The official cause of that helicopter crash following a white supremacist rally in Charlottesville back in 2017 is out. Investigators blame an unusual occurrence called a vortex ring state.
Helicopters are amazing flying machines. They can hover, go up, down, forward, backward – and a skilled pilot can even fly one upside down. The key is the rotor blades – wing-like structures shaped in such a way as to create low pressure above and higher pressure below – lifting the aircraft. Sometimes, however, a helicopter gets into a patch of unstable air, decreasing the ability of the blades to lift the chopper or maintain altitude according to Braxton Via with the Blue Ridge Aviation Flight School.
“It causes the lifting efficiency of the rotor blade to be reduced, so the helicopter is not generating enough lift," he explains. "That requires more engine power to overcome. Once the loss of lift has occurred the helicopter begins to descend downward.”
To recover, he says, you must do something counter-intuitive.
“You would push the nose down to gain more air speed. Once you’ve gained sufficient air speed you can apply more power to climb away from the ground, and that’s the thing with vortex ring. It’s hard to fix, especially at low altitudes.”
Unfortunately, the National Transportation Safety Board says a Virginia State Police officer at the controls after a white supremacist rally in Charlottesville had not been trained to deal with a vortex ring state during 16 years with the aviation unit.
