Kayode ICE Stephen

I agree that human error could have played a part in the Learjet crash, but a few things about this accident really stand out to me. There was already a convective SIGMET warning of storm tops above FL450 in the region, which makes me wonder why they chose that route and departure window. Was the weather expected to be manageable? Did it deteriorate faster than forecast? Was there pressure to get the flight done? Something else I noticed looking at the flight track: they were originally up at FL410, then descended to FL350 roughly 14 minutes before the crash. Why? Was that descent weather-related? Because shortly afterward, they were reporting moderate turbulence, icing and precipitation, and requesting a climb back to FL370. I'd be interested in why climbing seemed preferable to deviating laterally, and whether traffic or surrounding cells had already limited their options. The −47°C icing report is also interesting. Were they encountering high-altitude ice crystals instead? Those can cause engine problems without necessarily producing the obvious ice buildup you'd expect. And something worth remembering about the Learjet 60 specifically is that its wing anti-ice uses engine bleed air, which can cost you climb performance. What did their actual airspeed and available thrust look like when they requested that climb? Then there's the turbulence. They reportedly mentioned altitude fluctuations of 600-700 feet. At FL350, I'd be paying very close attention to airspeed and buffet margins, particularly if the autopilot was trying to hold altitude. I'd want to know whether it was still engaged when the upset started. And I wonder what their onboard weather radar was showing. Radar doesn't directly detect turbulence, and at those altitudes you can have relatively weak returns from ice crystals around some very nasty convection. Heavy precipitation can also mask what's behind it. The reported overspeed during the descent doesn't necessarily tell us what caused the initial loss of control. It may simply have been the result of the upset. Obviously far too early to conclude pilot error, but I think some of the most important answers may come from what happened 15–30 minutes before the aircraft went down.