Preliminary report on March 2023 Challenger 300 (jet) upset, 1 fatality [pdf]

Challenger 300 is a business jet. This flight had 2 passengers, 2 crew, and original reporting is the flight encountered severe turbulence. But this report explicitly says no turbulence was encountered.

A computer system (EICAS) reports multiple errors including ‘AP STAB TRIM FAIL, and pilots use a 'PRI STAB TRIM FAIL’ checklist that includes turning the stabilizer trim switch to off. Immediately after that the plane pitch changes multiple times, with G loading range +4.2g to -2.2g.

Edit: The link is bad for some reason I can't figure out, but the nonTLS URL seems to be working.

http://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/Ge...