplane was in visual meteorological conditions (VMC), but were approaching clouds that were known to remnants of a tropical storm. The pilots were unsure if they could remain in VMC and had decided to turn on the engine anti-ice. In accordance with the airplane flight manual (AFM) procedures, the pilots reduced the power to 89.5 percent N1 and both engines flamed out. The left and right engines restarted on their own as the airplane descended through FL 300 and 240, respectively. Testing of the airplane and engines immediately after the incident revealed that they were operating correctly. Testing of the fuel revealed that it conformed to the specifications for Jet A and the concentration of the fuel system icing inhibitor was within limits. Weather satellite imagery showed that there were convective weather cells in the area where the airplane's engines flamed out. Convective weather can lift significant amounts of water into the upper atmosphere that then form ice crystals. Research indicates that the ice crystals can partially melt passing through the JT15D-5 engine fan that can then accrete to an internal compressor stator. When any accreted ice was shed from the stator vanes, it would pass through the high pressure compressor and could be picked up by the pressure sense line to the fuel control. Flight tests confirmed that sense line could go below freezing at low power settings at high altitude. Tests also show that if the sense line was blocked and the power levers were retarded, the electronic engine control would reduce the fuel flow to reduce the power, but the sense pressure within the fuel control would be maintained. But when the blockage was cleared, the sudden reduction in the sense pressure in the fuel control would result in a reduction of the fuel flow at a rate that was much faster than a normal rapid power reduction and could result in the engine flaming out.
NTSB Probable Cause Narrative
High-altitude ice crystals that had accreted on the compressor vanes and were ingested into the engine high pressure compressor when the pilots retarded the power levers causing compressor surges and the flameouts of both engines. Contributing factors were the lack of training on the hazards of high-altitude ice crystals to gas turbine engines and guidance to the pilots to activate the engine anti-ice system in conditions where high-altitude ice crystals may exist.
Event Information
| Type of Event | Incident |
| Event Date | 6/14/2006 |
| Event Day of the Week | Wednesday |
| Time of Event | 1615 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Norfolk |
| Event State | VIRGINIA |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 2006 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | -- |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | -- |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | -- |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | -- |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 22988 |
| NTSB Notification Source | Pratt & Whitney Canada |
| NTSB Notification Date | Jun 16 2006 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jan 30 2008 4:08PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | -- |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N440DS |
| NTSB Number | ENG06IA020 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | None |
| Aircraft Fire | -- |
| Aircraft Explosion | -- |
| Aircraft Manufacturer's Full Name | Raytheon Corporate Jets |
| Aircraft Model | Beechjet 400A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | RK-8 |
| Certified Max Gross Weight | 16300 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | -- |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 10 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | -- |
| ELT Activated | -- |
| ELT Aided Location of Event Site | -- |
| ELT Type | -- |
| Aircraft Owner Name | -- |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | -- |
| Aircraft Owner State | -- |
| Aircraft Owner Country | -- |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | Southern Air Systems |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Tampa |
| Operator State | FL |
| Operator Country | USA |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Positioning |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | OQU |
| Departure City | Quonset Point |
| Departure State | RI |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | CHS |
| Destination City | CHARLESTON |
| Destination State | SC |
| Destination Country | USA |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Dec 17 2007 3:23PM |
| User who most recently changed record | defc |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |