Some interesting info. A number of pilot mistakes:
-penetrating the Restricted Airspace requiring altitude restrictions to be put on military aircraft
-acknowledging a "direct to" clearance but not doing it until being prompted by ATC
-instructed not to descend below 1900ft until the fix but they got down to 1700ft.
NTSB Prelim Report (PDF)
https://data.ntsb.gov/carol-repgen/a...ort/104634/pdf
Ad for the "Lightweight Data Recorder" this PC-12NG had on it:
https://www.l3harris.com/all-capabil...a-recorder-ldr
The NTSB recovered this item so that should help a lot in figuring this out.
Juan Browne's YouTube briefing on this report and some speculation on what happened:
https://www.youtube.com/watch?v=gh9Sw3xXuco