Incident Overview
While cruising at flight level 410, the flight crew encountered severe turbulence associated with a very intense thunderstorm (VIP level 4 to 5). The number two engine flamed out, even though continuous ignition had been selected. Following the flame-out, the aircraft began to descend, and the crew initiated a diversion to a nearby airport.
Descent and Engine Failure
During the descent, the aircraft encountered large hail, heavy rain, severe turbulence, lightning, and St. Elmo's fire. As the aircraft descended through flight level 330, the remaining engine flamed out, presumably due to hail and water ingestion. Attempted air starts—both windmilling and starter assisted—were unsuccessful. During the starter-assisted attempts, the interior lights became extremely dim.
Landing and Damage
The aircraft subsequently landed in a wheat field, sustaining damage during the landing. A post-incident examination revealed that all frontal areas of the aircraft received moderate to severe hail damage.
Investigation Findings
Investigation revealed that the crew did not receive a weather briefing before the flight. A convective SIGMET (6C) and an alert weather warning (AWW 163) were active for the area at the time. According to a weather study, there was a severe thunderstorm topped at or near flight level 410, with moderate to severe updrafts and downdrafts, large hail, heavy rain, strong wind gusts, and airframe icing above 12,000 feet MSL.