Large UAS (At or above 1320 lbs)
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 20; Flight Crew Total 2400; Flight Crew Type 553
Training / Qualification; Situational Awareness
Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Unauthorized Flight Operations (UAS)
General None Reported / Taken
Human Factors; Weather
Military Base started a controlled burn in a field adjacent to [the] runway in use (Runway XX). We were conducting a training flight under VFR in a Large UAS equipped with IR (infrared) cameras. Smoke from the fire was not visible on the IR cameras that we use for flight and visibility was unrestricted in IR. We decided to continue the training flight utilizing these cameras. After a couple hours; Tower queried us about our flight visibility. We responded that our visibility was unrestricted with the IR cameras. They had immediately prior to that question informed us that visibility to the North was 1 SM due to the smoke from the fires. They then said that we did not have an LAO (Local Area Orientation) with them to be able to use our IR visibility as flight visibility. We then told Tower that we would make the next landing to a full stop for flight termination. I am filing this report due to Tower reporting 1 SM of visibility which falls below Class D VFR weather minimums despite our actual visibility being unlimited.
UAS Flight crew was operating a large fixed wing UAS in low visibility conditions and returned for landing after being advised by ATC the flight crew did not have the proper authorization for conducting operations in those conditions.