Falcon 2000
Air Traffic Control Developmental
Communication Breakdown
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Air Traffic Control Issued New Clearance
Human Factors; Procedure
I was working Local Control on a day that several people had called in sick and were not replaced by anyone; therefore we were forced to take shorter breaks than normal to make up for it. I had multiple aircraft taxied to Runway XXR and 3 taxied out to Runway YY. The first aircraft in line at [Runway] YY was a Falcon; who spoke less than stellar English. I cleared an aircraft for take off on Runway XXR with traffic on a 4 mile final. I tried calling the Falcon so I could roll him on [Runway] YY prior to the arrival for [Runway] XXR. The Falcon was not on my frequency at the time. After the aircraft for [Runway] XXR landed I put an Air Carrier in position (LUAW) on Runway XXR. When the aircraft that had landed cleared Runway XXR; I cleared the Air Carrier for take off. We are required to call the Departure Controller if an aircraft doesn't tag up. The previous departure didn't tag up so after clearing the Air Carrier for take off I hit the land line to tell the Departure Controller that the other aircraft was untagged. During that time I heard the Air Carrier acknowledge his take off clearance. When the Air Carrier started rolling I scanned the runways and observed the Falcon pulling on to Runway YY. As I observed this; a voice keyed up and said; 'That Falcon's rolling on Runway YY.' I then told the Falcon to hold his position. I also let him know that I never cleared him for take off or to enter the runway. He told me; in his words; he 'understood clear for take off and read it back.' In my opinion he never began take off roll and was still turning onto the runway. More staffing and change the procedure of having to call the Departure Controller within 3 miles of the airport when an aircraft doesn't tag up to 5 miles; so I'm not stuck on a land line and unable to hear aircraft calling me on frequency.
Tower Controller described an unauthorized take off attempt by a foreign aircraft noting language barrier and procedural requirements as causal factors.