Helicopter
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (mon) 4
Situational Awareness
Conflict Airborne Conflict; Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Procedure
Aircraft X was on short final to land on B at B1. The pilot was advised of Aircraft Y on short final to land Runway 16L. The Aircraft X sad he was offsetting slightly to the East to make more room for Aircraft Y. Once Aircraft Y was abeam Aircraft X it began to roll hard right and then hard left as I assume the pilot was trying to correct and regain control of the aircraft. Aircraft Y landed without incident. Aircraft X ended up going around and landed safely without incident on the next time around. The loss of control appears to have been caused by wake turbulence generated by the rotor wash. Issue a caution wake turbulence to all aircraft on final to 16L with a helicopter on short final to B1. Delay clearing a helicopter to land B1 if traffic is on short final to 16L.
VNY Controller reports of observing an aircraft roll right and left; then regain control. Controller states it was possibly due to rotor wash from a helicopter.