Large UAS; Fixed Wing
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor
Flight Crew Total 700; Flight Crew Total (UAS) 700
Time Pressure
Conflict NMAC
Flight Crew Took Evasive Action
Environment - Non Weather Related; Human Factors
During takeoff at ZZZ we were conducting a training flight using a [large] unmanned aircraft under a [military] COA (Certificate Of Authority).  Immediately after takeoff on upwind runway XX our [Visual Observer]; notified us to immediately level off due to a potential collision with a Helicopter. The Helicopter flew directly over our departure end of runway at approx. 300 feet narrowly missing us on upwind by approx. 100 feet.
UAS flight crew operating at an uncontrolled airport had a near miss with a helicopter.