A dangerous “aerodynamic condition” may have contributed to a Virginia State Police helicopter crash that killed two troopers helping to monitor the clashes between white nationalists and counter-protesters in Charlottesville in 2017, according to investigators with the National Transportation Safety Board.
While the agency has not completed its investigation, it released a new factual report this week.
It said the condition known as “vortex ring state” may have caused the helicopter to spin and roll before crashing.
Vortex ring state can cause a helicopter to descend while stopping the main rotor blades from producing lift.
“The helicopter’s low forward speed while descending put it in or near a region conducive to a vortex ring state,” the report stated.
Investigators said there was no evidence that the pilot, Lt. H. Jay Cullen, had been trained on how to handle such a situation.
“Anecdotal information indicated that the pilot had knowledge of vortex ring state, but review of the pilot’s training records from 2001 to the accident found no record of him receiving vortex ring state recognition and recovery training on the accident helicopter make and model,” according to the report.
Cullen, 48, of Midlothian, was the commander of the Virginia State Police aviation unit.
“Review of the VSP aviation unit training manual revealed that vortex ring state was not listed in any of the sample lesson plans for initial or recurrent training,” the report stated.
Cullen died along with Trooper-Pilot Berke M.M. Bates, 40, of Quinton, when they crashed 7 miles southwest of the Charlottesville airport.
They had been providing surveillance of the rally in Charlottesville that turned violent when white nationalists clashed with counter-protesters.
The NTSB said there was no distress call as the helicopter descended into trees and caught fire.
The last radar contact showed the helicopter was flying at just 34 mph at an altitude of 2,300 feet.
It had been hovering over downtown Charlottesville for less than 40 minutes before leaving at 4:42 p.m. to provide support for a motorcade carrying then-Gov. Terry McAuliffe.
A final NTSB report identifying a probable cause in the crash is expected in the coming months.