“The pilot then requested a turn to the southwest (to intercept the 101) and Van Nuys approved. At 9:39 a.m. the pilot reported VFR and 1,500 feet. At 9:42 a.m., the pilot squawked ident with Socal Approach. At 9:43:58, Socal Approach informed the pilot that he was too low for flight following. Less than a minute later, at 9:44:22, Socal Approach unsuccessfully tried to reach the pilot. The pilot did not appear to issue any distress call.”
“Data from Radarbox and Flightradar24 both suggest that the final moments of the flight were unstabilized, with the aircraft climbing rapidly from an altitude of 1,200 to 2,150 feet within 40 seconds at speeds ranging from 110 to 153 knots.”
From another article it was reported after climbing, the Flightradar24 data suggested the helicopter was descending 4,000 feet a minute .at 184 mph