Accident Summary
During cruise flight at 11,000 feet, the airplane flew into an area of severe thunderstorms identified as a mesoscale convective system (MCS) with intense to extreme intensities. The aircraft then descended rapidly and impacted the terrain. The on-scene investigation revealed no preimpact mechanical malfunctions or anomalies that would have prevented normal operation of the airplane or its systems.
Weather Conditions
The pilot obtained several weather briefings before departure, which indicated significant convective activity and a moving squall line along the planned route. Forecasts predicted significant thunderstorm activity. The pilot also discussed the weather with an acquaintance, mentioning the need to work around some weather. Despite this awareness, by the time the aircraft encountered the weather, the pilot had been airborne for over an hour and had not requested any updated weather information from air traffic controllers.
ATC Actions
Before the airplane entered the weather, the controller's radar scope depicted a band of moderate to extreme weather consistent with an embedded, heavy-precipitation, supercell-type thunderstorm along the accident airplane's projected flightpath. However, the controller did not provide any severe weather advisories or advise the pilot of the depicted weather. Review of air traffic communications and radar data identified no ATC radar limitations, excessive traffic, radio frequency congestion, or controller workload issues that would have prevented issuing pertinent weather information. Based on workload and available resources, the controller should have recognized the adverse weather as an immediate safety hazard and provided appropriate advisories.
Pilot Actions
The pilot requested and received clearance from the air traffic controller to initiate a turn to escape the weather after entering the severe convective weather. The airplane was lost from radar about 30 seconds after the pilot initiated the turn. The aircraft was equipped with a BF Goodrich WX-950 Stormscope, which can depict lightning strike locations; however, the investigation could not determine if or how this equipment was used. The airplane was not configured to display satellite weather information on its global positioning systems.
NTSB Safety Alert
In October 2006, the National Transportation Safety Board issued Safety Alert SA-11, "Thunderstorm Encounters," as a result of this accident and three other fatal accidents involving in-flight encounters with severe weather. The alert addresses ATC involvement and emphasizes that IFR pilots need to actively maintain awareness of severe weather along their route. It provides suggestions to assist pilots in avoiding similar accidents.