Air transportation safety investigation A23W0122
The occurrence
Shortly before 1100 Mountain Daylight Time on 06 October 2023, 2 aircraft tow vehicles (tugs) (call sign ATSTOW504 +1) operated by Airport Terminal Services at Calgary International Airport (CYYC), Alberta, planned to drive from Apron 1, to the south side of the airport to reposition an aircraft that was parked on Runway 26. The lead tug driver was given instructions by the ground controller to proceed south on taxiways C, C1, and Y, and hold short of Runway 26.