Coverage depends on ground receiver reception and is not a complete picture of traffic.
The hex code is the aircraft's ICAO 24-bit address, broadcast by its ADS-B transponder. It is the key used to match live position reports to this registration.
The pilot's failure to maintain directional control during the takeoff roll.
The pilot-in-command's inadequate terrain clearance and failure to maintain directional control. Also, the overload of the aircraft's left main landing gear strut assembly. Factors contributing to the accident were high density altitude conditions, downdrafts (associated with the lee side of mountain flying), and crosswinds.