Narrative:

Training was in progress on local 1 and local assist was staffed. Runway 3/21 is shared by local controller and ground control. The portion from taxiway a to taxiway D1 is owned by ground control unless local control/local assistant calls 3/21 'hot' for landing traffic; or aircraft are taxied to 3/21 for departure. Runway 3/21 was not called hot and a guard sweeper called from the guard ramp; holding short of 3/21 at D2 requesting to cross 3/21 and sweep taxiways a and D. I told the sweeper to cross 3/21 and proceed as requested on taxiways a and D; holding short of all runways. As soon as he started to move; local control 1 said 'where is the sweeper going?' I told the sweeper to hold short of 3/21 and I saw him turn around and he read back the hold short instructions. Due to the angle from the tower I could not tell if he crossed the hold short line. Shortly thereafter; I saw a lear rolling at taxi speed down runway 3. Since 3/21 was never called hot; I was not sure if the lear had landed runway 3; or local control 1 was taxiing him down runway 3. Recommendation; other facilities have a runway which was shared by 2 locals; but this situation where part of the runway is owned by local; and part is owned by ground; leads to confusion. Either the runway should belong to local all the time and vehicles be required to use the perimeter road; or if local assist is staffed; they should be responsible for coordinating use of runway 3/21 with ground. I think local control 1 thought local assist had coordinated with ground control; or local assist thought local control 1 was going to due the coordination for training.

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Original NASA ASRS Text

Title: TUS Controller described a loss of separation event when a sweeper vehicle crossed a runway hold line without proper coordination; the reporter noting current guidelines referencing the shared use of Runway3/21 is unclear.

Narrative: Training was in progress on Local 1 and Local Assist was staffed. Runway 3/21 is shared by Local Controller and Ground Control. The portion from Taxiway A to Taxiway D1 is owned by Ground Control unless Local Control/Local Assistant calls 3/21 'hot' for landing traffic; or aircraft are taxied to 3/21 for departure. Runway 3/21 was not called hot and a Guard Sweeper called from the Guard Ramp; holding short of 3/21 at D2 requesting to cross 3/21 and sweep Taxiways A and D. I told the Sweeper to cross 3/21 and proceed as requested on Taxiways A and D; holding short of all runways. As soon as he started to move; Local Control 1 said 'where is the sweeper going?' I told the Sweeper to hold short of 3/21 and I saw him turn around and he read back the hold short instructions. Due to the angle from the Tower I could not tell if he crossed the hold short line. Shortly thereafter; I saw a Lear rolling at taxi speed down Runway 3. Since 3/21 was never called hot; I was not sure if the Lear had landed Runway 3; or Local Control 1 was taxiing him down Runway 3. Recommendation; other facilities have a runway which was shared by 2 Locals; but this situation where part of the runway is owned by Local; and part is owned by Ground; leads to confusion. Either the runway should belong to Local all the time and vehicles be required to use the perimeter road; or if Local Assist is staffed; they should be responsible for coordinating use of Runway 3/21 with Ground. I think Local Control 1 thought Local Assist had coordinated with Ground Control; or Local Assist thought Local Control 1 was going to due the coordination for training.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.